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authorLinus Torvalds <torvalds@linux-foundation.org>2021-05-01 20:14:08 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-05-01 20:14:08 +0300
commit152d32aa846835987966fd20ee1143b0e05036a0 (patch)
tree728cfb095b62bb3cb3ede5ff12f70d0042db49d4 /arch/x86/kvm/mmu
parent4f9701057a9cc1ae6bfc533204c9d3ba386687de (diff)
parent3bf0fcd754345d7ea63e1446015ba65ece6788ca (diff)
downloadlinux-152d32aa846835987966fd20ee1143b0e05036a0.tar.xz
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini: "This is a large update by KVM standards, including AMD PSP (Platform Security Processor, aka "AMD Secure Technology") and ARM CoreSight (debug and trace) changes. ARM: - CoreSight: Add support for ETE and TRBE - Stage-2 isolation for the host kernel when running in protected mode - Guest SVE support when running in nVHE mode - Force W^X hypervisor mappings in nVHE mode - ITS save/restore for guests using direct injection with GICv4.1 - nVHE panics now produce readable backtraces - Guest support for PTP using the ptp_kvm driver - Performance improvements in the S2 fault handler x86: - AMD PSP driver changes - Optimizations and cleanup of nested SVM code - AMD: Support for virtual SPEC_CTRL - Optimizations of the new MMU code: fast invalidation, zap under read lock, enable/disably dirty page logging under read lock - /dev/kvm API for AMD SEV live migration (guest API coming soon) - support SEV virtual machines sharing the same encryption context - support SGX in virtual machines - add a few more statistics - improved directed yield heuristics - Lots and lots of cleanups Generic: - Rework of MMU notifier interface, simplifying and optimizing the architecture-specific code - a handful of "Get rid of oprofile leftovers" patches - Some selftests improvements" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (379 commits) KVM: selftests: Speed up set_memory_region_test selftests: kvm: Fix the check of return value KVM: x86: Take advantage of kvm_arch_dy_has_pending_interrupt() KVM: SVM: Skip SEV cache flush if no ASIDs have been used KVM: SVM: Remove an unnecessary prototype declaration of sev_flush_asids() KVM: SVM: Drop redundant svm_sev_enabled() helper KVM: SVM: Move SEV VMCB tracking allocation to sev.c KVM: SVM: Explicitly check max SEV ASID during sev_hardware_setup() KVM: SVM: Unconditionally invoke sev_hardware_teardown() KVM: SVM: Enable SEV/SEV-ES functionality by default (when supported) KVM: SVM: Condition sev_enabled and sev_es_enabled on CONFIG_KVM_AMD_SEV=y KVM: SVM: Append "_enabled" to module-scoped SEV/SEV-ES control variables KVM: SEV: Mask CPUID[0x8000001F].eax according to supported features KVM: SVM: Move SEV module params/variables to sev.c KVM: SVM: Disable SEV/SEV-ES if NPT is disabled KVM: SVM: Free sev_asid_bitmap during init if SEV setup fails KVM: SVM: Zero out the VMCB array used to track SEV ASID association x86/sev: Drop redundant and potentially misleading 'sev_enabled' KVM: x86: Move reverse CPUID helpers to separate header file KVM: x86: Rename GPR accessors to make mode-aware variants the defaults ...
Diffstat (limited to 'arch/x86/kvm/mmu')
-rw-r--r--arch/x86/kvm/mmu/mmu.c637
-rw-r--r--arch/x86/kvm/mmu/mmu_audit.c2
-rw-r--r--arch/x86/kvm/mmu/mmu_internal.h44
-rw-r--r--arch/x86/kvm/mmu/paging_tmpl.h3
-rw-r--r--arch/x86/kvm/mmu/spte.c159
-rw-r--r--arch/x86/kvm/mmu/spte.h141
-rw-r--r--arch/x86/kvm/mmu/tdp_mmu.c740
-rw-r--r--arch/x86/kvm/mmu/tdp_mmu.h51
8 files changed, 1042 insertions, 735 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 62b1729277ef..4b3ee244ebe0 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -48,6 +48,7 @@
#include <asm/memtype.h>
#include <asm/cmpxchg.h>
#include <asm/io.h>
+#include <asm/set_memory.h>
#include <asm/vmx.h>
#include <asm/kvm_page_track.h>
#include "trace.h"
@@ -215,10 +216,10 @@ bool is_nx_huge_page_enabled(void)
static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn,
unsigned int access)
{
- u64 mask = make_mmio_spte(vcpu, gfn, access);
+ u64 spte = make_mmio_spte(vcpu, gfn, access);
- trace_mark_mmio_spte(sptep, gfn, mask);
- mmu_spte_set(sptep, mask);
+ trace_mark_mmio_spte(sptep, gfn, spte);
+ mmu_spte_set(sptep, spte);
}
static gfn_t get_mmio_spte_gfn(u64 spte)
@@ -236,17 +237,6 @@ static unsigned get_mmio_spte_access(u64 spte)
return spte & shadow_mmio_access_mask;
}
-static bool set_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn,
- kvm_pfn_t pfn, unsigned int access)
-{
- if (unlikely(is_noslot_pfn(pfn))) {
- mark_mmio_spte(vcpu, sptep, gfn, access);
- return true;
- }
-
- return false;
-}
-
static bool check_mmio_spte(struct kvm_vcpu *vcpu, u64 spte)
{
u64 kvm_gen, spte_gen, gen;
@@ -725,8 +715,7 @@ static void kvm_mmu_page_set_gfn(struct kvm_mmu_page *sp, int index, gfn_t gfn)
* handling slots that are not large page aligned.
*/
static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn,
- struct kvm_memory_slot *slot,
- int level)
+ const struct kvm_memory_slot *slot, int level)
{
unsigned long idx;
@@ -1118,7 +1107,7 @@ static bool spte_write_protect(u64 *sptep, bool pt_protect)
rmap_printk("spte %p %llx\n", sptep, *sptep);
if (pt_protect)
- spte &= ~SPTE_MMU_WRITEABLE;
+ spte &= ~shadow_mmu_writable_mask;
spte = spte & ~PT_WRITABLE_MASK;
return mmu_spte_update(sptep, spte);
@@ -1308,26 +1297,25 @@ static bool kvm_zap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
return flush;
}
-static int kvm_unmap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
- struct kvm_memory_slot *slot, gfn_t gfn, int level,
- unsigned long data)
+static bool kvm_unmap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
+ struct kvm_memory_slot *slot, gfn_t gfn, int level,
+ pte_t unused)
{
return kvm_zap_rmapp(kvm, rmap_head, slot);
}
-static int kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
- struct kvm_memory_slot *slot, gfn_t gfn, int level,
- unsigned long data)
+static bool kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
+ struct kvm_memory_slot *slot, gfn_t gfn, int level,
+ pte_t pte)
{
u64 *sptep;
struct rmap_iterator iter;
int need_flush = 0;
u64 new_spte;
- pte_t *ptep = (pte_t *)data;
kvm_pfn_t new_pfn;
- WARN_ON(pte_huge(*ptep));
- new_pfn = pte_pfn(*ptep);
+ WARN_ON(pte_huge(pte));
+ new_pfn = pte_pfn(pte);
restart:
for_each_rmap_spte(rmap_head, &iter, sptep) {
@@ -1336,7 +1324,7 @@ restart:
need_flush = 1;
- if (pte_write(*ptep)) {
+ if (pte_write(pte)) {
pte_list_remove(rmap_head, sptep);
goto restart;
} else {
@@ -1424,93 +1412,52 @@ static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator)
slot_rmap_walk_okay(_iter_); \
slot_rmap_walk_next(_iter_))
-static __always_inline int
-kvm_handle_hva_range(struct kvm *kvm,
- unsigned long start,
- unsigned long end,
- unsigned long data,
- int (*handler)(struct kvm *kvm,
- struct kvm_rmap_head *rmap_head,
- struct kvm_memory_slot *slot,
- gfn_t gfn,
- int level,
- unsigned long data))
+typedef bool (*rmap_handler_t)(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
+ struct kvm_memory_slot *slot, gfn_t gfn,
+ int level, pte_t pte);
+
+static __always_inline bool kvm_handle_gfn_range(struct kvm *kvm,
+ struct kvm_gfn_range *range,
+ rmap_handler_t handler)
{
- struct kvm_memslots *slots;
- struct kvm_memory_slot *memslot;
struct slot_rmap_walk_iterator iterator;
- int ret = 0;
- int i;
-
- for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
- slots = __kvm_memslots(kvm, i);
- kvm_for_each_memslot(memslot, slots) {
- unsigned long hva_start, hva_end;
- gfn_t gfn_start, gfn_end;
+ bool ret = false;
- hva_start = max(start, memslot->userspace_addr);
- hva_end = min(end, memslot->userspace_addr +
- (memslot->npages << PAGE_SHIFT));
- if (hva_start >= hva_end)
- continue;
- /*
- * {gfn(page) | page intersects with [hva_start, hva_end)} =
- * {gfn_start, gfn_start+1, ..., gfn_end-1}.
- */
- gfn_start = hva_to_gfn_memslot(hva_start, memslot);
- gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
-
- for_each_slot_rmap_range(memslot, PG_LEVEL_4K,
- KVM_MAX_HUGEPAGE_LEVEL,
- gfn_start, gfn_end - 1,
- &iterator)
- ret |= handler(kvm, iterator.rmap, memslot,
- iterator.gfn, iterator.level, data);
- }
- }
+ for_each_slot_rmap_range(range->slot, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL,
+ range->start, range->end - 1, &iterator)
+ ret |= handler(kvm, iterator.rmap, range->slot, iterator.gfn,
+ iterator.level, range->pte);
return ret;
}
-static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
- unsigned long data,
- int (*handler)(struct kvm *kvm,
- struct kvm_rmap_head *rmap_head,
- struct kvm_memory_slot *slot,
- gfn_t gfn, int level,
- unsigned long data))
+bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
{
- return kvm_handle_hva_range(kvm, hva, hva + 1, data, handler);
-}
-
-int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end,
- unsigned flags)
-{
- int r;
+ bool flush;
- r = kvm_handle_hva_range(kvm, start, end, 0, kvm_unmap_rmapp);
+ flush = kvm_handle_gfn_range(kvm, range, kvm_unmap_rmapp);
if (is_tdp_mmu_enabled(kvm))
- r |= kvm_tdp_mmu_zap_hva_range(kvm, start, end);
+ flush |= kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush);
- return r;
+ return flush;
}
-int kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
+bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
{
- int r;
+ bool flush;
- r = kvm_handle_hva(kvm, hva, (unsigned long)&pte, kvm_set_pte_rmapp);
+ flush = kvm_handle_gfn_range(kvm, range, kvm_set_pte_rmapp);
if (is_tdp_mmu_enabled(kvm))
- r |= kvm_tdp_mmu_set_spte_hva(kvm, hva, &pte);
+ flush |= kvm_tdp_mmu_set_spte_gfn(kvm, range);
- return r;
+ return flush;
}
-static int kvm_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
- struct kvm_memory_slot *slot, gfn_t gfn, int level,
- unsigned long data)
+static bool kvm_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
+ struct kvm_memory_slot *slot, gfn_t gfn, int level,
+ pte_t unused)
{
u64 *sptep;
struct rmap_iterator iter;
@@ -1519,13 +1466,12 @@ static int kvm_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
for_each_rmap_spte(rmap_head, &iter, sptep)
young |= mmu_spte_age(sptep);
- trace_kvm_age_page(gfn, level, slot, young);
return young;
}
-static int kvm_test_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
- struct kvm_memory_slot *slot, gfn_t gfn,
- int level, unsigned long data)
+static bool kvm_test_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
+ struct kvm_memory_slot *slot, gfn_t gfn,
+ int level, pte_t unused)
{
u64 *sptep;
struct rmap_iterator iter;
@@ -1547,29 +1493,31 @@ static void rmap_recycle(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn)
rmap_head = gfn_to_rmap(vcpu->kvm, gfn, sp);
- kvm_unmap_rmapp(vcpu->kvm, rmap_head, NULL, gfn, sp->role.level, 0);
+ kvm_unmap_rmapp(vcpu->kvm, rmap_head, NULL, gfn, sp->role.level, __pte(0));
kvm_flush_remote_tlbs_with_address(vcpu->kvm, sp->gfn,
KVM_PAGES_PER_HPAGE(sp->role.level));
}
-int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end)
+bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
{
- int young = false;
+ bool young;
+
+ young = kvm_handle_gfn_range(kvm, range, kvm_age_rmapp);
- young = kvm_handle_hva_range(kvm, start, end, 0, kvm_age_rmapp);
if (is_tdp_mmu_enabled(kvm))
- young |= kvm_tdp_mmu_age_hva_range(kvm, start, end);
+ young |= kvm_tdp_mmu_age_gfn_range(kvm, range);
return young;
}
-int kvm_test_age_hva(struct kvm *kvm, unsigned long hva)
+bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
{
- int young = false;
+ bool young;
+
+ young = kvm_handle_gfn_range(kvm, range, kvm_test_age_rmapp);
- young = kvm_handle_hva(kvm, hva, 0, kvm_test_age_rmapp);
if (is_tdp_mmu_enabled(kvm))
- young |= kvm_tdp_mmu_test_age_hva(kvm, hva);
+ young |= kvm_tdp_mmu_test_age_gfn(kvm, range);
return young;
}
@@ -2421,6 +2369,15 @@ static int make_mmu_pages_available(struct kvm_vcpu *vcpu)
kvm_mmu_zap_oldest_mmu_pages(vcpu->kvm, KVM_REFILL_PAGES - avail);
+ /*
+ * Note, this check is intentionally soft, it only guarantees that one
+ * page is available, while the caller may end up allocating as many as
+ * four pages, e.g. for PAE roots or for 5-level paging. Temporarily
+ * exceeding the (arbitrary by default) limit will not harm the host,
+ * being too agressive may unnecessarily kill the guest, and getting an
+ * exact count is far more trouble than it's worth, especially in the
+ * page fault paths.
+ */
if (!kvm_mmu_available_pages(vcpu->kvm))
return -ENOSPC;
return 0;
@@ -2561,9 +2518,6 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
struct kvm_mmu_page *sp;
int ret;
- if (set_mmio_spte(vcpu, sptep, gfn, pfn, pte_access))
- return 0;
-
sp = sptep_to_sp(sptep);
ret = make_spte(vcpu, pte_access, level, gfn, pfn, *sptep, speculative,
@@ -2593,6 +2547,11 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
pgprintk("%s: spte %llx write_fault %d gfn %llx\n", __func__,
*sptep, write_fault, gfn);
+ if (unlikely(is_noslot_pfn(pfn))) {
+ mark_mmio_spte(vcpu, sptep, gfn, pte_access);
+ return RET_PF_EMULATE;
+ }
+
if (is_shadow_present_pte(*sptep)) {
/*
* If we overwrite a PTE page pointer with a 2MB PMD, unlink
@@ -2626,9 +2585,6 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
kvm_flush_remote_tlbs_with_address(vcpu->kvm, gfn,
KVM_PAGES_PER_HPAGE(level));
- if (unlikely(is_mmio_spte(*sptep)))
- ret = RET_PF_EMULATE;
-
/*
* The fault is fully spurious if and only if the new SPTE and old SPTE
* are identical, and emulation is not required.
@@ -2745,7 +2701,7 @@ static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep)
}
static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn,
- struct kvm_memory_slot *slot)
+ const struct kvm_memory_slot *slot)
{
unsigned long hva;
pte_t *pte;
@@ -2771,8 +2727,9 @@ static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn,
return level;
}
-int kvm_mmu_max_mapping_level(struct kvm *kvm, struct kvm_memory_slot *slot,
- gfn_t gfn, kvm_pfn_t pfn, int max_level)
+int kvm_mmu_max_mapping_level(struct kvm *kvm,
+ const struct kvm_memory_slot *slot, gfn_t gfn,
+ kvm_pfn_t pfn, int max_level)
{
struct kvm_lpage_info *linfo;
@@ -2946,9 +2903,19 @@ static bool handle_abnormal_pfn(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn,
return true;
}
- if (unlikely(is_noslot_pfn(pfn)))
+ if (unlikely(is_noslot_pfn(pfn))) {
vcpu_cache_mmio_info(vcpu, gva, gfn,
access & shadow_mmio_access_mask);
+ /*
+ * If MMIO caching is disabled, emulate immediately without
+ * touching the shadow page tables as attempting to install an
+ * MMIO SPTE will just be an expensive nop.
+ */
+ if (unlikely(!shadow_mmio_value)) {
+ *ret_val = RET_PF_EMULATE;
+ return true;
+ }
+ }
return false;
}
@@ -3061,6 +3028,9 @@ static int fast_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
if (!is_shadow_present_pte(spte))
break;
+ if (!is_shadow_present_pte(spte))
+ break;
+
sp = sptep_to_sp(iterator.sptep);
if (!is_last_spte(spte, sp->role.level))
break;
@@ -3150,12 +3120,10 @@ static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa,
sp = to_shadow_page(*root_hpa & PT64_BASE_ADDR_MASK);
- if (kvm_mmu_put_root(kvm, sp)) {
- if (is_tdp_mmu_page(sp))
- kvm_tdp_mmu_free_root(kvm, sp);
- else if (sp->role.invalid)
- kvm_mmu_prepare_zap_page(kvm, sp, invalid_list);
- }
+ if (is_tdp_mmu_page(sp))
+ kvm_tdp_mmu_put_root(kvm, sp, false);
+ else if (!--sp->root_count && sp->role.invalid)
+ kvm_mmu_prepare_zap_page(kvm, sp, invalid_list);
*root_hpa = INVALID_PAGE;
}
@@ -3193,14 +3161,17 @@ void kvm_mmu_free_roots(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
if (mmu->shadow_root_level >= PT64_ROOT_4LEVEL &&
(mmu->root_level >= PT64_ROOT_4LEVEL || mmu->direct_map)) {
mmu_free_root_page(kvm, &mmu->root_hpa, &invalid_list);
- } else {
- for (i = 0; i < 4; ++i)
- if (mmu->pae_root[i] != 0)
- mmu_free_root_page(kvm,
- &mmu->pae_root[i],
- &invalid_list);
- mmu->root_hpa = INVALID_PAGE;
+ } else if (mmu->pae_root) {
+ for (i = 0; i < 4; ++i) {
+ if (!IS_VALID_PAE_ROOT(mmu->pae_root[i]))
+ continue;
+
+ mmu_free_root_page(kvm, &mmu->pae_root[i],
+ &invalid_list);
+ mmu->pae_root[i] = INVALID_PAE_ROOT;
+ }
}
+ mmu->root_hpa = INVALID_PAGE;
mmu->root_pgd = 0;
}
@@ -3226,155 +3197,208 @@ static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, gva_t gva,
{
struct kvm_mmu_page *sp;
- write_lock(&vcpu->kvm->mmu_lock);
-
- if (make_mmu_pages_available(vcpu)) {
- write_unlock(&vcpu->kvm->mmu_lock);
- return INVALID_PAGE;
- }
sp = kvm_mmu_get_page(vcpu, gfn, gva, level, direct, ACC_ALL);
++sp->root_count;
- write_unlock(&vcpu->kvm->mmu_lock);
return __pa(sp->spt);
}
static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu)
{
- u8 shadow_root_level = vcpu->arch.mmu->shadow_root_level;
+ struct kvm_mmu *mmu = vcpu->arch.mmu;
+ u8 shadow_root_level = mmu->shadow_root_level;
hpa_t root;
unsigned i;
+ int r;
+
+ write_lock(&vcpu->kvm->mmu_lock);
+ r = make_mmu_pages_available(vcpu);
+ if (r < 0)
+ goto out_unlock;
if (is_tdp_mmu_enabled(vcpu->kvm)) {
root = kvm_tdp_mmu_get_vcpu_root_hpa(vcpu);
-
- if (!VALID_PAGE(root))
- return -ENOSPC;
- vcpu->arch.mmu->root_hpa = root;
+ mmu->root_hpa = root;
} else if (shadow_root_level >= PT64_ROOT_4LEVEL) {
- root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level,
- true);
-
- if (!VALID_PAGE(root))
- return -ENOSPC;
- vcpu->arch.mmu->root_hpa = root;
+ root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level, true);
+ mmu->root_hpa = root;
} else if (shadow_root_level == PT32E_ROOT_LEVEL) {
+ if (WARN_ON_ONCE(!mmu->pae_root)) {
+ r = -EIO;
+ goto out_unlock;
+ }
+
for (i = 0; i < 4; ++i) {
- MMU_WARN_ON(VALID_PAGE(vcpu->arch.mmu->pae_root[i]));
+ WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i]));
root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT),
i << 30, PT32_ROOT_LEVEL, true);
- if (!VALID_PAGE(root))
- return -ENOSPC;
- vcpu->arch.mmu->pae_root[i] = root | PT_PRESENT_MASK;
+ mmu->pae_root[i] = root | PT_PRESENT_MASK |
+ shadow_me_mask;
}
- vcpu->arch.mmu->root_hpa = __pa(vcpu->arch.mmu->pae_root);
- } else
- BUG();
+ mmu->root_hpa = __pa(mmu->pae_root);
+ } else {
+ WARN_ONCE(1, "Bad TDP root level = %d\n", shadow_root_level);
+ r = -EIO;
+ goto out_unlock;
+ }
/* root_pgd is ignored for direct MMUs. */
- vcpu->arch.mmu->root_pgd = 0;
-
- return 0;
+ mmu->root_pgd = 0;
+out_unlock:
+ write_unlock(&vcpu->kvm->mmu_lock);
+ return r;
}
static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
{
- u64 pdptr, pm_mask;
+ struct kvm_mmu *mmu = vcpu->arch.mmu;
+ u64 pdptrs[4], pm_mask;
gfn_t root_gfn, root_pgd;
hpa_t root;
- int i;
+ unsigned i;
+ int r;
- root_pgd = vcpu->arch.mmu->get_guest_pgd(vcpu);
+ root_pgd = mmu->get_guest_pgd(vcpu);
root_gfn = root_pgd >> PAGE_SHIFT;
if (mmu_check_root(vcpu, root_gfn))
return 1;
/*
+ * On SVM, reading PDPTRs might access guest memory, which might fault
+ * and thus might sleep. Grab the PDPTRs before acquiring mmu_lock.
+ */
+ if (mmu->root_level == PT32E_ROOT_LEVEL) {
+ for (i = 0; i < 4; ++i) {
+ pdptrs[i] = mmu->get_pdptr(vcpu, i);
+ if (!(pdptrs[i] & PT_PRESENT_MASK))
+ continue;
+
+ if (mmu_check_root(vcpu, pdptrs[i] >> PAGE_SHIFT))
+ return 1;
+ }
+ }
+
+ write_lock(&vcpu->kvm->mmu_lock);
+ r = make_mmu_pages_available(vcpu);
+ if (r < 0)
+ goto out_unlock;
+
+ /*
* Do we shadow a long mode page table? If so we need to
* write-protect the guests page table root.
*/
- if (vcpu->arch.mmu->root_level >= PT64_ROOT_4LEVEL) {
- MMU_WARN_ON(VALID_PAGE(vcpu->arch.mmu->root_hpa));
-
+ if (mmu->root_level >= PT64_ROOT_4LEVEL) {
root = mmu_alloc_root(vcpu, root_gfn, 0,
- vcpu->arch.mmu->shadow_root_level, false);
- if (!VALID_PAGE(root))
- return -ENOSPC;
- vcpu->arch.mmu->root_hpa = root;
+ mmu->shadow_root_level, false);
+ mmu->root_hpa = root;
goto set_root_pgd;
}
+ if (WARN_ON_ONCE(!mmu->pae_root)) {
+ r = -EIO;
+ goto out_unlock;
+ }
+
/*
* We shadow a 32 bit page table. This may be a legacy 2-level
* or a PAE 3-level page table. In either case we need to be aware that
* the shadow page table may be a PAE or a long mode page table.
*/
- pm_mask = PT_PRESENT_MASK;
- if (vcpu->arch.mmu->shadow_root_level == PT64_ROOT_4LEVEL)
+ pm_mask = PT_PRESENT_MASK | shadow_me_mask;
+ if (mmu->shadow_root_level == PT64_ROOT_4LEVEL) {
pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK;
+ if (WARN_ON_ONCE(!mmu->lm_root)) {
+ r = -EIO;
+ goto out_unlock;
+ }
+
+ mmu->lm_root[0] = __pa(mmu->pae_root) | pm_mask;
+ }
+
for (i = 0; i < 4; ++i) {
- MMU_WARN_ON(VALID_PAGE(vcpu->arch.mmu->pae_root[i]));
- if (vcpu->arch.mmu->root_level == PT32E_ROOT_LEVEL) {
- pdptr = vcpu->arch.mmu->get_pdptr(vcpu, i);
- if (!(pdptr & PT_PRESENT_MASK)) {
- vcpu->arch.mmu->pae_root[i] = 0;
+ WARN_ON_ONCE(IS_VALID_PAE_ROOT(mmu->pae_root[i]));
+
+ if (mmu->root_level == PT32E_ROOT_LEVEL) {
+ if (!(pdptrs[i] & PT_PRESENT_MASK)) {
+ mmu->pae_root[i] = INVALID_PAE_ROOT;
continue;
}
- root_gfn = pdptr >> PAGE_SHIFT;
- if (mmu_check_root(vcpu, root_gfn))
- return 1;
+ root_gfn = pdptrs[i] >> PAGE_SHIFT;
}
root = mmu_alloc_root(vcpu, root_gfn, i << 30,
PT32_ROOT_LEVEL, false);
- if (!VALID_PAGE(root))
- return -ENOSPC;
- vcpu->arch.mmu->pae_root[i] = root | pm_mask;
+ mmu->pae_root[i] = root | pm_mask;
}
- vcpu->arch.mmu->root_hpa = __pa(vcpu->arch.mmu->pae_root);
+
+ if (mmu->shadow_root_level == PT64_ROOT_4LEVEL)
+ mmu->root_hpa = __pa(mmu->lm_root);
+ else
+ mmu->root_hpa = __pa(mmu->pae_root);
+
+set_root_pgd:
+ mmu->root_pgd = root_pgd;
+out_unlock:
+ write_unlock(&vcpu->kvm->mmu_lock);
+
+ return 0;
+}
+
+static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu)
+{
+ struct kvm_mmu *mmu = vcpu->arch.mmu;
+ u64 *lm_root, *pae_root;
/*
- * If we shadow a 32 bit page table with a long mode page
- * table we enter this path.
+ * When shadowing 32-bit or PAE NPT with 64-bit NPT, the PML4 and PDP
+ * tables are allocated and initialized at root creation as there is no
+ * equivalent level in the guest's NPT to shadow. Allocate the tables
+ * on demand, as running a 32-bit L1 VMM on 64-bit KVM is very rare.
*/
- if (vcpu->arch.mmu->shadow_root_level == PT64_ROOT_4LEVEL) {
- if (vcpu->arch.mmu->lm_root == NULL) {
- /*
- * The additional page necessary for this is only
- * allocated on demand.
- */
+ if (mmu->direct_map || mmu->root_level >= PT64_ROOT_4LEVEL ||
+ mmu->shadow_root_level < PT64_ROOT_4LEVEL)
+ return 0;
- u64 *lm_root;
+ /*
+ * This mess only works with 4-level paging and needs to be updated to
+ * work with 5-level paging.
+ */
+ if (WARN_ON_ONCE(mmu->shadow_root_level != PT64_ROOT_4LEVEL))
+ return -EIO;
- lm_root = (void*)get_zeroed_page(GFP_KERNEL_ACCOUNT);
- if (lm_root == NULL)
- return 1;
+ if (mmu->pae_root && mmu->lm_root)
+ return 0;
- lm_root[0] = __pa(vcpu->arch.mmu->pae_root) | pm_mask;
+ /*
+ * The special roots should always be allocated in concert. Yell and
+ * bail if KVM ends up in a state where only one of the roots is valid.
+ */
+ if (WARN_ON_ONCE(!tdp_enabled || mmu->pae_root || mmu->lm_root))
+ return -EIO;
- vcpu->arch.mmu->lm_root = lm_root;
- }
+ /*
+ * Unlike 32-bit NPT, the PDP table doesn't need to be in low mem, and
+ * doesn't need to be decrypted.
+ */
+ pae_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT);
+ if (!pae_root)
+ return -ENOMEM;
- vcpu->arch.mmu->root_hpa = __pa(vcpu->arch.mmu->lm_root);
+ lm_root = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT);
+ if (!lm_root) {
+ free_page((unsigned long)pae_root);
+ return -ENOMEM;
}
-set_root_pgd:
- vcpu->arch.mmu->root_pgd = root_pgd;
+ mmu->pae_root = pae_root;
+ mmu->lm_root = lm_root;
return 0;
}
-static int mmu_alloc_roots(struct kvm_vcpu *vcpu)
-{
- if (vcpu->arch.mmu->direct_map)
- return mmu_alloc_direct_roots(vcpu);
- else
- return mmu_alloc_shadow_roots(vcpu);
-}
-
void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu)
{
int i;
@@ -3422,7 +3446,7 @@ void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu)
for (i = 0; i < 4; ++i) {
hpa_t root = vcpu->arch.mmu->pae_root[i];
- if (root && VALID_PAGE(root)) {
+ if (IS_VALID_PAE_ROOT(root)) {
root &= PT64_BASE_ADDR_MASK;
sp = to_shadow_page(root);
mmu_sync_children(vcpu, sp);
@@ -3554,11 +3578,12 @@ static bool get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep)
__is_rsvd_bits_set(rsvd_check, sptes[level], level);
if (reserved) {
- pr_err("%s: detect reserved bits on spte, addr 0x%llx, dump hierarchy:\n",
+ pr_err("%s: reserved bits set on MMU-present spte, addr 0x%llx, hierarchy:\n",
__func__, addr);
for (level = root; level >= leaf; level--)
- pr_err("------ spte 0x%llx level %d.\n",
- sptes[level], level);
+ pr_err("------ spte = 0x%llx level = %d, rsvd bits = 0x%llx",
+ sptes[level], level,
+ rsvd_check->rsvd_bits_mask[(sptes[level] >> 7) & 1][level-1]);
}
return reserved;
@@ -3653,6 +3678,14 @@ static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,
struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
bool async;
+ /*
+ * Retry the page fault if the gfn hit a memslot that is being deleted
+ * or moved. This ensures any existing SPTEs for the old memslot will
+ * be zapped before KVM inserts a new MMIO SPTE for the gfn.
+ */
+ if (slot && (slot->flags & KVM_MEMSLOT_INVALID))
+ return true;
+
/* Don't expose private memslots to L2. */
if (is_guest_mode(vcpu) && !kvm_is_visible_memslot(slot)) {
*pfn = KVM_PFN_NOSLOT;
@@ -4615,12 +4648,17 @@ void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, u32 cr0, u32 cr4, u32 efer,
struct kvm_mmu *context = &vcpu->arch.guest_mmu;
union kvm_mmu_role new_role = kvm_calc_shadow_npt_root_page_role(vcpu);
- context->shadow_root_level = new_role.base.level;
-
__kvm_mmu_new_pgd(vcpu, nested_cr3, new_role.base, false, false);
- if (new_role.as_u64 != context->mmu_role.as_u64)
+ if (new_role.as_u64 != context->mmu_role.as_u64) {
shadow_mmu_init_context(vcpu, context, cr0, cr4, efer, new_role);
+
+ /*
+ * Override the level set by the common init helper, nested TDP
+ * always uses the host's TDP configuration.
+ */
+ context->shadow_root_level = new_role.base.level;
+ }
}
EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu);
@@ -4802,16 +4840,23 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu)
r = mmu_topup_memory_caches(vcpu, !vcpu->arch.mmu->direct_map);
if (r)
goto out;
- r = mmu_alloc_roots(vcpu);
- kvm_mmu_sync_roots(vcpu);
+ r = mmu_alloc_special_roots(vcpu);
+ if (r)
+ goto out;
+ if (vcpu->arch.mmu->direct_map)
+ r = mmu_alloc_direct_roots(vcpu);
+ else
+ r = mmu_alloc_shadow_roots(vcpu);
if (r)
goto out;
+
+ kvm_mmu_sync_roots(vcpu);
+
kvm_mmu_load_pgd(vcpu);
static_call(kvm_x86_tlb_flush_current)(vcpu);
out:
return r;
}
-EXPORT_SYMBOL_GPL(kvm_mmu_load);
void kvm_mmu_unload(struct kvm_vcpu *vcpu)
{
@@ -4820,7 +4865,6 @@ void kvm_mmu_unload(struct kvm_vcpu *vcpu)
kvm_mmu_free_roots(vcpu, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL);
WARN_ON(VALID_PAGE(vcpu->arch.guest_mmu.root_hpa));
}
-EXPORT_SYMBOL_GPL(kvm_mmu_unload);
static bool need_remote_flush(u64 old, u64 new)
{
@@ -5169,10 +5213,10 @@ typedef bool (*slot_level_handler) (struct kvm *kvm, struct kvm_rmap_head *rmap_
static __always_inline bool
slot_handle_level_range(struct kvm *kvm, struct kvm_memory_slot *memslot,
slot_level_handler fn, int start_level, int end_level,
- gfn_t start_gfn, gfn_t end_gfn, bool lock_flush_tlb)
+ gfn_t start_gfn, gfn_t end_gfn, bool flush_on_yield,
+ bool flush)
{
struct slot_rmap_walk_iterator iterator;
- bool flush = false;
for_each_slot_rmap_range(memslot, start_level, end_level, start_gfn,
end_gfn, &iterator) {
@@ -5180,7 +5224,7 @@ slot_handle_level_range(struct kvm *kvm, struct kvm_memory_slot *memslot,
flush |= fn(kvm, iterator.rmap, memslot);
if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) {
- if (flush && lock_flush_tlb) {
+ if (flush && flush_on_yield) {
kvm_flush_remote_tlbs_with_address(kvm,
start_gfn,
iterator.gfn - start_gfn + 1);
@@ -5190,36 +5234,32 @@ slot_handle_level_range(struct kvm *kvm, struct kvm_memory_slot *memslot,
}
}
- if (flush && lock_flush_tlb) {
- kvm_flush_remote_tlbs_with_address(kvm, start_gfn,
- end_gfn - start_gfn + 1);
- flush = false;
- }
-
return flush;
}
static __always_inline bool
slot_handle_level(struct kvm *kvm, struct kvm_memory_slot *memslot,
slot_level_handler fn, int start_level, int end_level,
- bool lock_flush_tlb)
+ bool flush_on_yield)
{
return slot_handle_level_range(kvm, memslot, fn, start_level,
end_level, memslot->base_gfn,
memslot->base_gfn + memslot->npages - 1,
- lock_flush_tlb);
+ flush_on_yield, false);
}
static __always_inline bool
slot_handle_leaf(struct kvm *kvm, struct kvm_memory_slot *memslot,
- slot_level_handler fn, bool lock_flush_tlb)
+ slot_level_handler fn, bool flush_on_yield)
{
return slot_handle_level(kvm, memslot, fn, PG_LEVEL_4K,
- PG_LEVEL_4K, lock_flush_tlb);
+ PG_LEVEL_4K, flush_on_yield);
}
static void free_mmu_pages(struct kvm_mmu *mmu)
{
+ if (!tdp_enabled && mmu->pae_root)
+ set_memory_encrypted((unsigned long)mmu->pae_root, 1);
free_page((unsigned long)mmu->pae_root);
free_page((unsigned long)mmu->lm_root);
}
@@ -5240,9 +5280,11 @@ static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu)
* while the PDP table is a per-vCPU construct that's allocated at MMU
* creation. When emulating 32-bit mode, cr3 is only 32 bits even on
* x86_64. Therefore we need to allocate the PDP table in the first
- * 4GB of memory, which happens to fit the DMA32 zone. Except for
- * SVM's 32-bit NPT support, TDP paging doesn't use PAE paging and can
- * skip allocating the PDP table.
+ * 4GB of memory, which happens to fit the DMA32 zone. TDP paging
+ * generally doesn't use PAE paging and can skip allocating the PDP
+ * table. The main exception, handled here, is SVM's 32-bit NPT. The
+ * other exception is for shadowing L1's 32-bit or PAE NPT on 64-bit
+ * KVM; that horror is handled on-demand by mmu_alloc_shadow_roots().
*/
if (tdp_enabled && kvm_mmu_get_tdp_level(vcpu) > PT32E_ROOT_LEVEL)
return 0;
@@ -5252,8 +5294,22 @@ static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu)
return -ENOMEM;
mmu->pae_root = page_address(page);
+
+ /*
+ * CR3 is only 32 bits when PAE paging is used, thus it's impossible to
+ * get the CPU to treat the PDPTEs as encrypted. Decrypt the page so
+ * that KVM's writes and the CPU's reads get along. Note, this is
+ * only necessary when using shadow paging, as 64-bit NPT can get at
+ * the C-bit even when shadowing 32-bit NPT, and SME isn't supported
+ * by 32-bit kernels (when KVM itself uses 32-bit NPT).
+ */
+ if (!tdp_enabled)
+ set_memory_decrypted((unsigned long)mmu->pae_root, 1);
+ else
+ WARN_ON_ONCE(shadow_me_mask);
+
for (i = 0; i < 4; ++i)
- mmu->pae_root[i] = INVALID_PAGE;
+ mmu->pae_root[i] = INVALID_PAE_ROOT;
return 0;
}
@@ -5365,6 +5421,15 @@ static void kvm_mmu_zap_all_fast(struct kvm *kvm)
*/
kvm->arch.mmu_valid_gen = kvm->arch.mmu_valid_gen ? 0 : 1;
+ /* In order to ensure all threads see this change when
+ * handling the MMU reload signal, this must happen in the
+ * same critical section as kvm_reload_remote_mmus, and
+ * before kvm_zap_obsolete_pages as kvm_zap_obsolete_pages
+ * could drop the MMU lock and yield.
+ */
+ if (is_tdp_mmu_enabled(kvm))
+ kvm_tdp_mmu_invalidate_all_roots(kvm);
+
/*
* Notify all vcpus to reload its shadow page table and flush TLB.
* Then all vcpus will switch to new shadow page table with the new
@@ -5377,10 +5442,13 @@ static void kvm_mmu_zap_all_fast(struct kvm *kvm)
kvm_zap_obsolete_pages(kvm);
- if (is_tdp_mmu_enabled(kvm))
- kvm_tdp_mmu_zap_all(kvm);
-
write_unlock(&kvm->mmu_lock);
+
+ if (is_tdp_mmu_enabled(kvm)) {
+ read_lock(&kvm->mmu_lock);
+ kvm_tdp_mmu_zap_invalidated_roots(kvm);
+ read_unlock(&kvm->mmu_lock);
+ }
}
static bool kvm_has_zapped_obsolete_pages(struct kvm *kvm)
@@ -5420,7 +5488,7 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end)
struct kvm_memslots *slots;
struct kvm_memory_slot *memslot;
int i;
- bool flush;
+ bool flush = false;
write_lock(&kvm->mmu_lock);
for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
@@ -5433,20 +5501,31 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end)
if (start >= end)
continue;
- slot_handle_level_range(kvm, memslot, kvm_zap_rmapp,
- PG_LEVEL_4K,
- KVM_MAX_HUGEPAGE_LEVEL,
- start, end - 1, true);
+ flush = slot_handle_level_range(kvm, memslot, kvm_zap_rmapp,
+ PG_LEVEL_4K,
+ KVM_MAX_HUGEPAGE_LEVEL,
+ start, end - 1, true, flush);
}
}
+ if (flush)
+ kvm_flush_remote_tlbs_with_address(kvm, gfn_start, gfn_end);
+
+ write_unlock(&kvm->mmu_lock);
+
if (is_tdp_mmu_enabled(kvm)) {
- flush = kvm_tdp_mmu_zap_gfn_range(kvm, gfn_start, gfn_end);
+ flush = false;
+
+ read_lock(&kvm->mmu_lock);
+ for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
+ flush = kvm_tdp_mmu_zap_gfn_range(kvm, i, gfn_start,
+ gfn_end, flush, true);
if (flush)
- kvm_flush_remote_tlbs(kvm);
- }
+ kvm_flush_remote_tlbs_with_address(kvm, gfn_start,
+ gfn_end);
- write_unlock(&kvm->mmu_lock);
+ read_unlock(&kvm->mmu_lock);
+ }
}
static bool slot_rmap_write_protect(struct kvm *kvm,
@@ -5465,10 +5544,14 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm,
write_lock(&kvm->mmu_lock);
flush = slot_handle_level(kvm, memslot, slot_rmap_write_protect,
start_level, KVM_MAX_HUGEPAGE_LEVEL, false);
- if (is_tdp_mmu_enabled(kvm))
- flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, PG_LEVEL_4K);
write_unlock(&kvm->mmu_lock);
+ if (is_tdp_mmu_enabled(kvm)) {
+ read_lock(&kvm->mmu_lock);
+ flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level);
+ read_unlock(&kvm->mmu_lock);
+ }
+
/*
* We can flush all the TLBs out of the mmu lock without TLB
* corruption since we just change the spte from writable to
@@ -5476,9 +5559,9 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm,
* spte from present to present (changing the spte from present
* to nonpresent will flush all the TLBs immediately), in other
* words, the only case we care is mmu_spte_update() where we
- * have checked SPTE_HOST_WRITEABLE | SPTE_MMU_WRITEABLE
- * instead of PT_WRITABLE_MASK, that means it does not depend
- * on PT_WRITABLE_MASK anymore.
+ * have checked Host-writable | MMU-writable instead of
+ * PT_WRITABLE_MASK, that means it does not depend on PT_WRITABLE_MASK
+ * anymore.
*/
if (flush)
kvm_arch_flush_remote_tlbs_memslot(kvm, memslot);
@@ -5529,21 +5612,32 @@ void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm,
{
/* FIXME: const-ify all uses of struct kvm_memory_slot. */
struct kvm_memory_slot *slot = (struct kvm_memory_slot *)memslot;
+ bool flush;
write_lock(&kvm->mmu_lock);
- slot_handle_leaf(kvm, slot, kvm_mmu_zap_collapsible_spte, true);
+ flush = slot_handle_leaf(kvm, slot, kvm_mmu_zap_collapsible_spte, true);
- if (is_tdp_mmu_enabled(kvm))
- kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot);
+ if (flush)
+ kvm_arch_flush_remote_tlbs_memslot(kvm, slot);
write_unlock(&kvm->mmu_lock);
+
+ if (is_tdp_mmu_enabled(kvm)) {
+ flush = false;
+
+ read_lock(&kvm->mmu_lock);
+ flush = kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot, flush);
+ if (flush)
+ kvm_arch_flush_remote_tlbs_memslot(kvm, slot);
+ read_unlock(&kvm->mmu_lock);
+ }
}
void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
- struct kvm_memory_slot *memslot)
+ const struct kvm_memory_slot *memslot)
{
/*
* All current use cases for flushing the TLBs for a specific memslot
- * are related to dirty logging, and do the TLB flush out of mmu_lock.
+ * related to dirty logging, and many do the TLB flush out of mmu_lock.
* The interaction between the various operations on memslot must be
* serialized by slots_locks to ensure the TLB flush from one operation
* is observed by any other operation on the same memslot.
@@ -5560,10 +5654,14 @@ void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm,
write_lock(&kvm->mmu_lock);
flush = slot_handle_leaf(kvm, memslot, __rmap_clear_dirty, false);
- if (is_tdp_mmu_enabled(kvm))
- flush |= kvm_tdp_mmu_clear_dirty_slot(kvm, memslot);
write_unlock(&kvm->mmu_lock);
+ if (is_tdp_mmu_enabled(kvm)) {
+ read_lock(&kvm->mmu_lock);
+ flush |= kvm_tdp_mmu_clear_dirty_slot(kvm, memslot);
+ read_unlock(&kvm->mmu_lock);
+ }
+
/*
* It's also safe to flush TLBs out of mmu lock here as currently this
* function is only used for dirty logging, in which case flushing TLB
@@ -5701,25 +5799,6 @@ static void mmu_destroy_caches(void)
kmem_cache_destroy(mmu_page_header_cache);
}
-static void kvm_set_mmio_spte_mask(void)
-{
- u64 mask;
-
- /*
- * Set a reserved PA bit in MMIO SPTEs to generate page faults with
- * PFEC.RSVD=1 on MMIO accesses. 64-bit PTEs (PAE, x86-64, and EPT
- * paging) support a maximum of 52 bits of PA, i.e. if the CPU supports
- * 52-bit physical addresses then there are no reserved PA bits in the
- * PTEs and so the reserved PA approach must be disabled.
- */
- if (shadow_phys_bits < 52)
- mask = BIT_ULL(51) | PT_PRESENT_MASK;
- else
- mask = 0;
-
- kvm_mmu_set_mmio_spte_mask(mask, ACC_WRITE_MASK | ACC_USER_MASK);
-}
-
static bool get_nx_auto_mode(void)
{
/* Return true when CPU has the bug, and mitigations are ON */
@@ -5785,8 +5864,6 @@ int kvm_mmu_module_init(void)
kvm_mmu_reset_all_pte_masks();
- kvm_set_mmio_spte_mask();
-
pte_list_desc_cache = kmem_cache_create("pte_list_desc",
sizeof(struct pte_list_desc),
0, SLAB_ACCOUNT, NULL);
diff --git a/arch/x86/kvm/mmu/mmu_audit.c b/arch/x86/kvm/mmu/mmu_audit.c
index ced15fd58fde..cedc17b2f60e 100644
--- a/arch/x86/kvm/mmu/mmu_audit.c
+++ b/arch/x86/kvm/mmu/mmu_audit.c
@@ -70,7 +70,7 @@ static void mmu_spte_walk(struct kvm_vcpu *vcpu, inspect_spte_fn fn)
for (i = 0; i < 4; ++i) {
hpa_t root = vcpu->arch.mmu->pae_root[i];
- if (root && VALID_PAGE(root)) {
+ if (IS_VALID_PAE_ROOT(root)) {
root &= PT64_BASE_ADDR_MASK;
sp = to_shadow_page(root);
__mmu_spte_walk(vcpu, sp, fn, 2);
diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index 360983865398..d64ccb417c60 100644
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -20,6 +20,16 @@ extern bool dbg;
#define MMU_WARN_ON(x) do { } while (0)
#endif
+/*
+ * Unlike regular MMU roots, PAE "roots", a.k.a. PDPTEs/PDPTRs, have a PRESENT
+ * bit, and thus are guaranteed to be non-zero when valid. And, when a guest
+ * PDPTR is !PRESENT, its corresponding PAE root cannot be set to INVALID_PAGE,
+ * as the CPU would treat that as PRESENT PDPTR with reserved bits set. Use
+ * '0' instead of INVALID_PAGE to indicate an invalid PAE root.
+ */
+#define INVALID_PAE_ROOT 0
+#define IS_VALID_PAE_ROOT(x) (!!(x))
+
struct kvm_mmu_page {
struct list_head link;
struct hlist_node hash_link;
@@ -40,7 +50,11 @@ struct kvm_mmu_page {
u64 *spt;
/* hold the gfn of each spte inside spt */
gfn_t *gfns;
- int root_count; /* Currently serving as active root */
+ /* Currently serving as active root */
+ union {
+ int root_count;
+ refcount_t tdp_mmu_root_count;
+ };
unsigned int unsync_children;
struct kvm_rmap_head parent_ptes; /* rmap pointers to parent sptes */
DECLARE_BITMAP(unsync_child_bitmap, 512);
@@ -78,9 +92,14 @@ static inline struct kvm_mmu_page *sptep_to_sp(u64 *sptep)
return to_shadow_page(__pa(sptep));
}
+static inline int kvm_mmu_role_as_id(union kvm_mmu_page_role role)
+{
+ return role.smm ? 1 : 0;
+}
+
static inline int kvm_mmu_page_as_id(struct kvm_mmu_page *sp)
{
- return sp->role.smm ? 1 : 0;
+ return kvm_mmu_role_as_id(sp->role);
}
static inline bool kvm_vcpu_ad_need_write_protect(struct kvm_vcpu *vcpu)
@@ -108,22 +127,6 @@ bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm,
void kvm_flush_remote_tlbs_with_address(struct kvm *kvm,
u64 start_gfn, u64 pages);
-static inline void kvm_mmu_get_root(struct kvm *kvm, struct kvm_mmu_page *sp)
-{
- BUG_ON(!sp->root_count);
- lockdep_assert_held(&kvm->mmu_lock);
-
- ++sp->root_count;
-}
-
-static inline bool kvm_mmu_put_root(struct kvm *kvm, struct kvm_mmu_page *sp)
-{
- lockdep_assert_held(&kvm->mmu_lock);
- --sp->root_count;
-
- return !sp->root_count;
-}
-
/*
* Return values of handle_mmio_page_fault, mmu.page_fault, and fast_page_fault().
*
@@ -146,8 +149,9 @@ enum {
#define SET_SPTE_NEED_REMOTE_TLB_FLUSH BIT(1)
#define SET_SPTE_SPURIOUS BIT(2)
-int kvm_mmu_max_mapping_level(struct kvm *kvm, struct kvm_memory_slot *slot,
- gfn_t gfn, kvm_pfn_t pfn, int max_level);
+int kvm_mmu_max_mapping_level(struct kvm *kvm,
+ const struct kvm_memory_slot *slot, gfn_t gfn,
+ kvm_pfn_t pfn, int max_level);
int kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, gfn_t gfn,
int max_level, kvm_pfn_t *pfnp,
bool huge_page_disallowed, int *req_level);
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index 55d7b473ac44..70b7e44e3035 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -503,6 +503,7 @@ error:
#endif
walker->fault.address = addr;
walker->fault.nested_page_fault = mmu != vcpu->arch.walk_mmu;
+ walker->fault.async_page_fault = false;
trace_kvm_mmu_walker_error(walker->fault.error_code);
return 0;
@@ -1084,7 +1085,7 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
nr_present++;
- host_writable = sp->spt[i] & SPTE_HOST_WRITEABLE;
+ host_writable = sp->spt[i] & shadow_host_writable_mask;
set_spte_ret |= set_spte(vcpu, &sp->spt[i],
pte_access, PG_LEVEL_4K,
diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c
index ef55f0bc4ccf..66d43cec0c31 100644
--- a/arch/x86/kvm/mmu/spte.c
+++ b/arch/x86/kvm/mmu/spte.c
@@ -16,13 +16,20 @@
#include "spte.h"
#include <asm/e820/api.h>
+#include <asm/vmx.h>
+static bool __read_mostly enable_mmio_caching = true;
+module_param_named(mmio_caching, enable_mmio_caching, bool, 0444);
+
+u64 __read_mostly shadow_host_writable_mask;
+u64 __read_mostly shadow_mmu_writable_mask;
u64 __read_mostly shadow_nx_mask;
u64 __read_mostly shadow_x_mask; /* mutual exclusive with nx_mask */
u64 __read_mostly shadow_user_mask;
u64 __read_mostly shadow_accessed_mask;
u64 __read_mostly shadow_dirty_mask;
u64 __read_mostly shadow_mmio_value;
+u64 __read_mostly shadow_mmio_mask;
u64 __read_mostly shadow_mmio_access_mask;
u64 __read_mostly shadow_present_mask;
u64 __read_mostly shadow_me_mask;
@@ -38,7 +45,6 @@ static u64 generation_mmio_spte_mask(u64 gen)
u64 mask;
WARN_ON(gen & ~MMIO_SPTE_GEN_MASK);
- BUILD_BUG_ON((MMIO_SPTE_GEN_HIGH_MASK | MMIO_SPTE_GEN_LOW_MASK) & SPTE_SPECIAL_MASK);
mask = (gen << MMIO_SPTE_GEN_LOW_SHIFT) & MMIO_SPTE_GEN_LOW_MASK;
mask |= (gen << MMIO_SPTE_GEN_HIGH_SHIFT) & MMIO_SPTE_GEN_HIGH_MASK;
@@ -48,16 +54,18 @@ static u64 generation_mmio_spte_mask(u64 gen)
u64 make_mmio_spte(struct kvm_vcpu *vcpu, u64 gfn, unsigned int access)
{
u64 gen = kvm_vcpu_memslots(vcpu)->generation & MMIO_SPTE_GEN_MASK;
- u64 mask = generation_mmio_spte_mask(gen);
+ u64 spte = generation_mmio_spte_mask(gen);
u64 gpa = gfn << PAGE_SHIFT;
+ WARN_ON_ONCE(!shadow_mmio_value);
+
access &= shadow_mmio_access_mask;
- mask |= shadow_mmio_value | access;
- mask |= gpa | shadow_nonpresent_or_rsvd_mask;
- mask |= (gpa & shadow_nonpresent_or_rsvd_mask)
+ spte |= shadow_mmio_value | access;
+ spte |= gpa | shadow_nonpresent_or_rsvd_mask;
+ spte |= (gpa & shadow_nonpresent_or_rsvd_mask)
<< SHADOW_NONPRESENT_OR_RSVD_MASK_LEN;
- return mask;
+ return spte;
}
static bool kvm_is_mmio_pfn(kvm_pfn_t pfn)
@@ -86,13 +94,20 @@ int make_spte(struct kvm_vcpu *vcpu, unsigned int pte_access, int level,
bool can_unsync, bool host_writable, bool ad_disabled,
u64 *new_spte)
{
- u64 spte = 0;
+ u64 spte = SPTE_MMU_PRESENT_MASK;
int ret = 0;
if (ad_disabled)
- spte |= SPTE_AD_DISABLED_MASK;
+ spte |= SPTE_TDP_AD_DISABLED_MASK;
else if (kvm_vcpu_ad_need_write_protect(vcpu))
- spte |= SPTE_AD_WRPROT_ONLY_MASK;
+ spte |= SPTE_TDP_AD_WRPROT_ONLY_MASK;
+
+ /*
+ * Bits 62:52 of PAE SPTEs are reserved. WARN if said bits are set
+ * if PAE paging may be employed (shadow paging or any 32-bit KVM).
+ */
+ WARN_ON_ONCE((!tdp_enabled || !IS_ENABLED(CONFIG_X86_64)) &&
+ (spte & SPTE_TDP_AD_MASK));
/*
* For the EPT case, shadow_present_mask is 0 if hardware
@@ -124,7 +139,7 @@ int make_spte(struct kvm_vcpu *vcpu, unsigned int pte_access, int level,
kvm_is_mmio_pfn(pfn));
if (host_writable)
- spte |= SPTE_HOST_WRITEABLE;
+ spte |= shadow_host_writable_mask;
else
pte_access &= ~ACC_WRITE_MASK;
@@ -134,7 +149,7 @@ int make_spte(struct kvm_vcpu *vcpu, unsigned int pte_access, int level,
spte |= (u64)pfn << PAGE_SHIFT;
if (pte_access & ACC_WRITE_MASK) {
- spte |= PT_WRITABLE_MASK | SPTE_MMU_WRITEABLE;
+ spte |= PT_WRITABLE_MASK | shadow_mmu_writable_mask;
/*
* Optimization: for pte sync, if spte was writable the hash
@@ -150,7 +165,7 @@ int make_spte(struct kvm_vcpu *vcpu, unsigned int pte_access, int level,
__func__, gfn);
ret |= SET_SPTE_WRITE_PROTECTED_PT;
pte_access &= ~ACC_WRITE_MASK;
- spte &= ~(PT_WRITABLE_MASK | SPTE_MMU_WRITEABLE);
+ spte &= ~(PT_WRITABLE_MASK | shadow_mmu_writable_mask);
}
}
@@ -161,19 +176,20 @@ int make_spte(struct kvm_vcpu *vcpu, unsigned int pte_access, int level,
spte = mark_spte_for_access_track(spte);
out:
+ WARN_ON(is_mmio_spte(spte));
*new_spte = spte;
return ret;
}
u64 make_nonleaf_spte(u64 *child_pt, bool ad_disabled)
{
- u64 spte;
+ u64 spte = SPTE_MMU_PRESENT_MASK;
- spte = __pa(child_pt) | shadow_present_mask | PT_WRITABLE_MASK |
- shadow_user_mask | shadow_x_mask | shadow_me_mask;
+ spte |= __pa(child_pt) | shadow_present_mask | PT_WRITABLE_MASK |
+ shadow_user_mask | shadow_x_mask | shadow_me_mask;
if (ad_disabled)
- spte |= SPTE_AD_DISABLED_MASK;
+ spte |= SPTE_TDP_AD_DISABLED_MASK;
else
spte |= shadow_accessed_mask;
@@ -188,7 +204,7 @@ u64 kvm_mmu_changed_pte_notifier_make_spte(u64 old_spte, kvm_pfn_t new_pfn)
new_spte |= (u64)new_pfn << PAGE_SHIFT;
new_spte &= ~PT_WRITABLE_MASK;
- new_spte &= ~SPTE_HOST_WRITEABLE;
+ new_spte &= ~shadow_host_writable_mask;
new_spte = mark_spte_for_access_track(new_spte);
@@ -242,53 +258,68 @@ u64 mark_spte_for_access_track(u64 spte)
return spte;
}
-void kvm_mmu_set_mmio_spte_mask(u64 mmio_value, u64 access_mask)
+void kvm_mmu_set_mmio_spte_mask(u64 mmio_value, u64 mmio_mask, u64 access_mask)
{
BUG_ON((u64)(unsigned)access_mask != access_mask);
- WARN_ON(mmio_value & (shadow_nonpresent_or_rsvd_mask << SHADOW_NONPRESENT_OR_RSVD_MASK_LEN));
WARN_ON(mmio_value & shadow_nonpresent_or_rsvd_lower_gfn_mask);
- shadow_mmio_value = mmio_value | SPTE_MMIO_MASK;
+
+ if (!enable_mmio_caching)
+ mmio_value = 0;
+
+ /*
+ * Disable MMIO caching if the MMIO value collides with the bits that
+ * are used to hold the relocated GFN when the L1TF mitigation is
+ * enabled. This should never fire as there is no known hardware that
+ * can trigger this condition, e.g. SME/SEV CPUs that require a custom
+ * MMIO value are not susceptible to L1TF.
+ */
+ if (WARN_ON(mmio_value & (shadow_nonpresent_or_rsvd_mask <<
+ SHADOW_NONPRESENT_OR_RSVD_MASK_LEN)))
+ mmio_value = 0;
+
+ /*
+ * The masked MMIO value must obviously match itself and a removed SPTE
+ * must not get a false positive. Removed SPTEs and MMIO SPTEs should
+ * never collide as MMIO must set some RWX bits, and removed SPTEs must
+ * not set any RWX bits.
+ */
+ if (WARN_ON((mmio_value & mmio_mask) != mmio_value) ||
+ WARN_ON(mmio_value && (REMOVED_SPTE & mmio_mask) == mmio_value))
+ mmio_value = 0;
+
+ shadow_mmio_value = mmio_value;
+ shadow_mmio_mask = mmio_mask;
shadow_mmio_access_mask = access_mask;
}
EXPORT_SYMBOL_GPL(kvm_mmu_set_mmio_spte_mask);
-/*
- * Sets the shadow PTE masks used by the MMU.
- *
- * Assumptions:
- * - Setting either @accessed_mask or @dirty_mask requires setting both
- * - At least one of @accessed_mask or @acc_track_mask must be set
- */
-void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask,
- u64 dirty_mask, u64 nx_mask, u64 x_mask, u64 p_mask,
- u64 acc_track_mask, u64 me_mask)
+void kvm_mmu_set_ept_masks(bool has_ad_bits, bool has_exec_only)
{
- BUG_ON(!dirty_mask != !accessed_mask);
- BUG_ON(!accessed_mask && !acc_track_mask);
- BUG_ON(acc_track_mask & SPTE_SPECIAL_MASK);
-
- shadow_user_mask = user_mask;
- shadow_accessed_mask = accessed_mask;
- shadow_dirty_mask = dirty_mask;
- shadow_nx_mask = nx_mask;
- shadow_x_mask = x_mask;
- shadow_present_mask = p_mask;
- shadow_acc_track_mask = acc_track_mask;
- shadow_me_mask = me_mask;
+ shadow_user_mask = VMX_EPT_READABLE_MASK;
+ shadow_accessed_mask = has_ad_bits ? VMX_EPT_ACCESS_BIT : 0ull;
+ shadow_dirty_mask = has_ad_bits ? VMX_EPT_DIRTY_BIT : 0ull;
+ shadow_nx_mask = 0ull;
+ shadow_x_mask = VMX_EPT_EXECUTABLE_MASK;
+ shadow_present_mask = has_exec_only ? 0ull : VMX_EPT_READABLE_MASK;
+ shadow_acc_track_mask = VMX_EPT_RWX_MASK;
+ shadow_me_mask = 0ull;
+
+ shadow_host_writable_mask = EPT_SPTE_HOST_WRITABLE;
+ shadow_mmu_writable_mask = EPT_SPTE_MMU_WRITABLE;
+
+ /*
+ * EPT Misconfigurations are generated if the value of bits 2:0
+ * of an EPT paging-structure entry is 110b (write/execute).
+ */
+ kvm_mmu_set_mmio_spte_mask(VMX_EPT_MISCONFIG_WX_VALUE,
+ VMX_EPT_RWX_MASK, 0);
}
-EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes);
+EXPORT_SYMBOL_GPL(kvm_mmu_set_ept_masks);
void kvm_mmu_reset_all_pte_masks(void)
{
u8 low_phys_bits;
-
- shadow_user_mask = 0;
- shadow_accessed_mask = 0;
- shadow_dirty_mask = 0;
- shadow_nx_mask = 0;
- shadow_x_mask = 0;
- shadow_present_mask = 0;
- shadow_acc_track_mask = 0;
+ u64 mask;
shadow_phys_bits = kvm_get_shadow_phys_bits();
@@ -315,4 +346,30 @@ void kvm_mmu_reset_all_pte_masks(void)
shadow_nonpresent_or_rsvd_lower_gfn_mask =
GENMASK_ULL(low_phys_bits - 1, PAGE_SHIFT);
+
+ shadow_user_mask = PT_USER_MASK;
+ shadow_accessed_mask = PT_ACCESSED_MASK;
+ shadow_dirty_mask = PT_DIRTY_MASK;
+ shadow_nx_mask = PT64_NX_MASK;
+ shadow_x_mask = 0;
+ shadow_present_mask = PT_PRESENT_MASK;
+ shadow_acc_track_mask = 0;
+ shadow_me_mask = sme_me_mask;
+
+ shadow_host_writable_mask = DEFAULT_SPTE_HOST_WRITEABLE;
+ shadow_mmu_writable_mask = DEFAULT_SPTE_MMU_WRITEABLE;
+
+ /*
+ * Set a reserved PA bit in MMIO SPTEs to generate page faults with
+ * PFEC.RSVD=1 on MMIO accesses. 64-bit PTEs (PAE, x86-64, and EPT
+ * paging) support a maximum of 52 bits of PA, i.e. if the CPU supports
+ * 52-bit physical addresses then there are no reserved PA bits in the
+ * PTEs and so the reserved PA approach must be disabled.
+ */
+ if (shadow_phys_bits < 52)
+ mask = BIT_ULL(51) | PT_PRESENT_MASK;
+ else
+ mask = 0;
+
+ kvm_mmu_set_mmio_spte_mask(mask, mask, ACC_WRITE_MASK | ACC_USER_MASK);
}
diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h
index 6de3950fd704..bca0ba11cccf 100644
--- a/arch/x86/kvm/mmu/spte.h
+++ b/arch/x86/kvm/mmu/spte.h
@@ -5,18 +5,33 @@
#include "mmu_internal.h"
-#define PT_FIRST_AVAIL_BITS_SHIFT 10
-#define PT64_SECOND_AVAIL_BITS_SHIFT 54
+/*
+ * A MMU present SPTE is backed by actual memory and may or may not be present
+ * in hardware. E.g. MMIO SPTEs are not considered present. Use bit 11, as it
+ * is ignored by all flavors of SPTEs and checking a low bit often generates
+ * better code than for a high bit, e.g. 56+. MMU present checks are pervasive
+ * enough that the improved code generation is noticeable in KVM's footprint.
+ */
+#define SPTE_MMU_PRESENT_MASK BIT_ULL(11)
/*
- * The mask used to denote special SPTEs, which can be either MMIO SPTEs or
- * Access Tracking SPTEs.
+ * TDP SPTES (more specifically, EPT SPTEs) may not have A/D bits, and may also
+ * be restricted to using write-protection (for L2 when CPU dirty logging, i.e.
+ * PML, is enabled). Use bits 52 and 53 to hold the type of A/D tracking that
+ * is must be employed for a given TDP SPTE.
+ *
+ * Note, the "enabled" mask must be '0', as bits 62:52 are _reserved_ for PAE
+ * paging, including NPT PAE. This scheme works because legacy shadow paging
+ * is guaranteed to have A/D bits and write-protection is forced only for
+ * TDP with CPU dirty logging (PML). If NPT ever gains PML-like support, it
+ * must be restricted to 64-bit KVM.
*/
-#define SPTE_SPECIAL_MASK (3ULL << 52)
-#define SPTE_AD_ENABLED_MASK (0ULL << 52)
-#define SPTE_AD_DISABLED_MASK (1ULL << 52)
-#define SPTE_AD_WRPROT_ONLY_MASK (2ULL << 52)
-#define SPTE_MMIO_MASK (3ULL << 52)
+#define SPTE_TDP_AD_SHIFT 52
+#define SPTE_TDP_AD_MASK (3ULL << SPTE_TDP_AD_SHIFT)
+#define SPTE_TDP_AD_ENABLED_MASK (0ULL << SPTE_TDP_AD_SHIFT)
+#define SPTE_TDP_AD_DISABLED_MASK (1ULL << SPTE_TDP_AD_SHIFT)
+#define SPTE_TDP_AD_WRPROT_ONLY_MASK (2ULL << SPTE_TDP_AD_SHIFT)
+static_assert(SPTE_TDP_AD_ENABLED_MASK == 0);
#ifdef CONFIG_DYNAMIC_PHYSICAL_MASK
#define PT64_BASE_ADDR_MASK (physical_mask & ~(u64)(PAGE_SIZE-1))
@@ -51,16 +66,46 @@
(((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
#define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
+/* Bits 9 and 10 are ignored by all non-EPT PTEs. */
+#define DEFAULT_SPTE_HOST_WRITEABLE BIT_ULL(9)
+#define DEFAULT_SPTE_MMU_WRITEABLE BIT_ULL(10)
+
+/*
+ * The mask/shift to use for saving the original R/X bits when marking the PTE
+ * as not-present for access tracking purposes. We do not save the W bit as the
+ * PTEs being access tracked also need to be dirty tracked, so the W bit will be
+ * restored only when a write is attempted to the page. This mask obviously
+ * must not overlap the A/D type mask.
+ */
+#define SHADOW_ACC_TRACK_SAVED_BITS_MASK (PT64_EPT_READABLE_MASK | \
+ PT64_EPT_EXECUTABLE_MASK)
+#define SHADOW_ACC_TRACK_SAVED_BITS_SHIFT 54
+#define SHADOW_ACC_TRACK_SAVED_MASK (SHADOW_ACC_TRACK_SAVED_BITS_MASK << \
+ SHADOW_ACC_TRACK_SAVED_BITS_SHIFT)
+static_assert(!(SPTE_TDP_AD_MASK & SHADOW_ACC_TRACK_SAVED_MASK));
+
+/*
+ * Low ignored bits are at a premium for EPT, use high ignored bits, taking care
+ * to not overlap the A/D type mask or the saved access bits of access-tracked
+ * SPTEs when A/D bits are disabled.
+ */
+#define EPT_SPTE_HOST_WRITABLE BIT_ULL(57)
+#define EPT_SPTE_MMU_WRITABLE BIT_ULL(58)
-#define SPTE_HOST_WRITEABLE (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
-#define SPTE_MMU_WRITEABLE (1ULL << (PT_FIRST_AVAIL_BITS_SHIFT + 1))
+static_assert(!(EPT_SPTE_HOST_WRITABLE & SPTE_TDP_AD_MASK));
+static_assert(!(EPT_SPTE_MMU_WRITABLE & SPTE_TDP_AD_MASK));
+static_assert(!(EPT_SPTE_HOST_WRITABLE & SHADOW_ACC_TRACK_SAVED_MASK));
+static_assert(!(EPT_SPTE_MMU_WRITABLE & SHADOW_ACC_TRACK_SAVED_MASK));
+
+/* Defined only to keep the above static asserts readable. */
+#undef SHADOW_ACC_TRACK_SAVED_MASK
/*
- * Due to limited space in PTEs, the MMIO generation is a 18 bit subset of
+ * Due to limited space in PTEs, the MMIO generation is a 19 bit subset of
* the memslots generation and is derived as follows:
*
- * Bits 0-8 of the MMIO generation are propagated to spte bits 3-11
- * Bits 9-17 of the MMIO generation are propagated to spte bits 54-62
+ * Bits 0-7 of the MMIO generation are propagated to spte bits 3-10
+ * Bits 8-18 of the MMIO generation are propagated to spte bits 52-62
*
* The KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS flag is intentionally not included in
* the MMIO generation number, as doing so would require stealing a bit from
@@ -71,39 +116,44 @@
*/
#define MMIO_SPTE_GEN_LOW_START 3
-#define MMIO_SPTE_GEN_LOW_END 11
+#define MMIO_SPTE_GEN_LOW_END 10
-#define MMIO_SPTE_GEN_HIGH_START PT64_SECOND_AVAIL_BITS_SHIFT
+#define MMIO_SPTE_GEN_HIGH_START 52
#define MMIO_SPTE_GEN_HIGH_END 62
#define MMIO_SPTE_GEN_LOW_MASK GENMASK_ULL(MMIO_SPTE_GEN_LOW_END, \
MMIO_SPTE_GEN_LOW_START)
#define MMIO_SPTE_GEN_HIGH_MASK GENMASK_ULL(MMIO_SPTE_GEN_HIGH_END, \
MMIO_SPTE_GEN_HIGH_START)
+static_assert(!(SPTE_MMU_PRESENT_MASK &
+ (MMIO_SPTE_GEN_LOW_MASK | MMIO_SPTE_GEN_HIGH_MASK)));
#define MMIO_SPTE_GEN_LOW_BITS (MMIO_SPTE_GEN_LOW_END - MMIO_SPTE_GEN_LOW_START + 1)
#define MMIO_SPTE_GEN_HIGH_BITS (MMIO_SPTE_GEN_HIGH_END - MMIO_SPTE_GEN_HIGH_START + 1)
/* remember to adjust the comment above as well if you change these */
-static_assert(MMIO_SPTE_GEN_LOW_BITS == 9 && MMIO_SPTE_GEN_HIGH_BITS == 9);
+static_assert(MMIO_SPTE_GEN_LOW_BITS == 8 && MMIO_SPTE_GEN_HIGH_BITS == 11);
#define MMIO_SPTE_GEN_LOW_SHIFT (MMIO_SPTE_GEN_LOW_START - 0)
#define MMIO_SPTE_GEN_HIGH_SHIFT (MMIO_SPTE_GEN_HIGH_START - MMIO_SPTE_GEN_LOW_BITS)
#define MMIO_SPTE_GEN_MASK GENMASK_ULL(MMIO_SPTE_GEN_LOW_BITS + MMIO_SPTE_GEN_HIGH_BITS - 1, 0)
+extern u64 __read_mostly shadow_host_writable_mask;
+extern u64 __read_mostly shadow_mmu_writable_mask;
extern u64 __read_mostly shadow_nx_mask;
extern u64 __read_mostly shadow_x_mask; /* mutual exclusive with nx_mask */
extern u64 __read_mostly shadow_user_mask;
extern u64 __read_mostly shadow_accessed_mask;
extern u64 __read_mostly shadow_dirty_mask;
extern u64 __read_mostly shadow_mmio_value;
+extern u64 __read_mostly shadow_mmio_mask;
extern u64 __read_mostly shadow_mmio_access_mask;
extern u64 __read_mostly shadow_present_mask;
extern u64 __read_mostly shadow_me_mask;
/*
- * SPTEs used by MMUs without A/D bits are marked with SPTE_AD_DISABLED_MASK;
+ * SPTEs in MMUs without A/D bits are marked with SPTE_TDP_AD_DISABLED_MASK;
* shadow_acc_track_mask is the set of bits to be cleared in non-accessed
* pages.
*/
@@ -121,28 +171,21 @@ extern u64 __read_mostly shadow_nonpresent_or_rsvd_mask;
#define SHADOW_NONPRESENT_OR_RSVD_MASK_LEN 5
/*
- * The mask/shift to use for saving the original R/X bits when marking the PTE
- * as not-present for access tracking purposes. We do not save the W bit as the
- * PTEs being access tracked also need to be dirty tracked, so the W bit will be
- * restored only when a write is attempted to the page.
- */
-#define SHADOW_ACC_TRACK_SAVED_BITS_MASK (PT64_EPT_READABLE_MASK | \
- PT64_EPT_EXECUTABLE_MASK)
-#define SHADOW_ACC_TRACK_SAVED_BITS_SHIFT PT64_SECOND_AVAIL_BITS_SHIFT
-
-/*
* If a thread running without exclusive control of the MMU lock must perform a
* multi-part operation on an SPTE, it can set the SPTE to REMOVED_SPTE as a
* non-present intermediate value. Other threads which encounter this value
* should not modify the SPTE.
*
- * This constant works because it is considered non-present on both AMD and
- * Intel CPUs and does not create a L1TF vulnerability because the pfn section
- * is zeroed out.
+ * Use a semi-arbitrary value that doesn't set RWX bits, i.e. is not-present on
+ * bot AMD and Intel CPUs, and doesn't set PFN bits, i.e. doesn't create a L1TF
+ * vulnerability. Use only low bits to avoid 64-bit immediates.
*
* Only used by the TDP MMU.
*/
-#define REMOVED_SPTE (1ull << 59)
+#define REMOVED_SPTE 0x5a0ULL
+
+/* Removed SPTEs must not be misconstrued as shadow present PTEs. */
+static_assert(!(REMOVED_SPTE & SPTE_MMU_PRESENT_MASK));
static inline bool is_removed_spte(u64 spte)
{
@@ -167,7 +210,13 @@ extern u8 __read_mostly shadow_phys_bits;
static inline bool is_mmio_spte(u64 spte)
{
- return (spte & SPTE_SPECIAL_MASK) == SPTE_MMIO_MASK;
+ return (spte & shadow_mmio_mask) == shadow_mmio_value &&
+ likely(shadow_mmio_value);
+}
+
+static inline bool is_shadow_present_pte(u64 pte)
+{
+ return !!(pte & SPTE_MMU_PRESENT_MASK);
}
static inline bool sp_ad_disabled(struct kvm_mmu_page *sp)
@@ -177,25 +226,30 @@ static inline bool sp_ad_disabled(struct kvm_mmu_page *sp)
static inline bool spte_ad_enabled(u64 spte)
{
- MMU_WARN_ON(is_mmio_spte(spte));
- return (spte & SPTE_SPECIAL_MASK) != SPTE_AD_DISABLED_MASK;
+ MMU_WARN_ON(!is_shadow_present_pte(spte));
+ return (spte & SPTE_TDP_AD_MASK) != SPTE_TDP_AD_DISABLED_MASK;
}
static inline bool spte_ad_need_write_protect(u64 spte)
{
- MMU_WARN_ON(is_mmio_spte(spte));
- return (spte & SPTE_SPECIAL_MASK) != SPTE_AD_ENABLED_MASK;
+ MMU_WARN_ON(!is_shadow_present_pte(spte));
+ /*
+ * This is benign for non-TDP SPTEs as SPTE_TDP_AD_ENABLED_MASK is '0',
+ * and non-TDP SPTEs will never set these bits. Optimize for 64-bit
+ * TDP and do the A/D type check unconditionally.
+ */
+ return (spte & SPTE_TDP_AD_MASK) != SPTE_TDP_AD_ENABLED_MASK;
}
static inline u64 spte_shadow_accessed_mask(u64 spte)
{
- MMU_WARN_ON(is_mmio_spte(spte));
+ MMU_WARN_ON(!is_shadow_present_pte(spte));
return spte_ad_enabled(spte) ? shadow_accessed_mask : 0;
}
static inline u64 spte_shadow_dirty_mask(u64 spte)
{
- MMU_WARN_ON(is_mmio_spte(spte));
+ MMU_WARN_ON(!is_shadow_present_pte(spte));
return spte_ad_enabled(spte) ? shadow_dirty_mask : 0;
}
@@ -204,11 +258,6 @@ static inline bool is_access_track_spte(u64 spte)
return !spte_ad_enabled(spte) && (spte & shadow_acc_track_mask) == 0;
}
-static inline bool is_shadow_present_pte(u64 pte)
-{
- return (pte != 0) && !is_mmio_spte(pte) && !is_removed_spte(pte);
-}
-
static inline bool is_large_pte(u64 pte)
{
return pte & PT_PAGE_SIZE_MASK;
@@ -246,8 +295,8 @@ static inline bool is_dirty_spte(u64 spte)
static inline bool spte_can_locklessly_be_made_writable(u64 spte)
{
- return (spte & (SPTE_HOST_WRITEABLE | SPTE_MMU_WRITEABLE)) ==
- (SPTE_HOST_WRITEABLE | SPTE_MMU_WRITEABLE);
+ return (spte & shadow_host_writable_mask) &&
+ (spte & shadow_mmu_writable_mask);
}
static inline u64 get_mmio_spte_generation(u64 spte)
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 34207b874886..88f69a6cc492 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -27,6 +27,15 @@ void kvm_mmu_init_tdp_mmu(struct kvm *kvm)
INIT_LIST_HEAD(&kvm->arch.tdp_mmu_pages);
}
+static __always_inline void kvm_lockdep_assert_mmu_lock_held(struct kvm *kvm,
+ bool shared)
+{
+ if (shared)
+ lockdep_assert_held_read(&kvm->mmu_lock);
+ else
+ lockdep_assert_held_write(&kvm->mmu_lock);
+}
+
void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm)
{
if (!kvm->arch.tdp_mmu_enabled)
@@ -41,32 +50,85 @@ void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm)
rcu_barrier();
}
-static void tdp_mmu_put_root(struct kvm *kvm, struct kvm_mmu_page *root)
+static bool zap_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
+ gfn_t start, gfn_t end, bool can_yield, bool flush,
+ bool shared);
+
+static void tdp_mmu_free_sp(struct kvm_mmu_page *sp)
{
- if (kvm_mmu_put_root(kvm, root))
- kvm_tdp_mmu_free_root(kvm, root);
+ free_page((unsigned long)sp->spt);
+ kmem_cache_free(mmu_page_header_cache, sp);
}
-static inline bool tdp_mmu_next_root_valid(struct kvm *kvm,
- struct kvm_mmu_page *root)
+/*
+ * This is called through call_rcu in order to free TDP page table memory
+ * safely with respect to other kernel threads that may be operating on
+ * the memory.
+ * By only accessing TDP MMU page table memory in an RCU read critical
+ * section, and freeing it after a grace period, lockless access to that
+ * memory won't use it after it is freed.
+ */
+static void tdp_mmu_free_sp_rcu_callback(struct rcu_head *head)
{
- lockdep_assert_held_write(&kvm->mmu_lock);
+ struct kvm_mmu_page *sp = container_of(head, struct kvm_mmu_page,
+ rcu_head);
- if (list_entry_is_head(root, &kvm->arch.tdp_mmu_roots, link))
- return false;
+ tdp_mmu_free_sp(sp);
+}
- kvm_mmu_get_root(kvm, root);
- return true;
+void kvm_tdp_mmu_put_root(struct kvm *kvm, struct kvm_mmu_page *root,
+ bool shared)
+{
+ gfn_t max_gfn = 1ULL << (shadow_phys_bits - PAGE_SHIFT);
+
+ kvm_lockdep_assert_mmu_lock_held(kvm, shared);
+ if (!refcount_dec_and_test(&root->tdp_mmu_root_count))
+ return;
+
+ WARN_ON(!root->tdp_mmu_page);
+
+ spin_lock(&kvm->arch.tdp_mmu_pages_lock);
+ list_del_rcu(&root->link);
+ spin_unlock(&kvm->arch.tdp_mmu_pages_lock);
+
+ zap_gfn_range(kvm, root, 0, max_gfn, false, false, shared);
+
+ call_rcu(&root->rcu_head, tdp_mmu_free_sp_rcu_callback);
}
-static inline struct kvm_mmu_page *tdp_mmu_next_root(struct kvm *kvm,
- struct kvm_mmu_page *root)
+/*
+ * Finds the next valid root after root (or the first valid root if root
+ * is NULL), takes a reference on it, and returns that next root. If root
+ * is not NULL, this thread should have already taken a reference on it, and
+ * that reference will be dropped. If no valid root is found, this
+ * function will return NULL.
+ */
+static struct kvm_mmu_page *tdp_mmu_next_root(struct kvm *kvm,
+ struct kvm_mmu_page *prev_root,
+ bool shared)
{
struct kvm_mmu_page *next_root;
- next_root = list_next_entry(root, link);
- tdp_mmu_put_root(kvm, root);
+ rcu_read_lock();
+
+ if (prev_root)
+ next_root = list_next_or_null_rcu(&kvm->arch.tdp_mmu_roots,
+ &prev_root->link,
+ typeof(*prev_root), link);
+ else
+ next_root = list_first_or_null_rcu(&kvm->arch.tdp_mmu_roots,
+ typeof(*next_root), link);
+
+ while (next_root && !kvm_tdp_mmu_get_root(kvm, next_root))
+ next_root = list_next_or_null_rcu(&kvm->arch.tdp_mmu_roots,
+ &next_root->link, typeof(*next_root), link);
+
+ rcu_read_unlock();
+
+ if (prev_root)
+ kvm_tdp_mmu_put_root(kvm, prev_root, shared);
+
return next_root;
}
@@ -75,35 +137,24 @@ static inline struct kvm_mmu_page *tdp_mmu_next_root(struct kvm *kvm,
* This makes it safe to release the MMU lock and yield within the loop, but
* if exiting the loop early, the caller must drop the reference to the most
* recent root. (Unless keeping a live reference is desirable.)
+ *
+ * If shared is set, this function is operating under the MMU lock in read
+ * mode. In the unlikely event that this thread must free a root, the lock
+ * will be temporarily dropped and reacquired in write mode.
*/
-#define for_each_tdp_mmu_root_yield_safe(_kvm, _root) \
- for (_root = list_first_entry(&_kvm->arch.tdp_mmu_roots, \
- typeof(*_root), link); \
- tdp_mmu_next_root_valid(_kvm, _root); \
- _root = tdp_mmu_next_root(_kvm, _root))
-
-#define for_each_tdp_mmu_root(_kvm, _root) \
- list_for_each_entry(_root, &_kvm->arch.tdp_mmu_roots, link)
-
-static bool zap_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
- gfn_t start, gfn_t end, bool can_yield, bool flush);
-
-void kvm_tdp_mmu_free_root(struct kvm *kvm, struct kvm_mmu_page *root)
-{
- gfn_t max_gfn = 1ULL << (shadow_phys_bits - PAGE_SHIFT);
-
- lockdep_assert_held_write(&kvm->mmu_lock);
-
- WARN_ON(root->root_count);
- WARN_ON(!root->tdp_mmu_page);
-
- list_del(&root->link);
-
- zap_gfn_range(kvm, root, 0, max_gfn, false, false);
-
- free_page((unsigned long)root->spt);
- kmem_cache_free(mmu_page_header_cache, root);
-}
+#define for_each_tdp_mmu_root_yield_safe(_kvm, _root, _as_id, _shared) \
+ for (_root = tdp_mmu_next_root(_kvm, NULL, _shared); \
+ _root; \
+ _root = tdp_mmu_next_root(_kvm, _root, _shared)) \
+ if (kvm_mmu_page_as_id(_root) != _as_id) { \
+ } else
+
+#define for_each_tdp_mmu_root(_kvm, _root, _as_id) \
+ list_for_each_entry_rcu(_root, &_kvm->arch.tdp_mmu_roots, link, \
+ lockdep_is_held_type(&kvm->mmu_lock, 0) || \
+ lockdep_is_held(&kvm->arch.tdp_mmu_pages_lock)) \
+ if (kvm_mmu_page_as_id(_root) != _as_id) { \
+ } else
static union kvm_mmu_page_role page_role_for_level(struct kvm_vcpu *vcpu,
int level)
@@ -137,81 +188,46 @@ static struct kvm_mmu_page *alloc_tdp_mmu_page(struct kvm_vcpu *vcpu, gfn_t gfn,
return sp;
}
-static struct kvm_mmu_page *get_tdp_mmu_vcpu_root(struct kvm_vcpu *vcpu)
+hpa_t kvm_tdp_mmu_get_vcpu_root_hpa(struct kvm_vcpu *vcpu)
{
union kvm_mmu_page_role role;
struct kvm *kvm = vcpu->kvm;
struct kvm_mmu_page *root;
- role = page_role_for_level(vcpu, vcpu->arch.mmu->shadow_root_level);
+ lockdep_assert_held_write(&kvm->mmu_lock);
- write_lock(&kvm->mmu_lock);
+ role = page_role_for_level(vcpu, vcpu->arch.mmu->shadow_root_level);
/* Check for an existing root before allocating a new one. */
- for_each_tdp_mmu_root(kvm, root) {
- if (root->role.word == role.word) {
- kvm_mmu_get_root(kvm, root);
- write_unlock(&kvm->mmu_lock);
- return root;
- }
+ for_each_tdp_mmu_root(kvm, root, kvm_mmu_role_as_id(role)) {
+ if (root->role.word == role.word &&
+ kvm_tdp_mmu_get_root(kvm, root))
+ goto out;
}
root = alloc_tdp_mmu_page(vcpu, 0, vcpu->arch.mmu->shadow_root_level);
- root->root_count = 1;
-
- list_add(&root->link, &kvm->arch.tdp_mmu_roots);
-
- write_unlock(&kvm->mmu_lock);
-
- return root;
-}
-
-hpa_t kvm_tdp_mmu_get_vcpu_root_hpa(struct kvm_vcpu *vcpu)
-{
- struct kvm_mmu_page *root;
+ refcount_set(&root->tdp_mmu_root_count, 1);
- root = get_tdp_mmu_vcpu_root(vcpu);
- if (!root)
- return INVALID_PAGE;
+ spin_lock(&kvm->arch.tdp_mmu_pages_lock);
+ list_add_rcu(&root->link, &kvm->arch.tdp_mmu_roots);
+ spin_unlock(&kvm->arch.tdp_mmu_pages_lock);
+out:
return __pa(root->spt);
}
-static void tdp_mmu_free_sp(struct kvm_mmu_page *sp)
-{
- free_page((unsigned long)sp->spt);
- kmem_cache_free(mmu_page_header_cache, sp);
-}
-
-/*
- * This is called through call_rcu in order to free TDP page table memory
- * safely with respect to other kernel threads that may be operating on
- * the memory.
- * By only accessing TDP MMU page table memory in an RCU read critical
- * section, and freeing it after a grace period, lockless access to that
- * memory won't use it after it is freed.
- */
-static void tdp_mmu_free_sp_rcu_callback(struct rcu_head *head)
-{
- struct kvm_mmu_page *sp = container_of(head, struct kvm_mmu_page,
- rcu_head);
-
- tdp_mmu_free_sp(sp);
-}
-
static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
u64 old_spte, u64 new_spte, int level,
bool shared);
static void handle_changed_spte_acc_track(u64 old_spte, u64 new_spte, int level)
{
- bool pfn_changed = spte_to_pfn(old_spte) != spte_to_pfn(new_spte);
-
if (!is_shadow_present_pte(old_spte) || !is_last_spte(old_spte, level))
return;
if (is_accessed_spte(old_spte) &&
- (!is_accessed_spte(new_spte) || pfn_changed))
+ (!is_shadow_present_pte(new_spte) || !is_accessed_spte(new_spte) ||
+ spte_to_pfn(old_spte) != spte_to_pfn(new_spte)))
kvm_set_pfn_accessed(spte_to_pfn(old_spte));
}
@@ -455,7 +471,7 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
if (was_leaf && is_dirty_spte(old_spte) &&
- (!is_dirty_spte(new_spte) || pfn_changed))
+ (!is_present || !is_dirty_spte(new_spte) || pfn_changed))
kvm_set_pfn_dirty(spte_to_pfn(old_spte));
/*
@@ -479,8 +495,9 @@ static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
}
/*
- * tdp_mmu_set_spte_atomic - Set a TDP MMU SPTE atomically and handle the
- * associated bookkeeping
+ * tdp_mmu_set_spte_atomic_no_dirty_log - Set a TDP MMU SPTE atomically
+ * and handle the associated bookkeeping, but do not mark the page dirty
+ * in KVM's dirty bitmaps.
*
* @kvm: kvm instance
* @iter: a tdp_iter instance currently on the SPTE that should be set
@@ -488,9 +505,9 @@ static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
* Returns: true if the SPTE was set, false if it was not. If false is returned,
* this function will have no side-effects.
*/
-static inline bool tdp_mmu_set_spte_atomic(struct kvm *kvm,
- struct tdp_iter *iter,
- u64 new_spte)
+static inline bool tdp_mmu_set_spte_atomic_no_dirty_log(struct kvm *kvm,
+ struct tdp_iter *iter,
+ u64 new_spte)
{
lockdep_assert_held_read(&kvm->mmu_lock);
@@ -498,19 +515,32 @@ static inline bool tdp_mmu_set_spte_atomic(struct kvm *kvm,
* Do not change removed SPTEs. Only the thread that froze the SPTE
* may modify it.
*/
- if (iter->old_spte == REMOVED_SPTE)
+ if (is_removed_spte(iter->old_spte))
return false;
if (cmpxchg64(rcu_dereference(iter->sptep), iter->old_spte,
new_spte) != iter->old_spte)
return false;
- handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte,
- new_spte, iter->level, true);
+ __handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte,
+ new_spte, iter->level, true);
+ handle_changed_spte_acc_track(iter->old_spte, new_spte, iter->level);
return true;
}
+static inline bool tdp_mmu_set_spte_atomic(struct kvm *kvm,
+ struct tdp_iter *iter,
+ u64 new_spte)
+{
+ if (!tdp_mmu_set_spte_atomic_no_dirty_log(kvm, iter, new_spte))
+ return false;
+
+ handle_changed_spte_dirty_log(kvm, iter->as_id, iter->gfn,
+ iter->old_spte, new_spte, iter->level);
+ return true;
+}
+
static inline bool tdp_mmu_zap_spte_atomic(struct kvm *kvm,
struct tdp_iter *iter)
{
@@ -569,7 +599,7 @@ static inline void __tdp_mmu_set_spte(struct kvm *kvm, struct tdp_iter *iter,
* should be used. If operating under the MMU lock in write mode, the
* use of the removed SPTE should not be necessary.
*/
- WARN_ON(iter->old_spte == REMOVED_SPTE);
+ WARN_ON(is_removed_spte(iter->old_spte));
WRITE_ONCE(*rcu_dereference(iter->sptep), new_spte);
@@ -634,7 +664,8 @@ static inline void tdp_mmu_set_spte_no_dirty_log(struct kvm *kvm,
* Return false if a yield was not needed.
*/
static inline bool tdp_mmu_iter_cond_resched(struct kvm *kvm,
- struct tdp_iter *iter, bool flush)
+ struct tdp_iter *iter, bool flush,
+ bool shared)
{
/* Ensure forward progress has been made before yielding. */
if (iter->next_last_level_gfn == iter->yielded_gfn)
@@ -646,7 +677,11 @@ static inline bool tdp_mmu_iter_cond_resched(struct kvm *kvm,
if (flush)
kvm_flush_remote_tlbs(kvm);
- cond_resched_rwlock_write(&kvm->mmu_lock);
+ if (shared)
+ cond_resched_rwlock_read(&kvm->mmu_lock);
+ else
+ cond_resched_rwlock_write(&kvm->mmu_lock);
+
rcu_read_lock();
WARN_ON(iter->gfn > iter->next_last_level_gfn);
@@ -664,24 +699,32 @@ static inline bool tdp_mmu_iter_cond_resched(struct kvm *kvm,
* non-root pages mapping GFNs strictly within that range. Returns true if
* SPTEs have been cleared and a TLB flush is needed before releasing the
* MMU lock.
+ *
* If can_yield is true, will release the MMU lock and reschedule if the
* scheduler needs the CPU or there is contention on the MMU lock. If this
* function cannot yield, it will not release the MMU lock or reschedule and
* the caller must ensure it does not supply too large a GFN range, or the
- * operation can cause a soft lockup. Note, in some use cases a flush may be
- * required by prior actions. Ensure the pending flush is performed prior to
- * yielding.
+ * operation can cause a soft lockup.
+ *
+ * If shared is true, this thread holds the MMU lock in read mode and must
+ * account for the possibility that other threads are modifying the paging
+ * structures concurrently. If shared is false, this thread should hold the
+ * MMU lock in write mode.
*/
static bool zap_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
- gfn_t start, gfn_t end, bool can_yield, bool flush)
+ gfn_t start, gfn_t end, bool can_yield, bool flush,
+ bool shared)
{
struct tdp_iter iter;
+ kvm_lockdep_assert_mmu_lock_held(kvm, shared);
+
rcu_read_lock();
tdp_root_for_each_pte(iter, root, start, end) {
+retry:
if (can_yield &&
- tdp_mmu_iter_cond_resched(kvm, &iter, flush)) {
+ tdp_mmu_iter_cond_resched(kvm, &iter, flush, shared)) {
flush = false;
continue;
}
@@ -699,8 +742,17 @@ static bool zap_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
!is_last_spte(iter.old_spte, iter.level))
continue;
- tdp_mmu_set_spte(kvm, &iter, 0);
- flush = true;
+ if (!shared) {
+ tdp_mmu_set_spte(kvm, &iter, 0);
+ flush = true;
+ } else if (!tdp_mmu_zap_spte_atomic(kvm, &iter)) {
+ /*
+ * The iter must explicitly re-read the SPTE because
+ * the atomic cmpxchg failed.
+ */
+ iter.old_spte = READ_ONCE(*rcu_dereference(iter.sptep));
+ goto retry;
+ }
}
rcu_read_unlock();
@@ -712,15 +764,21 @@ static bool zap_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
* non-root pages mapping GFNs strictly within that range. Returns true if
* SPTEs have been cleared and a TLB flush is needed before releasing the
* MMU lock.
+ *
+ * If shared is true, this thread holds the MMU lock in read mode and must
+ * account for the possibility that other threads are modifying the paging
+ * structures concurrently. If shared is false, this thread should hold the
+ * MMU in write mode.
*/
-bool __kvm_tdp_mmu_zap_gfn_range(struct kvm *kvm, gfn_t start, gfn_t end,
- bool can_yield)
+bool __kvm_tdp_mmu_zap_gfn_range(struct kvm *kvm, int as_id, gfn_t start,
+ gfn_t end, bool can_yield, bool flush,
+ bool shared)
{
struct kvm_mmu_page *root;
- bool flush = false;
- for_each_tdp_mmu_root_yield_safe(kvm, root)
- flush = zap_gfn_range(kvm, root, start, end, can_yield, flush);
+ for_each_tdp_mmu_root_yield_safe(kvm, root, as_id, shared)
+ flush = zap_gfn_range(kvm, root, start, end, can_yield, flush,
+ shared);
return flush;
}
@@ -728,14 +786,116 @@ bool __kvm_tdp_mmu_zap_gfn_range(struct kvm *kvm, gfn_t start, gfn_t end,
void kvm_tdp_mmu_zap_all(struct kvm *kvm)
{
gfn_t max_gfn = 1ULL << (shadow_phys_bits - PAGE_SHIFT);
- bool flush;
+ bool flush = false;
+ int i;
+
+ for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
+ flush = kvm_tdp_mmu_zap_gfn_range(kvm, i, 0, max_gfn,
+ flush, false);
+
+ if (flush)
+ kvm_flush_remote_tlbs(kvm);
+}
+
+static struct kvm_mmu_page *next_invalidated_root(struct kvm *kvm,
+ struct kvm_mmu_page *prev_root)
+{
+ struct kvm_mmu_page *next_root;
+
+ if (prev_root)
+ next_root = list_next_or_null_rcu(&kvm->arch.tdp_mmu_roots,
+ &prev_root->link,
+ typeof(*prev_root), link);
+ else
+ next_root = list_first_or_null_rcu(&kvm->arch.tdp_mmu_roots,
+ typeof(*next_root), link);
+
+ while (next_root && !(next_root->role.invalid &&
+ refcount_read(&next_root->tdp_mmu_root_count)))
+ next_root = list_next_or_null_rcu(&kvm->arch.tdp_mmu_roots,
+ &next_root->link,
+ typeof(*next_root), link);
+
+ return next_root;
+}
+
+/*
+ * Since kvm_tdp_mmu_zap_all_fast has acquired a reference to each
+ * invalidated root, they will not be freed until this function drops the
+ * reference. Before dropping that reference, tear down the paging
+ * structure so that whichever thread does drop the last reference
+ * only has to do a trivial amount of work. Since the roots are invalid,
+ * no new SPTEs should be created under them.
+ */
+void kvm_tdp_mmu_zap_invalidated_roots(struct kvm *kvm)
+{
+ gfn_t max_gfn = 1ULL << (shadow_phys_bits - PAGE_SHIFT);
+ struct kvm_mmu_page *next_root;
+ struct kvm_mmu_page *root;
+ bool flush = false;
+
+ lockdep_assert_held_read(&kvm->mmu_lock);
+
+ rcu_read_lock();
+
+ root = next_invalidated_root(kvm, NULL);
+
+ while (root) {
+ next_root = next_invalidated_root(kvm, root);
+
+ rcu_read_unlock();
+
+ flush = zap_gfn_range(kvm, root, 0, max_gfn, true, flush,
+ true);
+
+ /*
+ * Put the reference acquired in
+ * kvm_tdp_mmu_invalidate_roots
+ */
+ kvm_tdp_mmu_put_root(kvm, root, true);
+
+ root = next_root;
+
+ rcu_read_lock();
+ }
+
+ rcu_read_unlock();
- flush = kvm_tdp_mmu_zap_gfn_range(kvm, 0, max_gfn);
if (flush)
kvm_flush_remote_tlbs(kvm);
}
/*
+ * Mark each TDP MMU root as invalid so that other threads
+ * will drop their references and allow the root count to
+ * go to 0.
+ *
+ * Also take a reference on all roots so that this thread
+ * can do the bulk of the work required to free the roots
+ * once they are invalidated. Without this reference, a
+ * vCPU thread might drop the last reference to a root and
+ * get stuck with tearing down the entire paging structure.
+ *
+ * Roots which have a zero refcount should be skipped as
+ * they're already being torn down.
+ * Already invalid roots should be referenced again so that
+ * they aren't freed before kvm_tdp_mmu_zap_all_fast is
+ * done with them.
+ *
+ * This has essentially the same effect for the TDP MMU
+ * as updating mmu_valid_gen does for the shadow MMU.
+ */
+void kvm_tdp_mmu_invalidate_all_roots(struct kvm *kvm)
+{
+ struct kvm_mmu_page *root;
+
+ lockdep_assert_held_write(&kvm->mmu_lock);
+ list_for_each_entry(root, &kvm->arch.tdp_mmu_roots, link)
+ if (refcount_inc_not_zero(&root->tdp_mmu_root_count))
+ root->role.invalid = true;
+}
+
+/*
* Installs a last-level SPTE to handle a TDP page fault.
* (NPT/EPT violation/misconfiguration)
*/
@@ -777,12 +937,11 @@ static int tdp_mmu_map_handle_target_level(struct kvm_vcpu *vcpu, int write,
trace_mark_mmio_spte(rcu_dereference(iter->sptep), iter->gfn,
new_spte);
ret = RET_PF_EMULATE;
- } else
+ } else {
trace_kvm_mmu_set_spte(iter->level, iter->gfn,
rcu_dereference(iter->sptep));
+ }
- trace_kvm_mmu_set_spte(iter->level, iter->gfn,
- rcu_dereference(iter->sptep));
if (!prefault)
vcpu->stat.pf_fixed++;
@@ -882,199 +1041,139 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
return ret;
}
-static __always_inline int
-kvm_tdp_mmu_handle_hva_range(struct kvm *kvm,
- unsigned long start,
- unsigned long end,
- unsigned long data,
- int (*handler)(struct kvm *kvm,
- struct kvm_memory_slot *slot,
- struct kvm_mmu_page *root,
- gfn_t start,
- gfn_t end,
- unsigned long data))
+bool kvm_tdp_mmu_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range,
+ bool flush)
{
- struct kvm_memslots *slots;
- struct kvm_memory_slot *memslot;
struct kvm_mmu_page *root;
- int ret = 0;
- int as_id;
-
- for_each_tdp_mmu_root_yield_safe(kvm, root) {
- as_id = kvm_mmu_page_as_id(root);
- slots = __kvm_memslots(kvm, as_id);
- kvm_for_each_memslot(memslot, slots) {
- unsigned long hva_start, hva_end;
- gfn_t gfn_start, gfn_end;
-
- hva_start = max(start, memslot->userspace_addr);
- hva_end = min(end, memslot->userspace_addr +
- (memslot->npages << PAGE_SHIFT));
- if (hva_start >= hva_end)
- continue;
- /*
- * {gfn(page) | page intersects with [hva_start, hva_end)} =
- * {gfn_start, gfn_start+1, ..., gfn_end-1}.
- */
- gfn_start = hva_to_gfn_memslot(hva_start, memslot);
- gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
- ret |= handler(kvm, memslot, root, gfn_start,
- gfn_end, data);
- }
- }
+ for_each_tdp_mmu_root(kvm, root, range->slot->as_id)
+ flush |= zap_gfn_range(kvm, root, range->start, range->end,
+ range->may_block, flush, false);
- return ret;
+ return flush;
}
-static int zap_gfn_range_hva_wrapper(struct kvm *kvm,
- struct kvm_memory_slot *slot,
- struct kvm_mmu_page *root, gfn_t start,
- gfn_t end, unsigned long unused)
-{
- return zap_gfn_range(kvm, root, start, end, false, false);
-}
+typedef bool (*tdp_handler_t)(struct kvm *kvm, struct tdp_iter *iter,
+ struct kvm_gfn_range *range);
-int kvm_tdp_mmu_zap_hva_range(struct kvm *kvm, unsigned long start,
- unsigned long end)
+static __always_inline bool kvm_tdp_mmu_handle_gfn(struct kvm *kvm,
+ struct kvm_gfn_range *range,
+ tdp_handler_t handler)
{
- return kvm_tdp_mmu_handle_hva_range(kvm, start, end, 0,
- zap_gfn_range_hva_wrapper);
+ struct kvm_mmu_page *root;
+ struct tdp_iter iter;
+ bool ret = false;
+
+ rcu_read_lock();
+
+ /*
+ * Don't support rescheduling, none of the MMU notifiers that funnel
+ * into this helper allow blocking; it'd be dead, wasteful code.
+ */
+ for_each_tdp_mmu_root(kvm, root, range->slot->as_id) {
+ tdp_root_for_each_leaf_pte(iter, root, range->start, range->end)
+ ret |= handler(kvm, &iter, range);
+ }
+
+ rcu_read_unlock();
+
+ return ret;
}
/*
* Mark the SPTEs range of GFNs [start, end) unaccessed and return non-zero
* if any of the GFNs in the range have been accessed.
*/
-static int age_gfn_range(struct kvm *kvm, struct kvm_memory_slot *slot,
- struct kvm_mmu_page *root, gfn_t start, gfn_t end,
- unsigned long unused)
+static bool age_gfn_range(struct kvm *kvm, struct tdp_iter *iter,
+ struct kvm_gfn_range *range)
{
- struct tdp_iter iter;
- int young = 0;
u64 new_spte = 0;
- rcu_read_lock();
+ /* If we have a non-accessed entry we don't need to change the pte. */
+ if (!is_accessed_spte(iter->old_spte))
+ return false;
- tdp_root_for_each_leaf_pte(iter, root, start, end) {
+ new_spte = iter->old_spte;
+
+ if (spte_ad_enabled(new_spte)) {
+ new_spte &= ~shadow_accessed_mask;
+ } else {
/*
- * If we have a non-accessed entry we don't need to change the
- * pte.
+ * Capture the dirty status of the page, so that it doesn't get
+ * lost when the SPTE is marked for access tracking.
*/
- if (!is_accessed_spte(iter.old_spte))
- continue;
-
- new_spte = iter.old_spte;
-
- if (spte_ad_enabled(new_spte)) {
- clear_bit((ffs(shadow_accessed_mask) - 1),
- (unsigned long *)&new_spte);
- } else {
- /*
- * Capture the dirty status of the page, so that it doesn't get
- * lost when the SPTE is marked for access tracking.
- */
- if (is_writable_pte(new_spte))
- kvm_set_pfn_dirty(spte_to_pfn(new_spte));
+ if (is_writable_pte(new_spte))
+ kvm_set_pfn_dirty(spte_to_pfn(new_spte));
- new_spte = mark_spte_for_access_track(new_spte);
- }
- new_spte &= ~shadow_dirty_mask;
-
- tdp_mmu_set_spte_no_acc_track(kvm, &iter, new_spte);
- young = 1;
-
- trace_kvm_age_page(iter.gfn, iter.level, slot, young);
+ new_spte = mark_spte_for_access_track(new_spte);
}
- rcu_read_unlock();
+ tdp_mmu_set_spte_no_acc_track(kvm, iter, new_spte);
- return young;
+ return true;
}
-int kvm_tdp_mmu_age_hva_range(struct kvm *kvm, unsigned long start,
- unsigned long end)
+bool kvm_tdp_mmu_age_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
{
- return kvm_tdp_mmu_handle_hva_range(kvm, start, end, 0,
- age_gfn_range);
+ return kvm_tdp_mmu_handle_gfn(kvm, range, age_gfn_range);
}
-static int test_age_gfn(struct kvm *kvm, struct kvm_memory_slot *slot,
- struct kvm_mmu_page *root, gfn_t gfn, gfn_t unused,
- unsigned long unused2)
+static bool test_age_gfn(struct kvm *kvm, struct tdp_iter *iter,
+ struct kvm_gfn_range *range)
{
- struct tdp_iter iter;
-
- tdp_root_for_each_leaf_pte(iter, root, gfn, gfn + 1)
- if (is_accessed_spte(iter.old_spte))
- return 1;
-
- return 0;
+ return is_accessed_spte(iter->old_spte);
}
-int kvm_tdp_mmu_test_age_hva(struct kvm *kvm, unsigned long hva)
+bool kvm_tdp_mmu_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
{
- return kvm_tdp_mmu_handle_hva_range(kvm, hva, hva + 1, 0,
- test_age_gfn);
+ return kvm_tdp_mmu_handle_gfn(kvm, range, test_age_gfn);
}
-/*
- * Handle the changed_pte MMU notifier for the TDP MMU.
- * data is a pointer to the new pte_t mapping the HVA specified by the MMU
- * notifier.
- * Returns non-zero if a flush is needed before releasing the MMU lock.
- */
-static int set_tdp_spte(struct kvm *kvm, struct kvm_memory_slot *slot,
- struct kvm_mmu_page *root, gfn_t gfn, gfn_t unused,
- unsigned long data)
+static bool set_spte_gfn(struct kvm *kvm, struct tdp_iter *iter,
+ struct kvm_gfn_range *range)
{
- struct tdp_iter iter;
- pte_t *ptep = (pte_t *)data;
- kvm_pfn_t new_pfn;
u64 new_spte;
- int need_flush = 0;
-
- rcu_read_lock();
- WARN_ON(pte_huge(*ptep));
+ /* Huge pages aren't expected to be modified without first being zapped. */
+ WARN_ON(pte_huge(range->pte) || range->start + 1 != range->end);
- new_pfn = pte_pfn(*ptep);
-
- tdp_root_for_each_pte(iter, root, gfn, gfn + 1) {
- if (iter.level != PG_LEVEL_4K)
- continue;
-
- if (!is_shadow_present_pte(iter.old_spte))
- break;
-
- tdp_mmu_set_spte(kvm, &iter, 0);
-
- kvm_flush_remote_tlbs_with_address(kvm, iter.gfn, 1);
+ if (iter->level != PG_LEVEL_4K ||
+ !is_shadow_present_pte(iter->old_spte))
+ return false;
- if (!pte_write(*ptep)) {
- new_spte = kvm_mmu_changed_pte_notifier_make_spte(
- iter.old_spte, new_pfn);
+ /*
+ * Note, when changing a read-only SPTE, it's not strictly necessary to
+ * zero the SPTE before setting the new PFN, but doing so preserves the
+ * invariant that the PFN of a present * leaf SPTE can never change.
+ * See __handle_changed_spte().
+ */
+ tdp_mmu_set_spte(kvm, iter, 0);
- tdp_mmu_set_spte(kvm, &iter, new_spte);
- }
+ if (!pte_write(range->pte)) {
+ new_spte = kvm_mmu_changed_pte_notifier_make_spte(iter->old_spte,
+ pte_pfn(range->pte));
- need_flush = 1;
+ tdp_mmu_set_spte(kvm, iter, new_spte);
}
- if (need_flush)
- kvm_flush_remote_tlbs_with_address(kvm, gfn, 1);
-
- rcu_read_unlock();
-
- return 0;
+ return true;
}
-int kvm_tdp_mmu_set_spte_hva(struct kvm *kvm, unsigned long address,
- pte_t *host_ptep)
+/*
+ * Handle the changed_pte MMU notifier for the TDP MMU.
+ * data is a pointer to the new pte_t mapping the HVA specified by the MMU
+ * notifier.
+ * Returns non-zero if a flush is needed before releasing the MMU lock.
+ */
+bool kvm_tdp_mmu_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
{
- return kvm_tdp_mmu_handle_hva_range(kvm, address, address + 1,
- (unsigned long)host_ptep,
- set_tdp_spte);
+ bool flush = kvm_tdp_mmu_handle_gfn(kvm, range, set_spte_gfn);
+
+ /* FIXME: return 'flush' instead of flushing here. */
+ if (flush)
+ kvm_flush_remote_tlbs_with_address(kvm, range->start, 1);
+
+ return false;
}
/*
@@ -1095,7 +1194,8 @@ static bool wrprot_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
for_each_tdp_pte_min_level(iter, root->spt, root->role.level,
min_level, start, end) {
- if (tdp_mmu_iter_cond_resched(kvm, &iter, false))
+retry:
+ if (tdp_mmu_iter_cond_resched(kvm, &iter, false, true))
continue;
if (!is_shadow_present_pte(iter.old_spte) ||
@@ -1105,7 +1205,15 @@ static bool wrprot_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
new_spte = iter.old_spte & ~PT_WRITABLE_MASK;
- tdp_mmu_set_spte_no_dirty_log(kvm, &iter, new_spte);
+ if (!tdp_mmu_set_spte_atomic_no_dirty_log(kvm, &iter,
+ new_spte)) {
+ /*
+ * The iter must explicitly re-read the SPTE because
+ * the atomic cmpxchg failed.
+ */
+ iter.old_spte = READ_ONCE(*rcu_dereference(iter.sptep));
+ goto retry;
+ }
spte_set = true;
}
@@ -1122,17 +1230,13 @@ bool kvm_tdp_mmu_wrprot_slot(struct kvm *kvm, struct kvm_memory_slot *slot,
int min_level)
{
struct kvm_mmu_page *root;
- int root_as_id;
bool spte_set = false;
- for_each_tdp_mmu_root_yield_safe(kvm, root) {
- root_as_id = kvm_mmu_page_as_id(root);
- if (root_as_id != slot->as_id)
- continue;
+ lockdep_assert_held_read(&kvm->mmu_lock);
+ for_each_tdp_mmu_root_yield_safe(kvm, root, slot->as_id, true)
spte_set |= wrprot_gfn_range(kvm, root, slot->base_gfn,
slot->base_gfn + slot->npages, min_level);
- }
return spte_set;
}
@@ -1154,7 +1258,8 @@ static bool clear_dirty_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
rcu_read_lock();
tdp_root_for_each_leaf_pte(iter, root, start, end) {
- if (tdp_mmu_iter_cond_resched(kvm, &iter, false))
+retry:
+ if (tdp_mmu_iter_cond_resched(kvm, &iter, false, true))
continue;
if (spte_ad_need_write_protect(iter.old_spte)) {
@@ -1169,7 +1274,15 @@ static bool clear_dirty_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
continue;
}
- tdp_mmu_set_spte_no_dirty_log(kvm, &iter, new_spte);
+ if (!tdp_mmu_set_spte_atomic_no_dirty_log(kvm, &iter,
+ new_spte)) {
+ /*
+ * The iter must explicitly re-read the SPTE because
+ * the atomic cmpxchg failed.
+ */
+ iter.old_spte = READ_ONCE(*rcu_dereference(iter.sptep));
+ goto retry;
+ }
spte_set = true;
}
@@ -1187,17 +1300,13 @@ static bool clear_dirty_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
bool kvm_tdp_mmu_clear_dirty_slot(struct kvm *kvm, struct kvm_memory_slot *slot)
{
struct kvm_mmu_page *root;
- int root_as_id;
bool spte_set = false;
- for_each_tdp_mmu_root_yield_safe(kvm, root) {
- root_as_id = kvm_mmu_page_as_id(root);
- if (root_as_id != slot->as_id)
- continue;
+ lockdep_assert_held_read(&kvm->mmu_lock);
+ for_each_tdp_mmu_root_yield_safe(kvm, root, slot->as_id, true)
spte_set |= clear_dirty_gfn_range(kvm, root, slot->base_gfn,
slot->base_gfn + slot->npages);
- }
return spte_set;
}
@@ -1259,37 +1368,32 @@ void kvm_tdp_mmu_clear_dirty_pt_masked(struct kvm *kvm,
bool wrprot)
{
struct kvm_mmu_page *root;
- int root_as_id;
lockdep_assert_held_write(&kvm->mmu_lock);
- for_each_tdp_mmu_root(kvm, root) {
- root_as_id = kvm_mmu_page_as_id(root);
- if (root_as_id != slot->as_id)
- continue;
-
+ for_each_tdp_mmu_root(kvm, root, slot->as_id)
clear_dirty_pt_masked(kvm, root, gfn, mask, wrprot);
- }
}
/*
* Clear leaf entries which could be replaced by large mappings, for
* GFNs within the slot.
*/
-static void zap_collapsible_spte_range(struct kvm *kvm,
+static bool zap_collapsible_spte_range(struct kvm *kvm,
struct kvm_mmu_page *root,
- struct kvm_memory_slot *slot)
+ const struct kvm_memory_slot *slot,
+ bool flush)
{
gfn_t start = slot->base_gfn;
gfn_t end = start + slot->npages;
struct tdp_iter iter;
kvm_pfn_t pfn;
- bool spte_set = false;
rcu_read_lock();
tdp_root_for_each_pte(iter, root, start, end) {
- if (tdp_mmu_iter_cond_resched(kvm, &iter, spte_set)) {
- spte_set = false;
+retry:
+ if (tdp_mmu_iter_cond_resched(kvm, &iter, flush, true)) {
+ flush = false;
continue;
}
@@ -1303,38 +1407,43 @@ static void zap_collapsible_spte_range(struct kvm *kvm,
pfn, PG_LEVEL_NUM))
continue;
- tdp_mmu_set_spte(kvm, &iter, 0);
-
- spte_set = true;
+ if (!tdp_mmu_zap_spte_atomic(kvm, &iter)) {
+ /*
+ * The iter must explicitly re-read the SPTE because
+ * the atomic cmpxchg failed.
+ */
+ iter.old_spte = READ_ONCE(*rcu_dereference(iter.sptep));
+ goto retry;
+ }
+ flush = true;
}
rcu_read_unlock();
- if (spte_set)
- kvm_flush_remote_tlbs(kvm);
+
+ return flush;
}
/*
* Clear non-leaf entries (and free associated page tables) which could
* be replaced by large mappings, for GFNs within the slot.
*/
-void kvm_tdp_mmu_zap_collapsible_sptes(struct kvm *kvm,
- struct kvm_memory_slot *slot)
+bool kvm_tdp_mmu_zap_collapsible_sptes(struct kvm *kvm,
+ const struct kvm_memory_slot *slot,
+ bool flush)
{
struct kvm_mmu_page *root;
- int root_as_id;
- for_each_tdp_mmu_root_yield_safe(kvm, root) {
- root_as_id = kvm_mmu_page_as_id(root);
- if (root_as_id != slot->as_id)
- continue;
+ lockdep_assert_held_read(&kvm->mmu_lock);
- zap_collapsible_spte_range(kvm, root, slot);
- }
+ for_each_tdp_mmu_root_yield_safe(kvm, root, slot->as_id, true)
+ flush = zap_collapsible_spte_range(kvm, root, slot, flush);
+
+ return flush;
}
/*
* Removes write access on the last level SPTE mapping this GFN and unsets the
- * SPTE_MMU_WRITABLE bit to ensure future writes continue to be intercepted.
+ * MMU-writable bit to ensure future writes continue to be intercepted.
* Returns true if an SPTE was set and a TLB flush is needed.
*/
static bool write_protect_gfn(struct kvm *kvm, struct kvm_mmu_page *root,
@@ -1351,7 +1460,7 @@ static bool write_protect_gfn(struct kvm *kvm, struct kvm_mmu_page *root,
break;
new_spte = iter.old_spte &
- ~(PT_WRITABLE_MASK | SPTE_MMU_WRITEABLE);
+ ~(PT_WRITABLE_MASK | shadow_mmu_writable_mask);
tdp_mmu_set_spte(kvm, &iter, new_spte);
spte_set = true;
@@ -1364,24 +1473,19 @@ static bool write_protect_gfn(struct kvm *kvm, struct kvm_mmu_page *root,
/*
* Removes write access on the last level SPTE mapping this GFN and unsets the
- * SPTE_MMU_WRITABLE bit to ensure future writes continue to be intercepted.
+ * MMU-writable bit to ensure future writes continue to be intercepted.
* Returns true if an SPTE was set and a TLB flush is needed.
*/
bool kvm_tdp_mmu_write_protect_gfn(struct kvm *kvm,
struct kvm_memory_slot *slot, gfn_t gfn)
{
struct kvm_mmu_page *root;
- int root_as_id;
bool spte_set = false;
lockdep_assert_held_write(&kvm->mmu_lock);
- for_each_tdp_mmu_root(kvm, root) {
- root_as_id = kvm_mmu_page_as_id(root);
- if (root_as_id != slot->as_id)
- continue;
-
+ for_each_tdp_mmu_root(kvm, root, slot->as_id)
spte_set |= write_protect_gfn(kvm, root, gfn);
- }
+
return spte_set;
}
diff --git a/arch/x86/kvm/mmu/tdp_mmu.h b/arch/x86/kvm/mmu/tdp_mmu.h
index 31096ece9b14..5fdf63090451 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.h
+++ b/arch/x86/kvm/mmu/tdp_mmu.h
@@ -6,14 +6,28 @@
#include <linux/kvm_host.h>
hpa_t kvm_tdp_mmu_get_vcpu_root_hpa(struct kvm_vcpu *vcpu);
-void kvm_tdp_mmu_free_root(struct kvm *kvm, struct kvm_mmu_page *root);
-bool __kvm_tdp_mmu_zap_gfn_range(struct kvm *kvm, gfn_t start, gfn_t end,
- bool can_yield);
-static inline bool kvm_tdp_mmu_zap_gfn_range(struct kvm *kvm, gfn_t start,
- gfn_t end)
+__must_check static inline bool kvm_tdp_mmu_get_root(struct kvm *kvm,
+ struct kvm_mmu_page *root)
{
- return __kvm_tdp_mmu_zap_gfn_range(kvm, start, end, true);
+ if (root->role.invalid)
+ return false;
+
+ return refcount_inc_not_zero(&root->tdp_mmu_root_count);
+}
+
+void kvm_tdp_mmu_put_root(struct kvm *kvm, struct kvm_mmu_page *root,
+ bool shared);
+
+bool __kvm_tdp_mmu_zap_gfn_range(struct kvm *kvm, int as_id, gfn_t start,
+ gfn_t end, bool can_yield, bool flush,
+ bool shared);
+static inline bool kvm_tdp_mmu_zap_gfn_range(struct kvm *kvm, int as_id,
+ gfn_t start, gfn_t end, bool flush,
+ bool shared)
+{
+ return __kvm_tdp_mmu_zap_gfn_range(kvm, as_id, start, end, true, flush,
+ shared);
}
static inline bool kvm_tdp_mmu_zap_sp(struct kvm *kvm, struct kvm_mmu_page *sp)
{
@@ -29,23 +43,23 @@ static inline bool kvm_tdp_mmu_zap_sp(struct kvm *kvm, struct kvm_mmu_page *sp)
* of the shadow page's gfn range and stop iterating before yielding.
*/
lockdep_assert_held_write(&kvm->mmu_lock);
- return __kvm_tdp_mmu_zap_gfn_range(kvm, sp->gfn, end, false);
+ return __kvm_tdp_mmu_zap_gfn_range(kvm, kvm_mmu_page_as_id(sp),
+ sp->gfn, end, false, false, false);
}
+
void kvm_tdp_mmu_zap_all(struct kvm *kvm);
+void kvm_tdp_mmu_invalidate_all_roots(struct kvm *kvm);
+void kvm_tdp_mmu_zap_invalidated_roots(struct kvm *kvm);
int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
int map_writable, int max_level, kvm_pfn_t pfn,
bool prefault);
-int kvm_tdp_mmu_zap_hva_range(struct kvm *kvm, unsigned long start,
- unsigned long end);
-
-int kvm_tdp_mmu_age_hva_range(struct kvm *kvm, unsigned long start,
- unsigned long end);
-int kvm_tdp_mmu_test_age_hva(struct kvm *kvm, unsigned long hva);
-
-int kvm_tdp_mmu_set_spte_hva(struct kvm *kvm, unsigned long address,
- pte_t *host_ptep);
+bool kvm_tdp_mmu_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range,
+ bool flush);
+bool kvm_tdp_mmu_age_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range);
+bool kvm_tdp_mmu_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range);
+bool kvm_tdp_mmu_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range);
bool kvm_tdp_mmu_wrprot_slot(struct kvm *kvm, struct kvm_memory_slot *slot,
int min_level);
@@ -55,8 +69,9 @@ void kvm_tdp_mmu_clear_dirty_pt_masked(struct kvm *kvm,
struct kvm_memory_slot *slot,
gfn_t gfn, unsigned long mask,
bool wrprot);
-void kvm_tdp_mmu_zap_collapsible_sptes(struct kvm *kvm,
- struct kvm_memory_slot *slot);
+bool kvm_tdp_mmu_zap_collapsible_sptes(struct kvm *kvm,
+ const struct kvm_memory_slot *slot,
+ bool flush);
bool kvm_tdp_mmu_write_protect_gfn(struct kvm *kvm,
struct kvm_memory_slot *slot, gfn_t gfn);