diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/include/asm/kvm_arm.h | 5 | ||||
| -rw-r--r-- | arch/arm/include/asm/kvm_mmu.h | 17 | ||||
| -rw-r--r-- | arch/arm/include/asm/pgtable-3level.h | 2 | ||||
| -rw-r--r-- | arch/arm/kvm/Kconfig | 1 | ||||
| -rw-r--r-- | arch/arm/kvm/handle_exit.c | 20 | ||||
| -rw-r--r-- | arch/arm/kvm/mmu.c | 223 | ||||
| -rw-r--r-- | arch/arm64/include/asm/kvm_mmu.h | 12 | ||||
| -rw-r--r-- | arch/arm64/include/asm/pgtable-hwdef.h | 2 |
8 files changed, 230 insertions, 52 deletions
diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h index d556f03bca17..1d3153c7eb41 100644 --- a/arch/arm/include/asm/kvm_arm.h +++ b/arch/arm/include/asm/kvm_arm.h @@ -57,6 +57,7 @@ * TSC: Trap SMC * TSW: Trap cache operations by set/way * TWI: Trap WFI + * TWE: Trap WFE * TIDCP: Trap L2CTLR/L2ECTLR * BSU_IS: Upgrade barriers to the inner shareable domain * FB: Force broadcast of all maintainance operations @@ -67,7 +68,7 @@ */ #define HCR_GUEST_MASK (HCR_TSC | HCR_TSW | HCR_TWI | HCR_VM | HCR_BSU_IS | \ HCR_FB | HCR_TAC | HCR_AMO | HCR_IMO | HCR_FMO | \ - HCR_SWIO | HCR_TIDCP) + HCR_TWE | HCR_SWIO | HCR_TIDCP) #define HCR_VIRT_EXCP_MASK (HCR_VA | HCR_VI | HCR_VF) /* System Control Register (SCTLR) bits */ @@ -208,6 +209,8 @@ #define HSR_EC_DABT (0x24) #define HSR_EC_DABT_HYP (0x25) +#define HSR_WFI_IS_WFE (1U << 0) + #define HSR_HVC_IMM_MASK ((1UL << 16) - 1) #define HSR_DABT_S1PTW (1U << 7) diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index 9b28c41f4ba9..77de4a41cc50 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -62,6 +62,12 @@ phys_addr_t kvm_get_idmap_vector(void); int kvm_mmu_init(void); void kvm_clear_hyp_idmap(void); +static inline void kvm_set_pmd(pmd_t *pmd, pmd_t new_pmd) +{ + *pmd = new_pmd; + flush_pmd_entry(pmd); +} + static inline void kvm_set_pte(pte_t *pte, pte_t new_pte) { *pte = new_pte; @@ -103,9 +109,15 @@ static inline void kvm_set_s2pte_writable(pte_t *pte) pte_val(*pte) |= L_PTE_S2_RDWR; } +static inline void kvm_set_s2pmd_writable(pmd_t *pmd) +{ + pmd_val(*pmd) |= L_PMD_S2_RDWR; +} + struct kvm; -static inline void coherent_icache_guest_page(struct kvm *kvm, gfn_t gfn) +static inline void coherent_icache_guest_page(struct kvm *kvm, hva_t hva, + unsigned long size) { /* * If we are going to insert an instruction page and the icache is @@ -120,8 +132,7 @@ static inline void coherent_icache_guest_page(struct kvm *kvm, gfn_t gfn) * need any kind of flushing (DDI 0406C.b - Page B3-1392). */ if (icache_is_pipt()) { - unsigned long hva = gfn_to_hva(kvm, gfn); - __cpuc_coherent_user_range(hva, hva + PAGE_SIZE); + __cpuc_coherent_user_range(hva, hva + size); } else if (!icache_is_vivt_asid_tagged()) { /* any kind of VIPT cache */ __flush_icache_all(); diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h index 5689c18c85f5..a331d2527342 100644 --- a/arch/arm/include/asm/pgtable-3level.h +++ b/arch/arm/include/asm/pgtable-3level.h @@ -126,6 +126,8 @@ #define L_PTE_S2_RDONLY (_AT(pteval_t, 1) << 6) /* HAP[1] */ #define L_PTE_S2_RDWR (_AT(pteval_t, 3) << 6) /* HAP[2:1] */ +#define L_PMD_S2_RDWR (_AT(pmdval_t, 3) << 6) /* HAP[2:1] */ + /* * Hyp-mode PL2 PTE definitions for LPAE. */ diff --git a/arch/arm/kvm/Kconfig b/arch/arm/kvm/Kconfig index ebf5015508b5..466bd299b1a8 100644 --- a/arch/arm/kvm/Kconfig +++ b/arch/arm/kvm/Kconfig @@ -20,6 +20,7 @@ config KVM bool "Kernel-based Virtual Machine (KVM) support" select PREEMPT_NOTIFIERS select ANON_INODES + select HAVE_KVM_CPU_RELAX_INTERCEPT select KVM_MMIO select KVM_ARM_HOST depends on ARM_VIRT_EXT && ARM_LPAE diff --git a/arch/arm/kvm/handle_exit.c b/arch/arm/kvm/handle_exit.c index df4c82d47ad7..a92079011a83 100644 --- a/arch/arm/kvm/handle_exit.c +++ b/arch/arm/kvm/handle_exit.c @@ -73,23 +73,29 @@ static int handle_dabt_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run) } /** - * kvm_handle_wfi - handle a wait-for-interrupts instruction executed by a guest + * kvm_handle_wfx - handle a WFI or WFE instructions trapped in guests * @vcpu: the vcpu pointer * @run: the kvm_run structure pointer * - * Simply sets the wait_for_interrupts flag on the vcpu structure, which will - * halt execution of world-switches and schedule other host processes until - * there is an incoming IRQ or FIQ to the VM. + * WFE: Yield the CPU and come back to this vcpu when the scheduler + * decides to. + * WFI: Simply call kvm_vcpu_block(), which will halt execution of + * world-switches and schedule other host processes until there is an + * incoming IRQ or FIQ to the VM. */ -static int kvm_handle_wfi(struct kvm_vcpu *vcpu, struct kvm_run *run) +static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run) { trace_kvm_wfi(*vcpu_pc(vcpu)); - kvm_vcpu_block(vcpu); + if (kvm_vcpu_get_hsr(vcpu) & HSR_WFI_IS_WFE) + kvm_vcpu_on_spin(vcpu); + else + kvm_vcpu_block(vcpu); + return 1; } static exit_handle_fn arm_exit_handlers[] = { - [HSR_EC_WFI] = kvm_handle_wfi, + [HSR_EC_WFI] = kvm_handle_wfx, [HSR_EC_CP15_32] = kvm_handle_cp15_32, [HSR_EC_CP15_64] = kvm_handle_cp15_64, [HSR_EC_CP14_MR] = kvm_handle_cp14_access, diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index b0de86b56c13..371958370de4 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -19,6 +19,7 @@ #include <linux/mman.h> #include <linux/kvm_host.h> #include <linux/io.h> +#include <linux/hugetlb.h> #include <trace/events/kvm.h> #include <asm/pgalloc.h> #include <asm/cacheflush.h> @@ -41,6 +42,8 @@ static unsigned long hyp_idmap_start; static unsigned long hyp_idmap_end; static phys_addr_t hyp_idmap_vector; +#define kvm_pmd_huge(_x) (pmd_huge(_x) || pmd_trans_huge(_x)) + static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa) { /* @@ -93,19 +96,29 @@ static bool page_empty(void *ptr) static void clear_pud_entry(struct kvm *kvm, pud_t *pud, phys_addr_t addr) { - pmd_t *pmd_table = pmd_offset(pud, 0); - pud_clear(pud); - kvm_tlb_flush_vmid_ipa(kvm, addr); - pmd_free(NULL, pmd_table); + if (pud_huge(*pud)) { + pud_clear(pud); + kvm_tlb_flush_vmid_ipa(kvm, addr); + } else { + pmd_t *pmd_table = pmd_offset(pud, 0); + pud_clear(pud); + kvm_tlb_flush_vmid_ipa(kvm, addr); + pmd_free(NULL, pmd_table); + } put_page(virt_to_page(pud)); } static void clear_pmd_entry(struct kvm *kvm, pmd_t *pmd, phys_addr_t addr) { - pte_t *pte_table = pte_offset_kernel(pmd, 0); - pmd_clear(pmd); - kvm_tlb_flush_vmid_ipa(kvm, addr); - pte_free_kernel(NULL, pte_table); + if (kvm_pmd_huge(*pmd)) { + pmd_clear(pmd); + kvm_tlb_flush_vmid_ipa(kvm, addr); + } else { + pte_t *pte_table = pte_offset_kernel(pmd, 0); + pmd_clear(pmd); + kvm_tlb_flush_vmid_ipa(kvm, addr); + pte_free_kernel(NULL, pte_table); + } put_page(virt_to_page(pmd)); } @@ -136,18 +149,32 @@ static void unmap_range(struct kvm *kvm, pgd_t *pgdp, continue; } + if (pud_huge(*pud)) { + /* + * If we are dealing with a huge pud, just clear it and + * move on. + */ + clear_pud_entry(kvm, pud, addr); + addr = pud_addr_end(addr, end); + continue; + } + pmd = pmd_offset(pud, addr); if (pmd_none(*pmd)) { addr = pmd_addr_end(addr, end); continue; } - pte = pte_offset_kernel(pmd, addr); - clear_pte_entry(kvm, pte, addr); - next = addr + PAGE_SIZE; + if (!kvm_pmd_huge(*pmd)) { + pte = pte_offset_kernel(pmd, addr); + clear_pte_entry(kvm, pte, addr); + next = addr + PAGE_SIZE; + } - /* If we emptied the pte, walk back up the ladder */ - if (page_empty(pte)) { + /* + * If the pmd entry is to be cleared, walk back up the ladder + */ + if (kvm_pmd_huge(*pmd) || page_empty(pte)) { clear_pmd_entry(kvm, pmd, addr); next = pmd_addr_end(addr, end); if (page_empty(pmd) && !page_empty(pud)) { @@ -420,29 +447,71 @@ void kvm_free_stage2_pgd(struct kvm *kvm) kvm->arch.pgd = NULL; } - -static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, - phys_addr_t addr, const pte_t *new_pte, bool iomap) +static pmd_t *stage2_get_pmd(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, + phys_addr_t addr) { pgd_t *pgd; pud_t *pud; pmd_t *pmd; - pte_t *pte, old_pte; - /* Create 2nd stage page table mapping - Level 1 */ pgd = kvm->arch.pgd + pgd_index(addr); pud = pud_offset(pgd, addr); if (pud_none(*pud)) { if (!cache) - return 0; /* ignore calls from kvm_set_spte_hva */ + return NULL; pmd = mmu_memory_cache_alloc(cache); pud_populate(NULL, pud, pmd); get_page(virt_to_page(pud)); } - pmd = pmd_offset(pud, addr); + return pmd_offset(pud, addr); +} + +static int stage2_set_pmd_huge(struct kvm *kvm, struct kvm_mmu_memory_cache + *cache, phys_addr_t addr, const pmd_t *new_pmd) +{ + pmd_t *pmd, old_pmd; + + pmd = stage2_get_pmd(kvm, cache, addr); + VM_BUG_ON(!pmd); + + /* + * Mapping in huge pages should only happen through a fault. If a + * page is merged into a transparent huge page, the individual + * subpages of that huge page should be unmapped through MMU + * notifiers before we get here. + * + * Merging of CompoundPages is not supported; they should become + * splitting first, unmapped, merged, and mapped back in on-demand. + */ + VM_BUG_ON(pmd_present(*pmd) && pmd_pfn(*pmd) != pmd_pfn(*new_pmd)); + + old_pmd = *pmd; + kvm_set_pmd(pmd, *new_pmd); + if (pmd_present(old_pmd)) + kvm_tlb_flush_vmid_ipa(kvm, addr); + else + get_page(virt_to_page(pmd)); + return 0; +} + +static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, + phys_addr_t addr, const pte_t *new_pte, bool iomap) +{ + pmd_t *pmd; + pte_t *pte, old_pte; - /* Create 2nd stage page table mapping - Level 2 */ + /* Create stage-2 page table mapping - Level 1 */ + pmd = stage2_get_pmd(kvm, cache, addr); + if (!pmd) { + /* + * Ignore calls from kvm_set_spte_hva for unallocated + * address ranges. + */ + return 0; + } + + /* Create stage-2 page mappings - Level 2 */ if (pmd_none(*pmd)) { if (!cache) return 0; /* ignore calls from kvm_set_spte_hva */ @@ -507,16 +576,60 @@ out: return ret; } +static bool transparent_hugepage_adjust(pfn_t *pfnp, phys_addr_t *ipap) +{ + pfn_t pfn = *pfnp; + gfn_t gfn = *ipap >> PAGE_SHIFT; + + if (PageTransCompound(pfn_to_page(pfn))) { + unsigned long mask; + /* + * The address we faulted on is backed by a transparent huge + * page. However, because we map the compound huge page and + * not the individual tail page, we need to transfer the + * refcount to the head page. We have to be careful that the + * THP doesn't start to split while we are adjusting the + * refcounts. + * + * We are sure this doesn't happen, because mmu_notifier_retry + * was successful and we are holding the mmu_lock, so if this + * THP is trying to split, it will be blocked in the mmu + * notifier before touching any of the pages, specifically + * before being able to call __split_huge_page_refcount(). + * + * We can therefore safely transfer the refcount from PG_tail + * to PG_head and switch the pfn from a tail page to the head + * page accordingly. + */ + mask = PTRS_PER_PMD - 1; + VM_BUG_ON((gfn & mask) != (pfn & mask)); + if (pfn & mask) { + *ipap &= PMD_MASK; + kvm_release_pfn_clean(pfn); + pfn &= ~mask; + kvm_get_pfn(pfn); + *pfnp = pfn; + } + + return true; + } + + return false; +} + static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, - gfn_t gfn, struct kvm_memory_slot *memslot, + struct kvm_memory_slot *memslot, unsigned long fault_status) { - pte_t new_pte; - pfn_t pfn; int ret; - bool write_fault, writable; + bool write_fault, writable, hugetlb = false, force_pte = false; unsigned long mmu_seq; + gfn_t gfn = fault_ipa >> PAGE_SHIFT; + unsigned long hva = gfn_to_hva(vcpu->kvm, gfn); + struct kvm *kvm = vcpu->kvm; struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache; + struct vm_area_struct *vma; + pfn_t pfn; write_fault = kvm_is_write_fault(kvm_vcpu_get_hsr(vcpu)); if (fault_status == FSC_PERM && !write_fault) { @@ -524,6 +637,26 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, return -EFAULT; } + /* Let's check if we will get back a huge page backed by hugetlbfs */ + down_read(¤t->mm->mmap_sem); + vma = find_vma_intersection(current->mm, hva, hva + 1); + if (is_vm_hugetlb_page(vma)) { + hugetlb = true; + gfn = (fault_ipa & PMD_MASK) >> PAGE_SHIFT; + } else { + /* + * Pages belonging to VMAs not aligned to the PMD mapping + * granularity cannot be mapped using block descriptors even + * if the pages belong to a THP for the process, because the + * stage-2 block descriptor will cover more than a single THP + * and we loose atomicity for unmapping, updates, and splits + * of the THP or other pages in the stage-2 block range. + */ + if (vma->vm_start & ~PMD_MASK) + force_pte = true; + } + up_read(¤t->mm->mmap_sem); + /* We need minimum second+third level pages */ ret = mmu_topup_memory_cache(memcache, 2, KVM_NR_MEM_OBJS); if (ret) @@ -541,26 +674,40 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, */ smp_rmb(); - pfn = gfn_to_pfn_prot(vcpu->kvm, gfn, write_fault, &writable); + pfn = gfn_to_pfn_prot(kvm, gfn, write_fault, &writable); if (is_error_pfn(pfn)) return -EFAULT; - new_pte = pfn_pte(pfn, PAGE_S2); - coherent_icache_guest_page(vcpu->kvm, gfn); - - spin_lock(&vcpu->kvm->mmu_lock); - if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) + spin_lock(&kvm->mmu_lock); + if (mmu_notifier_retry(kvm, mmu_seq)) goto out_unlock; - if (writable) { - kvm_set_s2pte_writable(&new_pte); - kvm_set_pfn_dirty(pfn); + if (!hugetlb && !force_pte) + hugetlb = transparent_hugepage_adjust(&pfn, &fault_ipa); + + if (hugetlb) { + pmd_t new_pmd = pfn_pmd(pfn, PAGE_S2); + new_pmd = pmd_mkhuge(new_pmd); + if (writable) { + kvm_set_s2pmd_writable(&new_pmd); + kvm_set_pfn_dirty(pfn); + } + coherent_icache_guest_page(kvm, hva & PMD_MASK, PMD_SIZE); + ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd); + } else { + pte_t new_pte = pfn_pte(pfn, PAGE_S2); + if (writable) { + kvm_set_s2pte_writable(&new_pte); + kvm_set_pfn_dirty(pfn); + } + coherent_icache_guest_page(kvm, hva, PAGE_SIZE); + ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, false); } - stage2_set_pte(vcpu->kvm, memcache, fault_ipa, &new_pte, false); + out_unlock: - spin_unlock(&vcpu->kvm->mmu_lock); + spin_unlock(&kvm->mmu_lock); kvm_release_pfn_clean(pfn); - return 0; + return ret; } /** @@ -629,7 +776,7 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run) memslot = gfn_to_memslot(vcpu->kvm, gfn); - ret = user_mem_abort(vcpu, fault_ipa, gfn, memslot, fault_status); + ret = user_mem_abort(vcpu, fault_ipa, memslot, fault_status); if (ret == 0) ret = 1; out_unlock: diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index efe609c6a3c9..680f74e67497 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -91,6 +91,7 @@ int kvm_mmu_init(void); void kvm_clear_hyp_idmap(void); #define kvm_set_pte(ptep, pte) set_pte(ptep, pte) +#define kvm_set_pmd(pmdp, pmd) set_pmd(pmdp, pmd) static inline bool kvm_is_write_fault(unsigned long esr) { @@ -116,13 +117,18 @@ static inline void kvm_set_s2pte_writable(pte_t *pte) pte_val(*pte) |= PTE_S2_RDWR; } +static inline void kvm_set_s2pmd_writable(pmd_t *pmd) +{ + pmd_val(*pmd) |= PMD_S2_RDWR; +} + struct kvm; -static inline void coherent_icache_guest_page(struct kvm *kvm, gfn_t gfn) +static inline void coherent_icache_guest_page(struct kvm *kvm, hva_t hva, + unsigned long size) { if (!icache_is_aliasing()) { /* PIPT */ - unsigned long hva = gfn_to_hva(kvm, gfn); - flush_icache_range(hva, hva + PAGE_SIZE); + flush_icache_range(hva, hva + size); } else if (!icache_is_aivivt()) { /* non ASID-tagged VIVT */ /* any kind of VIPT cache */ __flush_icache_all(); diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h index d57e66845c86..755f86143320 100644 --- a/arch/arm64/include/asm/pgtable-hwdef.h +++ b/arch/arm64/include/asm/pgtable-hwdef.h @@ -85,6 +85,8 @@ #define PTE_S2_RDONLY (_AT(pteval_t, 1) << 6) /* HAP[2:1] */ #define PTE_S2_RDWR (_AT(pteval_t, 3) << 6) /* HAP[2:1] */ +#define PMD_S2_RDWR (_AT(pmdval_t, 3) << 6) /* HAP[2:1] */ + /* * Memory Attribute override for Stage-2 (MemAttr[3:0]) */ |