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Diffstat (limited to 'arch/arm64/include/asm/kvm_mmu.h')
-rw-r--r--arch/arm64/include/asm/kvm_mmu.h191
1 files changed, 131 insertions, 60 deletions
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 9679067a1574..082110993647 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -69,9 +69,6 @@
* mappings, and none of this applies in that case.
*/
-#define HYP_PAGE_OFFSET_HIGH_MASK ((UL(1) << VA_BITS) - 1)
-#define HYP_PAGE_OFFSET_LOW_MASK ((UL(1) << (VA_BITS - 1)) - 1)
-
#ifdef __ASSEMBLY__
#include <asm/alternative.h>
@@ -81,28 +78,19 @@
* Convert a kernel VA into a HYP VA.
* reg: VA to be converted.
*
- * This generates the following sequences:
- * - High mask:
- * and x0, x0, #HYP_PAGE_OFFSET_HIGH_MASK
- * nop
- * - Low mask:
- * and x0, x0, #HYP_PAGE_OFFSET_HIGH_MASK
- * and x0, x0, #HYP_PAGE_OFFSET_LOW_MASK
- * - VHE:
- * nop
- * nop
- *
- * The "low mask" version works because the mask is a strict subset of
- * the "high mask", hence performing the first mask for nothing.
- * Should be completely invisible on any viable CPU.
+ * The actual code generation takes place in kvm_update_va_mask, and
+ * the instructions below are only there to reserve the space and
+ * perform the register allocation (kvm_update_va_mask uses the
+ * specific registers encoded in the instructions).
*/
.macro kern_hyp_va reg
-alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
- and \reg, \reg, #HYP_PAGE_OFFSET_HIGH_MASK
-alternative_else_nop_endif
-alternative_if ARM64_HYP_OFFSET_LOW
- and \reg, \reg, #HYP_PAGE_OFFSET_LOW_MASK
-alternative_else_nop_endif
+alternative_cb kvm_update_va_mask
+ and \reg, \reg, #1 /* mask with va_mask */
+ ror \reg, \reg, #1 /* rotate to the first tag bit */
+ add \reg, \reg, #0 /* insert the low 12 bits of the tag */
+ add \reg, \reg, #0, lsl 12 /* insert the top 12 bits of the tag */
+ ror \reg, \reg, #63 /* rotate back */
+alternative_cb_end
.endm
#else
@@ -113,24 +101,44 @@ alternative_else_nop_endif
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
+void kvm_update_va_mask(struct alt_instr *alt,
+ __le32 *origptr, __le32 *updptr, int nr_inst);
+
static inline unsigned long __kern_hyp_va(unsigned long v)
{
- asm volatile(ALTERNATIVE("and %0, %0, %1",
- "nop",
- ARM64_HAS_VIRT_HOST_EXTN)
- : "+r" (v)
- : "i" (HYP_PAGE_OFFSET_HIGH_MASK));
- asm volatile(ALTERNATIVE("nop",
- "and %0, %0, %1",
- ARM64_HYP_OFFSET_LOW)
- : "+r" (v)
- : "i" (HYP_PAGE_OFFSET_LOW_MASK));
+ asm volatile(ALTERNATIVE_CB("and %0, %0, #1\n"
+ "ror %0, %0, #1\n"
+ "add %0, %0, #0\n"
+ "add %0, %0, #0, lsl 12\n"
+ "ror %0, %0, #63\n",
+ kvm_update_va_mask)
+ : "+r" (v));
return v;
}
#define kern_hyp_va(v) ((typeof(v))(__kern_hyp_va((unsigned long)(v))))
/*
+ * Obtain the PC-relative address of a kernel symbol
+ * s: symbol
+ *
+ * The goal of this macro is to return a symbol's address based on a
+ * PC-relative computation, as opposed to a loading the VA from a
+ * constant pool or something similar. This works well for HYP, as an
+ * absolute VA is guaranteed to be wrong. Only use this if trying to
+ * obtain the address of a symbol (i.e. not something you obtained by
+ * following a pointer).
+ */
+#define hyp_symbol_addr(s) \
+ ({ \
+ typeof(s) *addr; \
+ asm("adrp %0, %1\n" \
+ "add %0, %0, :lo12:%1\n" \
+ : "=r" (addr) : "S" (&s)); \
+ addr; \
+ })
+
+/*
* We currently only support a 40bit IPA.
*/
#define KVM_PHYS_SHIFT (40)
@@ -140,7 +148,11 @@ static inline unsigned long __kern_hyp_va(unsigned long v)
#include <asm/stage2_pgtable.h>
int create_hyp_mappings(void *from, void *to, pgprot_t prot);
-int create_hyp_io_mappings(void *from, void *to, phys_addr_t);
+int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size,
+ void __iomem **kaddr,
+ void __iomem **haddr);
+int create_hyp_exec_mappings(phys_addr_t phys_addr, size_t size,
+ void **haddr);
void free_hyp_pgds(void);
void stage2_unmap_vm(struct kvm *kvm);
@@ -185,42 +197,42 @@ static inline pmd_t kvm_s2pmd_mkexec(pmd_t pmd)
return pmd;
}
-static inline void kvm_set_s2pte_readonly(pte_t *pte)
+static inline void kvm_set_s2pte_readonly(pte_t *ptep)
{
pteval_t old_pteval, pteval;
- pteval = READ_ONCE(pte_val(*pte));
+ pteval = READ_ONCE(pte_val(*ptep));
do {
old_pteval = pteval;
pteval &= ~PTE_S2_RDWR;
pteval |= PTE_S2_RDONLY;
- pteval = cmpxchg_relaxed(&pte_val(*pte), old_pteval, pteval);
+ pteval = cmpxchg_relaxed(&pte_val(*ptep), old_pteval, pteval);
} while (pteval != old_pteval);
}
-static inline bool kvm_s2pte_readonly(pte_t *pte)
+static inline bool kvm_s2pte_readonly(pte_t *ptep)
{
- return (pte_val(*pte) & PTE_S2_RDWR) == PTE_S2_RDONLY;
+ return (READ_ONCE(pte_val(*ptep)) & PTE_S2_RDWR) == PTE_S2_RDONLY;
}
-static inline bool kvm_s2pte_exec(pte_t *pte)
+static inline bool kvm_s2pte_exec(pte_t *ptep)
{
- return !(pte_val(*pte) & PTE_S2_XN);
+ return !(READ_ONCE(pte_val(*ptep)) & PTE_S2_XN);
}
-static inline void kvm_set_s2pmd_readonly(pmd_t *pmd)
+static inline void kvm_set_s2pmd_readonly(pmd_t *pmdp)
{
- kvm_set_s2pte_readonly((pte_t *)pmd);
+ kvm_set_s2pte_readonly((pte_t *)pmdp);
}
-static inline bool kvm_s2pmd_readonly(pmd_t *pmd)
+static inline bool kvm_s2pmd_readonly(pmd_t *pmdp)
{
- return kvm_s2pte_readonly((pte_t *)pmd);
+ return kvm_s2pte_readonly((pte_t *)pmdp);
}
-static inline bool kvm_s2pmd_exec(pmd_t *pmd)
+static inline bool kvm_s2pmd_exec(pmd_t *pmdp)
{
- return !(pmd_val(*pmd) & PMD_S2_XN);
+ return !(READ_ONCE(pmd_val(*pmdp)) & PMD_S2_XN);
}
static inline bool kvm_page_empty(void *ptr)
@@ -249,7 +261,7 @@ struct kvm;
static inline bool vcpu_has_cache_enabled(struct kvm_vcpu *vcpu)
{
- return (vcpu_sys_reg(vcpu, SCTLR_EL1) & 0b101) == 0b101;
+ return (vcpu_read_sys_reg(vcpu, SCTLR_EL1) & 0b101) == 0b101;
}
static inline void __clean_dcache_guest_page(kvm_pfn_t pfn, unsigned long size)
@@ -348,36 +360,95 @@ static inline unsigned int kvm_get_vmid_bits(void)
return (cpuid_feature_extract_unsigned_field(reg, ID_AA64MMFR1_VMIDBITS_SHIFT) == 2) ? 16 : 8;
}
-#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+#ifdef CONFIG_KVM_INDIRECT_VECTORS
+/*
+ * EL2 vectors can be mapped and rerouted in a number of ways,
+ * depending on the kernel configuration and CPU present:
+ *
+ * - If the CPU has the ARM64_HARDEN_BRANCH_PREDICTOR cap, the
+ * hardening sequence is placed in one of the vector slots, which is
+ * executed before jumping to the real vectors.
+ *
+ * - If the CPU has both the ARM64_HARDEN_EL2_VECTORS cap and the
+ * ARM64_HARDEN_BRANCH_PREDICTOR cap, the slot containing the
+ * hardening sequence is mapped next to the idmap page, and executed
+ * before jumping to the real vectors.
+ *
+ * - If the CPU only has the ARM64_HARDEN_EL2_VECTORS cap, then an
+ * empty slot is selected, mapped next to the idmap page, and
+ * executed before jumping to the real vectors.
+ *
+ * Note that ARM64_HARDEN_EL2_VECTORS is somewhat incompatible with
+ * VHE, as we don't have hypervisor-specific mappings. If the system
+ * is VHE and yet selects this capability, it will be ignored.
+ */
#include <asm/mmu.h>
+extern void *__kvm_bp_vect_base;
+extern int __kvm_harden_el2_vector_slot;
+
static inline void *kvm_get_hyp_vector(void)
{
struct bp_hardening_data *data = arm64_get_bp_hardening_data();
- void *vect = kvm_ksym_ref(__kvm_hyp_vector);
+ void *vect = kern_hyp_va(kvm_ksym_ref(__kvm_hyp_vector));
+ int slot = -1;
- if (data->fn) {
- vect = __bp_harden_hyp_vecs_start +
- data->hyp_vectors_slot * SZ_2K;
+ if (cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR) && data->fn) {
+ vect = kern_hyp_va(kvm_ksym_ref(__bp_harden_hyp_vecs_start));
+ slot = data->hyp_vectors_slot;
+ }
- if (!has_vhe())
- vect = lm_alias(vect);
+ if (this_cpu_has_cap(ARM64_HARDEN_EL2_VECTORS) && !has_vhe()) {
+ vect = __kvm_bp_vect_base;
+ if (slot == -1)
+ slot = __kvm_harden_el2_vector_slot;
}
+ if (slot != -1)
+ vect += slot * SZ_2K;
+
return vect;
}
+/* This is only called on a !VHE system */
static inline int kvm_map_vectors(void)
{
- return create_hyp_mappings(kvm_ksym_ref(__bp_harden_hyp_vecs_start),
- kvm_ksym_ref(__bp_harden_hyp_vecs_end),
- PAGE_HYP_EXEC);
-}
+ /*
+ * HBP = ARM64_HARDEN_BRANCH_PREDICTOR
+ * HEL2 = ARM64_HARDEN_EL2_VECTORS
+ *
+ * !HBP + !HEL2 -> use direct vectors
+ * HBP + !HEL2 -> use hardened vectors in place
+ * !HBP + HEL2 -> allocate one vector slot and use exec mapping
+ * HBP + HEL2 -> use hardened vertors and use exec mapping
+ */
+ if (cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR)) {
+ __kvm_bp_vect_base = kvm_ksym_ref(__bp_harden_hyp_vecs_start);
+ __kvm_bp_vect_base = kern_hyp_va(__kvm_bp_vect_base);
+ }
+
+ if (cpus_have_const_cap(ARM64_HARDEN_EL2_VECTORS)) {
+ phys_addr_t vect_pa = __pa_symbol(__bp_harden_hyp_vecs_start);
+ unsigned long size = (__bp_harden_hyp_vecs_end -
+ __bp_harden_hyp_vecs_start);
+
+ /*
+ * Always allocate a spare vector slot, as we don't
+ * know yet which CPUs have a BP hardening slot that
+ * we can reuse.
+ */
+ __kvm_harden_el2_vector_slot = atomic_inc_return(&arm64_el2_vector_last_slot);
+ BUG_ON(__kvm_harden_el2_vector_slot >= BP_HARDEN_EL2_SLOTS);
+ return create_hyp_exec_mappings(vect_pa, size,
+ &__kvm_bp_vect_base);
+ }
+ return 0;
+}
#else
static inline void *kvm_get_hyp_vector(void)
{
- return kvm_ksym_ref(__kvm_hyp_vector);
+ return kern_hyp_va(kvm_ksym_ref(__kvm_hyp_vector));
}
static inline int kvm_map_vectors(void)
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-12 13:53:58 +0300