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Date: Thu, 6 Oct 2022 00:45:12 +0000
From: Sean Christopherson <seanjc@...gle.com>
To: Paolo Bonzini <pbonzini@...hat.com>
Cc: kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
Sean Christopherson <seanjc@...gle.com>
Subject: [PATCH 7/7] KVM: selftests: Play nice with huge pages when getting PTEs/GPAs
Play nice with huge pages when getting PTEs and translating GVAs to GPAs,
there's no reason to disallow using huge pages in selftests. Use
PG_LEVEL_NONE to indicate that the caller doesn't care about the mapping
level and just wants to get the pte+level.
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
.../selftests/kvm/include/x86_64/processor.h | 11 ++++-
.../selftests/kvm/lib/x86_64/processor.c | 45 ++++++++++++++++---
2 files changed, 47 insertions(+), 9 deletions(-)
diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
index 9676a3464758..e000e35c948f 100644
--- a/tools/testing/selftests/kvm/include/x86_64/processor.h
+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -172,11 +172,16 @@ struct kvm_x86_cpu_feature {
#define PTE_GLOBAL_MASK BIT_ULL(8)
#define PTE_NX_MASK BIT_ULL(63)
+#define PHYSICAL_PAGE_MASK GENMASK_ULL(51, 12)
+
#define PAGE_SHIFT 12
#define PAGE_SIZE (1ULL << PAGE_SHIFT)
-#define PAGE_MASK (~(PAGE_SIZE-1))
+#define PAGE_MASK (~(PAGE_SIZE-1) & PHYSICAL_PAGE_MASK)
+
+#define HUGEPAGE_SHIFT(x) (PAGE_SHIFT + (((x) - 1) * 9))
+#define HUGEPAGE_SIZE(x) (1UL << HUGEPAGE_SHIFT(x))
+#define HUGEPAGE_MASK(x) (~(HUGEPAGE_SIZE(x) - 1) & PHYSICAL_PAGE_MASK)
-#define PHYSICAL_PAGE_MASK GENMASK_ULL(51, 12)
#define PTE_GET_PA(pte) ((pte) & PHYSICAL_PAGE_MASK)
#define PTE_GET_PFN(pte) (PTE_GET_PA(pte) >> PAGE_SHIFT)
@@ -828,6 +833,8 @@ static inline uint8_t wrmsr_safe(uint32_t msr, uint64_t val)
bool kvm_is_tdp_enabled(void);
+uint64_t *__vm_get_page_table_entry(struct kvm_vm *vm, uint64_t vaddr,
+ int *level);
uint64_t *vm_get_page_table_entry(struct kvm_vm *vm, uint64_t vaddr);
uint64_t kvm_hypercall(uint64_t nr, uint64_t a0, uint64_t a1, uint64_t a2,
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index 053f64191122..efa20d0f9927 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -245,10 +245,26 @@ void virt_map_level(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
}
}
-uint64_t *vm_get_page_table_entry(struct kvm_vm *vm, uint64_t vaddr)
+static bool vm_is_target_pte(uint64_t *pte, int *level, int current_level)
+{
+ if (*pte & PTE_LARGE_MASK) {
+ TEST_ASSERT(*level == PG_LEVEL_NONE ||
+ *level == current_level,
+ "Unexpected hugepage at level %d\n", current_level);
+ *level = current_level;
+ }
+
+ return *level == current_level;
+}
+
+uint64_t *__vm_get_page_table_entry(struct kvm_vm *vm, uint64_t vaddr,
+ int *level)
{
uint64_t *pml4e, *pdpe, *pde;
+ TEST_ASSERT(*level >= PG_LEVEL_NONE && *level < PG_LEVEL_NUM,
+ "Invalid PG_LEVEL_* '%d'", *level);
+
TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K, "Attempt to use "
"unknown or unsupported guest mode, mode: 0x%x", vm->mode);
TEST_ASSERT(sparsebit_is_set(vm->vpages_valid,
@@ -263,18 +279,27 @@ uint64_t *vm_get_page_table_entry(struct kvm_vm *vm, uint64_t vaddr)
"Canonical check failed. The virtual address is invalid.");
pml4e = virt_get_pte(vm, &vm->pgd, vaddr, PG_LEVEL_512G);
+ if (vm_is_target_pte(pml4e, level, PG_LEVEL_512G))
+ return pml4e;
pdpe = virt_get_pte(vm, pml4e, vaddr, PG_LEVEL_1G);
- TEST_ASSERT(!(*pdpe & PTE_LARGE_MASK),
- "Expected pdpe to map a pde not a 1-GByte page.");
+ if (vm_is_target_pte(pdpe, level, PG_LEVEL_1G))
+ return pdpe;
pde = virt_get_pte(vm, pdpe, vaddr, PG_LEVEL_2M);
- TEST_ASSERT(!(*pde & PTE_LARGE_MASK),
- "Expected pde to map a pte not a 2-MByte page.");
+ if (vm_is_target_pte(pde, level, PG_LEVEL_2M))
+ return pde;
return virt_get_pte(vm, pde, vaddr, PG_LEVEL_4K);
}
+uint64_t *vm_get_page_table_entry(struct kvm_vm *vm, uint64_t vaddr)
+{
+ int level = PG_LEVEL_4K;
+
+ return __vm_get_page_table_entry(vm, vaddr, &level);
+}
+
void virt_arch_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent)
{
uint64_t *pml4e, *pml4e_start;
@@ -458,11 +483,17 @@ static void kvm_seg_set_kernel_data_64bit(struct kvm_vm *vm, uint16_t selector,
vm_paddr_t addr_arch_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
{
- uint64_t *pte = vm_get_page_table_entry(vm, gva);
+ int level = PG_LEVEL_NONE;
+ uint64_t *pte = __vm_get_page_table_entry(vm, gva, &level);
TEST_ASSERT(*pte & PTE_PRESENT_MASK,
"Leaf PTE not PRESENT for gva: 0x%08lx", gva);
- return PTE_GET_PA(*pte) | (gva & ~PAGE_MASK);
+
+ /*
+ * No need for a hugepage mask on the PTE, x86-64 requires the "unused"
+ * address bits to be zero.
+ */
+ return PTE_GET_PA(*pte) | (gva & ~HUGEPAGE_MASK(level));
}
static void kvm_setup_gdt(struct kvm_vm *vm, struct kvm_dtable *dt)
--
2.38.0.rc1.362.ged0d419d3c-goog
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