[PATCH 1/7] KVM: selftests: Drop helpers to read/write page table entries

From: Sean Christopherson
Date: Wed Oct 05 2022 - 20:45:43 EST


Drop vm_{g,s}et_page_table_entry() and instead expose the "inner"
helper (was _vm_get_page_table_entry()) that returns a _pointer_ to the
PTE, i.e. let tests directly modify PTEs instead of bouncing through
helpers that just make life difficult.

Opportunsitically use BIT_ULL() in emulator_error_test, and use the
MAXPHYADDR define to set the "rogue" GPA bit instead of open coding the
same value.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
.../selftests/kvm/include/x86_64/processor.h | 6 ++----
.../selftests/kvm/lib/x86_64/processor.c | 21 ++-----------------
.../kvm/x86_64/emulator_error_test.c | 6 ++++--
3 files changed, 8 insertions(+), 25 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
index e8ca0d8a6a7e..30d5df1ebaad 100644
--- a/tools/testing/selftests/kvm/include/x86_64/processor.h
+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -827,10 +827,8 @@ 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, struct kvm_vcpu *vcpu,
- uint64_t vaddr);
-void vm_set_page_table_entry(struct kvm_vm *vm, struct kvm_vcpu *vcpu,
- uint64_t vaddr, uint64_t pte);
+uint64_t *vm_get_page_table_entry(struct kvm_vm *vm, struct kvm_vcpu *vcpu,
+ uint64_t vaddr);

uint64_t kvm_hypercall(uint64_t nr, uint64_t a0, uint64_t a1, uint64_t a2,
uint64_t a3);
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index 39c4409ef56a..90b35998b0f3 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -241,9 +241,8 @@ void virt_map_level(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
}
}

-static uint64_t *_vm_get_page_table_entry(struct kvm_vm *vm,
- struct kvm_vcpu *vcpu,
- uint64_t vaddr)
+uint64_t *vm_get_page_table_entry(struct kvm_vm *vm, struct kvm_vcpu *vcpu,
+ uint64_t vaddr)
{
uint16_t index[4];
uint64_t *pml4e, *pdpe, *pde;
@@ -313,22 +312,6 @@ static uint64_t *_vm_get_page_table_entry(struct kvm_vm *vm,
return &pte[index[0]];
}

-uint64_t vm_get_page_table_entry(struct kvm_vm *vm, struct kvm_vcpu *vcpu,
- uint64_t vaddr)
-{
- uint64_t *pte = _vm_get_page_table_entry(vm, vcpu, vaddr);
-
- return *(uint64_t *)pte;
-}
-
-void vm_set_page_table_entry(struct kvm_vm *vm, struct kvm_vcpu *vcpu,
- uint64_t vaddr, uint64_t pte)
-{
- uint64_t *new_pte = _vm_get_page_table_entry(vm, vcpu, vaddr);
-
- *(uint64_t *)new_pte = pte;
-}
-
void virt_arch_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent)
{
uint64_t *pml4e, *pml4e_start;
diff --git a/tools/testing/selftests/kvm/x86_64/emulator_error_test.c b/tools/testing/selftests/kvm/x86_64/emulator_error_test.c
index 236e11755ba6..bde247f3c8a1 100644
--- a/tools/testing/selftests/kvm/x86_64/emulator_error_test.c
+++ b/tools/testing/selftests/kvm/x86_64/emulator_error_test.c
@@ -152,8 +152,9 @@ int main(int argc, char *argv[])
{
struct kvm_vcpu *vcpu;
struct kvm_vm *vm;
- uint64_t gpa, pte;
+ uint64_t *pte;
uint64_t *hva;
+ uint64_t gpa;
int rc;

/* Tell stdout not to buffer its content */
@@ -178,8 +179,9 @@ int main(int argc, char *argv[])
virt_map(vm, MEM_REGION_GVA, MEM_REGION_GPA, 1);
hva = addr_gpa2hva(vm, MEM_REGION_GPA);
memset(hva, 0, PAGE_SIZE);
+
pte = vm_get_page_table_entry(vm, vcpu, MEM_REGION_GVA);
- vm_set_page_table_entry(vm, vcpu, MEM_REGION_GVA, pte | (1ull << 36));
+ *pte |= BIT_ULL(MAXPHYADDR);

vcpu_run(vcpu);
process_exit_on_emulation_error(vcpu);
--
2.38.0.rc1.362.ged0d419d3c-goog