Re: [PATCH v3 25/34] KVM: selftests: Make it possible to replace PTEs with __virt_pg_map()

Maxim Levitsky
2022-05-11T11:34:44Z

On Thu, 2022-04-14 at 15:20 +0200, Vitaly Kuznetsov wrote:
> __virt_pg_map() makes an assumption that leaf PTE is not present. This
> is not suitable if the test wants to replace an already present
> PTE. Hyper-V PV TLB flush test is going to need that.
>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> ---
> tools/testing/selftests/kvm/include/x86_64/processor.h | 2 +-
> tools/testing/selftests/kvm/lib/x86_64/processor.c | 6 +++---
> tools/testing/selftests/kvm/max_guest_memory_test.c | 2 +-
> tools/testing/selftests/kvm/x86_64/mmu_role_test.c | 2 +-
> 4 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
> index 9ad7602a257b..c20b18d05119 100644
> --- a/tools/testing/selftests/kvm/include/x86_64/processor.h
> +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
> @@ -473,7 +473,7 @@ enum x86_page_size {
> X86_PAGE_SIZE_1G,
> };
> void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
> - enum x86_page_size page_size);
> + enum x86_page_size page_size, bool replace);
>
> /*
> * Basic CPU control in CR0
> diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
> index 9f000dfb5594..20df3e84d777 100644
> --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
> +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
> @@ -229,7 +229,7 @@ static struct pageUpperEntry *virt_create_upper_pte(struct kvm_vm *vm,
> }
>
> void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
> - enum x86_page_size page_size)
> + enum x86_page_size page_size, bool replace)
> {
> const uint64_t pg_size = 1ull << ((page_size * 9) + 12);
> struct pageUpperEntry *pml4e, *pdpe, *pde;
> @@ -270,7 +270,7 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
>
> /* Fill in page table entry. */
> pte = virt_get_pte(vm, pde->pfn, vaddr, 0);
> - TEST_ASSERT(!pte->present,
> + TEST_ASSERT(replace || !pte->present,
> "PTE already present for 4k page at vaddr: 0x%lx\n", vaddr);
> pte->pfn = paddr >> vm->page_shift;
> pte->writable = true;
> @@ -279,7 +279,7 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
>
> void virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr)
> {
> - __virt_pg_map(vm, vaddr, paddr, X86_PAGE_SIZE_4K);
> + __virt_pg_map(vm, vaddr, paddr, X86_PAGE_SIZE_4K, false);
> }
>
> static struct pageTableEntry *_vm_get_page_table_entry(struct kvm_vm *vm, int vcpuid,
> diff --git a/tools/testing/selftests/kvm/max_guest_memory_test.c b/tools/testing/selftests/kvm/max_guest_memory_test.c
> index 3875c4b23a04..437f77633b0e 100644
> --- a/tools/testing/selftests/kvm/max_guest_memory_test.c
> +++ b/tools/testing/selftests/kvm/max_guest_memory_test.c
> @@ -244,7 +244,7 @@ int main(int argc, char *argv[])
> #ifdef __x86_64__
> /* Identity map memory in the guest using 1gb pages. */
> for (i = 0; i < slot_size; i += size_1gb)
> - __virt_pg_map(vm, gpa + i, gpa + i, X86_PAGE_SIZE_1G);
> + __virt_pg_map(vm, gpa + i, gpa + i, X86_PAGE_SIZE_1G, false);
> #else
> for (i = 0; i < slot_size; i += vm_get_page_size(vm))
> virt_pg_map(vm, gpa + i, gpa + i);
> diff --git a/tools/testing/selftests/kvm/x86_64/mmu_role_test.c b/tools/testing/selftests/kvm/x86_64/mmu_role_test.c
> index da2325fcad87..e3fdf320b9f4 100644
> --- a/tools/testing/selftests/kvm/x86_64/mmu_role_test.c
> +++ b/tools/testing/selftests/kvm/x86_64/mmu_role_test.c
> @@ -35,7 +35,7 @@ static void mmu_role_test(u32 *cpuid_reg, u32 evil_cpuid_val)
> run = vcpu_state(vm, VCPU_ID);
>
> /* Map 1gb page without a backing memlot. */
> - __virt_pg_map(vm, MMIO_GPA, MMIO_GPA, X86_PAGE_SIZE_1G);
> + __virt_pg_map(vm, MMIO_GPA, MMIO_GPA, X86_PAGE_SIZE_1G, false);
>
> r = _vcpu_run(vm, VCPU_ID);
>

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>

Best regards,
Maxim Levitsky