Commit 11825209 authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: selftests: Plumb "struct kvm_mmu" into x86's MMU APIs 



In preparation for generalizing the x86 virt mapping APIs to work with
TDP (stage-2) page tables, plumb "struct kvm_mmu" into all of the helper
functions instead of operating on vm->mmu directly.

Opportunistically swap the order of the check in virt_get_pte() to first
assert that the parent is the PGD, and then check that the PTE is present,
as it makes more sense to check if the parent PTE is the PGD/root (i.e.
not a PTE) before checking that the PTE is PRESENT.

No functional change intended.

Suggested-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarYosry Ahmed <yosry.ahmed@linux.dev>
[sean: rebase on common kvm_mmu structure, rewrite changelog]
Link: https://patch.msgid.link/20251230230150.4150236-8-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 9f073ac2

tools/testing/selftests/kvm/include/x86/processor.h

+2 −1
Original line number Diff line number Diff line
@@ -1451,7 +1451,8 @@ enum pg_level { 
#define PG_SIZE_2M PG_LEVEL_SIZE(PG_LEVEL_2M)

#define PG_SIZE_1G PG_LEVEL_SIZE(PG_LEVEL_1G)



void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, int level);

void __virt_pg_map(struct kvm_vm *vm, struct kvm_mmu *mmu, uint64_t vaddr,

		   uint64_t paddr,  int level);

void virt_map_level(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,

		    uint64_t nr_bytes, int level);

tools/testing/selftests/kvm/lib/x86/processor.c

+37 −27
Original line number Diff line number Diff line
@@ -156,26 +156,31 @@ bool kvm_is_tdp_enabled(void) 
		return get_kvm_amd_param_bool("npt");

}



static void virt_mmu_init(struct kvm_vm *vm, struct kvm_mmu *mmu)

{

	/* If needed, create the top-level page table. */

	if (!mmu->pgd_created) {

		mmu->pgd = vm_alloc_page_table(vm);

		mmu->pgd_created = true;

	}

}



void virt_arch_pgd_alloc(struct kvm_vm *vm)

{

	TEST_ASSERT(vm->mode == VM_MODE_PXXVYY_4K,

		    "Unknown or unsupported guest mode: 0x%x", vm->mode);



	/* If needed, create the top-level page table. */

	if (!vm->mmu.pgd_created) {

		vm->mmu.pgd = vm_alloc_page_table(vm);

		vm->mmu.pgd_created = true;

	}

	virt_mmu_init(vm, &vm->mmu);

}



static void *virt_get_pte(struct kvm_vm *vm, uint64_t *parent_pte,

			  uint64_t vaddr, int level)

static void *virt_get_pte(struct kvm_vm *vm, struct kvm_mmu *mmu,

			  uint64_t *parent_pte, uint64_t vaddr, int level)

{

	uint64_t pt_gpa = PTE_GET_PA(*parent_pte);

	uint64_t *page_table = addr_gpa2hva(vm, pt_gpa);

	int index = (vaddr >> PG_LEVEL_SHIFT(level)) & 0x1ffu;



	TEST_ASSERT((*parent_pte & PTE_PRESENT_MASK) || parent_pte == &vm->mmu.pgd,

	TEST_ASSERT((*parent_pte == mmu->pgd) || (*parent_pte & PTE_PRESENT_MASK),

		    "Parent PTE (level %d) not PRESENT for gva: 0x%08lx",

		    level + 1, vaddr);
@@ -183,13 +188,14 @@ static void *virt_get_pte(struct kvm_vm *vm, uint64_t *parent_pte, 
}



static uint64_t *virt_create_upper_pte(struct kvm_vm *vm,

				       struct kvm_mmu *mmu,

				       uint64_t *parent_pte,

				       uint64_t vaddr,

				       uint64_t paddr,

				       int current_level,

				       int target_level)

{

	uint64_t *pte = virt_get_pte(vm, parent_pte, vaddr, current_level);

	uint64_t *pte = virt_get_pte(vm, mmu, parent_pte, vaddr, current_level);



	paddr = vm_untag_gpa(vm, paddr);
@@ -215,10 +221,11 @@ static uint64_t *virt_create_upper_pte(struct kvm_vm *vm, 
	return pte;

}



void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, int level)

void __virt_pg_map(struct kvm_vm *vm, struct kvm_mmu *mmu, uint64_t vaddr,

		   uint64_t paddr, int level)

{

	const uint64_t pg_size = PG_LEVEL_SIZE(level);

	uint64_t *pte = &vm->mmu.pgd;

	uint64_t *pte = &mmu->pgd;

	int current_level;



	TEST_ASSERT(vm->mode == VM_MODE_PXXVYY_4K,
@@ -243,17 +250,17 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, int level) 
	 * Allocate upper level page tables, if not already present.  Return

	 * early if a hugepage was created.

	 */

	for (current_level = vm->mmu.pgtable_levels;

	for (current_level = mmu->pgtable_levels;

	     current_level > PG_LEVEL_4K;

	     current_level--) {

		pte = virt_create_upper_pte(vm, pte, vaddr, paddr,

		pte = virt_create_upper_pte(vm, mmu, pte, vaddr, paddr,

					    current_level, level);

		if (*pte & PTE_LARGE_MASK)

			return;

	}



	/* Fill in page table entry. */

	pte = virt_get_pte(vm, pte, vaddr, PG_LEVEL_4K);

	pte = virt_get_pte(vm, mmu, pte, vaddr, PG_LEVEL_4K);

	TEST_ASSERT(!(*pte & PTE_PRESENT_MASK),

		    "PTE already present for 4k page at vaddr: 0x%lx", vaddr);

	*pte = PTE_PRESENT_MASK | PTE_WRITABLE_MASK | (paddr & PHYSICAL_PAGE_MASK);
@@ -270,7 +277,7 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, int level) 


void virt_arch_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr)

{

	__virt_pg_map(vm, vaddr, paddr, PG_LEVEL_4K);

	__virt_pg_map(vm, &vm->mmu, vaddr, paddr, PG_LEVEL_4K);

}



void virt_map_level(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
@@ -285,7 +292,7 @@ void virt_map_level(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, 
		    nr_bytes, pg_size);



	for (i = 0; i < nr_pages; i++) {

		__virt_pg_map(vm, vaddr, paddr, level);

		__virt_pg_map(vm, &vm->mmu, vaddr, paddr, level);

		sparsebit_set_num(vm->vpages_mapped, vaddr >> vm->page_shift,

				  nr_bytes / PAGE_SIZE);
@@ -294,7 +301,8 @@ void virt_map_level(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, 
	}

}



static bool vm_is_target_pte(uint64_t *pte, int *level, int current_level)

static bool vm_is_target_pte(struct kvm_mmu *mmu, uint64_t *pte,

			     int *level, int current_level)

{

	if (*pte & PTE_LARGE_MASK) {

		TEST_ASSERT(*level == PG_LEVEL_NONE ||
@@ -306,17 +314,19 @@ static bool vm_is_target_pte(uint64_t *pte, int *level, int current_level) 
	return *level == current_level;

}



static uint64_t *__vm_get_page_table_entry(struct kvm_vm *vm, uint64_t vaddr,

static uint64_t *__vm_get_page_table_entry(struct kvm_vm *vm,

					   struct kvm_mmu *mmu,

					   uint64_t vaddr,

					   int *level)

{

	int va_width = 12 + (vm->mmu.pgtable_levels) * 9;

	uint64_t *pte = &vm->mmu.pgd;

	int va_width = 12 + (mmu->pgtable_levels) * 9;

	uint64_t *pte = &mmu->pgd;

	int current_level;



	TEST_ASSERT(!vm->arch.is_pt_protected,

		    "Walking page tables of protected guests is impossible");



	TEST_ASSERT(*level >= PG_LEVEL_NONE && *level <= vm->mmu.pgtable_levels,

	TEST_ASSERT(*level >= PG_LEVEL_NONE && *level <= mmu->pgtable_levels,

		    "Invalid PG_LEVEL_* '%d'", *level);



	TEST_ASSERT(vm->mode == VM_MODE_PXXVYY_4K,
@@ -332,22 +342,22 @@ static uint64_t *__vm_get_page_table_entry(struct kvm_vm *vm, uint64_t vaddr, 
		    (((int64_t)vaddr << (64 - va_width) >> (64 - va_width))),

		    "Canonical check failed.  The virtual address is invalid.");



	for (current_level = vm->mmu.pgtable_levels;

	for (current_level = mmu->pgtable_levels;

	     current_level > PG_LEVEL_4K;

	     current_level--) {

		pte = virt_get_pte(vm, pte, vaddr, current_level);

		if (vm_is_target_pte(pte, level, current_level))

		pte = virt_get_pte(vm, mmu, pte, vaddr, current_level);

		if (vm_is_target_pte(mmu, pte, level, current_level))

			return pte;

	}



	return virt_get_pte(vm, pte, vaddr, PG_LEVEL_4K);

	return virt_get_pte(vm, mmu, pte, 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);

	return __vm_get_page_table_entry(vm, &vm->mmu, vaddr, &level);

}



void virt_arch_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent)
@@ -497,7 +507,7 @@ static void kvm_seg_set_kernel_data_64bit(struct kvm_segment *segp) 
vm_paddr_t addr_arch_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)

{

	int level = PG_LEVEL_NONE;

	uint64_t *pte = __vm_get_page_table_entry(vm, gva, &level);

	uint64_t *pte = __vm_get_page_table_entry(vm, &vm->mmu, gva, &level);



	TEST_ASSERT(*pte & PTE_PRESENT_MASK,

		    "Leaf PTE not PRESENT for gva: 0x%08lx", gva);