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* [PATCH 0/2] kvm: selftests: cleanup PTE definitions
@ 2022-04-21 16:28 Paolo Bonzini
  2022-04-21 16:28 ` [PATCH 1/2] kvm: selftests: do not use bitfields larger than 32-bits for PTEs Paolo Bonzini
  2022-04-21 16:28 ` [PATCH 2/2] kvm: selftests: introduce and use more page size-related constants Paolo Bonzini
  0 siblings, 2 replies; 4+ messages in thread
From: Paolo Bonzini @ 2022-04-21 16:28 UTC (permalink / raw)
  To: linux-kernel, kvm; +Cc: peterx, seanjc

The width of operations on bit fields greater than 32-bit is
implementation defined, and differs between GCC (which uses the bitfield
precision) and clang (which uses 64-bit arithmetic), so this is a
minefield that is already causing bugs (see patch 1).  Remove the bit
fields and using manual masking instead.

Mostly the same as yesterday's patch, but with constants moved to
processor.h and extended to include common idioms such as PAGE_MASK
and PAGE_SIZE.

Paolo

Supersedes: <20220420103624.1143824-1-pbonzini@redhat.com>

Paolo Bonzini (2):
  kvm: selftests: do not use bitfields larger than 32-bits for PTEs
  kvm: selftests: introduce and use more page size-related constants

 .../selftests/kvm/include/x86_64/processor.h  |  17 ++
 .../selftests/kvm/lib/x86_64/processor.c      | 202 +++++++-----------
 tools/testing/selftests/kvm/x86_64/amx_test.c |   1 -
 .../kvm/x86_64/emulator_error_test.c          |   1 -
 tools/testing/selftests/kvm/x86_64/smm_test.c |   2 -
 .../kvm/x86_64/vmx_tsc_adjust_test.c          |   1 -
 .../selftests/kvm/x86_64/xen_shinfo_test.c    |   1 -
 .../selftests/kvm/x86_64/xen_vmcall_test.c    |   1 -
 8 files changed, 99 insertions(+), 127 deletions(-)

-- 
2.31.1


^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH 1/2] kvm: selftests: do not use bitfields larger than 32-bits for PTEs
  2022-04-21 16:28 [PATCH 0/2] kvm: selftests: cleanup PTE definitions Paolo Bonzini
@ 2022-04-21 16:28 ` Paolo Bonzini
  2022-04-21 16:28 ` [PATCH 2/2] kvm: selftests: introduce and use more page size-related constants Paolo Bonzini
  1 sibling, 0 replies; 4+ messages in thread
From: Paolo Bonzini @ 2022-04-21 16:28 UTC (permalink / raw)
  To: linux-kernel, kvm; +Cc: peterx, seanjc, Nana Liu

Red Hat's QE team reported test failure on access_tracking_perf_test:

Testing guest mode: PA-bits:ANY, VA-bits:48,  4K pages
guest physical test memory offset: 0x3fffbffff000

Populating memory             : 0.684014577s
Writing to populated memory   : 0.006230175s
Reading from populated memory : 0.004557805s
==== Test Assertion Failure ====
  lib/kvm_util.c:1411: false
  pid=125806 tid=125809 errno=4 - Interrupted system call
     1  0x0000000000402f7c: addr_gpa2hva at kvm_util.c:1411
     2   (inlined by) addr_gpa2hva at kvm_util.c:1405
     3  0x0000000000401f52: lookup_pfn at access_tracking_perf_test.c:98
     4   (inlined by) mark_vcpu_memory_idle at access_tracking_perf_test.c:152
     5   (inlined by) vcpu_thread_main at access_tracking_perf_test.c:232
     6  0x00007fefe9ff81ce: ?? ??:0
     7  0x00007fefe9c64d82: ?? ??:0
  No vm physical memory at 0xffbffff000

I can easily reproduce it with a Intel(R) Xeon(R) CPU E5-2630 with 46 bits
PA.

It turns out that the address translation for clearing idle page tracking
returned a wrong result; addr_gva2gpa()'s last step, which is based on
"pte[index[0]].pfn", did the calculation with 40 bits length and the
high 12 bits got truncated.  In above case the GPA address to be returned
should be 0x3fffbffff000 for GVA 0xc0000000, but it got truncated into
0xffbffff000 and the subsequent gpa2hva lookup failed.

The width of operations on bit fields greater than 32-bit is
implementation defined, and differs between GCC (which uses the bitfield
precision) and clang (which uses 64-bit arithmetic), so this is a
potential minefield.  Remove the bit fields and using manual masking
instead.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2075036
Reported-by: Nana Liu <nanliu@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Tested-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 .../selftests/kvm/include/x86_64/processor.h  |  15 ++
 .../selftests/kvm/lib/x86_64/processor.c      | 192 +++++++-----------
 2 files changed, 92 insertions(+), 115 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
index 37db341d4cc5..86e79af64dea 100644
--- a/tools/testing/selftests/kvm/include/x86_64/processor.h
+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -60,6 +60,21 @@
 /* CPUID.0x8000_0001.EDX */
 #define CPUID_GBPAGES		(1ul << 26)
 
+/* Page table bitfield declarations */
+#define PTE_PRESENT_MASK        BIT_ULL(0)
+#define PTE_WRITABLE_MASK       BIT_ULL(1)
+#define PTE_USER_MASK           BIT_ULL(2)
+#define PTE_ACCESSED_MASK       BIT_ULL(5)
+#define PTE_DIRTY_MASK          BIT_ULL(6)
+#define PTE_LARGE_MASK          BIT_ULL(7)
+#define PTE_GLOBAL_MASK         BIT_ULL(8)
+#define PTE_NX_MASK             BIT_ULL(63)
+
+#define PAGE_SHIFT		12
+
+#define PHYSICAL_PAGE_MASK      GENMASK_ULL(51, 12)
+#define PTE_GET_PFN(pte)        (((pte) & PHYSICAL_PAGE_MASK) >> PAGE_SHIFT)
+
 /* General Registers in 64-Bit Mode */
 struct gpr64_regs {
 	u64 rax;
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index 9f000dfb5594..0dd442c26015 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -19,38 +19,6 @@
 
 vm_vaddr_t exception_handlers;
 
-/* Virtual translation table structure declarations */
-struct pageUpperEntry {
-	uint64_t present:1;
-	uint64_t writable:1;
-	uint64_t user:1;
-	uint64_t write_through:1;
-	uint64_t cache_disable:1;
-	uint64_t accessed:1;
-	uint64_t ignored_06:1;
-	uint64_t page_size:1;
-	uint64_t ignored_11_08:4;
-	uint64_t pfn:40;
-	uint64_t ignored_62_52:11;
-	uint64_t execute_disable:1;
-};
-
-struct pageTableEntry {
-	uint64_t present:1;
-	uint64_t writable:1;
-	uint64_t user:1;
-	uint64_t write_through:1;
-	uint64_t cache_disable:1;
-	uint64_t accessed:1;
-	uint64_t dirty:1;
-	uint64_t reserved_07:1;
-	uint64_t global:1;
-	uint64_t ignored_11_09:3;
-	uint64_t pfn:40;
-	uint64_t ignored_62_52:11;
-	uint64_t execute_disable:1;
-};
-
 void regs_dump(FILE *stream, struct kvm_regs *regs,
 	       uint8_t indent)
 {
@@ -195,23 +163,21 @@ static void *virt_get_pte(struct kvm_vm *vm, uint64_t pt_pfn, uint64_t vaddr,
 	return &page_table[index];
 }
 
-static struct pageUpperEntry *virt_create_upper_pte(struct kvm_vm *vm,
-						    uint64_t pt_pfn,
-						    uint64_t vaddr,
-						    uint64_t paddr,
-						    int level,
-						    enum x86_page_size page_size)
+static uint64_t *virt_create_upper_pte(struct kvm_vm *vm,
+				       uint64_t pt_pfn,
+				       uint64_t vaddr,
+				       uint64_t paddr,
+				       int level,
+				       enum x86_page_size page_size)
 {
-	struct pageUpperEntry *pte = virt_get_pte(vm, pt_pfn, vaddr, level);
-
-	if (!pte->present) {
-		pte->writable = true;
-		pte->present = true;
-		pte->page_size = (level == page_size);
-		if (pte->page_size)
-			pte->pfn = paddr >> vm->page_shift;
+	uint64_t *pte = virt_get_pte(vm, pt_pfn, vaddr, level);
+
+	if (!(*pte & PTE_PRESENT_MASK)) {
+		*pte = PTE_PRESENT_MASK | PTE_WRITABLE_MASK;
+		if (level == page_size)
+			*pte |= PTE_LARGE_MASK | (paddr & PHYSICAL_PAGE_MASK);
 		else
-			pte->pfn = vm_alloc_page_table(vm) >> vm->page_shift;
+			*pte |= vm_alloc_page_table(vm) & PHYSICAL_PAGE_MASK;
 	} else {
 		/*
 		 * Entry already present.  Assert that the caller doesn't want
@@ -221,7 +187,7 @@ static struct pageUpperEntry *virt_create_upper_pte(struct kvm_vm *vm,
 		TEST_ASSERT(level != page_size,
 			    "Cannot create hugepage at level: %u, vaddr: 0x%lx\n",
 			    page_size, vaddr);
-		TEST_ASSERT(!pte->page_size,
+		TEST_ASSERT(!(*pte & PTE_LARGE_MASK),
 			    "Cannot create page table at level: %u, vaddr: 0x%lx\n",
 			    level, vaddr);
 	}
@@ -232,8 +198,8 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
 		   enum x86_page_size page_size)
 {
 	const uint64_t pg_size = 1ull << ((page_size * 9) + 12);
-	struct pageUpperEntry *pml4e, *pdpe, *pde;
-	struct pageTableEntry *pte;
+	uint64_t *pml4e, *pdpe, *pde;
+	uint64_t *pte;
 
 	TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K,
 		    "Unknown or unsupported guest mode, mode: 0x%x", vm->mode);
@@ -257,24 +223,22 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
 	 */
 	pml4e = virt_create_upper_pte(vm, vm->pgd >> vm->page_shift,
 				      vaddr, paddr, 3, page_size);
-	if (pml4e->page_size)
+	if (*pml4e & PTE_LARGE_MASK)
 		return;
 
-	pdpe = virt_create_upper_pte(vm, pml4e->pfn, vaddr, paddr, 2, page_size);
-	if (pdpe->page_size)
+	pdpe = virt_create_upper_pte(vm, PTE_GET_PFN(*pml4e), vaddr, paddr, 2, page_size);
+	if (*pdpe & PTE_LARGE_MASK)
 		return;
 
-	pde = virt_create_upper_pte(vm, pdpe->pfn, vaddr, paddr, 1, page_size);
-	if (pde->page_size)
+	pde = virt_create_upper_pte(vm, PTE_GET_PFN(*pdpe), vaddr, paddr, 1, page_size);
+	if (*pde & PTE_LARGE_MASK)
 		return;
 
 	/* Fill in page table entry. */
-	pte = virt_get_pte(vm, pde->pfn, vaddr, 0);
-	TEST_ASSERT(!pte->present,
+	pte = virt_get_pte(vm, PTE_GET_PFN(*pde), vaddr, 0);
+	TEST_ASSERT(!(*pte & PTE_PRESENT_MASK),
 		    "PTE already present for 4k page at vaddr: 0x%lx\n", vaddr);
-	pte->pfn = paddr >> vm->page_shift;
-	pte->writable = true;
-	pte->present = 1;
+	*pte = PTE_PRESENT_MASK | PTE_WRITABLE_MASK | (paddr & PHYSICAL_PAGE_MASK);
 }
 
 void virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr)
@@ -282,12 +246,12 @@ void virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr)
 	__virt_pg_map(vm, vaddr, paddr, X86_PAGE_SIZE_4K);
 }
 
-static struct pageTableEntry *_vm_get_page_table_entry(struct kvm_vm *vm, int vcpuid,
+static uint64_t *_vm_get_page_table_entry(struct kvm_vm *vm, int vcpuid,
 						       uint64_t vaddr)
 {
 	uint16_t index[4];
-	struct pageUpperEntry *pml4e, *pdpe, *pde;
-	struct pageTableEntry *pte;
+	uint64_t *pml4e, *pdpe, *pde;
+	uint64_t *pte;
 	struct kvm_cpuid_entry2 *entry;
 	struct kvm_sregs sregs;
 	int max_phy_addr;
@@ -329,30 +293,29 @@ static struct pageTableEntry *_vm_get_page_table_entry(struct kvm_vm *vm, int vc
 	index[3] = (vaddr >> 39) & 0x1ffu;
 
 	pml4e = addr_gpa2hva(vm, vm->pgd);
-	TEST_ASSERT(pml4e[index[3]].present,
+	TEST_ASSERT(pml4e[index[3]] & PTE_PRESENT_MASK,
 		"Expected pml4e to be present for gva: 0x%08lx", vaddr);
-	TEST_ASSERT((*(uint64_t*)(&pml4e[index[3]]) &
-		(rsvd_mask | (1ull << 7))) == 0,
+	TEST_ASSERT((pml4e[index[3]] & (rsvd_mask | PTE_LARGE_MASK)) == 0,
 		"Unexpected reserved bits set.");
 
-	pdpe = addr_gpa2hva(vm, pml4e[index[3]].pfn * vm->page_size);
-	TEST_ASSERT(pdpe[index[2]].present,
+	pdpe = addr_gpa2hva(vm, PTE_GET_PFN(pml4e[index[3]]) * vm->page_size);
+	TEST_ASSERT(pdpe[index[2]] & PTE_PRESENT_MASK,
 		"Expected pdpe to be present for gva: 0x%08lx", vaddr);
-	TEST_ASSERT(pdpe[index[2]].page_size == 0,
+	TEST_ASSERT(!(pdpe[index[2]] & PTE_LARGE_MASK),
 		"Expected pdpe to map a pde not a 1-GByte page.");
-	TEST_ASSERT((*(uint64_t*)(&pdpe[index[2]]) & rsvd_mask) == 0,
+	TEST_ASSERT((pdpe[index[2]] & rsvd_mask) == 0,
 		"Unexpected reserved bits set.");
 
-	pde = addr_gpa2hva(vm, pdpe[index[2]].pfn * vm->page_size);
-	TEST_ASSERT(pde[index[1]].present,
+	pde = addr_gpa2hva(vm, PTE_GET_PFN(pdpe[index[2]]) * vm->page_size);
+	TEST_ASSERT(pde[index[1]] & PTE_PRESENT_MASK,
 		"Expected pde to be present for gva: 0x%08lx", vaddr);
-	TEST_ASSERT(pde[index[1]].page_size == 0,
+	TEST_ASSERT(!(pde[index[1]] & PTE_LARGE_MASK),
 		"Expected pde to map a pte not a 2-MByte page.");
-	TEST_ASSERT((*(uint64_t*)(&pde[index[1]]) & rsvd_mask) == 0,
+	TEST_ASSERT((pde[index[1]] & rsvd_mask) == 0,
 		"Unexpected reserved bits set.");
 
-	pte = addr_gpa2hva(vm, pde[index[1]].pfn * vm->page_size);
-	TEST_ASSERT(pte[index[0]].present,
+	pte = addr_gpa2hva(vm, PTE_GET_PFN(pde[index[1]]) * vm->page_size);
+	TEST_ASSERT(pte[index[0]] & PTE_PRESENT_MASK,
 		"Expected pte to be present for gva: 0x%08lx", vaddr);
 
 	return &pte[index[0]];
@@ -360,7 +323,7 @@ static struct pageTableEntry *_vm_get_page_table_entry(struct kvm_vm *vm, int vc
 
 uint64_t vm_get_page_table_entry(struct kvm_vm *vm, int vcpuid, uint64_t vaddr)
 {
-	struct pageTableEntry *pte = _vm_get_page_table_entry(vm, vcpuid, vaddr);
+	uint64_t *pte = _vm_get_page_table_entry(vm, vcpuid, vaddr);
 
 	return *(uint64_t *)pte;
 }
@@ -368,18 +331,17 @@ uint64_t vm_get_page_table_entry(struct kvm_vm *vm, int vcpuid, uint64_t vaddr)
 void vm_set_page_table_entry(struct kvm_vm *vm, int vcpuid, uint64_t vaddr,
 			     uint64_t pte)
 {
-	struct pageTableEntry *new_pte = _vm_get_page_table_entry(vm, vcpuid,
-								  vaddr);
+	uint64_t *new_pte = _vm_get_page_table_entry(vm, vcpuid, vaddr);
 
 	*(uint64_t *)new_pte = pte;
 }
 
 void virt_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent)
 {
-	struct pageUpperEntry *pml4e, *pml4e_start;
-	struct pageUpperEntry *pdpe, *pdpe_start;
-	struct pageUpperEntry *pde, *pde_start;
-	struct pageTableEntry *pte, *pte_start;
+	uint64_t *pml4e, *pml4e_start;
+	uint64_t *pdpe, *pdpe_start;
+	uint64_t *pde, *pde_start;
+	uint64_t *pte, *pte_start;
 
 	if (!vm->pgd_created)
 		return;
@@ -389,58 +351,58 @@ void virt_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent)
 	fprintf(stream, "%*s      index hvaddr         gpaddr         "
 		"addr         w exec dirty\n",
 		indent, "");
-	pml4e_start = (struct pageUpperEntry *) addr_gpa2hva(vm, vm->pgd);
+	pml4e_start = (uint64_t *) addr_gpa2hva(vm, vm->pgd);
 	for (uint16_t n1 = 0; n1 <= 0x1ffu; n1++) {
 		pml4e = &pml4e_start[n1];
-		if (!pml4e->present)
+		if (!(*pml4e & PTE_PRESENT_MASK))
 			continue;
-		fprintf(stream, "%*spml4e 0x%-3zx %p 0x%-12lx 0x%-10lx %u "
+		fprintf(stream, "%*spml4e 0x%-3zx %p 0x%-12lx 0x%-10llx %u "
 			" %u\n",
 			indent, "",
 			pml4e - pml4e_start, pml4e,
-			addr_hva2gpa(vm, pml4e), (uint64_t) pml4e->pfn,
-			pml4e->writable, pml4e->execute_disable);
+			addr_hva2gpa(vm, pml4e), PTE_GET_PFN(*pml4e),
+			!!(*pml4e & PTE_WRITABLE_MASK), !!(*pml4e & PTE_NX_MASK));
 
-		pdpe_start = addr_gpa2hva(vm, pml4e->pfn * vm->page_size);
+		pdpe_start = addr_gpa2hva(vm, *pml4e & PHYSICAL_PAGE_MASK);
 		for (uint16_t n2 = 0; n2 <= 0x1ffu; n2++) {
 			pdpe = &pdpe_start[n2];
-			if (!pdpe->present)
+			if (!(*pdpe & PTE_PRESENT_MASK))
 				continue;
-			fprintf(stream, "%*spdpe  0x%-3zx %p 0x%-12lx 0x%-10lx "
+			fprintf(stream, "%*spdpe  0x%-3zx %p 0x%-12lx 0x%-10llx "
 				"%u  %u\n",
 				indent, "",
 				pdpe - pdpe_start, pdpe,
 				addr_hva2gpa(vm, pdpe),
-				(uint64_t) pdpe->pfn, pdpe->writable,
-				pdpe->execute_disable);
+				PTE_GET_PFN(*pdpe), !!(*pdpe & PTE_WRITABLE_MASK),
+				!!(*pdpe & PTE_NX_MASK));
 
-			pde_start = addr_gpa2hva(vm, pdpe->pfn * vm->page_size);
+			pde_start = addr_gpa2hva(vm, *pdpe & PHYSICAL_PAGE_MASK);
 			for (uint16_t n3 = 0; n3 <= 0x1ffu; n3++) {
 				pde = &pde_start[n3];
-				if (!pde->present)
+				if (!(*pde & PTE_PRESENT_MASK))
 					continue;
 				fprintf(stream, "%*spde   0x%-3zx %p "
-					"0x%-12lx 0x%-10lx %u  %u\n",
+					"0x%-12lx 0x%-10llx %u  %u\n",
 					indent, "", pde - pde_start, pde,
 					addr_hva2gpa(vm, pde),
-					(uint64_t) pde->pfn, pde->writable,
-					pde->execute_disable);
+					PTE_GET_PFN(*pde), !!(*pde & PTE_WRITABLE_MASK),
+					!!(*pde & PTE_NX_MASK));
 
-				pte_start = addr_gpa2hva(vm, pde->pfn * vm->page_size);
+				pte_start = addr_gpa2hva(vm, *pde & PHYSICAL_PAGE_MASK);
 				for (uint16_t n4 = 0; n4 <= 0x1ffu; n4++) {
 					pte = &pte_start[n4];
-					if (!pte->present)
+					if (!(*pte & PTE_PRESENT_MASK))
 						continue;
 					fprintf(stream, "%*spte   0x%-3zx %p "
-						"0x%-12lx 0x%-10lx %u  %u "
+						"0x%-12lx 0x%-10llx %u  %u "
 						"    %u    0x%-10lx\n",
 						indent, "",
 						pte - pte_start, pte,
 						addr_hva2gpa(vm, pte),
-						(uint64_t) pte->pfn,
-						pte->writable,
-						pte->execute_disable,
-						pte->dirty,
+						PTE_GET_PFN(*pte),
+						!!(*pte & PTE_WRITABLE_MASK),
+						!!(*pte & PTE_NX_MASK),
+						!!(*pte & PTE_DIRTY_MASK),
 						((uint64_t) n1 << 27)
 							| ((uint64_t) n2 << 18)
 							| ((uint64_t) n3 << 9)
@@ -558,8 +520,8 @@ static void kvm_seg_set_kernel_data_64bit(struct kvm_vm *vm, uint16_t selector,
 vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
 {
 	uint16_t index[4];
-	struct pageUpperEntry *pml4e, *pdpe, *pde;
-	struct pageTableEntry *pte;
+	uint64_t *pml4e, *pdpe, *pde;
+	uint64_t *pte;
 
 	TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K, "Attempt to use "
 		"unknown or unsupported guest mode, mode: 0x%x", vm->mode);
@@ -572,22 +534,22 @@ vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
 	if (!vm->pgd_created)
 		goto unmapped_gva;
 	pml4e = addr_gpa2hva(vm, vm->pgd);
-	if (!pml4e[index[3]].present)
+	if (!(pml4e[index[3]] & PTE_PRESENT_MASK))
 		goto unmapped_gva;
 
-	pdpe = addr_gpa2hva(vm, pml4e[index[3]].pfn * vm->page_size);
-	if (!pdpe[index[2]].present)
+	pdpe = addr_gpa2hva(vm, PTE_GET_PFN(pml4e[index[3]]) * vm->page_size);
+	if (!(pdpe[index[2]] & PTE_PRESENT_MASK))
 		goto unmapped_gva;
 
-	pde = addr_gpa2hva(vm, pdpe[index[2]].pfn * vm->page_size);
-	if (!pde[index[1]].present)
+	pde = addr_gpa2hva(vm, PTE_GET_PFN(pdpe[index[2]]) * vm->page_size);
+	if (!(pde[index[1]] & PTE_PRESENT_MASK))
 		goto unmapped_gva;
 
-	pte = addr_gpa2hva(vm, pde[index[1]].pfn * vm->page_size);
-	if (!pte[index[0]].present)
+	pte = addr_gpa2hva(vm, PTE_GET_PFN(pde[index[1]]) * vm->page_size);
+	if (!(pte[index[0]] & PTE_PRESENT_MASK))
 		goto unmapped_gva;
 
-	return (pte[index[0]].pfn * vm->page_size) + (gva & 0xfffu);
+	return (PTE_GET_PFN(pte[index[0]]) * vm->page_size) + (gva & 0xfffu);
 
 unmapped_gva:
 	TEST_FAIL("No mapping for vm virtual address, gva: 0x%lx", gva);
-- 
2.31.1



^ permalink raw reply related	[flat|nested] 4+ messages in thread

* [PATCH 2/2] kvm: selftests: introduce and use more page size-related constants
  2022-04-21 16:28 [PATCH 0/2] kvm: selftests: cleanup PTE definitions Paolo Bonzini
  2022-04-21 16:28 ` [PATCH 1/2] kvm: selftests: do not use bitfields larger than 32-bits for PTEs Paolo Bonzini
@ 2022-04-21 16:28 ` Paolo Bonzini
  2022-04-21 19:38   ` Peter Xu
  1 sibling, 1 reply; 4+ messages in thread
From: Paolo Bonzini @ 2022-04-21 16:28 UTC (permalink / raw)
  To: linux-kernel, kvm; +Cc: peterx, seanjc

Clean up code that was hardcoding masks for various fields,
now that the masks are included in processor.h.

For more cleanup, define PAGE_SIZE and PAGE_MASK just like in Linux.
PAGE_SIZE in particular was defined by several tests.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 .../testing/selftests/kvm/include/x86_64/processor.h |  2 ++
 tools/testing/selftests/kvm/lib/x86_64/processor.c   | 12 ++++++------
 tools/testing/selftests/kvm/x86_64/amx_test.c        |  1 -
 .../selftests/kvm/x86_64/emulator_error_test.c       |  1 -
 tools/testing/selftests/kvm/x86_64/smm_test.c        |  2 --
 .../selftests/kvm/x86_64/vmx_tsc_adjust_test.c       |  1 -
 tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c |  1 -
 tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c |  1 -
 8 files changed, 8 insertions(+), 13 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
index 86e79af64dea..d0d51adec76e 100644
--- a/tools/testing/selftests/kvm/include/x86_64/processor.h
+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -71,6 +71,8 @@
 #define PTE_NX_MASK             BIT_ULL(63)
 
 #define PAGE_SHIFT		12
+#define PAGE_SIZE		(1ULL << PAGE_SHIFT)
+#define PAGE_MASK		(~(PAGE_SIZE-1))
 
 #define PHYSICAL_PAGE_MASK      GENMASK_ULL(51, 12)
 #define PTE_GET_PFN(pte)        (((pte) & PHYSICAL_PAGE_MASK) >> PAGE_SHIFT)
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index 0dd442c26015..33ea5e9955d9 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -255,13 +255,13 @@ static uint64_t *_vm_get_page_table_entry(struct kvm_vm *vm, int vcpuid,
 	struct kvm_cpuid_entry2 *entry;
 	struct kvm_sregs sregs;
 	int max_phy_addr;
-	/* Set the bottom 52 bits. */
-	uint64_t rsvd_mask = 0x000fffffffffffff;
+	uint64_t rsvd_mask = 0;
 
 	entry = kvm_get_supported_cpuid_index(0x80000008, 0);
 	max_phy_addr = entry->eax & 0x000000ff;
-	/* Clear the bottom bits of the reserved mask. */
-	rsvd_mask = (rsvd_mask >> max_phy_addr) << max_phy_addr;
+	/* Set the high bits in the reserved mask. */
+	if (max_phy_addr < 52)
+		rsvd_mask = GENMASK_ULL(51, max_phy_addr);
 
 	/*
 	 * SDM vol 3, fig 4-11 "Formats of CR3 and Paging-Structure Entries
@@ -271,7 +271,7 @@ static uint64_t *_vm_get_page_table_entry(struct kvm_vm *vm, int vcpuid,
 	 */
 	vcpu_sregs_get(vm, vcpuid, &sregs);
 	if ((sregs.efer & EFER_NX) == 0) {
-		rsvd_mask |= (1ull << 63);
+		rsvd_mask |= PTE_NX_MASK;
 	}
 
 	TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K, "Attempt to use "
@@ -549,7 +549,7 @@ vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
 	if (!(pte[index[0]] & PTE_PRESENT_MASK))
 		goto unmapped_gva;
 
-	return (PTE_GET_PFN(pte[index[0]]) * vm->page_size) + (gva & 0xfffu);
+	return (PTE_GET_PFN(pte[index[0]]) * vm->page_size) + (gva & ~PAGE_MASK);
 
 unmapped_gva:
 	TEST_FAIL("No mapping for vm virtual address, gva: 0x%lx", gva);
diff --git a/tools/testing/selftests/kvm/x86_64/amx_test.c b/tools/testing/selftests/kvm/x86_64/amx_test.c
index 52a3ef6629e8..76f65c22796f 100644
--- a/tools/testing/selftests/kvm/x86_64/amx_test.c
+++ b/tools/testing/selftests/kvm/x86_64/amx_test.c
@@ -29,7 +29,6 @@
 #define X86_FEATURE_XSAVE		(1 << 26)
 #define X86_FEATURE_OSXSAVE		(1 << 27)
 
-#define PAGE_SIZE			(1 << 12)
 #define NUM_TILES			8
 #define TILE_SIZE			1024
 #define XSAVE_SIZE			((NUM_TILES * TILE_SIZE) + PAGE_SIZE)
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 f070ff0224fa..aeb3850f81bd 100644
--- a/tools/testing/selftests/kvm/x86_64/emulator_error_test.c
+++ b/tools/testing/selftests/kvm/x86_64/emulator_error_test.c
@@ -12,7 +12,6 @@
 #include "vmx.h"
 
 #define VCPU_ID	   1
-#define PAGE_SIZE  4096
 #define MAXPHYADDR 36
 
 #define MEM_REGION_GVA	0x0000123456789000
diff --git a/tools/testing/selftests/kvm/x86_64/smm_test.c b/tools/testing/selftests/kvm/x86_64/smm_test.c
index a626d40fdb48..b4e0c860769e 100644
--- a/tools/testing/selftests/kvm/x86_64/smm_test.c
+++ b/tools/testing/selftests/kvm/x86_64/smm_test.c
@@ -21,8 +21,6 @@
 
 #define VCPU_ID	      1
 
-#define PAGE_SIZE  4096
-
 #define SMRAM_SIZE 65536
 #define SMRAM_MEMSLOT ((1 << 16) | 1)
 #define SMRAM_PAGES (SMRAM_SIZE / PAGE_SIZE)
diff --git a/tools/testing/selftests/kvm/x86_64/vmx_tsc_adjust_test.c b/tools/testing/selftests/kvm/x86_64/vmx_tsc_adjust_test.c
index e683d0ac3e45..19b35c607dc6 100644
--- a/tools/testing/selftests/kvm/x86_64/vmx_tsc_adjust_test.c
+++ b/tools/testing/selftests/kvm/x86_64/vmx_tsc_adjust_test.c
@@ -32,7 +32,6 @@
 #define MSR_IA32_TSC_ADJUST 0x3b
 #endif
 
-#define PAGE_SIZE	4096
 #define VCPU_ID		5
 
 #define TSC_ADJUST_VALUE (1ll << 32)
diff --git a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c b/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
index 865e17146815..bcd370827859 100644
--- a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
+++ b/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
@@ -23,7 +23,6 @@
 #define SHINFO_REGION_GVA	0xc0000000ULL
 #define SHINFO_REGION_GPA	0xc0000000ULL
 #define SHINFO_REGION_SLOT	10
-#define PAGE_SIZE		4096
 
 #define DUMMY_REGION_GPA	(SHINFO_REGION_GPA + (2 * PAGE_SIZE))
 #define DUMMY_REGION_SLOT	11
diff --git a/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c b/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c
index adc94452b57c..b30fe9de1d4f 100644
--- a/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c
+++ b/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c
@@ -15,7 +15,6 @@
 
 #define HCALL_REGION_GPA	0xc0000000ULL
 #define HCALL_REGION_SLOT	10
-#define PAGE_SIZE		4096
 
 static struct kvm_vm *vm;
 
-- 
2.31.1


^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH 2/2] kvm: selftests: introduce and use more page size-related constants
  2022-04-21 16:28 ` [PATCH 2/2] kvm: selftests: introduce and use more page size-related constants Paolo Bonzini
@ 2022-04-21 19:38   ` Peter Xu
  0 siblings, 0 replies; 4+ messages in thread
From: Peter Xu @ 2022-04-21 19:38 UTC (permalink / raw)
  To: Paolo Bonzini; +Cc: linux-kernel, kvm, seanjc

On Thu, Apr 21, 2022 at 12:28:25PM -0400, Paolo Bonzini wrote:
> Clean up code that was hardcoding masks for various fields,
> now that the masks are included in processor.h.
> 
> For more cleanup, define PAGE_SIZE and PAGE_MASK just like in Linux.
> PAGE_SIZE in particular was defined by several tests.
> 
> Suggested-by: Sean Christopherson <seanjc@google.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Reviewed-by: Peter Xu <peterx@redhat.com>

-- 
Peter Xu


^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2022-04-21 19:38 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-04-21 16:28 [PATCH 0/2] kvm: selftests: cleanup PTE definitions Paolo Bonzini
2022-04-21 16:28 ` [PATCH 1/2] kvm: selftests: do not use bitfields larger than 32-bits for PTEs Paolo Bonzini
2022-04-21 16:28 ` [PATCH 2/2] kvm: selftests: introduce and use more page size-related constants Paolo Bonzini
2022-04-21 19:38   ` Peter Xu

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