linux-kernel - [PATCH 3/7] KVM: selftests: Remove useless shifts when creating guest page tables

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Date:   Thu,  6 Oct 2022 00:45:08 +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 3/7] KVM: selftests: Remove useless shifts when creating guest
 page tables

Remove the pointless shift from GPA=>GFN and immediately back to
GFN=>GPA when creating guest page tables.  Ignore the other walkers
that have a similar pattern for the moment, they will be converted
to use virt_get_pte() in the near future.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 .../selftests/kvm/include/x86_64/processor.h    |  3 ++-
 .../selftests/kvm/lib/x86_64/processor.c        | 17 ++++++++---------
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
index 53d52a5ace48..9676a3464758 100644
--- a/tools/testing/selftests/kvm/include/x86_64/processor.h
+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -177,7 +177,8 @@ struct kvm_x86_cpu_feature {
 #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)
+#define PTE_GET_PA(pte)		((pte) & PHYSICAL_PAGE_MASK)
+#define PTE_GET_PFN(pte)        (PTE_GET_PA(pte) >> PAGE_SHIFT)
 
 /* General Registers in 64-Bit Mode */
 struct gpr64_regs {
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index 9e196837a794..324bf24564a1 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -131,23 +131,23 @@ void virt_arch_pgd_alloc(struct kvm_vm *vm)
 	}
 }
 
-static void *virt_get_pte(struct kvm_vm *vm, uint64_t pt_pfn, uint64_t vaddr,
+static void *virt_get_pte(struct kvm_vm *vm, uint64_t pt_gpa, uint64_t vaddr,
 			  int level)
 {
-	uint64_t *page_table = addr_gpa2hva(vm, pt_pfn << vm->page_shift);
+	uint64_t *page_table = addr_gpa2hva(vm, pt_gpa);
 	int index = (vaddr >> PG_LEVEL_SHIFT(level)) & 0x1ffu;
 
 	return &page_table[index];
 }
 
 static uint64_t *virt_create_upper_pte(struct kvm_vm *vm,
-				       uint64_t pt_pfn,
+				       uint64_t pt_gpa,
 				       uint64_t vaddr,
 				       uint64_t paddr,
 				       int current_level,
 				       int target_level)
 {
-	uint64_t *pte = virt_get_pte(vm, pt_pfn, vaddr, current_level);
+	uint64_t *pte = virt_get_pte(vm, pt_gpa, vaddr, current_level);
 
 	if (!(*pte & PTE_PRESENT_MASK)) {
 		*pte = PTE_PRESENT_MASK | PTE_WRITABLE_MASK;
@@ -197,21 +197,20 @@ 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.
 	 */
-	pml4e = virt_create_upper_pte(vm, vm->pgd >> vm->page_shift,
-				      vaddr, paddr, PG_LEVEL_512G, level);
+	pml4e = virt_create_upper_pte(vm, vm->pgd, vaddr, paddr, PG_LEVEL_512G, level);
 	if (*pml4e & PTE_LARGE_MASK)
 		return;
 
-	pdpe = virt_create_upper_pte(vm, PTE_GET_PFN(*pml4e), vaddr, paddr, PG_LEVEL_1G, level);
+	pdpe = virt_create_upper_pte(vm, PTE_GET_PA(*pml4e), vaddr, paddr, PG_LEVEL_1G, level);
 	if (*pdpe & PTE_LARGE_MASK)
 		return;
 
-	pde = virt_create_upper_pte(vm, PTE_GET_PFN(*pdpe), vaddr, paddr, PG_LEVEL_2M, level);
+	pde = virt_create_upper_pte(vm, PTE_GET_PA(*pdpe), vaddr, paddr, PG_LEVEL_2M, level);
 	if (*pde & PTE_LARGE_MASK)
 		return;
 
 	/* Fill in page table entry. */
-	pte = virt_get_pte(vm, PTE_GET_PFN(*pde), vaddr, PG_LEVEL_4K);
+	pte = virt_get_pte(vm, PTE_GET_PA(*pde), vaddr, PG_LEVEL_4K);
 	TEST_ASSERT(!(*pte & PTE_PRESENT_MASK),
 		    "PTE already present for 4k page at vaddr: 0x%lx\n", vaddr);
 	*pte = PTE_PRESENT_MASK | PTE_WRITABLE_MASK | (paddr & PHYSICAL_PAGE_MASK);
-- 
2.38.0.rc1.362.ged0d419d3c-goog