KVM: x86/mmu: Replace PFERR_NESTED_GUEST_PAGE with a more descriptive helper

Drop the globally visible PFERR_NESTED_GUEST_PAGE and replace it with a
more appropriately named is_write_to_guest_page_table().  The macro name
is misleading, because while all nNPT walks match PAGE|WRITE|PRESENT, the
reverse is not true.

No functional change intended.

Link: https://lore.kernel.org/r/20240831001538.336683-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 4a68cb3eba78f81d4187cbdc3f5f6b529b001140..797433994d566c4008bf2c5fbc38bfef59e06534 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -280,10 +280,6 @@ enum x86_intercept_stage;
 #define PFERR_PRIVATE_ACCESS   BIT_ULL(49)
 #define PFERR_SYNTHETIC_MASK   (PFERR_IMPLICIT_ACCESS | PFERR_PRIVATE_ACCESS)
 
-#define PFERR_NESTED_GUEST_PAGE (PFERR_GUEST_PAGE_MASK |       \
-                                PFERR_WRITE_MASK |             \
-                                PFERR_PRESENT_MASK)
-
 /* apic attention bits */
 #define KVM_APIC_CHECK_VAPIC   0
 /*

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 5226bb055d99cbc871a60d8a97914a1f2b9be8be..1eedd1932e5f23888aeeafd1f7b191ae5dec3ff4 100644 (file)
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5945,6 +5945,13 @@ void kvm_mmu_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new,
        write_unlock(&vcpu->kvm->mmu_lock);
 }
 
+static bool is_write_to_guest_page_table(u64 error_code)
+{
+       const u64 mask = PFERR_GUEST_PAGE_MASK | PFERR_WRITE_MASK | PFERR_PRESENT_MASK;
+
+       return (error_code & mask) == mask;
+}
+
 int noinline kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code,
                       void *insn, int insn_len)
 {
@@ -6008,7 +6015,7 @@ int noinline kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 err
         * and resume the guest.
         */
        if (vcpu->arch.mmu->root_role.direct &&
-           (error_code & PFERR_NESTED_GUEST_PAGE) == PFERR_NESTED_GUEST_PAGE) {
+           is_write_to_guest_page_table(error_code)) {
                kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(cr2_or_gpa));
                return 1;
        }