[PATCH 37/54] KVM: x86/mmu: Use MMU's role to get EFER.NX during MMU configuration

From: Sean Christopherson
Date: Tue Jun 22 2021 - 14:02:38 EST


Get the MMU's effective EFER.NX from its role instead of using the
one-off, dedicated flag. This will allow dropping said flag in a
future commit.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/mmu/mmu.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 30cbc6cdb0db..eb6386bcc2ef 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4212,7 +4212,7 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu,
{
__reset_rsvds_bits_mask(&context->guest_rsvd_check,
vcpu->arch.reserved_gpa_bits,
- context->root_level, context->nx,
+ context->root_level, is_efer_nx(context),
guest_cpuid_has(vcpu, X86_FEATURE_GBPAGES),
is_cr4_pse(context),
guest_cpuid_is_amd_or_hygon(vcpu));
@@ -4278,7 +4278,7 @@ static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu,
* NX can be used by any non-nested shadow MMU to avoid having to reset
* MMU contexts. Note, KVM forces EFER.NX=1 when TDP is disabled.
*/
- bool uses_nx = context->nx || !tdp_enabled;
+ bool uses_nx = is_efer_nx(context) || !tdp_enabled;

/* @amd adds a check on bit of SPTEs, which KVM shouldn't use anyways. */
bool is_amd = true;
@@ -4375,6 +4375,7 @@ static void update_permission_bitmask(struct kvm_mmu *mmu, bool ept)
bool cr4_smep = is_cr4_smep(mmu);
bool cr4_smap = is_cr4_smap(mmu);
bool cr0_wp = is_cr0_wp(mmu);
+ bool efer_nx = is_efer_nx(mmu);

for (byte = 0; byte < ARRAY_SIZE(mmu->permissions); ++byte) {
unsigned pfec = byte << 1;
@@ -4400,7 +4401,7 @@ static void update_permission_bitmask(struct kvm_mmu *mmu, bool ept)
u8 kf = (pfec & PFERR_USER_MASK) ? 0 : u;

/* Not really needed: !nx will cause pte.nx to fault */
- if (!mmu->nx)
+ if (!efer_nx)
ff = 0;

/* Allow supervisor writes if !cr0.wp */
--
2.32.0.288.g62a8d224e6-goog