[5.15,6/8] KVM: X86: Don't reset mmu context when toggling X86_CR4_PGE

Commit Message

Mathias Krause May 8, 2023, 3:47 p.m. UTC

From: Lai Jiangshan <[e-mail]>

[ Upstream commit a91a7c7096005113d8e749fd8dfdd3e1eecee263 ]

X86_CR4_PGE doesn't participate in kvm_mmu_role, so the mmu context
doesn't need to be reset.  It is only required to flush all the guest
tlb.

It is also inconsistent that X86_CR4_PGE is in KVM_MMU_CR4_ROLE_BITS
while kvm_mmu_role doesn't use X86_CR4_PGE.  So X86_CR4_PGE is also
removed from KVM_MMU_CR4_ROLE_BITS.

Signed-off-by: Lai Jiangshan <[e-mail]>
Reviewed-by: Sean Christopherson <[e-mail]>
Message-Id: <[e-mail]>
Signed-off-by: Paolo Bonzini <[e-mail]>
Signed-off-by: Mathias Krause <[e-mail]>
---
 arch/x86/kvm/mmu.h | 5 ++---
 arch/x86/kvm/x86.c | 3 ++-
 2 files changed, 4 insertions(+), 4 deletions(-)

Patch

diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index baafc5d8bb9e..03a9e37e446a 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -44,9 +44,8 @@ 
 #define PT32_ROOT_LEVEL 2
 #define PT32E_ROOT_LEVEL 3
 
-#define KVM_MMU_CR4_ROLE_BITS (X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PAE | \
-			       X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_PKE | \
-			       X86_CR4_LA57)
+#define KVM_MMU_CR4_ROLE_BITS (X86_CR4_PSE | X86_CR4_PAE | X86_CR4_LA57 | \
+			       X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_PKE)
 
 #define KVM_MMU_CR0_ROLE_BITS (X86_CR0_PG | X86_CR0_WP)
 #define KVM_MMU_EFER_ROLE_BITS (EFER_LME | EFER_NX)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 515033d01b12..ea3bdc4f2284 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1083,7 +1083,8 @@  void kvm_post_set_cr4(struct kvm_vcpu *vcpu, unsigned long old_cr4, unsigned lon
 {
 	if ((cr4 ^ old_cr4) & KVM_MMU_CR4_ROLE_BITS)
 		kvm_mmu_reset_context(vcpu);
-	else if (!(cr4 & X86_CR4_PCIDE) && (old_cr4 & X86_CR4_PCIDE))
+	else if (((cr4 ^ old_cr4) & X86_CR4_PGE) ||
+		 (!(cr4 & X86_CR4_PCIDE) && (old_cr4 & X86_CR4_PCIDE)))
 		kvm_make_request(KVM_REQ_TLB_FLUSH_GUEST, vcpu);
 }
 EXPORT_SYMBOL_GPL(kvm_post_set_cr4);