diff mbox series

[30/43] KVM: SVM: Drop redundant writes to vmcb->save.cr4 at RESET/INIT

Message ID 20210424004645.3950558-31-seanjc@google.com (mailing list archive)
State New, archived
Headers show
Series KVM: x86: vCPU RESET/INIT fixes and consolidation | expand

Commit Message

Sean Christopherson April 24, 2021, 12:46 a.m. UTC
Drop direct writes to vmcb->save.cr4 during vCPU RESET/INIT, as the
values being written are fully redundant with respect to
svm_set_cr4(vcpu, 0) a few lines earlier.  Note, svm_set_cr4() also
correctly forces X86_CR4_PAE when NPT is disabled.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/kvm/svm/svm.c | 3 ---
 1 file changed, 3 deletions(-)

Comments

Reiji Watanabe May 19, 2021, 5:35 a.m. UTC | #1
On Fri, Apr 23, 2021 at 5:54 PM Sean Christopherson <seanjc@google.com> wrote:
>
> Drop direct writes to vmcb->save.cr4 during vCPU RESET/INIT, as the
> values being written are fully redundant with respect to
> svm_set_cr4(vcpu, 0) a few lines earlier.  Note, svm_set_cr4() also
> correctly forces X86_CR4_PAE when NPT is disabled.
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <seanjc@google.com>

Reviewed-by: Reiji Watanabe <reijiw@google.com>
diff mbox series

Patch

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 88d34fa93d8b..558329f53709 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1211,8 +1211,6 @@  static void init_vmcb(struct kvm_vcpu *vcpu)
 	kvm_set_rflags(vcpu, X86_EFLAGS_FIXED);
 	vcpu->arch.regs[VCPU_REGS_RIP] = 0x0000fff0;
 
-	save->cr4 = X86_CR4_PAE;
-
 	if (npt_enabled) {
 		/* Setup VMCB for Nested Paging */
 		control->nested_ctl |= SVM_NESTED_CTL_NP_ENABLE;
@@ -1222,7 +1220,6 @@  static void init_vmcb(struct kvm_vcpu *vcpu)
 		svm_clr_intercept(svm, INTERCEPT_CR3_WRITE);
 		save->g_pat = vcpu->arch.pat;
 		save->cr3 = 0;
-		save->cr4 = 0;
 	}
 	svm->current_vmcb->asid_generation = 0;
 	svm->asid = 0;