[PATCH v2 37/46] KVM: VMX: Remove obsolete MSR bitmap refresh at vCPU RESET/INIT
From: Sean Christopherson <seanjc@google.com>
Date: 2021-07-13 16:36:21
Also in:
lkml
Subsystem:
kernel virtual machine for x86 (kvm/x86), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Sean Christopherson, Paolo Bonzini, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
Remove an unnecessary MSR bitmap refresh during vCPU RESET/INIT. In both cases, the MSR bitmap already has the desired values and state. At RESET, the vCPU is guaranteed to be running with x2APIC disabled, the x2APIC MSRs are guaranteed to be intercepted due to the MSR bitmap being initialized to all ones by alloc_loaded_vmcs(), and vmx->msr_bitmap_mode is guaranteed to be zero, i.e. reflecting x2APIC disabled. At INIT, the APIC_BASE MSR is not modified, thus there can't be any change in x2APIC state. Signed-off-by: Sean Christopherson <seanjc@google.com> --- arch/x86/kvm/vmx/vmx.c | 3 --- 1 file changed, 3 deletions(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index ef92ec40d3d9..7e99535a4cbb 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c@@ -4466,9 +4466,6 @@ static void vmx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) if (kvm_mpx_supported()) vmcs_write64(GUEST_BNDCFGS, 0); - if (cpu_has_vmx_msr_bitmap()) - vmx_update_msr_bitmap(&vmx->vcpu); - vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, 0); /* 22.2.1 */ if (cpu_has_vmx_tpr_shadow() && !init_event) {
--
2.32.0.93.g670b81a890-goog