From 5a5e8a15d76e6dd62e3a94fea499057bd048abbc Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 26 Sep 2018 09:23:56 -0700 Subject: [PATCH] KVM: vmx: write HOST_IA32_EFER in vmx_set_constant_host_state() EFER is constant in the host and writing it once during setup means we can skip writing the host value in add_atomic_switch_msr_special(). Signed-off-by: Sean Christopherson Reviewed-by: Jim Mattson Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 2d120de..5367afe 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2696,7 +2696,8 @@ static void add_atomic_switch_msr_special(struct vcpu_vmx *vmx, u64 guest_val, u64 host_val) { vmcs_write64(guest_val_vmcs, guest_val); - vmcs_write64(host_val_vmcs, host_val); + if (host_val_vmcs != HOST_IA32_EFER) + vmcs_write64(host_val_vmcs, host_val); vm_entry_controls_setbit(vmx, entry); vm_exit_controls_setbit(vmx, exit); } @@ -6333,6 +6334,9 @@ static void vmx_set_constant_host_state(struct vcpu_vmx *vmx) rdmsr(MSR_IA32_CR_PAT, low32, high32); vmcs_write64(HOST_IA32_PAT, low32 | ((u64) high32 << 32)); } + + if (cpu_has_load_ia32_efer) + vmcs_write64(HOST_IA32_EFER, host_efer); } static void set_cr4_guest_host_mask(struct vcpu_vmx *vmx) -- 2.7.4