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 <sean.j.christopherson@xxxxxxxxx>
Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>
---
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 e6d3c22fe718..fa0b1674db0d 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2704,7 +2704,8 @@ 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);
}
@@ -6336,6 +6337,9 @@ 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)
--
2.18.0
