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Message-Id: <8c96514e921897d40c79d4892fcbadee46aff8e9.1415646977.git.luto@amacapital.net> Date: Mon, 10 Nov 2014 11:19:15 -0800 From: Andy Lutomirski <luto@...capital.net> To: kvm@...r.kernel.org, linux-kernel@...r.kernel.org, Paolo Bonzini <pbonzini@...hat.com>, Gleb Natapov <gleb@...nel.org> Cc: Avi Kivity <avi.kivity@...il.com>, Andy Lutomirski <luto@...capital.net> Subject: [PATCH] x86, kvm, vmx: Don't set LOAD_IA32_EFER when host and guest match There's nothing to switch if the host and guest values are the same. I am unable to find evidence that this makes any difference whatsoever. Signed-off-by: Andy Lutomirski <luto@...capital.net> --- arch/x86/kvm/vmx.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index e72b9660e51c..c430b01b012b 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1670,7 +1670,9 @@ static bool update_transition_efer(struct vcpu_vmx *vmx, int efer_offset) guest_efer = vmx->vcpu.arch.efer; if (!(guest_efer & EFER_LMA)) guest_efer &= ~EFER_LME; - add_atomic_switch_msr(vmx, MSR_EFER, guest_efer, host_efer); + if (guest_efer != host_efer) + add_atomic_switch_msr(vmx, MSR_EFER, + guest_efer, host_efer); return false; } -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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