[PATCH AUTOSEL 4.14 027/127] kvm: vmx: Set IA32_TSC_AUX for legacy mode guests

From: Sasha Levin
Date: Fri Nov 22 2019 - 01:12:01 EST


From: Jim Mattson <jmattson@xxxxxxxxxx>

[ Upstream commit 0023ef39dc35c773c436eaa46ca539a26b308b55 ]

RDTSCP is supported in legacy mode as well as long mode. The
IA32_TSC_AUX MSR should be set to the correct guest value before
entering any guest that supports RDTSCP.

Fixes: 4e47c7a6d714 ("KVM: VMX: Add instruction rdtscp support for guest")
Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
Reviewed-by: Peter Shier <pshier@xxxxxxxxxx>
Reviewed-by: Marc Orr <marcorr@xxxxxxxxxx>
Reviewed-by: Liran Alon <liran.alon@xxxxxxxxxx>
Reviewed-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index cd5a8e888eb6b..df37901f4a435 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2818,9 +2818,6 @@ static void setup_msrs(struct vcpu_vmx *vmx)
index = __find_msr_index(vmx, MSR_CSTAR);
if (index >= 0)
move_msr_up(vmx, index, save_nmsrs++);
- index = __find_msr_index(vmx, MSR_TSC_AUX);
- if (index >= 0 && guest_cpuid_has(&vmx->vcpu, X86_FEATURE_RDTSCP))
- move_msr_up(vmx, index, save_nmsrs++);
/*
* MSR_STAR is only needed on long mode guests, and only
* if efer.sce is enabled.
@@ -2833,6 +2830,9 @@ static void setup_msrs(struct vcpu_vmx *vmx)
index = __find_msr_index(vmx, MSR_EFER);
if (index >= 0 && update_transition_efer(vmx, index))
move_msr_up(vmx, index, save_nmsrs++);
+ index = __find_msr_index(vmx, MSR_TSC_AUX);
+ if (index >= 0 && guest_cpuid_has(&vmx->vcpu, X86_FEATURE_RDTSCP))
+ move_msr_up(vmx, index, save_nmsrs++);

vmx->save_nmsrs = save_nmsrs;

--
2.20.1