[PATCH 4.14 056/209] kvm: vmx: Set IA32_TSC_AUX for legacy mode guests

Greg Kroah-Hartman
2019-12-04T18:03:10Z

From: Jim Mattson <jmattson@google.com>

[ 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@google.com>
Reviewed-by: Peter Shier <pshier@google.com>
Reviewed-by: Marc Orr <marcorr@google.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 f67fc0f359ff3..76f353aef577f 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