[PATCH 33/43] KVM: VMX: Refresh list of user return MSRs after setting guest CPUID

From: Sean Christopherson
Date: Fri Apr 23 2021 - 20:54:09 EST


After a CPUID update, refresh the list of user return MSRs that are
loaded into hardware when running the vCPU. This is necessary to handle
the oddball case where userspace exposes X86_FEATURE_RDTSCP to the guest
after the vCPU is running.

Fixes: 0023ef39dc35 ("kvm: vmx: Set IA32_TSC_AUX for legacy mode guests")
Fixes: 4e47c7a6d714 ("KVM: VMX: Add instruction rdtscp support for guest")
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/vmx/vmx.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index bdfb3def8526..57cabef3ffd9 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7313,6 +7313,8 @@ static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
/* xsaves_enabled is recomputed in vmx_compute_secondary_exec_control(). */
vcpu->arch.xsaves_enabled = false;

+ vmx_setup_uret_msrs(vmx);
+
if (cpu_has_secondary_exec_ctrls()) {
vmx_compute_secondary_exec_control(vmx);
vmcs_set_secondary_exec_control(vmx);
--
2.31.1.498.g6c1eba8ee3d-goog