[PATCH 3/5] KVM: nVMX: Update VMX controls MSR according to guest CPUID after setting VMX MSRs

From: Chenyi Qiang
Date: Fri Aug 28 2020 - 04:54:36 EST


Update the fields (i.e. VM_{ENTRY_LOAD, EXIT_CLEAR}_BNDCFGS and
VM_{ENTRY, EXIT}_LOAD_IA32_PERF_GLOBAL_CTRL) in
nested MSR_IA32_VMX_TRUE_{ENTRY, EXIT}_CTLS according to guest CPUID
when user space initializes the features MSRs. Regardless of the order
of SET_CPUID and SET_MSRS from the user space, do the update to avoid
MSR values overriding.

Signed-off-by: Chenyi Qiang <chenyi.qiang@xxxxxxxxx>
---
arch/x86/kvm/vmx/vmx.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 819c185adf09..f9664ccc003b 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -345,6 +345,7 @@ static bool guest_state_valid(struct kvm_vcpu *vcpu);
static u32 vmx_segment_access_rights(struct kvm_segment *var);
static __always_inline void vmx_disable_intercept_for_msr(unsigned long *msr_bitmap,
u32 msr, int type);
+static void nested_vmx_entry_exit_ctls_update(struct kvm_vcpu *vcpu);

void vmx_vmexit(void);

@@ -2161,7 +2162,10 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
return 1; /* they are read-only */
if (!nested_vmx_allowed(vcpu))
return 1;
- return vmx_set_vmx_msr(vcpu, msr_index, data);
+ ret = vmx_set_vmx_msr(vcpu, msr_index, data);
+ nested_vmx_pmu_entry_exit_ctls_update(vcpu);
+ nested_vmx_entry_exit_ctls_update(vcpu);
+ break;
case MSR_IA32_RTIT_CTL:
if (!vmx_pt_mode_is_host_guest() ||
vmx_rtit_ctl_check(vcpu, data) ||
--
2.17.1