KVM: VMX: Set msr bitmap correctly if vcpu is in guest mode

In commit 3af18d9c5fe9 ("KVM: nVMX: Prepare for using hardware MSR bitmap"),
we are setting MSR_BITMAP in prepare_vmcs02 if we should use hardware. This
is not enough since the field will be modified by following vmx_set_efer.

Fix this by setting vmx_msr_bitmap_nested in vmx_set_msr_bitmap if vcpu is
in guest mode.

Signed-off-by: Wincy Van <fanwenyi0529@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 7 insertions, 4 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index f7b20b417a3a..10a481b7674d 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2168,7 +2168,10 @@ static void vmx_set_msr_bitmap(struct kvm_vcpu *vcpu)
 {
         unsigned long *msr_bitmap;
 
-        if (irqchip_in_kernel(vcpu->kvm) && apic_x2apic_mode(vcpu->arch.apic)) {
+        if (is_guest_mode(vcpu))
+                msr_bitmap = vmx_msr_bitmap_nested;
+        else if (irqchip_in_kernel(vcpu->kvm) &&
+                apic_x2apic_mode(vcpu->arch.apic)) {
                 if (is_long_mode(vcpu))
                         msr_bitmap = vmx_msr_bitmap_longmode_x2apic;
                 else
@@ -9218,9 +9221,9 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
         }
 
         if (cpu_has_vmx_msr_bitmap() &&
-            exec_control & CPU_BASED_USE_MSR_BITMAPS &&
-            nested_vmx_merge_msr_bitmap(vcpu, vmcs12)) {
-                vmcs_write64(MSR_BITMAP, __pa(vmx_msr_bitmap_nested));
+            exec_control & CPU_BASED_USE_MSR_BITMAPS) {
+                nested_vmx_merge_msr_bitmap(vcpu, vmcs12);
+                /* MSR_BITMAP will be set by following vmx_set_efer. */
         } else
                 exec_control &= ~CPU_BASED_USE_MSR_BITMAPS;