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Diffstat (limited to 'arch/x86/kvm/hyperv.c')
-rw-r--r--arch/x86/kvm/hyperv.c26
1 files changed, 23 insertions, 3 deletions
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index c8764faf783b..f94dedd7ae6d 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1045,11 +1045,31 @@ static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
struct kvm_vcpu_hv *hv_vcpu = &vcpu->arch.hyperv;
switch (msr) {
- case HV_X64_MSR_VP_INDEX:
- if (!host || (u32)data >= KVM_MAX_VCPUS)
+ case HV_X64_MSR_VP_INDEX: {
+ struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
+ int vcpu_idx = kvm_vcpu_get_idx(vcpu);
+ u32 new_vp_index = (u32)data;
+
+ if (!host || new_vp_index >= KVM_MAX_VCPUS)
return 1;
- hv_vcpu->vp_index = (u32)data;
+
+ if (new_vp_index == hv_vcpu->vp_index)
+ return 0;
+
+ /*
+ * The VP index is initialized to vcpu_index by
+ * kvm_hv_vcpu_postcreate so they initially match. Now the
+ * VP index is changing, adjust num_mismatched_vp_indexes if
+ * it now matches or no longer matches vcpu_idx.
+ */
+ if (hv_vcpu->vp_index == vcpu_idx)
+ atomic_inc(&hv->num_mismatched_vp_indexes);
+ else if (new_vp_index == vcpu_idx)
+ atomic_dec(&hv->num_mismatched_vp_indexes);
+
+ hv_vcpu->vp_index = new_vp_index;
break;
+ }
case HV_X64_MSR_VP_ASSIST_PAGE: {
u64 gfn;
unsigned long addr;