[PATCH v2 2/2] x86/kvm/hyper-v: recommend using eVMCS only when it is enabled

From: Vitaly Kuznetsov
Date: Fri Jan 25 2019 - 06:19:58 EST


We shouldn't probably be suggesting using Enlightened VMCS when it's not
enabled (not supported from guest's point of view). Hyper-V on KVM seems
to be fine either way but let's be consistent.

Reviewed-by: Liran Alon <liran.alon@xxxxxxxxxx>
Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
---
arch/x86/kvm/hyperv.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 4840f5b3c88f..4730fcaa70cf 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1850,7 +1850,8 @@ int kvm_vcpu_ioctl_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
ent->eax |= HV_X64_RELAXED_TIMING_RECOMMENDED;
ent->eax |= HV_X64_CLUSTER_IPI_RECOMMENDED;
ent->eax |= HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED;
- ent->eax |= HV_X64_ENLIGHTENED_VMCS_RECOMMENDED;
+ if (evmcs_ver)
+ ent->eax |= HV_X64_ENLIGHTENED_VMCS_RECOMMENDED;

/*
* Default number of spinlock retry attempts, matches
--
2.20.1