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* [PATCH v2 0/2] tweak HYPERV_CPUID_ENLIGHTMENT_INFO
@ 2019-01-25 11:19 Vitaly Kuznetsov
  2019-01-25 11:19 ` [PATCH v2 1/2] x86/kvm/hyper-v: don't recommend doing reset via synthetic MSR Vitaly Kuznetsov
                   ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Vitaly Kuznetsov @ 2019-01-25 11:19 UTC (permalink / raw)
  To: kvm
  Cc: Paolo Bonzini, Radim Krčmář,
	Roman Kagan, Liran Alon, linux-kernel

Be more consistent with genuine Hyper-V: don't recommend using Enlightened
VMCS when it wasn't enabled, don't advertise reset via synthetic MSR.

Vitaly Kuznetsov (2):
  x86/kvm/hyper-v: don't recommend doing reset via synthetic MSR
  x86/kvm/hyper-v: recommend using eVMCS only when it is enabled

 arch/x86/kvm/hyperv.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

-- 
2.20.1


^ permalink raw reply	[flat|nested] 6+ messages in thread
* [PATCH v2 1/2] x86/kvm/hyper-v: don't recommend doing reset via synthetic MSR
  2019-01-25 11:19 [PATCH v2 0/2] tweak HYPERV_CPUID_ENLIGHTMENT_INFO Vitaly Kuznetsov
@ 2019-01-25 11:19 ` Vitaly Kuznetsov
  2019-01-25 11:19 ` [PATCH v2 2/2] x86/kvm/hyper-v: recommend using eVMCS only when it is enabled Vitaly Kuznetsov
  2019-01-25 17:51 ` [PATCH v2 0/2] tweak HYPERV_CPUID_ENLIGHTMENT_INFO Paolo Bonzini
  2 siblings, 0 replies; 6+ messages in thread
From: Vitaly Kuznetsov @ 2019-01-25 11:19 UTC (permalink / raw)
  To: kvm
  Cc: Paolo Bonzini, Radim Krčmář,
	Roman Kagan, Liran Alon, linux-kernel

System reset through synthetic MSR is not recommended neither by genuine
Hyper-V nor my QEMU.

Fixes: 2bc39970e932 ("x86/kvm/hyper-v: Introduce KVM_GET_SUPPORTED_HV_CPUID")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
---
 arch/x86/kvm/hyperv.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index ac44a681f065..4840f5b3c88f 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1847,7 +1847,6 @@ int kvm_vcpu_ioctl_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
 		case HYPERV_CPUID_ENLIGHTMENT_INFO:
 			ent->eax |= HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED;
 			ent->eax |= HV_X64_APIC_ACCESS_RECOMMENDED;
-			ent->eax |= HV_X64_SYSTEM_RESET_RECOMMENDED;
 			ent->eax |= HV_X64_RELAXED_TIMING_RECOMMENDED;
 			ent->eax |= HV_X64_CLUSTER_IPI_RECOMMENDED;
 			ent->eax |= HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED;
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* [PATCH v2 2/2] x86/kvm/hyper-v: recommend using eVMCS only when it is enabled
  2019-01-25 11:19 [PATCH v2 0/2] tweak HYPERV_CPUID_ENLIGHTMENT_INFO Vitaly Kuznetsov
  2019-01-25 11:19 ` [PATCH v2 1/2] x86/kvm/hyper-v: don't recommend doing reset via synthetic MSR Vitaly Kuznetsov
@ 2019-01-25 11:19 ` Vitaly Kuznetsov
  2019-01-25 11:43   ` Vitaly Kuznetsov
  2019-01-25 17:51 ` [PATCH v2 0/2] tweak HYPERV_CPUID_ENLIGHTMENT_INFO Paolo Bonzini
  2 siblings, 1 reply; 6+ messages in thread
From: Vitaly Kuznetsov @ 2019-01-25 11:19 UTC (permalink / raw)
  To: kvm
  Cc: Paolo Bonzini, Radim Krčmář,
	Roman Kagan, Liran Alon, linux-kernel

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@oracle.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 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


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* Re: [PATCH v2 2/2] x86/kvm/hyper-v: recommend using eVMCS only when it is enabled
  2019-01-25 11:19 ` [PATCH v2 2/2] x86/kvm/hyper-v: recommend using eVMCS only when it is enabled Vitaly Kuznetsov
@ 2019-01-25 11:43   ` Vitaly Kuznetsov
  2019-01-25 18:11     ` Paolo Bonzini
  0 siblings, 1 reply; 6+ messages in thread
From: Vitaly Kuznetsov @ 2019-01-25 11:43 UTC (permalink / raw)
  To: kvm
  Cc: Paolo Bonzini, Radim Krčmář,
	Roman Kagan, Liran Alon, linux-kernel

Vitaly Kuznetsov <vkuznets@redhat.com> writes:

> 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.
>

Fixes: 2bc39970e932 ("x86/kvm/hyper-v: Introduce KVM_GET_SUPPORTED_HV_CPUID")

is missing here. Hope it can be added upon commit.

> Reviewed-by: Liran Alon <liran.alon@oracle.com>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> ---
>  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

-- 
Vitaly

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH v2 0/2] tweak HYPERV_CPUID_ENLIGHTMENT_INFO
  2019-01-25 11:19 [PATCH v2 0/2] tweak HYPERV_CPUID_ENLIGHTMENT_INFO Vitaly Kuznetsov
  2019-01-25 11:19 ` [PATCH v2 1/2] x86/kvm/hyper-v: don't recommend doing reset via synthetic MSR Vitaly Kuznetsov
  2019-01-25 11:19 ` [PATCH v2 2/2] x86/kvm/hyper-v: recommend using eVMCS only when it is enabled Vitaly Kuznetsov
@ 2019-01-25 17:51 ` Paolo Bonzini
  2 siblings, 0 replies; 6+ messages in thread
From: Paolo Bonzini @ 2019-01-25 17:51 UTC (permalink / raw)
  To: Vitaly Kuznetsov, kvm
  Cc: Radim Krčmář, Roman Kagan, Liran Alon, linux-kernel

On 25/01/19 12:19, Vitaly Kuznetsov wrote:
> Be more consistent with genuine Hyper-V: don't recommend using Enlightened
> VMCS when it wasn't enabled, don't advertise reset via synthetic MSR.
> 
> Vitaly Kuznetsov (2):
>   x86/kvm/hyper-v: don't recommend doing reset via synthetic MSR
>   x86/kvm/hyper-v: recommend using eVMCS only when it is enabled
> 
>  arch/x86/kvm/hyperv.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 

Queued, thanks.

Paolo

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH v2 2/2] x86/kvm/hyper-v: recommend using eVMCS only when it is enabled
  2019-01-25 11:43   ` Vitaly Kuznetsov
@ 2019-01-25 18:11     ` Paolo Bonzini
  0 siblings, 0 replies; 6+ messages in thread
From: Paolo Bonzini @ 2019-01-25 18:11 UTC (permalink / raw)
  To: Vitaly Kuznetsov, kvm
  Cc: Radim Krčmář, Roman Kagan, Liran Alon, linux-kernel

On 25/01/19 12:43, Vitaly Kuznetsov wrote:
> Fixes: 2bc39970e932 ("x86/kvm/hyper-v: Introduce KVM_GET_SUPPORTED_HV_CPUID")

Added, thanks.

Paolo

^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2019-01-25 18:11 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2019-01-25 11:19 [PATCH v2 0/2] tweak HYPERV_CPUID_ENLIGHTMENT_INFO Vitaly Kuznetsov
2019-01-25 11:19 ` [PATCH v2 1/2] x86/kvm/hyper-v: don't recommend doing reset via synthetic MSR Vitaly Kuznetsov
2019-01-25 11:19 ` [PATCH v2 2/2] x86/kvm/hyper-v: recommend using eVMCS only when it is enabled Vitaly Kuznetsov
2019-01-25 11:43   ` Vitaly Kuznetsov
2019-01-25 18:11     ` Paolo Bonzini
2019-01-25 17:51 ` [PATCH v2 0/2] tweak HYPERV_CPUID_ENLIGHTMENT_INFO Paolo Bonzini

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