Re: [PATCH v3 2/2] arm/arm64: KVM: enable 32 bits kvm vcpu events support

Re: [PATCH v3 2/2] arm/arm64: KVM: enable 32 bits kvm vcpu events support

[gengdongjiu]

Hi James,

> Hi Dongjiu Geng,
> 
> On 11/10/2018 20:07, Dongjiu Geng wrote:
> > The commit 539aee0edb9f ("KVM: arm64: Share the parts of get/set
> > events useful to 32bit") shares the get/set events helper for arm64
> > and arm32,
> 
> Oops. I evidently didn't test this bit. Looks like I just depended on the symbol to be defined, I didn't check the CAP was exposed.

Yes, you do not check the CAP when you test it.

> 
> 
> > it is better also share the check
> > for vcpu events capability to enable 32 bit kvm vcpu events support.
> 
> not just better, necessary for correctly-written user-space to know the feature is supported. This last bit would be clearer as: "but forgot to
> share the cap extension code."

Ok, will update it.

> 
> 
> Thanks for catching this!

You are welcome

> 
> Acked-by: James Morse <james.morse@arm.com>
> 
> 
> Thanks,
> 
> James

Re: [PATCH v3 2/2] arm/arm64: KVM: enable 32 bits kvm vcpu events support

[gengdongjiu]

Hi James,

> Hi Dongjiu Geng,
> 
> On 11/10/2018 20:07, Dongjiu Geng wrote:
> > The commit 539aee0edb9f ("KVM: arm64: Share the parts of get/set
> > events useful to 32bit") shares the get/set events helper for arm64
> > and arm32,
> 
> Oops. I evidently didn't test this bit. Looks like I just depended on the symbol to be defined, I didn't check the CAP was exposed.

Yes, you do not check the CAP when you test it.

> 
> 
> > it is better also share the check
> > for vcpu events capability to enable 32 bit kvm vcpu events support.
> 
> not just better, necessary for correctly-written user-space to know the feature is supported. This last bit would be clearer as: "but forgot to
> share the cap extension code."

Ok, will update it.

> 
> 
> Thanks for catching this!

You are welcome

> 
> Acked-by: James Morse <james.morse@arm.com>
> 
> 
> Thanks,
> 
> James

[PATCH v3 0/2] rename function name and enable 32bit vcpu events

[Dongjiu Geng]

Rename the kvm_arch_dev_ioctl_check_extension() to 
kvm_arch_vm_ioctl_check_extension, because the name
is not reasonable; 

Enable the 32 bit vcpu events support.

Change since v2:
1. Address Suzuki's comments to update the patch commit messages

change since v1:
1. Update patch commit messages.

Dongjiu Geng (2):
  arm/arm64: KVM: rename function kvm_arch_dev_ioctl_check_extension()
  arm/arm64: KVM: enable 32 bits kvm vcpu events support

 arch/arm/include/asm/kvm_host.h   | 2 +-
 arch/arm64/include/asm/kvm_host.h | 2 +-
 arch/arm64/kvm/reset.c            | 5 ++---
 virt/kvm/arm/arm.c                | 3 ++-
 4 files changed, 6 insertions(+), 6 deletions(-)

-- 
1.9.1

[PATCH v3 2/2] arm/arm64: KVM: enable 32 bits kvm vcpu events support

[Dongjiu Geng]

The commit 539aee0edb9f ("KVM: arm64: Share the parts of
get/set events useful to 32bit") shares the get/set events
helper for arm64 and arm32, it is better also share the check
for vcpu events capability to enable 32 bit kvm vcpu events
support.

User space will check whether KVM supports vcpu events by checking
the KVM_CAP_VCPU_EVENTS extension

Cc: James Morse <james.morse@arm.com>
Reviewed-by : Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
---
For the 32 bits kvm migration, it needs to enable the vcpu events,
this patch will enable it. The user space QEMU patch is here:
https://patchwork.ozlabs.org/patch/975615/
---
 arch/arm64/kvm/reset.c | 1 -
 virt/kvm/arm/arm.c     | 1 +
 2 files changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index fd37c53..e50245e 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -82,7 +82,6 @@ int kvm_arch_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 		break;
 	case KVM_CAP_SET_GUEST_DEBUG:
 	case KVM_CAP_VCPU_ATTRIBUTES:
-	case KVM_CAP_VCPU_EVENTS:
 		r = 1;
 		break;
 	default:
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index 40e79ea..64e5d97 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -212,6 +212,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_READONLY_MEM:
 	case KVM_CAP_MP_STATE:
 	case KVM_CAP_IMMEDIATE_EXIT:
+	case KVM_CAP_VCPU_EVENTS:
 		r = 1;
 		break;
 	case KVM_CAP_ARM_SET_DEVICE_ADDR:
-- 
1.9.1

[PATCH v3 2/2] arm/arm64: KVM: enable 32 bits kvm vcpu events support

[Dongjiu Geng]

The commit 539aee0edb9f ("KVM: arm64: Share the parts of
get/set events useful to 32bit") shares the get/set events
helper for arm64 and arm32, it is better also share the check
for vcpu events capability to enable 32 bit kvm vcpu events
support.

User space will check whether KVM supports vcpu events by checking
the KVM_CAP_VCPU_EVENTS extension

Cc: James Morse <james.morse@arm.com>
Reviewed-by : Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
---
For the 32 bits kvm migration, it needs to enable the vcpu events,
this patch will enable it. The user space QEMU patch is here:
https://patchwork.ozlabs.org/patch/975615/
---
 arch/arm64/kvm/reset.c | 1 -
 virt/kvm/arm/arm.c     | 1 +
 2 files changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index fd37c53..e50245e 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -82,7 +82,6 @@ int kvm_arch_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 		break;
 	case KVM_CAP_SET_GUEST_DEBUG:
 	case KVM_CAP_VCPU_ATTRIBUTES:
-	case KVM_CAP_VCPU_EVENTS:
 		r = 1;
 		break;
 	default:
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index 40e79ea..64e5d97 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -212,6 +212,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_READONLY_MEM:
 	case KVM_CAP_MP_STATE:
 	case KVM_CAP_IMMEDIATE_EXIT:
+	case KVM_CAP_VCPU_EVENTS:
 		r = 1;
 		break;
 	case KVM_CAP_ARM_SET_DEVICE_ADDR:
-- 
1.9.1

[PATCH v3 2/2] arm/arm64: KVM: enable 32 bits kvm vcpu events support

[Dongjiu Geng]

The commit 539aee0edb9f ("KVM: arm64: Share the parts of
get/set events useful to 32bit") shares the get/set events
helper for arm64 and arm32, it is better also share the check
for vcpu events capability to enable 32 bit kvm vcpu events
support.

User space will check whether KVM supports vcpu events by checking
the KVM_CAP_VCPU_EVENTS extension

Cc: James Morse <james.morse@arm.com>
Reviewed-by : Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
---
For the 32 bits kvm migration, it needs to enable the vcpu events,
this patch will enable it. The user space QEMU patch is here:
https://patchwork.ozlabs.org/patch/975615/
---
 arch/arm64/kvm/reset.c | 1 -
 virt/kvm/arm/arm.c     | 1 +
 2 files changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index fd37c53..e50245e 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -82,7 +82,6 @@ int kvm_arch_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 		break;
 	case KVM_CAP_SET_GUEST_DEBUG:
 	case KVM_CAP_VCPU_ATTRIBUTES:
-	case KVM_CAP_VCPU_EVENTS:
 		r = 1;
 		break;
 	default:
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index 40e79ea..64e5d97 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -212,6 +212,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_READONLY_MEM:
 	case KVM_CAP_MP_STATE:
 	case KVM_CAP_IMMEDIATE_EXIT:
+	case KVM_CAP_VCPU_EVENTS:
 		r = 1;
 		break;
 	case KVM_CAP_ARM_SET_DEVICE_ADDR:
-- 
1.9.1

Re: [PATCH v3 2/2] arm/arm64: KVM: enable 32 bits kvm vcpu events support

[James Morse]

Hi Dongjiu Geng,

On 11/10/2018 20:07, Dongjiu Geng wrote:
> The commit 539aee0edb9f ("KVM: arm64: Share the parts of
> get/set events useful to 32bit") shares the get/set events
> helper for arm64 and arm32, 

Oops. I evidently didn't test this bit. Looks like I just depended on the symbol
to be defined, I didn't check the CAP was exposed.


> it is better also share the check
> for vcpu events capability to enable 32 bit kvm vcpu events
> support.

not just better, necessary for correctly-written user-space to know the feature
is supported. This last bit would be clearer as: "but forgot to share the cap
extension code."


Thanks for catching this!

Acked-by: James Morse <james.morse@arm.com>


Thanks,

James

[PATCH v3 2/2] arm/arm64: KVM: enable 32 bits kvm vcpu events support

[James Morse]

Hi Dongjiu Geng,

On 11/10/2018 20:07, Dongjiu Geng wrote:
> The commit 539aee0edb9f ("KVM: arm64: Share the parts of
> get/set events useful to 32bit") shares the get/set events
> helper for arm64 and arm32, 

Oops. I evidently didn't test this bit. Looks like I just depended on the symbol
to be defined, I didn't check the CAP was exposed.


> it is better also share the check
> for vcpu events capability to enable 32 bit kvm vcpu events
> support.

not just better, necessary for correctly-written user-space to know the feature
is supported. This last bit would be clearer as: "but forgot to share the cap
extension code."


Thanks for catching this!

Acked-by: James Morse <james.morse@arm.com>


Thanks,

James