diff mbox

[v11,1/4] arm64: KVM: export the capability to set guest SError syndrome

Message ID 1523309796-36423-2-git-send-email-gengdongjiu@huawei.com (mailing list archive)
State New, archived
Headers show

Commit Message

Dongjiu Geng April 9, 2018, 9:36 p.m. UTC
Before user space injects a SError, it needs to know whether it can
specify the guest Exception Syndrome, so KVM should tell user space
whether it has such capability.

Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
---
 Documentation/virtual/kvm/api.txt | 11 +++++++++++
 arch/arm64/kvm/reset.c            |  3 +++
 include/uapi/linux/kvm.h          |  1 +
 3 files changed, 15 insertions(+)

Comments

James Morse April 10, 2018, 2:15 p.m. UTC | #1
Hi Dongjiu Geng,

On 09/04/18 22:36, Dongjiu Geng wrote:
> Before user space injects a SError, it needs to know whether it can
> specify the guest Exception Syndrome, so KVM should tell user space
> whether it has such capability.

(you could improve the commit message by briefly explaining how/why user-space
would want to do this. As this is patch 1, you don't have the context of the
previous patch to say that some systems can provide an ESR with virtual-SError)


> diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
> index fc3ae95..8a3d708 100644
> --- a/Documentation/virtual/kvm/api.txt
> +++ b/Documentation/virtual/kvm/api.txt
> @@ -4415,3 +4415,14 @@ Parameters: none
>  This capability indicates if the flic device will be able to get/set the
>  AIS states for migration via the KVM_DEV_FLIC_AISM_ALL attribute and allows
>  to discover this without having to create a flic device.
> +
> +8.14 KVM_CAP_ARM_SET_SERROR_ESR
> +
> +Architectures: arm, arm64
> +
> +This capability indicates that userspace can specify syndrome value reported to

(Nit: 'the syndrome value')

> +guest OS when guest takes a virtual SError interrupt exception.

(Nit: 'the guest')

> +If KVM has this capability, userspace can only specify the ISS field for the ESR
> +syndrome, can not specify the EC field which is not under control by KVM.

(Nit: 'it can not specify...')

> +If this virtual SError is taken to EL1 using AArch64, this value will be reported
> +into ISS filed of ESR_EL1.

(Nit: 'in the ISS field')


> diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
> index 3256b92..38c8a64 100644
> --- a/arch/arm64/kvm/reset.c
> +++ b/arch/arm64/kvm/reset.c
> @@ -77,6 +77,9 @@ int kvm_arch_dev_ioctl_check_extension(struct kvm *kvm, long ext)
>  	case KVM_CAP_ARM_PMU_V3:
>  		r = kvm_arm_support_pmu_v3();
>  		break;
> +	case KVM_CAP_ARM_INJECT_SERROR_ESR:
> +		r = cpus_have_const_cap(ARM64_HAS_RAS_EXTN);
> +		break;
>  	case KVM_CAP_SET_GUEST_DEBUG:
>  	case KVM_CAP_VCPU_ATTRIBUTES:
>  		r = 1;

'dev_ioctl' feels a bit weird, but we already have cpu_has_32bit_el1() in here.


> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index 8fb90a0..3587b33 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -934,6 +934,7 @@ struct kvm_ppc_resize_hpt {
>  #define KVM_CAP_S390_AIS_MIGRATION 150
>  #define KVM_CAP_PPC_GET_CPU_CHAR 151
>  #define KVM_CAP_S390_BPB 152
> +#define KVM_CAP_ARM_INJECT_SERROR_ESR 153
>  
>  #ifdef KVM_CAP_IRQ_ROUTING

(patch 1&2 should probably be swapped around, as on its own this does thing).

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


Thanks,

James
gengdongjiu April 12, 2018, 12:55 p.m. UTC | #2
HI James,
  Thanks for the review.


2018-04-10 22:15 GMT+08:00, James Morse <james.morse@arm.com>:
> Hi Dongjiu Geng,
>
> On 09/04/18 22:36, Dongjiu Geng wrote:
>> Before user space injects a SError, it needs to know whether it can
>> specify the guest Exception Syndrome, so KVM should tell user space
>> whether it has such capability.
>
> (you could improve the commit message by briefly explaining how/why
> user-space
> would want to do this. As this is patch 1, you don't have the context of
> the
> previous patch to say that some systems can provide an ESR with
> virtual-SError)
Exactly, thanks for the good comments.

>
>
>> diff --git a/Documentation/virtual/kvm/api.txt
>> b/Documentation/virtual/kvm/api.txt
>> index fc3ae95..8a3d708 100644
>> --- a/Documentation/virtual/kvm/api.txt
>> +++ b/Documentation/virtual/kvm/api.txt
>> @@ -4415,3 +4415,14 @@ Parameters: none
>>  This capability indicates if the flic device will be able to get/set the
>>  AIS states for migration via the KVM_DEV_FLIC_AISM_ALL attribute and
>> allows
>>  to discover this without having to create a flic device.
>> +
>> +8.14 KVM_CAP_ARM_SET_SERROR_ESR
>> +
>> +Architectures: arm, arm64
>> +
>> +This capability indicates that userspace can specify syndrome value
>> reported to
>
> (Nit: 'the syndrome value')
will fix it.

>
>> +guest OS when guest takes a virtual SError interrupt exception.
>
> (Nit: 'the guest')
will fix it.

>
>> +If KVM has this capability, userspace can only specify the ISS field for
>> the ESR
>> +syndrome, can not specify the EC field which is not under control by
>> KVM.
>
> (Nit: 'it can not specify...')
will fix it.

>
>> +If this virtual SError is taken to EL1 using AArch64, this value will be
>> reported
>> +into ISS filed of ESR_EL1.
>
> (Nit: 'in the ISS field')
will fix it.

>
>
>> diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
>> index 3256b92..38c8a64 100644
>> --- a/arch/arm64/kvm/reset.c
>> +++ b/arch/arm64/kvm/reset.c
>> @@ -77,6 +77,9 @@ int kvm_arch_dev_ioctl_check_extension(struct kvm *kvm,
>> long ext)
>>  	case KVM_CAP_ARM_PMU_V3:
>>  		r = kvm_arm_support_pmu_v3();
>>  		break;
>> +	case KVM_CAP_ARM_INJECT_SERROR_ESR:
>> +		r = cpus_have_const_cap(ARM64_HAS_RAS_EXTN);
>> +		break;
>>  	case KVM_CAP_SET_GUEST_DEBUG:
>>  	case KVM_CAP_VCPU_ATTRIBUTES:
>>  		r = 1;
>
> 'dev_ioctl' feels a bit weird, but we already have cpu_has_32bit_el1() in
> here.

Yes, although the name is "dev_ioctl", it does not have relationship
with the device.
here it mainly check vcpu capability, such as PMU, 32bit EL1 etc.

>
>
>> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
>> index 8fb90a0..3587b33 100644
>> --- a/include/uapi/linux/kvm.h
>> +++ b/include/uapi/linux/kvm.h
>> @@ -934,6 +934,7 @@ struct kvm_ppc_resize_hpt {
>>  #define KVM_CAP_S390_AIS_MIGRATION 150
>>  #define KVM_CAP_PPC_GET_CPU_CHAR 151
>>  #define KVM_CAP_S390_BPB 152
>> +#define KVM_CAP_ARM_INJECT_SERROR_ESR 153
>>
>>  #ifdef KVM_CAP_IRQ_ROUTING
>
> (patch 1&2 should probably be swapped around, as on its own this does
> thing).
ok, I will do it.

>
> Reviewed-by: James Morse <james.morse@arm.com>
thanks this Reviewed-by

>
>
> Thanks,
>
> James
> _______________________________________________
> kvmarm mailing list
> kvmarm@lists.cs.columbia.edu
> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
>
diff mbox

Patch

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index fc3ae95..8a3d708 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -4415,3 +4415,14 @@  Parameters: none
 This capability indicates if the flic device will be able to get/set the
 AIS states for migration via the KVM_DEV_FLIC_AISM_ALL attribute and allows
 to discover this without having to create a flic device.
+
+8.14 KVM_CAP_ARM_SET_SERROR_ESR
+
+Architectures: arm, arm64
+
+This capability indicates that userspace can specify syndrome value reported to
+guest OS when guest takes a virtual SError interrupt exception.
+If KVM has this capability, userspace can only specify the ISS field for the ESR
+syndrome, can not specify the EC field which is not under control by KVM.
+If this virtual SError is taken to EL1 using AArch64, this value will be reported
+into ISS filed of ESR_EL1.
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index 3256b92..38c8a64 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -77,6 +77,9 @@  int kvm_arch_dev_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_ARM_PMU_V3:
 		r = kvm_arm_support_pmu_v3();
 		break;
+	case KVM_CAP_ARM_INJECT_SERROR_ESR:
+		r = cpus_have_const_cap(ARM64_HAS_RAS_EXTN);
+		break;
 	case KVM_CAP_SET_GUEST_DEBUG:
 	case KVM_CAP_VCPU_ATTRIBUTES:
 		r = 1;
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 8fb90a0..3587b33 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -934,6 +934,7 @@  struct kvm_ppc_resize_hpt {
 #define KVM_CAP_S390_AIS_MIGRATION 150
 #define KVM_CAP_PPC_GET_CPU_CHAR 151
 #define KVM_CAP_S390_BPB 152
+#define KVM_CAP_ARM_INJECT_SERROR_ESR 153
 
 #ifdef KVM_CAP_IRQ_ROUTING