diff mbox series

[23/37] arm64: KVM: export the capability to set guest SError syndrome

Message ID 20180813145755.16566-24-marc.zyngier@arm.com (mailing list archive)
State New, archived
Headers show
Series [01/37] arm64: KVM: Add support for Stage-2 control of memory types and cacheability | expand

Commit Message

Marc Zyngier Aug. 13, 2018, 2:57 p.m. UTC 
From: Dongjiu Geng <gengdongjiu@huawei.com>

For the arm64 RAS Extension, user space can inject a virtual-SError
with specified ESR. So user space needs to know whether KVM support
to inject such SError, this interface adds this query for this capability.

KVM will check whether system support RAS Extension, if supported, KVM
returns true to user space, otherwise returns false.

Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
Reviewed-by: James Morse <james.morse@arm.com>
[expanded documentation wording]
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 Documentation/virtual/kvm/api.txt | 26 ++++++++++++++++++++++++++
 arch/arm64/kvm/reset.c            |  3 +++
 include/uapi/linux/kvm.h          |  1 +
 3 files changed, 30 insertions(+)

Comments

Andrew Jones Aug. 15, 2018, 12:13 p.m. UTC | #1 
On Mon, Aug 13, 2018 at 03:57:41PM +0100, Marc Zyngier wrote:
> From: Dongjiu Geng <gengdongjiu@huawei.com>
> 
> For the arm64 RAS Extension, user space can inject a virtual-SError
> with specified ESR. So user space needs to know whether KVM support
> to inject such SError, this interface adds this query for this capability.
> 
> KVM will check whether system support RAS Extension, if supported, KVM
> returns true to user space, otherwise returns false.
> 
> Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
> Reviewed-by: James Morse <james.morse@arm.com>
> [expanded documentation wording]
> Signed-off-by: James Morse <james.morse@arm.com>
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  Documentation/virtual/kvm/api.txt | 26 ++++++++++++++++++++++++++
>  arch/arm64/kvm/reset.c            |  3 +++
>  include/uapi/linux/kvm.h          |  1 +
>  3 files changed, 30 insertions(+)
> 
> diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
> index 284d36e72f28..dbbb95d5798a 100644
> --- a/Documentation/virtual/kvm/api.txt
> +++ b/Documentation/virtual/kvm/api.txt
> @@ -907,6 +907,18 @@ SError is pending, the architecture's 'Multiple SError interrupts' rules should
>  be followed. (2.5.3 of DDI0587.a "ARM Reliability, Availability, and
>  Serviceability (RAS) Specification").
>  
> +SError exceptions always have an ESR value. Some CPUs have the ability to
> +specify what the virtual SError's ESR value should be. These systems will
> +advertise KVM_CAP_ARM_SET_SERROR_ESR. In this case exception.has_esr will
> +always have a non-zero value when read, and the agent making an SError pending
> +should specify the ISS field in the lower 24 bits of exception.serror_esr. If
> +the system supports KVM_CAP_ARM_SET_SERROR_ESR, but user-space sets the events
> +with exception.has_esr as zero, KVM will choose an ESR.
> +
> +Specifying exception.has_esr on a system that does not support it will return
> +-EINVAL. Setting anything other than the lower 24bits of exception.serror_esr
> +will return -EINVAL.
> +
>  struct kvm_vcpu_events {
>  	struct {
>  		__u8 serror_pending;
> @@ -4664,3 +4676,17 @@ This capability indicates that KVM supports paravirtualized Hyper-V TLB Flush
>  hypercalls:
>  HvFlushVirtualAddressSpace, HvFlushVirtualAddressSpaceEx,
>  HvFlushVirtualAddressList, HvFlushVirtualAddressListEx.
> +
> +8.19 KVM_CAP_ARM_SET_SERROR_ESR
> +
> +Architectures: arm, arm64
> +
> +This capability indicates that userspace can specify (via the
> +KVM_SET_VCPU_EVENTS ioctl) the syndrome value reported to the guest when it
> +takes a virtual SError interrupt exception.
> +If KVM advertises this capability, userspace can only specify the ISS field for
> +the ESR syndrome. Other parts of the ESR, such as the EC are generated by the
> +CPU when the exception is taken. If this virtual SError is taken to EL1 using
> +AArch64, this value will be reported in the ISS field of ESR_ELx.
> +
> +See KVM_CAP_VCPU_EVENTS for more details.
> diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
> index a3db01a28062..067c6ba969bd 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:
>  	case KVM_CAP_VCPU_EVENTS:
> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index b6270a3b38e9..a7d9bc4e4068 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -949,6 +949,7 @@ struct kvm_ppc_resize_hpt {
>  #define KVM_CAP_GET_MSR_FEATURES 153
>  #define KVM_CAP_HYPERV_EVENTFD 154
>  #define KVM_CAP_HYPERV_TLBFLUSH 155
> +#define KVM_CAP_ARM_INJECT_SERROR_ESR 156
>  
>  #ifdef KVM_CAP_IRQ_ROUTING
>  
> -- 
> 2.18.0
>

Hi All,

I was just skimming over this patch and see that the documentation refers
to KVM_CAP_ARM_SET_SERROR_ESR, but the code implements
KVM_CAP_ARM_INJECT_SERROR_ESR. One or other needs a change. I suppose at
this point the documentation would be easiest.

Thanks,
drew
Marc Zyngier Aug. 15, 2018, 12:24 p.m. UTC | #2 
On 15/08/18 13:13, Andrew Jones wrote:
> On Mon, Aug 13, 2018 at 03:57:41PM +0100, Marc Zyngier wrote:
>> From: Dongjiu Geng <gengdongjiu@huawei.com>
>>
>> For the arm64 RAS Extension, user space can inject a virtual-SError
>> with specified ESR. So user space needs to know whether KVM support
>> to inject such SError, this interface adds this query for this capability.
>>
>> KVM will check whether system support RAS Extension, if supported, KVM
>> returns true to user space, otherwise returns false.
>>
>> Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
>> Reviewed-by: James Morse <james.morse@arm.com>
>> [expanded documentation wording]
>> Signed-off-by: James Morse <james.morse@arm.com>
>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>> ---
>>  Documentation/virtual/kvm/api.txt | 26 ++++++++++++++++++++++++++
>>  arch/arm64/kvm/reset.c            |  3 +++
>>  include/uapi/linux/kvm.h          |  1 +
>>  3 files changed, 30 insertions(+)
>>
>> diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
>> index 284d36e72f28..dbbb95d5798a 100644
>> --- a/Documentation/virtual/kvm/api.txt
>> +++ b/Documentation/virtual/kvm/api.txt
>> @@ -907,6 +907,18 @@ SError is pending, the architecture's 'Multiple SError interrupts' rules should
>>  be followed. (2.5.3 of DDI0587.a "ARM Reliability, Availability, and
>>  Serviceability (RAS) Specification").
>>  
>> +SError exceptions always have an ESR value. Some CPUs have the ability to
>> +specify what the virtual SError's ESR value should be. These systems will
>> +advertise KVM_CAP_ARM_SET_SERROR_ESR. In this case exception.has_esr will
>> +always have a non-zero value when read, and the agent making an SError pending
>> +should specify the ISS field in the lower 24 bits of exception.serror_esr. If
>> +the system supports KVM_CAP_ARM_SET_SERROR_ESR, but user-space sets the events
>> +with exception.has_esr as zero, KVM will choose an ESR.
>> +
>> +Specifying exception.has_esr on a system that does not support it will return
>> +-EINVAL. Setting anything other than the lower 24bits of exception.serror_esr
>> +will return -EINVAL.
>> +
>>  struct kvm_vcpu_events {
>>  	struct {
>>  		__u8 serror_pending;
>> @@ -4664,3 +4676,17 @@ This capability indicates that KVM supports paravirtualized Hyper-V TLB Flush
>>  hypercalls:
>>  HvFlushVirtualAddressSpace, HvFlushVirtualAddressSpaceEx,
>>  HvFlushVirtualAddressList, HvFlushVirtualAddressListEx.
>> +
>> +8.19 KVM_CAP_ARM_SET_SERROR_ESR
>> +
>> +Architectures: arm, arm64
>> +
>> +This capability indicates that userspace can specify (via the
>> +KVM_SET_VCPU_EVENTS ioctl) the syndrome value reported to the guest when it
>> +takes a virtual SError interrupt exception.
>> +If KVM advertises this capability, userspace can only specify the ISS field for
>> +the ESR syndrome. Other parts of the ESR, such as the EC are generated by the
>> +CPU when the exception is taken. If this virtual SError is taken to EL1 using
>> +AArch64, this value will be reported in the ISS field of ESR_ELx.
>> +
>> +See KVM_CAP_VCPU_EVENTS for more details.
>> diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
>> index a3db01a28062..067c6ba969bd 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:
>>  	case KVM_CAP_VCPU_EVENTS:
>> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
>> index b6270a3b38e9..a7d9bc4e4068 100644
>> --- a/include/uapi/linux/kvm.h
>> +++ b/include/uapi/linux/kvm.h
>> @@ -949,6 +949,7 @@ struct kvm_ppc_resize_hpt {
>>  #define KVM_CAP_GET_MSR_FEATURES 153
>>  #define KVM_CAP_HYPERV_EVENTFD 154
>>  #define KVM_CAP_HYPERV_TLBFLUSH 155
>> +#define KVM_CAP_ARM_INJECT_SERROR_ESR 156
>>  
>>  #ifdef KVM_CAP_IRQ_ROUTING
>>  
>> -- 
>> 2.18.0
>>
> 
> Hi All,
> 
> I was just skimming over this patch and see that the documentation refers
> to KVM_CAP_ARM_SET_SERROR_ESR, but the code implements
> KVM_CAP_ARM_INJECT_SERROR_ESR. One or other needs a change. I suppose at
> this point the documentation would be easiest.

Oops. Don't know how we missed that. I'll queue another patch on top and
send another pull request after -rc1 (I have another nit patch already
on my plate).

Thanks,

	M.
diff mbox series

Patch

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 284d36e72f28..dbbb95d5798a 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -907,6 +907,18 @@  SError is pending, the architecture's 'Multiple SError interrupts' rules should
 be followed. (2.5.3 of DDI0587.a "ARM Reliability, Availability, and
 Serviceability (RAS) Specification").
 
+SError exceptions always have an ESR value. Some CPUs have the ability to
+specify what the virtual SError's ESR value should be. These systems will
+advertise KVM_CAP_ARM_SET_SERROR_ESR. In this case exception.has_esr will
+always have a non-zero value when read, and the agent making an SError pending
+should specify the ISS field in the lower 24 bits of exception.serror_esr. If
+the system supports KVM_CAP_ARM_SET_SERROR_ESR, but user-space sets the events
+with exception.has_esr as zero, KVM will choose an ESR.
+
+Specifying exception.has_esr on a system that does not support it will return
+-EINVAL. Setting anything other than the lower 24bits of exception.serror_esr
+will return -EINVAL.
+
 struct kvm_vcpu_events {
 	struct {
 		__u8 serror_pending;
@@ -4664,3 +4676,17 @@  This capability indicates that KVM supports paravirtualized Hyper-V TLB Flush
 hypercalls:
 HvFlushVirtualAddressSpace, HvFlushVirtualAddressSpaceEx,
 HvFlushVirtualAddressList, HvFlushVirtualAddressListEx.
+
+8.19 KVM_CAP_ARM_SET_SERROR_ESR
+
+Architectures: arm, arm64
+
+This capability indicates that userspace can specify (via the
+KVM_SET_VCPU_EVENTS ioctl) the syndrome value reported to the guest when it
+takes a virtual SError interrupt exception.
+If KVM advertises this capability, userspace can only specify the ISS field for
+the ESR syndrome. Other parts of the ESR, such as the EC are generated by the
+CPU when the exception is taken. If this virtual SError is taken to EL1 using
+AArch64, this value will be reported in the ISS field of ESR_ELx.
+
+See KVM_CAP_VCPU_EVENTS for more details.
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index a3db01a28062..067c6ba969bd 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:
 	case KVM_CAP_VCPU_EVENTS:
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index b6270a3b38e9..a7d9bc4e4068 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -949,6 +949,7 @@  struct kvm_ppc_resize_hpt {
 #define KVM_CAP_GET_MSR_FEATURES 153
 #define KVM_CAP_HYPERV_EVENTFD 154
 #define KVM_CAP_HYPERV_TLBFLUSH 155
+#define KVM_CAP_ARM_INJECT_SERROR_ESR 156
 
 #ifdef KVM_CAP_IRQ_ROUTING