Re: [PATCH 2/3] KVM: uapi: Remove KVM_DEV_TYPE_ARM_PV_TIME in kvm_device_type
Hi Steven, On 2020/8/17 17:49, Steven Price wrote: > On 17/08/2020 09:43, zhukeqian wrote: >> Hi Marc, >> [...] >>> >>> It is pretty unfortunate that PV time has turned into such a train wreck, >>> but that's what we have now, and it has to stay. >> Well, I see. It is a sad thing indeed. > > Sorry about that, this got refactored so many times I guess I lost track of > what was actually needed and this hunk remained when it should have been > removed. > It's fine :-) , not a serious problem. > I would hope that I'm the only one who has any userspace code which uses > this, but I guess we should still be cautious since this has been in several > releases now. > OK. For insurance purposes, we ought to ignore this patch to avoid breaking any user-space program. > Steve > . Thanks, Keqian >
Re: [PATCH 2/3] KVM: uapi: Remove KVM_DEV_TYPE_ARM_PV_TIME in kvm_device_type
On 17/08/2020 09:43, zhukeqian wrote:
Hi Marc,
On 2020/8/17 15:39, Marc Zyngier wrote:
On 2020-08-17 04:37, Keqian Zhu wrote:
ARM64 PV-time ST is configured by userspace through vCPU attribute,
and KVM_DEV_TYPE_ARM_PV_TIME is unused.
Signed-off-by: Keqian Zhu
---
include/uapi/linux/kvm.h | 2 --
tools/include/uapi/linux/kvm.h | 2 --
2 files changed, 4 deletions(-)
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 4fdf303..9a6b97e 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1258,8 +1258,6 @@ enum kvm_device_type {
#define KVM_DEV_TYPE_ARM_VGIC_ITSKVM_DEV_TYPE_ARM_VGIC_ITS
KVM_DEV_TYPE_XIVE,
#define KVM_DEV_TYPE_XIVEKVM_DEV_TYPE_XIVE
-KVM_DEV_TYPE_ARM_PV_TIME,
-#define KVM_DEV_TYPE_ARM_PV_TIMEKVM_DEV_TYPE_ARM_PV_TIME
KVM_DEV_TYPE_MAX,
};
diff --git a/tools/include/uapi/linux/kvm.h b/tools/include/uapi/linux/kvm.h
index 4fdf303..9a6b97e 100644
--- a/tools/include/uapi/linux/kvm.h
+++ b/tools/include/uapi/linux/kvm.h
@@ -1258,8 +1258,6 @@ enum kvm_device_type {
#define KVM_DEV_TYPE_ARM_VGIC_ITSKVM_DEV_TYPE_ARM_VGIC_ITS
KVM_DEV_TYPE_XIVE,
#define KVM_DEV_TYPE_XIVEKVM_DEV_TYPE_XIVE
-KVM_DEV_TYPE_ARM_PV_TIME,
-#define KVM_DEV_TYPE_ARM_PV_TIMEKVM_DEV_TYPE_ARM_PV_TIME
KVM_DEV_TYPE_MAX,
};
No. You can't drop anything from UAPI, used or not. Doing so will
break the compilation of any userspace that, for any reason, references
this value. We cannot reuse this value in the future either, as it would
create a we wouldn't know which device to create.
It is pretty unfortunate that PV time has turned into such a train wreck,
but that's what we have now, and it has to stay.
Well, I see. It is a sad thing indeed.
Sorry about that, this got refactored so many times I guess I lost track
of what was actually needed and this hunk remained when it should have
been removed.
I would hope that I'm the only one who has any userspace code which uses
this, but I guess we should still be cautious since this has been in
several releases now.
Steve
Re: [PATCH 2/3] KVM: uapi: Remove KVM_DEV_TYPE_ARM_PV_TIME in kvm_device_type
Hi Marc,
On 2020/8/17 15:39, Marc Zyngier wrote:
> On 2020-08-17 04:37, Keqian Zhu wrote:
>> ARM64 PV-time ST is configured by userspace through vCPU attribute,
>> and KVM_DEV_TYPE_ARM_PV_TIME is unused.
>>
>> Signed-off-by: Keqian Zhu
>> ---
>> include/uapi/linux/kvm.h | 2 --
>> tools/include/uapi/linux/kvm.h | 2 --
>> 2 files changed, 4 deletions(-)
>>
>> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
>> index 4fdf303..9a6b97e 100644
>> --- a/include/uapi/linux/kvm.h
>> +++ b/include/uapi/linux/kvm.h
>> @@ -1258,8 +1258,6 @@ enum kvm_device_type {
>> #define KVM_DEV_TYPE_ARM_VGIC_ITSKVM_DEV_TYPE_ARM_VGIC_ITS
>> KVM_DEV_TYPE_XIVE,
>> #define KVM_DEV_TYPE_XIVEKVM_DEV_TYPE_XIVE
>> -KVM_DEV_TYPE_ARM_PV_TIME,
>> -#define KVM_DEV_TYPE_ARM_PV_TIMEKVM_DEV_TYPE_ARM_PV_TIME
>> KVM_DEV_TYPE_MAX,
>> };
>>
>> diff --git a/tools/include/uapi/linux/kvm.h b/tools/include/uapi/linux/kvm.h
>> index 4fdf303..9a6b97e 100644
>> --- a/tools/include/uapi/linux/kvm.h
>> +++ b/tools/include/uapi/linux/kvm.h
>> @@ -1258,8 +1258,6 @@ enum kvm_device_type {
>> #define KVM_DEV_TYPE_ARM_VGIC_ITSKVM_DEV_TYPE_ARM_VGIC_ITS
>> KVM_DEV_TYPE_XIVE,
>> #define KVM_DEV_TYPE_XIVEKVM_DEV_TYPE_XIVE
>> -KVM_DEV_TYPE_ARM_PV_TIME,
>> -#define KVM_DEV_TYPE_ARM_PV_TIMEKVM_DEV_TYPE_ARM_PV_TIME
>> KVM_DEV_TYPE_MAX,
>> };
>
> No. You can't drop anything from UAPI, used or not. Doing so will
> break the compilation of any userspace that, for any reason, references
> this value. We cannot reuse this value in the future either, as it would
> create a we wouldn't know which device to create.
>
> It is pretty unfortunate that PV time has turned into such a train wreck,
> but that's what we have now, and it has to stay.
Well, I see. It is a sad thing indeed.
Thanks,
Keqian
Re: [PATCH 2/3] KVM: uapi: Remove KVM_DEV_TYPE_ARM_PV_TIME in kvm_device_type
On 2020-08-17 04:37, Keqian Zhu wrote:
ARM64 PV-time ST is configured by userspace through vCPU attribute,
and KVM_DEV_TYPE_ARM_PV_TIME is unused.
Signed-off-by: Keqian Zhu
---
include/uapi/linux/kvm.h | 2 --
tools/include/uapi/linux/kvm.h | 2 --
2 files changed, 4 deletions(-)
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 4fdf303..9a6b97e 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1258,8 +1258,6 @@ enum kvm_device_type {
#define KVM_DEV_TYPE_ARM_VGIC_ITS KVM_DEV_TYPE_ARM_VGIC_ITS
KVM_DEV_TYPE_XIVE,
#define KVM_DEV_TYPE_XIVE KVM_DEV_TYPE_XIVE
- KVM_DEV_TYPE_ARM_PV_TIME,
-#define KVM_DEV_TYPE_ARM_PV_TIME KVM_DEV_TYPE_ARM_PV_TIME
KVM_DEV_TYPE_MAX,
};
diff --git a/tools/include/uapi/linux/kvm.h
b/tools/include/uapi/linux/kvm.h
index 4fdf303..9a6b97e 100644
--- a/tools/include/uapi/linux/kvm.h
+++ b/tools/include/uapi/linux/kvm.h
@@ -1258,8 +1258,6 @@ enum kvm_device_type {
#define KVM_DEV_TYPE_ARM_VGIC_ITS KVM_DEV_TYPE_ARM_VGIC_ITS
KVM_DEV_TYPE_XIVE,
#define KVM_DEV_TYPE_XIVE KVM_DEV_TYPE_XIVE
- KVM_DEV_TYPE_ARM_PV_TIME,
-#define KVM_DEV_TYPE_ARM_PV_TIME KVM_DEV_TYPE_ARM_PV_TIME
KVM_DEV_TYPE_MAX,
};
No. You can't drop anything from UAPI, used or not. Doing so will
break the compilation of any userspace that, for any reason, references
this value. We cannot reuse this value in the future either, as it would
create a we wouldn't know which device to create.
It is pretty unfortunate that PV time has turned into such a train
wreck,
but that's what we have now, and it has to stay.
M.
--
Jazz is not dead. It just smells funny...
[PATCH 2/3] KVM: uapi: Remove KVM_DEV_TYPE_ARM_PV_TIME in kvm_device_type
ARM64 PV-time ST is configured by userspace through vCPU attribute,
and KVM_DEV_TYPE_ARM_PV_TIME is unused.
Signed-off-by: Keqian Zhu
---
include/uapi/linux/kvm.h | 2 --
tools/include/uapi/linux/kvm.h | 2 --
2 files changed, 4 deletions(-)
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 4fdf303..9a6b97e 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1258,8 +1258,6 @@ enum kvm_device_type {
#define KVM_DEV_TYPE_ARM_VGIC_ITS KVM_DEV_TYPE_ARM_VGIC_ITS
KVM_DEV_TYPE_XIVE,
#define KVM_DEV_TYPE_XIVE KVM_DEV_TYPE_XIVE
- KVM_DEV_TYPE_ARM_PV_TIME,
-#define KVM_DEV_TYPE_ARM_PV_TIME KVM_DEV_TYPE_ARM_PV_TIME
KVM_DEV_TYPE_MAX,
};
diff --git a/tools/include/uapi/linux/kvm.h b/tools/include/uapi/linux/kvm.h
index 4fdf303..9a6b97e 100644
--- a/tools/include/uapi/linux/kvm.h
+++ b/tools/include/uapi/linux/kvm.h
@@ -1258,8 +1258,6 @@ enum kvm_device_type {
#define KVM_DEV_TYPE_ARM_VGIC_ITS KVM_DEV_TYPE_ARM_VGIC_ITS
KVM_DEV_TYPE_XIVE,
#define KVM_DEV_TYPE_XIVE KVM_DEV_TYPE_XIVE
- KVM_DEV_TYPE_ARM_PV_TIME,
-#define KVM_DEV_TYPE_ARM_PV_TIME KVM_DEV_TYPE_ARM_PV_TIME
KVM_DEV_TYPE_MAX,
};
--
1.8.3.1
