* [PATCH] KVM: arm64: Resolve all pending PC updates before immediate exit
@ 2021-05-26 14:18 ` Zenghui Yu
0 siblings, 0 replies; 6+ messages in thread
From: Zenghui Yu @ 2021-05-26 14:18 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm, linux-kernel
Cc: maz, james.morse, alexandru.elisei, suzuki.poulose,
wanghaibin.wang, Zenghui Yu
Commit 26778aaa134a ("KVM: arm64: Commit pending PC adjustemnts before
returning to userspace") fixed the PC updating issue by forcing an explicit
synchronisation of the exception state on vcpu exit to userspace.
However, we forgot to take into account the case where immediate_exit is
set by userspace and KVM_RUN will exit immediately. Fix it by resolving all
pending PC updates before returning to userspace.
Since __kvm_adjust_pc() relies on a loaded vcpu context, I moved the
immediate_exit checking right after vcpu_load(). We will get some overhead
if immediate_exit is true (which should hopefully be rare).
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
---
This patch can be applied on top of kvmarm/fixes and help me to PASS all
kvm-unit-tests cases in the migration group.
arch/arm64/kvm/arm.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 1126eae27400..e720148232a0 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -720,11 +720,13 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
return ret;
}
- if (run->immediate_exit)
- return -EINTR;
-
vcpu_load(vcpu);
+ if (run->immediate_exit) {
+ ret = -EINTR;
+ goto out;
+ }
+
kvm_sigset_activate(vcpu);
ret = 1;
@@ -897,6 +899,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
kvm_sigset_deactivate(vcpu);
+out:
/*
* In the unlikely event that we are returning to userspace
* with pending exceptions or PC adjustment, commit these
--
2.19.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH] KVM: arm64: Resolve all pending PC updates before immediate exit
@ 2021-05-26 14:18 ` Zenghui Yu
0 siblings, 0 replies; 6+ messages in thread
From: Zenghui Yu @ 2021-05-26 14:18 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm, linux-kernel; +Cc: maz
Commit 26778aaa134a ("KVM: arm64: Commit pending PC adjustemnts before
returning to userspace") fixed the PC updating issue by forcing an explicit
synchronisation of the exception state on vcpu exit to userspace.
However, we forgot to take into account the case where immediate_exit is
set by userspace and KVM_RUN will exit immediately. Fix it by resolving all
pending PC updates before returning to userspace.
Since __kvm_adjust_pc() relies on a loaded vcpu context, I moved the
immediate_exit checking right after vcpu_load(). We will get some overhead
if immediate_exit is true (which should hopefully be rare).
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
---
This patch can be applied on top of kvmarm/fixes and help me to PASS all
kvm-unit-tests cases in the migration group.
arch/arm64/kvm/arm.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 1126eae27400..e720148232a0 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -720,11 +720,13 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
return ret;
}
- if (run->immediate_exit)
- return -EINTR;
-
vcpu_load(vcpu);
+ if (run->immediate_exit) {
+ ret = -EINTR;
+ goto out;
+ }
+
kvm_sigset_activate(vcpu);
ret = 1;
@@ -897,6 +899,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
kvm_sigset_deactivate(vcpu);
+out:
/*
* In the unlikely event that we are returning to userspace
* with pending exceptions or PC adjustment, commit these
--
2.19.1
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH] KVM: arm64: Resolve all pending PC updates before immediate exit
@ 2021-05-26 14:18 ` Zenghui Yu
0 siblings, 0 replies; 6+ messages in thread
From: Zenghui Yu @ 2021-05-26 14:18 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm, linux-kernel
Cc: maz, james.morse, alexandru.elisei, suzuki.poulose,
wanghaibin.wang, Zenghui Yu
Commit 26778aaa134a ("KVM: arm64: Commit pending PC adjustemnts before
returning to userspace") fixed the PC updating issue by forcing an explicit
synchronisation of the exception state on vcpu exit to userspace.
However, we forgot to take into account the case where immediate_exit is
set by userspace and KVM_RUN will exit immediately. Fix it by resolving all
pending PC updates before returning to userspace.
Since __kvm_adjust_pc() relies on a loaded vcpu context, I moved the
immediate_exit checking right after vcpu_load(). We will get some overhead
if immediate_exit is true (which should hopefully be rare).
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
---
This patch can be applied on top of kvmarm/fixes and help me to PASS all
kvm-unit-tests cases in the migration group.
arch/arm64/kvm/arm.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 1126eae27400..e720148232a0 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -720,11 +720,13 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
return ret;
}
- if (run->immediate_exit)
- return -EINTR;
-
vcpu_load(vcpu);
+ if (run->immediate_exit) {
+ ret = -EINTR;
+ goto out;
+ }
+
kvm_sigset_activate(vcpu);
ret = 1;
@@ -897,6 +899,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
kvm_sigset_deactivate(vcpu);
+out:
/*
* In the unlikely event that we are returning to userspace
* with pending exceptions or PC adjustment, commit these
--
2.19.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: arm64: Resolve all pending PC updates before immediate exit
2021-05-26 14:18 ` Zenghui Yu
(?)
@ 2021-05-27 9:36 ` Marc Zyngier
-1 siblings, 0 replies; 6+ messages in thread
From: Marc Zyngier @ 2021-05-27 9:36 UTC (permalink / raw)
To: Zenghui Yu, kvmarm, linux-arm-kernel, linux-kernel; +Cc: stable
On Wed, 26 May 2021 22:18:31 +0800, Zenghui Yu wrote:
> Commit 26778aaa134a ("KVM: arm64: Commit pending PC adjustemnts before
> returning to userspace") fixed the PC updating issue by forcing an explicit
> synchronisation of the exception state on vcpu exit to userspace.
>
> However, we forgot to take into account the case where immediate_exit is
> set by userspace and KVM_RUN will exit immediately. Fix it by resolving all
> pending PC updates before returning to userspace.
>
> [...]
Applied to fixes, thanks!
[1/1] KVM: arm64: Resolve all pending PC updates before immediate exit
commit: e3e880bb1518eb10a4b4bb4344ed614d6856f190
with:
Fixes: 26778aaa134a ("KVM: arm64: Commit pending PC adjustemnts before returning to userspace")
Cc: stable@vger.kernel.org # 5.11
Cheers,
M.
--
Without deviation from the norm, progress is not possible.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: arm64: Resolve all pending PC updates before immediate exit
@ 2021-05-27 9:36 ` Marc Zyngier
0 siblings, 0 replies; 6+ messages in thread
From: Marc Zyngier @ 2021-05-27 9:36 UTC (permalink / raw)
To: Zenghui Yu, kvmarm, linux-arm-kernel, linux-kernel; +Cc: stable
On Wed, 26 May 2021 22:18:31 +0800, Zenghui Yu wrote:
> Commit 26778aaa134a ("KVM: arm64: Commit pending PC adjustemnts before
> returning to userspace") fixed the PC updating issue by forcing an explicit
> synchronisation of the exception state on vcpu exit to userspace.
>
> However, we forgot to take into account the case where immediate_exit is
> set by userspace and KVM_RUN will exit immediately. Fix it by resolving all
> pending PC updates before returning to userspace.
>
> [...]
Applied to fixes, thanks!
[1/1] KVM: arm64: Resolve all pending PC updates before immediate exit
commit: e3e880bb1518eb10a4b4bb4344ed614d6856f190
with:
Fixes: 26778aaa134a ("KVM: arm64: Commit pending PC adjustemnts before returning to userspace")
Cc: stable@vger.kernel.org # 5.11
Cheers,
M.
--
Without deviation from the norm, progress is not possible.
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: arm64: Resolve all pending PC updates before immediate exit
@ 2021-05-27 9:36 ` Marc Zyngier
0 siblings, 0 replies; 6+ messages in thread
From: Marc Zyngier @ 2021-05-27 9:36 UTC (permalink / raw)
To: Zenghui Yu, kvmarm, linux-arm-kernel, linux-kernel; +Cc: stable
On Wed, 26 May 2021 22:18:31 +0800, Zenghui Yu wrote:
> Commit 26778aaa134a ("KVM: arm64: Commit pending PC adjustemnts before
> returning to userspace") fixed the PC updating issue by forcing an explicit
> synchronisation of the exception state on vcpu exit to userspace.
>
> However, we forgot to take into account the case where immediate_exit is
> set by userspace and KVM_RUN will exit immediately. Fix it by resolving all
> pending PC updates before returning to userspace.
>
> [...]
Applied to fixes, thanks!
[1/1] KVM: arm64: Resolve all pending PC updates before immediate exit
commit: e3e880bb1518eb10a4b4bb4344ed614d6856f190
with:
Fixes: 26778aaa134a ("KVM: arm64: Commit pending PC adjustemnts before returning to userspace")
Cc: stable@vger.kernel.org # 5.11
Cheers,
M.
--
Without deviation from the norm, progress is not possible.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-05-27 9:38 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2021-05-26 14:18 [PATCH] KVM: arm64: Resolve all pending PC updates before immediate exit Zenghui Yu
2021-05-26 14:18 ` Zenghui Yu
2021-05-26 14:18 ` Zenghui Yu
2021-05-27 9:36 ` Marc Zyngier
2021-05-27 9:36 ` Marc Zyngier
2021-05-27 9:36 ` Marc Zyngier
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