* [RFC PATCH] riscv: kvm: return SBI_ERR_FAILURE for PMU shmem OOM
@ 2026-04-15 22:09 Osama Abdelkader
2026-05-06 13:21 ` Osama Abdelkader
2026-05-14 13:43 ` Anup Patel
0 siblings, 2 replies; 4+ messages in thread
From: Osama Abdelkader @ 2026-04-15 22:09 UTC (permalink / raw)
To: Anup Patel, Atish Patra, Paul Walmsley, Palmer Dabbelt, Albert Ou,
Alexandre Ghiti, kvm, kvm-riscv, linux-riscv, linux-kernel
Cc: Osama Abdelkader
kvm_riscv_vcpu_pmu_snapshot_set_shmem() and kvm_riscv_vcpu_pmu_event_info()
returned -ENOMEM from the SBI extension handler, which caused
kvm_riscv_vcpu_sbi_ecall() to abort KVM_RUN and surface the error to
userspace instead of completing the ECALL with a negative SBI error in a0.
Use SBI_ERR_FAILURE and the normal retdata path, matching other PMU
handlers and kvm_sbi_ext_pmu_handler comment.
Signed-off-by: Osama Abdelkader <osama.abdelkader@gmail.com>
---
arch/riscv/kvm/vcpu_pmu.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/arch/riscv/kvm/vcpu_pmu.c b/arch/riscv/kvm/vcpu_pmu.c
index e873430e596b..f36b099f447c 100644
--- a/arch/riscv/kvm/vcpu_pmu.c
+++ b/arch/riscv/kvm/vcpu_pmu.c
@@ -435,8 +435,10 @@ int kvm_riscv_vcpu_pmu_snapshot_set_shmem(struct kvm_vcpu *vcpu, unsigned long s
}
kvpmu->sdata = kzalloc(snapshot_area_size, GFP_ATOMIC);
- if (!kvpmu->sdata)
- return -ENOMEM;
+ if (!kvpmu->sdata) {
+ sbiret = SBI_ERR_FAILURE;
+ goto out;
+ }
/* No need to check writable slot explicitly as kvm_vcpu_write_guest does it internally */
if (kvm_vcpu_write_guest(vcpu, saddr, kvpmu->sdata, snapshot_area_size)) {
@@ -480,8 +482,10 @@ int kvm_riscv_vcpu_pmu_event_info(struct kvm_vcpu *vcpu, unsigned long saddr_low
}
einfo = kzalloc(shmem_size, GFP_KERNEL);
- if (!einfo)
- return -ENOMEM;
+ if (!einfo) {
+ ret = SBI_ERR_FAILURE;
+ goto out;
+ }
ret = kvm_vcpu_read_guest(vcpu, shmem, einfo, shmem_size);
if (ret) {
--
2.43.0
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^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [RFC PATCH] riscv: kvm: return SBI_ERR_FAILURE for PMU shmem OOM
2026-04-15 22:09 [RFC PATCH] riscv: kvm: return SBI_ERR_FAILURE for PMU shmem OOM Osama Abdelkader
@ 2026-05-06 13:21 ` Osama Abdelkader
2026-05-14 13:43 ` Anup Patel
1 sibling, 0 replies; 4+ messages in thread
From: Osama Abdelkader @ 2026-05-06 13:21 UTC (permalink / raw)
To: Anup Patel, Atish Patra, Paul Walmsley, Palmer Dabbelt, Albert Ou,
Alexandre Ghiti, kvm, kvm-riscv, linux-riscv, linux-kernel
On Thu, Apr 16, 2026 at 12:09:30AM +0200, Osama Abdelkader wrote:
> kvm_riscv_vcpu_pmu_snapshot_set_shmem() and kvm_riscv_vcpu_pmu_event_info()
> returned -ENOMEM from the SBI extension handler, which caused
> kvm_riscv_vcpu_sbi_ecall() to abort KVM_RUN and surface the error to
> userspace instead of completing the ECALL with a negative SBI error in a0.
> Use SBI_ERR_FAILURE and the normal retdata path, matching other PMU
> handlers and kvm_sbi_ext_pmu_handler comment.
>
> Signed-off-by: Osama Abdelkader <osama.abdelkader@gmail.com>
> ---
> arch/riscv/kvm/vcpu_pmu.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/arch/riscv/kvm/vcpu_pmu.c b/arch/riscv/kvm/vcpu_pmu.c
> index e873430e596b..f36b099f447c 100644
> --- a/arch/riscv/kvm/vcpu_pmu.c
> +++ b/arch/riscv/kvm/vcpu_pmu.c
> @@ -435,8 +435,10 @@ int kvm_riscv_vcpu_pmu_snapshot_set_shmem(struct kvm_vcpu *vcpu, unsigned long s
> }
>
> kvpmu->sdata = kzalloc(snapshot_area_size, GFP_ATOMIC);
> - if (!kvpmu->sdata)
> - return -ENOMEM;
> + if (!kvpmu->sdata) {
> + sbiret = SBI_ERR_FAILURE;
> + goto out;
> + }
>
> /* No need to check writable slot explicitly as kvm_vcpu_write_guest does it internally */
> if (kvm_vcpu_write_guest(vcpu, saddr, kvpmu->sdata, snapshot_area_size)) {
> @@ -480,8 +482,10 @@ int kvm_riscv_vcpu_pmu_event_info(struct kvm_vcpu *vcpu, unsigned long saddr_low
> }
>
> einfo = kzalloc(shmem_size, GFP_KERNEL);
> - if (!einfo)
> - return -ENOMEM;
> + if (!einfo) {
> + ret = SBI_ERR_FAILURE;
> + goto out;
> + }
>
> ret = kvm_vcpu_read_guest(vcpu, shmem, einfo, shmem_size);
> if (ret) {
> --
> 2.43.0
>
ping.
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http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [RFC PATCH] riscv: kvm: return SBI_ERR_FAILURE for PMU shmem OOM
2026-04-15 22:09 [RFC PATCH] riscv: kvm: return SBI_ERR_FAILURE for PMU shmem OOM Osama Abdelkader
2026-05-06 13:21 ` Osama Abdelkader
@ 2026-05-14 13:43 ` Anup Patel
2026-05-14 17:40 ` Osama Abdelkader
1 sibling, 1 reply; 4+ messages in thread
From: Anup Patel @ 2026-05-14 13:43 UTC (permalink / raw)
To: Osama Abdelkader
Cc: Atish Patra, Paul Walmsley, Palmer Dabbelt, Albert Ou,
Alexandre Ghiti, kvm, kvm-riscv, linux-riscv, linux-kernel
On Thu, Apr 16, 2026 at 3:40 AM Osama Abdelkader
<osama.abdelkader@gmail.com> wrote:
>
> kvm_riscv_vcpu_pmu_snapshot_set_shmem() and kvm_riscv_vcpu_pmu_event_info()
> returned -ENOMEM from the SBI extension handler, which caused
> kvm_riscv_vcpu_sbi_ecall() to abort KVM_RUN and surface the error to
> userspace instead of completing the ECALL with a negative SBI error in a0.
> Use SBI_ERR_FAILURE and the normal retdata path, matching other PMU
> handlers and kvm_sbi_ext_pmu_handler comment.
>
> Signed-off-by: Osama Abdelkader <osama.abdelkader@gmail.com>
Split this into two patches where:
1) One patch fixing kvm_riscv_vcpu_pmu_snapshot_set_shmem()
2) Second patch fixing kvm_riscv_vcpu_pmu_event_info()
Make sure to add Fixes tag in both patches.
Regards,
Anup
> ---
> arch/riscv/kvm/vcpu_pmu.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/arch/riscv/kvm/vcpu_pmu.c b/arch/riscv/kvm/vcpu_pmu.c
> index e873430e596b..f36b099f447c 100644
> --- a/arch/riscv/kvm/vcpu_pmu.c
> +++ b/arch/riscv/kvm/vcpu_pmu.c
> @@ -435,8 +435,10 @@ int kvm_riscv_vcpu_pmu_snapshot_set_shmem(struct kvm_vcpu *vcpu, unsigned long s
> }
>
> kvpmu->sdata = kzalloc(snapshot_area_size, GFP_ATOMIC);
> - if (!kvpmu->sdata)
> - return -ENOMEM;
> + if (!kvpmu->sdata) {
> + sbiret = SBI_ERR_FAILURE;
> + goto out;
> + }
>
> /* No need to check writable slot explicitly as kvm_vcpu_write_guest does it internally */
> if (kvm_vcpu_write_guest(vcpu, saddr, kvpmu->sdata, snapshot_area_size)) {
> @@ -480,8 +482,10 @@ int kvm_riscv_vcpu_pmu_event_info(struct kvm_vcpu *vcpu, unsigned long saddr_low
> }
>
> einfo = kzalloc(shmem_size, GFP_KERNEL);
> - if (!einfo)
> - return -ENOMEM;
> + if (!einfo) {
> + ret = SBI_ERR_FAILURE;
> + goto out;
> + }
>
> ret = kvm_vcpu_read_guest(vcpu, shmem, einfo, shmem_size);
> if (ret) {
> --
> 2.43.0
>
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http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [RFC PATCH] riscv: kvm: return SBI_ERR_FAILURE for PMU shmem OOM
2026-05-14 13:43 ` Anup Patel
@ 2026-05-14 17:40 ` Osama Abdelkader
0 siblings, 0 replies; 4+ messages in thread
From: Osama Abdelkader @ 2026-05-14 17:40 UTC (permalink / raw)
To: Anup Patel
Cc: Atish Patra, Paul Walmsley, Palmer Dabbelt, Albert Ou,
Alexandre Ghiti, kvm, kvm-riscv, linux-riscv, linux-kernel
On Thu, May 14, 2026 at 07:13:04PM +0530, Anup Patel wrote:
> On Thu, Apr 16, 2026 at 3:40 AM Osama Abdelkader
> <osama.abdelkader@gmail.com> wrote:
> >
> > kvm_riscv_vcpu_pmu_snapshot_set_shmem() and kvm_riscv_vcpu_pmu_event_info()
> > returned -ENOMEM from the SBI extension handler, which caused
> > kvm_riscv_vcpu_sbi_ecall() to abort KVM_RUN and surface the error to
> > userspace instead of completing the ECALL with a negative SBI error in a0.
> > Use SBI_ERR_FAILURE and the normal retdata path, matching other PMU
> > handlers and kvm_sbi_ext_pmu_handler comment.
> >
> > Signed-off-by: Osama Abdelkader <osama.abdelkader@gmail.com>
>
> Split this into two patches where:
>
> 1) One patch fixing kvm_riscv_vcpu_pmu_snapshot_set_shmem()
> 2) Second patch fixing kvm_riscv_vcpu_pmu_event_info()
>
> Make sure to add Fixes tag in both patches.
>
> Regards,
> Anup
Thanks Anup for the review, I just did that.
Regards,
Osama
>
> > ---
> > arch/riscv/kvm/vcpu_pmu.c | 12 ++++++++----
> > 1 file changed, 8 insertions(+), 4 deletions(-)
> >
> > diff --git a/arch/riscv/kvm/vcpu_pmu.c b/arch/riscv/kvm/vcpu_pmu.c
> > index e873430e596b..f36b099f447c 100644
> > --- a/arch/riscv/kvm/vcpu_pmu.c
> > +++ b/arch/riscv/kvm/vcpu_pmu.c
> > @@ -435,8 +435,10 @@ int kvm_riscv_vcpu_pmu_snapshot_set_shmem(struct kvm_vcpu *vcpu, unsigned long s
> > }
> >
> > kvpmu->sdata = kzalloc(snapshot_area_size, GFP_ATOMIC);
> > - if (!kvpmu->sdata)
> > - return -ENOMEM;
> > + if (!kvpmu->sdata) {
> > + sbiret = SBI_ERR_FAILURE;
> > + goto out;
> > + }
> >
> > /* No need to check writable slot explicitly as kvm_vcpu_write_guest does it internally */
> > if (kvm_vcpu_write_guest(vcpu, saddr, kvpmu->sdata, snapshot_area_size)) {
> > @@ -480,8 +482,10 @@ int kvm_riscv_vcpu_pmu_event_info(struct kvm_vcpu *vcpu, unsigned long saddr_low
> > }
> >
> > einfo = kzalloc(shmem_size, GFP_KERNEL);
> > - if (!einfo)
> > - return -ENOMEM;
> > + if (!einfo) {
> > + ret = SBI_ERR_FAILURE;
> > + goto out;
> > + }
> >
> > ret = kvm_vcpu_read_guest(vcpu, shmem, einfo, shmem_size);
> > if (ret) {
> > --
> > 2.43.0
> >
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linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 4+ messages in thread
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2026-04-15 22:09 [RFC PATCH] riscv: kvm: return SBI_ERR_FAILURE for PMU shmem OOM Osama Abdelkader
2026-05-06 13:21 ` Osama Abdelkader
2026-05-14 13:43 ` Anup Patel
2026-05-14 17:40 ` Osama Abdelkader
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