diff mbox series

KVM: PPC: Don't return -ENOTSUPP to userspace in ioctls

Message ID 159982162511.459323.13495475646618845164.stgit@bahia.lan
State New
Headers show
Series KVM: PPC: Don't return -ENOTSUPP to userspace in ioctls | expand

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Context Check Description
snowpatch_ozlabs/needsstable success Patch has no Fixes tags
snowpatch_ozlabs/checkpatch warning total: 0 errors, 1 warnings, 0 checks, 36 lines checked
snowpatch_ozlabs/build-pmac32 warning Upstream build failed, couldn't test patch
snowpatch_ozlabs/build-ppc64e warning Upstream build failed, couldn't test patch
snowpatch_ozlabs/build-ppc64be warning Upstream build failed, couldn't test patch
snowpatch_ozlabs/build-ppc64le warning Upstream build failed, couldn't test patch
snowpatch_ozlabs/apply_patch success Successfully applied on branch powerpc/merge (4b552a4cbf286ff9dcdab19153f3c1c7d1680fab)

Commit Message

Greg Kurz Sept. 11, 2020, 10:53 a.m. UTC
ENOTSUPP is a linux only thingy, the value of which is unknown to
userspace, not to be confused with ENOTSUP which linux maps to
EOPNOTSUPP, as permitted by POSIX [1]:

[EOPNOTSUPP]
Operation not supported on socket. The type of socket (address family
or protocol) does not support the requested operation. A conforming
implementation may assign the same values for [EOPNOTSUPP] and [ENOTSUP].

Return -EOPNOTSUPP instead of -ENOTSUPP for the following ioctls:
- KVM_GET_FPU for Book3s and BookE
- KVM_SET_FPU for Book3s and BookE
- KVM_GET_DIRTY_LOG for BookE

This doesn't affect QEMU which doesn't call the KVM_GET_FPU and
KVM_SET_FPU ioctls on POWER anyway since they are not supported,
and _buggily_ ignores anything but -EPERM for KVM_GET_DIRTY_LOG.

[1] https://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html

Signed-off-by: Greg Kurz <groug@kaod.org>
---
 arch/powerpc/kvm/book3s.c |    4 ++--
 arch/powerpc/kvm/booke.c  |    6 +++---
 2 files changed, 5 insertions(+), 5 deletions(-)

Comments

Thadeu Lima de Souza Cascardo Sept. 11, 2020, 12:08 p.m. UTC | #1
On Fri, Sep 11, 2020 at 12:53:45PM +0200, Greg Kurz wrote:
> ENOTSUPP is a linux only thingy, the value of which is unknown to
> userspace, not to be confused with ENOTSUP which linux maps to
> EOPNOTSUPP, as permitted by POSIX [1]:
> 
> [EOPNOTSUPP]
> Operation not supported on socket. The type of socket (address family
> or protocol) does not support the requested operation. A conforming
> implementation may assign the same values for [EOPNOTSUPP] and [ENOTSUP].
> 
> Return -EOPNOTSUPP instead of -ENOTSUPP for the following ioctls:
> - KVM_GET_FPU for Book3s and BookE
> - KVM_SET_FPU for Book3s and BookE
> - KVM_GET_DIRTY_LOG for BookE
> 
> This doesn't affect QEMU which doesn't call the KVM_GET_FPU and
> KVM_SET_FPU ioctls on POWER anyway since they are not supported,
> and _buggily_ ignores anything but -EPERM for KVM_GET_DIRTY_LOG.
> 
> [1] https://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html
> 
> Signed-off-by: Greg Kurz <groug@kaod.org>

Agreed. ENOTSUPP should never be returned to userspace.

Acked-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

> ---
>  arch/powerpc/kvm/book3s.c |    4 ++--
>  arch/powerpc/kvm/booke.c  |    6 +++---
>  2 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
> index 1fce9777af1c..44bf567b6589 100644
> --- a/arch/powerpc/kvm/book3s.c
> +++ b/arch/powerpc/kvm/book3s.c
> @@ -558,12 +558,12 @@ int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
>  
>  int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
>  {
> -	return -ENOTSUPP;
> +	return -EOPNOTSUPP;
>  }
>  
>  int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
>  {
> -	return -ENOTSUPP;
> +	return -EOPNOTSUPP;
>  }
>  
>  int kvmppc_get_one_reg(struct kvm_vcpu *vcpu, u64 id,
> diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
> index 3e1c9f08e302..b1abcb816439 100644
> --- a/arch/powerpc/kvm/booke.c
> +++ b/arch/powerpc/kvm/booke.c
> @@ -1747,12 +1747,12 @@ int kvmppc_set_one_reg(struct kvm_vcpu *vcpu, u64 id,
>  
>  int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
>  {
> -	return -ENOTSUPP;
> +	return -EOPNOTSUPP;
>  }
>  
>  int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
>  {
> -	return -ENOTSUPP;
> +	return -EOPNOTSUPP;
>  }
>  
>  int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
> @@ -1773,7 +1773,7 @@ void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot)
>  
>  int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
>  {
> -	return -ENOTSUPP;
> +	return -EOPNOTSUPP;
>  }
>  
>  void kvmppc_core_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot)
> 
>
Paul Mackerras Sept. 23, 2020, 12:10 a.m. UTC | #2
On Fri, Sep 11, 2020 at 12:53:45PM +0200, Greg Kurz wrote:
> ENOTSUPP is a linux only thingy, the value of which is unknown to
> userspace, not to be confused with ENOTSUP which linux maps to
> EOPNOTSUPP, as permitted by POSIX [1]:
> 
> [EOPNOTSUPP]
> Operation not supported on socket. The type of socket (address family
> or protocol) does not support the requested operation. A conforming
> implementation may assign the same values for [EOPNOTSUPP] and [ENOTSUP].
> 
> Return -EOPNOTSUPP instead of -ENOTSUPP for the following ioctls:
> - KVM_GET_FPU for Book3s and BookE
> - KVM_SET_FPU for Book3s and BookE
> - KVM_GET_DIRTY_LOG for BookE
> 
> This doesn't affect QEMU which doesn't call the KVM_GET_FPU and
> KVM_SET_FPU ioctls on POWER anyway since they are not supported,
> and _buggily_ ignores anything but -EPERM for KVM_GET_DIRTY_LOG.
> 
> [1] https://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html
> 
> Signed-off-by: Greg Kurz <groug@kaod.org>

Thanks, applied.

Paul.
diff mbox series

Patch

diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 1fce9777af1c..44bf567b6589 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -558,12 +558,12 @@  int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 
 int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 
 int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 
 int kvmppc_get_one_reg(struct kvm_vcpu *vcpu, u64 id,
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 3e1c9f08e302..b1abcb816439 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -1747,12 +1747,12 @@  int kvmppc_set_one_reg(struct kvm_vcpu *vcpu, u64 id,
 
 int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 
 int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 
 int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
@@ -1773,7 +1773,7 @@  void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot)
 
 int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 
 void kvmppc_core_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot)