Re: [PATCH] s390x/pv: Retry ioctls on -EINTR

[David Hildenbrand]

On 27.03.20 10:43, Christian Borntraeger wrote:
> PV_ENABLE (and maybe others) might return -EINTR when a signal is
> pending. Let us retry the ioctl in that case.
> 
> Fixes: 4d226deafc44 ("s390x: protvirt: Support unpack facility")
> Reported-by: Marc Hartmayer <address@hidden>
> Tested-by: Marc Hartmayer <address@hidden>
> Signed-off-by: Christian Borntraeger <address@hidden>
> ---
>  hw/s390x/pv.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/s390x/pv.c b/hw/s390x/pv.c
> index 8cf5cd2c9b..2758b02c96 100644
> --- a/hw/s390x/pv.c
> +++ b/hw/s390x/pv.c
> @@ -23,7 +23,11 @@ static int __s390_pv_cmd(uint32_t cmd, const char 
> *cmdname, void *data)
>          .cmd = cmd,
>          .data = (uint64_t)data,
>      };
> -    int rc = kvm_vm_ioctl(kvm_state, KVM_S390_PV_COMMAND, &pv_cmd);
> +    int rc;
> +
> +    do {
> +        rc  = kvm_vm_ioctl(kvm_state, KVM_S390_PV_COMMAND, &pv_cmd);
> +    } while (rc == -EINTR);
>  
>      if (rc) {
>          error_report("KVM PV command %d (%s) failed: header rc %x rrc %x "
> 

I fail to see where that is triggered in the kernel.

t480s: ~/git/linux/arch/s390/kvm (HEAD losgelöst bei next/master) $ git
grep "EINTR"
kvm-s390.c:     if (exit_reason == -EINTR) {
kvm-s390.c:             return -EINTR;
kvm-s390.c:             rc = -EINTR;
vsie.c: if (rc == -EINTR) {


Can you help me out? Is that documented?

-- 
Thanks,

David / dhildenb