[PATCH v2] s390x/pv: Retry ioctls on -EINTR

[PATCH v2] s390x/pv: Retry ioctls on -EINTR

[Christian Borntraeger]

PV_ENABLE (and maybe others) might return -EINTR when a signal is
pending. See the Linux kernel patch "s390/gmap: return proper error code
on ksm unsharing" for details. Let us retry the ioctl in that case.

Fixes: 4d226deafc44 ("s390x: protvirt: Support unpack facility")
Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Acked-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Tested-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 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..d3333d6e13 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 "
-- 
2.25.1

Re: [PATCH v2] s390x/pv: Retry ioctls on -EINTR

[Cornelia Huck]

On Fri, 27 Mar 2020 08:46:16 -0400
Christian Borntraeger <borntraeger@de.ibm.com> wrote:

> PV_ENABLE (and maybe others) might return -EINTR when a signal is
> pending. See the Linux kernel patch "s390/gmap: return proper error code
> on ksm unsharing" for details. Let us retry the ioctl in that case.
> 
> Fixes: 4d226deafc44 ("s390x: protvirt: Support unpack facility")

I'll update that when the commit ids are stable.

> Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
> Acked-by: Janosch Frank <frankja@linux.vnet.ibm.com>
> Tested-by: Marc Hartmayer <mhartmay@linux.ibm.com>
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> ---
>  hw/s390x/pv.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)

Thanks, queued to s390-next.