Re: [PATCH 2/3] s390x/pci: refresh fh before disabling aif

[Matthew Rosato]

On 1/17/24 5:31 AM, Cédric Le Goater wrote:
> Hello Matthew,
> 
> On 1/16/24 23:31, Matthew Rosato wrote:
>> Typically we refresh the host fh during CLP enable, however it's possible
>> that the device goes through multiple reset events before the guest
>> performs another CLP enable.  Let's handle this for now by refreshing the
>> host handle from vfio before disabling aif.
>>
>> Fixes: 03451953c7 ("s390x/pci: reset ISM passthrough devices on shutdown and 
>> system reset")
>> Reported-by: Cédric Le Goater <clg@redhat.com>
>> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
>> ---
>>   hw/s390x/s390-pci-kvm.c | 11 ++++++++++-
>>   1 file changed, 10 insertions(+), 1 deletion(-)
>>
>> diff --git a/hw/s390x/s390-pci-kvm.c b/hw/s390x/s390-pci-kvm.c
>> index f7e10cfa72..9eef4fc3ec 100644
>> --- a/hw/s390x/s390-pci-kvm.c
>> +++ b/hw/s390x/s390-pci-kvm.c
>> @@ -18,6 +18,7 @@
>>   #include "hw/s390x/s390-pci-bus.h"
>>   #include "hw/s390x/s390-pci-kvm.h"
>>   #include "hw/s390x/s390-pci-inst.h"
>> +#include "hw/s390x/s390-pci-vfio.h"
>>   #include "cpu_models.h"
>>     bool s390_pci_kvm_interp_allowed(void)
>> @@ -64,9 +65,17 @@ int s390_pci_kvm_aif_disable(S390PCIBusDevice *pbdev)
>>           return -EINVAL;
>>       }
>>   +    /*
>> +     * The device may have already been reset but we still want to 
>> relinquish
>> +     * the guest ISC, so always be sure to use an up-to-date host fh.
>> +     */
>> +    if (!s390_pci_get_host_fh(pbdev, &args.fh)) {
>> +        return -EPERM;
>> +    }
>> +
>>       rc = kvm_vm_ioctl(kvm_state, KVM_S390_ZPCI_OP, &args);
>>       if (rc == 0) {
>> -        pbev->aif = false;
>> +        pbdev->aif = false;
>>       }
> 
> This belongs to patch 1.
> 
> 

Thanks for pointing that out, will fix.