Re: [RFC 3/8] s390x/pci: fix pcistb length

[Matthew Rosato <mjrosato@linux.ibm.com>]

On 12/10/20 5:30 AM, Cornelia Huck wrote:
> On Wed,  9 Dec 2020 15:34:21 -0500
> Matthew Rosato <mjrosato@linux.ibm.com> wrote:
> 
>> In pcistb_service_call, we are grabbing 8 bits from a guest register to
>> indicate the length of the store operation -- but per the architecture
>> the length is actually defined by 13 bits of the guest register.
>>
>> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
>> Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
>> ---
>>   hw/s390x/s390-pci-inst.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/hw/s390x/s390-pci-inst.c b/hw/s390x/s390-pci-inst.c
>> index 70bfd91..db86f12 100644
>> --- a/hw/s390x/s390-pci-inst.c
>> +++ b/hw/s390x/s390-pci-inst.c
>> @@ -750,7 +750,7 @@ int pcistb_service_call(S390CPU *cpu, uint8_t r1, uint8_t r3, uint64_t gaddr,
>>       int i;
>>       uint32_t fh;
>>       uint8_t pcias;
>> -    uint8_t len;
>> +    uint16_t len;
>>       uint8_t buffer[128];
>>   
>>       if (env->psw.mask & PSW_MASK_PSTATE) {
>> @@ -760,7 +760,7 @@ int pcistb_service_call(S390CPU *cpu, uint8_t r1, uint8_t r3, uint64_t gaddr,
>>   
>>       fh = env->regs[r1] >> 32;
>>       pcias = (env->regs[r1] >> 16) & 0xf;
>> -    len = env->regs[r1] & 0xff;
>> +    len = env->regs[r1] & 0x1fff;
>>       offset = env->regs[r3];
>>   
>>       if (!(fh & FH_MASK_ENABLE)) {
> 
> Is that a general problem that we just did not notice before?
> 
> If yes, this probably deserves a Fixes: tag and can be queued
> independently of the rest of the series.
> 

Good point.  I can split this out, and same for "s390x/pci: Fix 
memory_region_access_valid call"