Re: [PATCH v9 11/15] s390x: protvirt: Disable address checks for PV guest IO emulation

[Janosch Frank]

On 3/17/20 12:36 PM, Cornelia Huck wrote:
> On Wed, 11 Mar 2020 09:21:47 -0400
> Janosch Frank <address@hidden> wrote:
> 
>> IO instruction data is routed through SIDAD for protected guests, so
>> adresses do not need to be checked, as this is kernel memory.
>>
>> Signed-off-by: Janosch Frank <address@hidden>
>> Reviewed-by: Thomas Huth <address@hidden>
>> Reviewed-by: David Hildenbrand <address@hidden>
>> ---
>>  target/s390x/ioinst.c | 33 ++++++++++++++++++++++++++-------
>>  1 file changed, 26 insertions(+), 7 deletions(-)
>>
>> diff --git a/target/s390x/ioinst.c b/target/s390x/ioinst.c
>> index c437a1d8c6afed80..481d789de9e09a04 100644
>> --- a/target/s390x/ioinst.c
>> +++ b/target/s390x/ioinst.c
>> @@ -16,6 +16,23 @@
>>  #include "hw/s390x/ioinst.h"
>>  #include "trace.h"
>>  #include "hw/s390x/s390-pci-bus.h"
>> +#include "hw/s390x/pv.h"
>> +
> 
> Maybe add
> 
> /* all I/O instructions but chsc use the s format *>
> to emphasize that this is not a generic decoder?

Ack

> 
>> +static uint64_t get_address_from_regs(CPUS390XState *env, uint32_t ipb,
>> +                                      uint8_t *ar)
>> +{
>> +    /*
>> +     * Addresses for protected guests are all offsets into the
>> +     * satellite block which holds the IO control structures. Those
>> +     * control structures are always aligned and accessible, so we can
>> +     * return 0 here which will pass the following address checks.
>> +     */
>> +    if (s390_is_pv()) {
>> +        *ar = 0;
>> +        return 0;
>> +    }
>> +    return decode_basedisp_s(env, ipb, ar);
>> +}
>>  
>>  int ioinst_disassemble_sch_ident(uint32_t value, int *m, int *cssid, int 
>> *ssid,
>>                                   int *schid)
> 
> With the other comment updates,
> 
> Reviewed-by: Cornelia Huck <address@hidden>
> 
> 
Thanks