Re: [PATCH] softmmu/memory: Log invalid memory accesses

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 10/5/20 7:57 PM, Michael S. Tsirkin wrote:
> On Mon, Oct 05, 2020 at 05:27:25PM +0200, Philippe Mathieu-Daudé wrote:
>> Log invalid memory accesses with as GUEST_ERROR.
>>
>> This is particularly useful since commit 5d971f9e67 which reverted
>> ("memory: accept mismatching sizes in memory_region_access_valid").
>>
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> 
> Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
> 
> Paolo's tree I assume?

Or qemu-trivial, whichever is less busy :)

> 
>> ---
>>  softmmu/memory.c | 16 ++++++++++++++++
>>  1 file changed, 16 insertions(+)
>>
>> diff --git a/softmmu/memory.c b/softmmu/memory.c
>> index fa280a19f7..403ff3abc9 100644
>> --- a/softmmu/memory.c
>> +++ b/softmmu/memory.c
>> @@ -14,6 +14,7 @@
>>   */
>>  
>>  #include "qemu/osdep.h"
>> +#include "qemu/log.h"
>>  #include "qapi/error.h"
>>  #include "cpu.h"
>>  #include "exec/memory.h"
>> @@ -1353,10 +1354,18 @@ bool memory_region_access_valid(MemoryRegion *mr,
>>  {
>>      if (mr->ops->valid.accepts
>>          && !mr->ops->valid.accepts(mr->opaque, addr, size, is_write, attrs)) {
>> +        qemu_log_mask(LOG_GUEST_ERROR, "Invalid access at addr "
>> +                                       "0x%" HWADDR_PRIX ", size %u, "
>> +                                       "region '%s', reason: rejected\n",
>> +                      addr, size, memory_region_name(mr));
>>          return false;
>>      }
>>  
>>      if (!mr->ops->valid.unaligned && (addr & (size - 1))) {
>> +        qemu_log_mask(LOG_GUEST_ERROR, "Invalid access at addr "
>> +                                       "0x%" HWADDR_PRIX ", size %u, "
>> +                                       "region '%s', reason: unaligned\n",
>> +                      addr, size, memory_region_name(mr));
>>          return false;
>>      }
>>  
>> @@ -1367,6 +1376,13 @@ bool memory_region_access_valid(MemoryRegion *mr,
>>  
>>      if (size > mr->ops->valid.max_access_size
>>          || size < mr->ops->valid.min_access_size) {
>> +        qemu_log_mask(LOG_GUEST_ERROR, "Invalid access at addr "
>> +                                       "0x%" HWADDR_PRIX ", size %u, "
>> +                                       "region '%s', reason: invalid size "
>> +                                       "(min:%u max:%u)\n",
>> +                      addr, size, memory_region_name(mr),
>> +                      mr->ops->valid.min_access_size,
>> +                      mr->ops->valid.max_access_size);
>>          return false;
>>      }
>>      return true;
>> -- 
>> 2.26.2
>