Re: [PATCH v5 2/3] hw/vfio: drop guest writes to ro regions

[Philippe Mathieu-Daudé]

On 4/30/20 7:23 AM, Yan Zhao wrote:
> for vfio regions that are without write permission,
> drop guest writes to those regions.
>
> Cc: Philippe Mathieu-Daudé <address@hidden>
> Reviewed-by: Philippe Mathieu-Daudé <address@hidden>

The full domain name is redhat.com.

> Signed-off-by: Yan Zhao <address@hidden>
> Signed-off-by: Xin Zeng <address@hidden>
> ---
>   hw/vfio/common.c | 13 +++++++++++--
>   1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 0b3593b3c0..2a4fedfeaa 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -38,6 +38,7 @@
>   #include "sysemu/reset.h"
>   #include "trace.h"
>   #include "qapi/error.h"
> +#include "qemu/log.h"
>   
>   VFIOGroupList vfio_group_list =
>       QLIST_HEAD_INITIALIZER(vfio_group_list);
> @@ -190,6 +191,16 @@ void vfio_region_write(void *opaque, hwaddr addr,
>           uint64_t qword;
>       } buf;
>   
> +    trace_vfio_region_write(vbasedev->name, region->nr, addr, data, size);
> +    if (!(region->flags & VFIO_REGION_INFO_FLAG_WRITE)) {
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                      "Invalid write to read only vfio region (%s:region%d"
> +                      "+0x%"HWADDR_PRIx" size %d)\n", vbasedev->name,
> +                      region->nr, addr, size);
> +
> +        return;
> +    }
> +
>       switch (size) {
>       case 1:
>           buf.byte = data;
> @@ -215,8 +226,6 @@ void vfio_region_write(void *opaque, hwaddr addr,
>                        addr, data, size);
>       }
>   
> -    trace_vfio_region_write(vbasedev->name, region->nr, addr, data, size);
> -
>       /*
>        * A read or write to a BAR always signals an INTx EOI.  This will
>        * do nothing if not pending (including not in INTx mode).  We assume