Re: [PATCH] msix: allow qword MSI-X table accesses

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

On 5/14/20 5:16 PM, Michael S. Tsirkin wrote:
> PCI spec says:
> 
> For all accesses to MSI-X Table and MSI-X PBA fields, software must use
> aligned full DWORD or aligned full QWORD transactions; otherwise, the
> result is undefined.
> 
> However, since MSI-X was converted to use memory API, QEMU
> started blocking qword transactions, only allowing DWORD
> ones. Guests do not seem to use QWORD accesses, but let's
> be spec compliant.
> 
> Fixes: 95524ae8dc8f ("msix: convert to memory API")

9 years =)

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>   hw/pci/msix.c | 6 ++++++
>   1 file changed, 6 insertions(+)
> 
> diff --git a/hw/pci/msix.c b/hw/pci/msix.c
> index 29187898f2..e6a5559038 100644
> --- a/hw/pci/msix.c
> +++ b/hw/pci/msix.c
> @@ -199,6 +199,9 @@ static const MemoryRegionOps msix_table_mmio_ops = {
>       .endianness = DEVICE_LITTLE_ENDIAN,
>       .valid = {
>           .min_access_size = 4,
> +        .max_access_size = 8,
> +    },
> +    .impl = {
>           .max_access_size = 4,
>       },
>   };
> @@ -227,6 +230,9 @@ static const MemoryRegionOps msix_pba_mmio_ops = {
>       .endianness = DEVICE_LITTLE_ENDIAN,
>       .valid = {
>           .min_access_size = 4,
> +        .max_access_size = 8,
> +    },
> +    .impl = {
>           .max_access_size = 4,
>       },
>   };
>