Re: [PATCH v2 2/2] virtio: Add shared memory capability

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Aug 03, 2022 at 05:21:35PM +0200, Antonio Caggiano wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> 
> Define a new capability type 'VIRTIO_PCI_CAP_SHARED_MEMORY_CFG'
> and the data structure 'virtio_pci_shm_cap' to go with it.
> They allow defining shared memory regions with sizes and offsets
> of 2^32 and more.
> Multiple instances of the capability are allowed and distinguished
> by a device-specific 'id'.
> 
> v2: Remove virtio_pci_shm_cap as virtio_pci_cap64 is used instead.
> v3: No need for mask32 as cpu_to_le32 truncates the value.
> 
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> Signed-off-by: Antonio Caggiano <antonio.caggiano@collabora.com>


looks like the patches are in the reverse order, 1/2 won't
build without 2/2
> ---
>  hw/virtio/virtio-pci.c         | 18 ++++++++++++++++++
>  include/hw/virtio/virtio-pci.h |  4 ++++
>  2 files changed, 22 insertions(+)
> 
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index 45327f0b31..50bd230122 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -1164,6 +1164,24 @@ static int virtio_pci_add_mem_cap(VirtIOPCIProxy *proxy,
>      return offset;
>  }
>  
> +int virtio_pci_add_shm_cap(VirtIOPCIProxy *proxy,
> +                           uint8_t bar, uint64_t offset, uint64_t length,
> +                           uint8_t id)
> +{
> +    struct virtio_pci_cap64 cap = {
> +        .cap.cap_len = sizeof cap,
> +        .cap.cfg_type = VIRTIO_PCI_CAP_SHARED_MEMORY_CFG,
> +    };
> +
> +    cap.cap.bar = bar;
> +    cap.cap.length = cpu_to_le32(length);
> +    cap.length_hi = cpu_to_le32(length >> 32);
> +    cap.cap.offset = cpu_to_le32(offset);
> +    cap.offset_hi = cpu_to_le32(offset >> 32);
> +    cap.cap.id = id;
> +    return virtio_pci_add_mem_cap(proxy, &cap.cap);
> +}
> +
>  static uint64_t virtio_pci_common_read(void *opaque, hwaddr addr,
>                                         unsigned size)
>  {
> diff --git a/include/hw/virtio/virtio-pci.h b/include/hw/virtio/virtio-pci.h
> index 2446dcd9ae..5e5c4a4c6d 100644
> --- a/include/hw/virtio/virtio-pci.h
> +++ b/include/hw/virtio/virtio-pci.h
> @@ -252,4 +252,8 @@ void virtio_pci_types_register(const VirtioPCIDeviceTypeInfo *t);
>   */
>  unsigned virtio_pci_optimal_num_queues(unsigned fixed_queues);
>  
> +int virtio_pci_add_shm_cap(VirtIOPCIProxy *proxy,
> +                           uint8_t bar, uint64_t offset, uint64_t length,
> +                           uint8_t id);
> +
>  #endif
> -- 
> 2.34.1