On Wed, Oct 14, 2026 at 09:10:41PM +0000, Naman Gulati wrote:
> diff --git a/hw/vfio-user/protocol.h b/hw/vfio-user/protocol.h
> index c478d1353f..b823689254 100644
> --- a/hw/vfio-user/protocol.h
> +++ b/hw/vfio-user/protocol.h
> @@ -15,6 +15,8 @@
> * SPDX-License-Identifier: GPL-2.0-or-later
> */
>
> +#define VFIO_USER_MAX_REGIONS 100
> +
> typedef struct {
> uint16_t id;
> uint16_t command;
> @@ -69,12 +71,13 @@ typedef struct {
> #define VFIO_USER_CAP "capabilities"
>
> /* "capabilities" members */
> -#define VFIO_USER_CAP_MAX_FDS "max_msg_fds"
> -#define VFIO_USER_CAP_MAX_XFER "max_data_xfer_size"
> -#define VFIO_USER_CAP_PGSIZES "pgsizes"
> -#define VFIO_USER_CAP_MAP_MAX "max_dma_maps"
> -#define VFIO_USER_CAP_MIGR "migration"
> -#define VFIO_USER_CAP_MULTI "write_multiple"
> +#define VFIO_USER_CAP_MAX_FDS "max_msg_fds"
> +#define VFIO_USER_CAP_MAX_XFER "max_data_xfer_size"
> +#define VFIO_USER_CAP_PGSIZES "pgsizes"
> +#define VFIO_USER_CAP_MAP_MAX "max_dma_maps"
> +#define VFIO_USER_CAP_MIGR "migration"
> +#define VFIO_USER_CAP_MULTI "write_multiple"
> +#define VFIO_USER_CAP_SPARSE_MMAP_FDS "sparse_mmap_fds"
>
> /* "migration" members */
> #define VFIO_USER_CAP_PGSIZE "pgsize"
> @@ -166,6 +169,26 @@ typedef struct {
> uint64_t offset;
> } VFIOUserRegionInfo;
>
> +/*
> + * VFIO_REGION_INFO_CAP_SPARSE_MMAP_FDS
> + */
> +#define VFIO_REGION_INFO_CAP_SPARSE_MMAP_FDS 0x8001
I think a brief note on the "0x8000..." space WRT kernel vfio is worthwhile
here.
Otherwise seems good modulo the other comments.
Please do send out your libvfio-user PR for review as well.
thanks
john
