Hi
On Thu, May 21, 2020 at 7:00 AM Raphael Norwitz <raphael.norw...@nutanix.com>
wrote:
> When setting the memory tables, qemu uses a memory region's userspace
> address to look up the region's MemoryRegion struct. Among other things,
> the MemoryRegion contains the region's offset and associated file
> descriptor, all of which need to be sent to the backend.
>
> With VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS, this logic will be
> needed in multiple places, so before feature support is added it
> should be moved to a helper function.
>
> This helper is also used to simplify the vhost_user_can_merge()
> function.
>
> Signed-off-by: Raphael Norwitz <raphael.norw...@nutanix.com>
>
Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com>
---
> hw/virtio/vhost-user.c | 25 +++++++++++++++----------
> 1 file changed, 15 insertions(+), 10 deletions(-)
>
> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> index 2e0552d..442b0d6 100644
> --- a/hw/virtio/vhost-user.c
> +++ b/hw/virtio/vhost-user.c
> @@ -407,6 +407,18 @@ static int vhost_user_set_log_base(struct vhost_dev
> *dev, uint64_t base,
> return 0;
> }
>
> +static MemoryRegion *vhost_user_get_mr_data(uint64_t addr, ram_addr_t
> *offset,
> + int *fd)
> +{
> + MemoryRegion *mr;
> +
> + assert((uintptr_t)addr == addr);
> + mr = memory_region_from_host((void *)(uintptr_t)addr, offset);
> + *fd = memory_region_get_fd(mr);
> +
> + return mr;
> +}
> +
> static void vhost_user_fill_msg_region(VhostUserMemoryRegion *dst,
> struct vhost_memory_region *src)
> {
> @@ -433,10 +445,7 @@ static int vhost_user_fill_set_mem_table_msg(struct
> vhost_user *u,
> for (i = 0; i < dev->mem->nregions; ++i) {
> reg = dev->mem->regions + i;
>
> - assert((uintptr_t)reg->userspace_addr == reg->userspace_addr);
> - mr = memory_region_from_host((void
> *)(uintptr_t)reg->userspace_addr,
> - &offset);
> - fd = memory_region_get_fd(mr);
> + mr = vhost_user_get_mr_data(reg->userspace_addr, &offset, &fd);
> if (fd > 0) {
> if (track_ramblocks) {
> assert(*fd_num < VHOST_MEMORY_MAX_NREGIONS);
> @@ -1551,13 +1560,9 @@ static bool vhost_user_can_merge(struct vhost_dev
> *dev,
> {
> ram_addr_t offset;
> int mfd, rfd;
> - MemoryRegion *mr;
> -
> - mr = memory_region_from_host((void *)(uintptr_t)start1, &offset);
> - mfd = memory_region_get_fd(mr);
>
> - mr = memory_region_from_host((void *)(uintptr_t)start2, &offset);
> - rfd = memory_region_get_fd(mr);
> + (void)vhost_user_get_mr_data(start1, &offset, &mfd);
> + (void)vhost_user_get_mr_data(start2, &offset, &rfd);
>
> return mfd == rfd;
> }
> --
> 1.8.3.1
>
>
--
Marc-André Lureau
