On Wed, 29 Nov 2017 18:50:23 +0000
"Dr. David Alan Gilbert (git)" <dgilb...@redhat.com> wrote:
> From: "Dr. David Alan Gilbert" <dgilb...@redhat.com>
>
> Add the meat of update_mem_cb; this is called for each region,
> to add a region to our temporary list.
> Our temporary list is in order we look to see if this
> region can be merged with the current head of list.
>
> Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> ---
> hw/virtio/trace-events | 2 ++
> hw/virtio/vhost.c | 55
> +++++++++++++++++++++++++++++++++++++++++++++++++-
> 2 files changed, 56 insertions(+), 1 deletion(-)
>
> diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
> index 4a493bcd46..92fadec192 100644
> --- a/hw/virtio/trace-events
> +++ b/hw/virtio/trace-events
> @@ -2,6 +2,8 @@
>
> # hw/virtio/vhost.c
> vhost_section(const char *name, int r) "%s:%d"
> +vhost_update_mem_cb(const char *name, uint64_t gpa, uint64_t size, uint64_t
> host) "%s: 0x%"PRIx64"+0x%"PRIx64" @ 0x%"PRIx64
> +vhost_update_mem_cb_abut(const char *name, uint64_t new_size) "%s: 0x%"PRIx64
>
> # hw/virtio/virtio.c
> virtqueue_alloc_element(void *elem, size_t sz, unsigned in_num, unsigned
> out_num) "elem %p size %zd in_num %u out_num %u"
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index c959a59fb3..7e3c6ae032 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -638,11 +638,64 @@ struct vhost_update_mem_tmp {
> /* Called for each MRS from vhost_update_mem */
> static int vhost_update_mem_cb(MemoryRegionSection *mrs, void *opaque)
> {
> + struct vhost_update_mem_tmp *vtmp = opaque;
> + struct vhost_memory_region *cur_vmr;
> + bool need_add = true;
> + uint64_t mrs_size;
> + uint64_t mrs_gpa;
> + uintptr_t mrs_host;
> +
> if (!vhost_section(mrs)) {
> return 0;
> }
> + mrs_size = int128_get64(mrs->size);
> + mrs_gpa = mrs->offset_within_address_space;
> + mrs_host = (uintptr_t)memory_region_get_ram_ptr(mrs->mr) +
> + mrs->offset_within_region;
> +
> + trace_vhost_update_mem_cb(mrs->mr->name, mrs_gpa, mrs_size,
> + (uint64_t)mrs_host);
> +
> + if (vtmp->nregions) {
What forces you to maintain helper vhost_memory_region array
instead of MemoryRegionSection array?
> + /* Since we already have at least one region, lets see if
> + * this extends it; since we're scanning in order, we only
> + * have to look at the last one, and the FlatView that calls
> + * us shouldn't have overlaps.
> + */
> + struct vhost_memory_region *prev_vmr = vtmp->regions +
> + (vtmp->nregions - 1);
> + uint64_t prev_gpa_start = prev_vmr->guest_phys_addr;
> + uint64_t prev_gpa_end = range_get_last(prev_gpa_start,
> + prev_vmr->memory_size);
> + uint64_t prev_host_start = prev_vmr->userspace_addr;
> + uint64_t prev_host_end = range_get_last(prev_host_start,
> + prev_vmr->memory_size);
> +
> + if (prev_gpa_end + 1 == mrs_gpa &&
> + prev_host_end + 1 == mrs_host &&
> + (!vtmp->dev->vhost_ops->vhost_backend_can_merge ||
> + vtmp->dev->vhost_ops->vhost_backend_can_merge(vtmp->dev,
> + mrs_host, mrs_size,
> + prev_host_start, prev_vmr->memory_size))) {
> + /* The two regions abut */
> + need_add = false;
> + mrs_size = mrs_size + prev_vmr->memory_size;
> + prev_vmr->memory_size = mrs_size;
> + trace_vhost_update_mem_cb_abut(mrs->mr->name, mrs_size);
> + }
> + }
> +
> + if (need_add) {
> + vtmp->nregions++;
> + vtmp->regions = g_realloc_n(vtmp->regions, vtmp->nregions,
> + sizeof(vtmp->regions[0]));
> + cur_vmr = &vtmp->regions[vtmp->nregions - 1];
> + cur_vmr->guest_phys_addr = mrs_gpa;
> + cur_vmr->memory_size = mrs_size;
> + cur_vmr->userspace_addr = mrs_host;
> + cur_vmr->flags_padding = 0;
> + }
>
> - /* TODO */
> return 0;
> }
>
