On Mon, 18 Dec 2017 20:13:38 +0000
"Dr. David Alan Gilbert (git)" <dgilb...@redhat.com> wrote:
> From: "Dr. David Alan Gilbert" <dgilb...@redhat.com>
>
> Compare the sections list that's just been generated, and if it's
> different from the old one regenerate the region list.
>
> Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> ---
> hw/virtio/trace-events | 1 +
> hw/virtio/vhost.c | 34 ++++++++++++++++++++++++++++++----
> 2 files changed, 31 insertions(+), 4 deletions(-)
>
> diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
> index 0e63c8739d..742ff0f90b 100644
> --- a/hw/virtio/trace-events
> +++ b/hw/virtio/trace-events
> @@ -1,6 +1,7 @@
> # See docs/devel/tracing.txt for syntax documentation.
>
> # hw/virtio/vhost.c
> +vhost_commit(bool started, bool changed) "Started: %d Changed: %d"
> vhost_region_add_section(const char *name, uint64_t gpa, uint64_t size,
> uint64_t host) "%s: 0x%"PRIx64"+0x%"PRIx64" @ 0x%"PRIx64
> vhost_region_add_section_abut(const char *name, uint64_t new_size) "%s:
> 0x%"PRIx64
> vhost_section(const char *name, int r) "%s:%d"
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index 57d15acd2b..4394ac0275 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -643,21 +643,47 @@ static void vhost_commit(MemoryListener *listener)
> MemoryRegionSection *old_sections;
> int n_old_sections;
> uint64_t log_size;
> + size_t regions_size;
> int r;
> int i;
> + bool changed = false;
>
> old_sections = dev->mem_sections;
> n_old_sections = dev->n_mem_sections;
> dev->mem_sections = dev->tmp_sections;
> dev->n_mem_sections = dev->n_tmp_sections;
>
> - if (!dev->memory_changed) {
> - goto out;
> + if (dev->n_mem_sections != n_old_sections) {
> + changed = true;
> + } else {
> + /* Same size, lets check the contents */
> + changed = memcmp(dev->mem_sections, old_sections,
> + n_old_sections * sizeof(old_sections[0])) != 0;
> }
> - if (!dev->started) {
> +
> + trace_vhost_commit(dev->started, changed);
> + if (!changed) {
> goto out;
> }
> - if (dev->mem_changed_start_addr > dev->mem_changed_end_addr) {
> +
> + /* Rebuild the regions list from the new sections list */
> + regions_size = offsetof(struct vhost_memory, regions) +
> + dev->n_mem_sections * sizeof dev->mem->regions[0];
> + dev->mem = g_realloc(dev->mem, regions_size);
> + dev->mem->nregions = dev->n_mem_sections;
> + for (i = 0; i < dev->n_mem_sections; i++) {
> + struct vhost_memory_region *cur_vmr = dev->mem->regions + i;
> + struct MemoryRegionSection *mrs = dev->mem_sections + i;
> +
> + cur_vmr->guest_phys_addr = mrs->offset_within_address_space;
> + cur_vmr->memory_size = int128_get64(mrs->size);
> + cur_vmr->userspace_addr =
> + (uintptr_t)memory_region_get_ram_ptr(mrs->mr) +
> + mrs->offset_within_region;
> + cur_vmr->flags_padding = 0;
> + }
is there a reason to keep dev->mem around after vhost_commit executed?
I'd suggest to use temporary local variable and free it on exit from function.
> + if (!dev->started) {
also why memmap is generated this early and not right before first use?
here we might generate memap but not actually use it.
> goto out;
> }
>
