From: "Dr. David Alan Gilbert" <dgilb...@redhat.com>
Compare the memory section list we've just built with the old one
and produce an upper/lower bound of addresses changed.
Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
---
hw/virtio/trace-events | 3 ++
hw/virtio/vhost.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 77 insertions(+)
diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
index 92fadec192..ba85a1855b 100644
--- a/hw/virtio/trace-events
+++ b/hw/virtio/trace-events
@@ -2,6 +2,9 @@
# hw/virtio/vhost.c
vhost_section(const char *name, int r) "%s:%d"
+vhost_update_compare_list_loopn(int newi, int oldi, uint64_t gpa, uint64_t
size) "%d/%d: (new) 0x%"PRIx64"+0x%"PRIx64
+vhost_update_compare_list_loopo(int newi, int oldi, uint64_t gpa, uint64_t
size) "%d/%d: (old) 0x%"PRIx64"+0x%"PRIx64
+vhost_update_mem_comparison(bool update, uint64_t start, uint64_t end)
"update: %d 0x%"PRIx64" - 0x%"PRIx64
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
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 7e3c6ae032..ae3d57df1d 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -699,10 +699,79 @@ static int vhost_update_mem_cb(MemoryRegionSection *mrs,
void *opaque)
return 0;
}
+static bool vhost_update_compare_list(struct vhost_dev *dev,
+ struct vhost_update_mem_tmp *vtmp,
+ hwaddr *change_start, hwaddr *change_end)
+{
+ uint32_t oldi, newi;
+ *change_start = 0;
+ *change_end = 0;
+
+ for (newi = 0, oldi = 0; newi < vtmp->nregions; newi++) {
+ struct vhost_memory_region *newr = &vtmp->regions[newi];
+ hwaddr newr_last = range_get_last(newr->guest_phys_addr,
+ newr->memory_size);
+ trace_vhost_update_compare_list_loopn(newi, oldi,
+ newr->guest_phys_addr,
+ newr->memory_size);
+ bool whole_change = true;
+ while (oldi < dev->mem->nregions) {
+ struct vhost_memory_region *oldr = &dev->mem->regions[oldi];
+ hwaddr oldr_last = range_get_last(oldr->guest_phys_addr,
+ oldr->memory_size);
+ trace_vhost_update_compare_list_loopo(newi, oldi,
+ oldr->guest_phys_addr,
+ oldr->memory_size);
+ if (newr->guest_phys_addr == oldr->guest_phys_addr &&
+ newr->memory_size == oldr->memory_size) {
+ /* Match in GPA and size, but it could be different
+ * in host address or flags
+ */
+ whole_change = newr->userspace_addr != oldr->userspace_addr ||
+ newr->flags_padding != oldr->flags_padding;
+ oldi++;
+ break; /* inner old loop */
+ }
+ /* There's a difference - need to figure out what */
+ if (oldr_last < newr->guest_phys_addr) {
+ /* There used to be a region before us that's gone */
+ *change_start = MIN(*change_start, oldr->guest_phys_addr);
+ *change_end = MAX(*change_end, oldr_last);
+ oldi++;
+ continue; /* inner old loop */
+ }
+ if (oldr->guest_phys_addr > newr_last) {
+ /* We've passed all the old mappings that could have overlapped
+ * this one
+ */
+ break; /* Inner old loop */
+ }
+ /* Overlap case */
+ *change_start = MIN(*change_start,
+ MIN(oldr->guest_phys_addr,
+ newr->guest_phys_addr));
+ *change_end = MAX(*change_end,
+ MAX(oldr_last, newr_last));
+ whole_change = false;
+ /* There might be more old mappings that overlap */
+ oldi++;
+ }
+ if (whole_change) {
+ /* No old region to compare against, this must be a change */
+ *change_start = MIN(*change_start, newr->guest_phys_addr);
+ *change_end = MAX(*change_end, newr_last);
+ }
+ }
+
+ return *change_start || *change_end;
+}
+
static int vhost_update_mem(struct vhost_dev *dev)
{
int res;
struct vhost_update_mem_tmp vtmp;
+ hwaddr change_start, change_end;
+ bool need_update;
vtmp.regions = 0;
vtmp.nregions = 0;
vtmp.dev = dev;
@@ -713,6 +782,11 @@ static int vhost_update_mem(struct vhost_dev *dev)
goto out;
}
+ need_update = vhost_update_compare_list(dev, &vtmp,
+ &change_start, &change_end);
+ trace_vhost_update_mem_comparison(need_update,
+ (uint64_t)change_start,
+ (uint64_t)change_end);
/* TODO */
out:
g_free(vtmp.regions);
--
2.14.3
