[Qemu-devel] [PATCH v6 16/29] vhost+postcopy: Stash RAMBlock and offset

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <address@hidden>

Stash the RAMBlock and offset for later use looking up
addresses.

Signed-off-by: Dr. David Alan Gilbert <address@hidden>
---
 hw/virtio/trace-events |  1 +
 hw/virtio/vhost-user.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+)

diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
index 05d18ada77..d7e9e1084b 100644
--- a/hw/virtio/trace-events
+++ b/hw/virtio/trace-events
@@ -9,6 +9,7 @@ vhost_section(const char *name, int r) "%s:%d"
 # hw/virtio/vhost-user.c
 vhost_user_postcopy_listen(void) ""
 vhost_user_set_mem_table_postcopy(uint64_t client_addr, uint64_t qhva, int 
reply_i, int region_i) "client:0x%"PRIx64" for hva: 0x%"PRIx64" reply %d region 
%d"
+vhost_user_set_mem_table_withfd(int index, const char *name, uint64_t 
memory_size, uint64_t guest_phys_addr, uint64_t userspace_addr, uint64_t 
offset) "%d:%s: size:0x%"PRIx64" GPA:0x%"PRIx64" QVA/userspace:0x%"PRIx64" RB 
offset: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-user.c b/hw/virtio/vhost-user.c
index 62a667ade0..2112a055c8 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -177,6 +177,15 @@ struct vhost_user {
     NotifierWithReturn postcopy_notifier;
     struct PostCopyFD  postcopy_fd;
     uint64_t           postcopy_client_bases[VHOST_MEMORY_MAX_NREGIONS];
+    /* Length of the region_rb and region_rb_offset arrays */
+    size_t             region_rb_len;
+    /* RAMBlock associated with a given region */
+    RAMBlock         **region_rb;
+    /* The offset from the start of the RAMBlock to the start of the
+     * vhost region.
+     */
+    ram_addr_t        *region_rb_offset;
+
     /* True once we've entered postcopy_listen */
     bool               postcopy_listen;
 };
@@ -380,6 +389,7 @@ static int vhost_user_set_mem_table_postcopy(struct 
vhost_dev *dev,
 {
     struct vhost_user *u = dev->opaque;
     int fds[VHOST_MEMORY_MAX_NREGIONS];
+    int i, fd;
     size_t fd_num;
     bool reply_supported = virtio_has_feature(dev->protocol_features,
                                               VHOST_USER_PROTOCOL_F_REPLY_ACK);
@@ -408,6 +418,40 @@ static int vhost_user_set_mem_table_postcopy(struct 
vhost_dev *dev,
         return -1;
     }
 
+    /* Stash the offsets and RAMBlock for later use during fault lookup */
+    if (u->region_rb_len < dev->mem->nregions) {
+        u->region_rb = g_renew(RAMBlock*, u->region_rb, dev->mem->nregions);
+        u->region_rb_offset = g_renew(ram_addr_t, u->region_rb_offset,
+                                      dev->mem->nregions);
+        memset(&(u->region_rb[u->region_rb_len]), '\0',
+               sizeof(RAMBlock *) * (dev->mem->nregions - u->region_rb_len));
+        memset(&(u->region_rb_offset[u->region_rb_len]), '\0',
+               sizeof(ram_addr_t) * (dev->mem->nregions - u->region_rb_len));
+        u->region_rb_len = dev->mem->nregions;
+    }
+
+    for (i = 0; i < dev->mem->nregions; ++i) {
+        struct vhost_memory_region *reg = dev->mem->regions + i;
+        ram_addr_t offset;
+        MemoryRegion *mr;
+
+        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);
+        if (fd > 0) {
+            trace_vhost_user_set_mem_table_withfd(fd_num, mr->name,
+                                                  reg->memory_size,
+                                                  reg->guest_phys_addr,
+                                                  reg->userspace_addr, offset);
+            u->region_rb_offset[i] = offset;
+            u->region_rb[i] = mr->ram_block;
+        } else {
+            u->region_rb_offset[i] = 0;
+            u->region_rb[i] = NULL;
+        }
+    }
+
     msg.hdr.size = sizeof(msg.payload.memory.nregions);
     msg.hdr.size += sizeof(msg.payload.memory.padding);
     msg.hdr.size += fd_num * sizeof(VhostUserMemoryRegion);
@@ -1145,6 +1189,11 @@ static int vhost_user_cleanup(struct vhost_dev *dev)
         close(u->slave_fd);
         u->slave_fd = -1;
     }
+    g_free(u->region_rb);
+    u->region_rb = NULL;
+    g_free(u->region_rb_offset);
+    u->region_rb_offset = NULL;
+    u->region_rb_len = 0;
     g_free(u);
     dev->opaque = 0;
 
-- 
2.14.3