During migration devices continue writing to the guest's memory.
These writes have to be reported to QEMU. The change implements
minimal support in vhost-user-bridge required for successful
migration of a guest with virtio-net device.
Signed-off-by: Victor Kaplansky <vict...@redhat.com>
---
tests/vhost-user-bridge.c | 168 ++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 156 insertions(+), 12 deletions(-)
diff --git a/tests/vhost-user-bridge.c b/tests/vhost-user-bridge.c
index fa18ad5..8bab0bb 100644
--- a/tests/vhost-user-bridge.c
+++ b/tests/vhost-user-bridge.c
@@ -173,6 +173,9 @@ typedef struct VubrVirtq {
#define VHOST_MEMORY_MAX_NREGIONS 8
#define VHOST_USER_F_PROTOCOL_FEATURES 30
+typedef uint8_t vhost_log_chunk_t;
+#define VHOST_LOG_PAGE 4096
+
enum VhostUserProtocolFeature {
VHOST_USER_PROTOCOL_F_MQ = 0,
VHOST_USER_PROTOCOL_F_LOG_SHMFD = 1,
@@ -265,8 +268,12 @@ typedef struct VubrDev {
uint32_t nregions;
VubrDevRegion regions[VHOST_MEMORY_MAX_NREGIONS];
VubrVirtq vq[MAX_NR_VIRTQUEUE];
+ int log_call_fd;
+ uint64_t log_size;
+ vhost_log_chunk_t *log_table;
int backend_udp_sock;
struct sockaddr_in backend_udp_dest;
+ int ready;
} VubrDev;
static const char *vubr_request_str[] = {
@@ -329,6 +336,27 @@ gpa_to_va(VubrDev *dev, uint64_t guest_addr)
return 0;
}
+/* Translate our virtual address to guest physical address. */
+static uint64_t
+va_to_gpa(VubrDev *dev, void *obj)
+{
+ int i;
+ uint64_t va = (uint64_t) obj;
+
+ /* Find matching memory region. */
+ for (i = 0; i < dev->nregions; i++) {
+ VubrDevRegion *r = &dev->regions[i];
+
+ if ((va >= r->mmap_addr + r->mmap_offset) &&
+ (va < r->mmap_addr + r->mmap_offset + r->size)) {
+ return va - r->mmap_addr - r->mmap_offset + r->gpa;
+ }
+ }
+
+ assert(!"address not found in regions");
+ return 0;
+}
+
/* Translate qemu virtual address to our virtual address. */
static uint64_t
qva_to_va(VubrDev *dev, uint64_t qemu_addr)
@@ -368,7 +396,12 @@ vubr_message_read(int conn_fd, VhostUserMsg *vmsg)
rc = recvmsg(conn_fd, &msg, 0);
- if (rc <= 0) {
+ if (rc == 0) {
+ vubr_die("recvmsg");
+ fprintf(stderr, "Peer disconnected.\n");
+ exit(1);
+ }
+ if (rc < 0) {
vubr_die("recvmsg");
}
@@ -395,7 +428,12 @@ vubr_message_read(int conn_fd, VhostUserMsg *vmsg)
if (vmsg->size) {
rc = read(conn_fd, &vmsg->payload, vmsg->size);
- if (rc <= 0) {
+ if (rc == 0) {
+ vubr_die("recvmsg");
+ fprintf(stderr, "Peer disconnected.\n");
+ exit(1);
+ }
+ if (rc < 0) {
vubr_die("recvmsg");
}
@@ -465,6 +503,32 @@ vubr_virtqueue_kick(VubrVirtq *vq)
}
}
+
+static void
+vubr_log_page(uint8_t *log_table, uint64_t page)
+{
+ DPRINT("Logged dirty guest page: %"PRId64"\n", page);
+ log_table[page / 8] |= 1 << (page % 8);
+}
+
+static void
+vubr_log_write(VubrDev *dev, uint64_t address, uint64_t length)
+{
+ uint64_t page;
+
+ if (!dev->log_table || !length) {
+ return;
+ }
+
+ assert(dev->log_size >= ((address + length) / VHOST_LOG_PAGE / 8));
+
+ page = address / VHOST_LOG_PAGE;
+ while (page * VHOST_LOG_PAGE < address + length) {
+ vubr_log_page(dev->log_table, page);
+ page += VHOST_LOG_PAGE;
+ }
+}
+
static void
vubr_post_buffer(VubrDev *dev, VubrVirtq *vq, uint8_t *buf, int32_t len)
{
@@ -510,6 +574,7 @@ vubr_post_buffer(VubrDev *dev, VubrVirtq *vq, uint8_t *buf,
int32_t len)
if (len <= chunk_len) {
memcpy(chunk_start, buf, len);
+ vubr_log_write(dev, desc[i].addr, len);
} else {
fprintf(stderr,
"Received too long packet from the backend. Dropping...\n");
@@ -519,11 +584,14 @@ vubr_post_buffer(VubrDev *dev, VubrVirtq *vq, uint8_t
*buf, int32_t len)
/* Add descriptor to the used ring. */
used->ring[u_index].id = d_index;
used->ring[u_index].len = len;
+ vubr_log_write(dev, va_to_gpa(dev, &used->ring[u_index]),
+ sizeof(used->ring[u_index]));
vq->last_avail_index++;
vq->last_used_index++;
atomic_mb_set(&used->idx, vq->last_used_index);
+ vubr_log_write(dev, va_to_gpa(dev, &used->idx), sizeof(used->idx));
/* Kick the guest if necessary. */
vubr_virtqueue_kick(vq);
@@ -552,6 +620,8 @@ vubr_process_desc(VubrDev *dev, VubrVirtq *vq)
void *chunk_start = (void *)gpa_to_va(dev, desc[i].addr);
uint32_t chunk_len = desc[i].len;
+ assert(!(desc[i].flags & VRING_DESC_F_WRITE));
+
if (len + chunk_len < buf_size) {
memcpy(buf + len, chunk_start, chunk_len);
DPRINT("%d ", chunk_len);
@@ -577,6 +647,8 @@ vubr_process_desc(VubrDev *dev, VubrVirtq *vq)
/* Add descriptor to the used ring. */
used->ring[u_index].id = d_index;
used->ring[u_index].len = len;
+ vubr_log_write(dev, va_to_gpa(dev, &used->ring[u_index]),
+ sizeof(used->ring[u_index]));
vubr_consume_raw_packet(dev, buf, len);
@@ -596,6 +668,7 @@ vubr_process_avail(VubrDev *dev, VubrVirtq *vq)
}
atomic_mb_set(&used->idx, vq->last_used_index);
+ vubr_log_write(dev, va_to_gpa(dev, &used->idx), sizeof(used->idx));
}
static void
@@ -609,6 +682,10 @@ vubr_backend_recv_cb(int sock, void *ctx)
int buflen = sizeof(buf);
int len;
+ if (!dev->ready) {
+ return;
+ }
+
DPRINT("\n\n *** IN UDP RECEIVE CALLBACK ***\n\n");
uint16_t avail_index = atomic_mb_read(&rx_vq->avail->idx);
@@ -656,9 +733,9 @@ vubr_get_features_exec(VubrDev *dev, VhostUserMsg *vmsg)
{
vmsg->payload.u64 =
((1ULL << VIRTIO_NET_F_MRG_RXBUF) |
- (1ULL << VIRTIO_NET_F_CTRL_VQ) |
- (1ULL << VIRTIO_NET_F_CTRL_RX) |
- (1ULL << VHOST_F_LOG_ALL));
+ (1ULL << VHOST_F_LOG_ALL) |
+ (1ULL << VHOST_USER_F_PROTOCOL_FEATURES));
+
vmsg->size = sizeof(vmsg->payload.u64);
DPRINT("Sending back to guest u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
@@ -680,10 +757,27 @@ vubr_set_owner_exec(VubrDev *dev, VhostUserMsg *vmsg)
return 0;
}
+static void
+vubr_close_log(VubrDev *dev)
+{
+ if (dev->log_table) {
+ if (munmap(dev->log_table, dev->log_size) != 0) {
+ vubr_die("munmap()");
+ }
+
+ dev->log_table = 0;
+ }
+ if (dev->log_call_fd != -1) {
+ close(dev->log_call_fd);
+ dev->log_call_fd = -1;
+ }
+}
+
static int
vubr_reset_device_exec(VubrDev *dev, VhostUserMsg *vmsg)
{
- DPRINT("Function %s() not implemented yet.\n", __func__);
+ vubr_close_log(dev);
+ dev->ready = 0;
return 0;
}
@@ -736,8 +830,39 @@ vubr_set_mem_table_exec(VubrDev *dev, VhostUserMsg *vmsg)
static int
vubr_set_log_base_exec(VubrDev *dev, VhostUserMsg *vmsg)
{
- DPRINT("Function %s() not implemented yet.\n", __func__);
- return 0;
+ int fd, i;
+ uint64_t last_addr = 0;
+ uint64_t log_size;
+ void *rc;
+
+ assert(vmsg->fd_num == 1);
+ fd = vmsg->fds[0];
+
+ /* Calculate size of vlog_table. Each entry is 32 bits. */
+ for (i = 0; i < dev->nregions; i++) {
+ VubrDevRegion *dev_region = &dev->regions[i];
+
+ uint64_t last_region_addr = dev_region->gpa + dev_region->size;
+
+ if (last_addr < last_region_addr) {
+ last_addr = last_region_addr;
+ }
+ }
+
+ log_size = last_addr / (VHOST_LOG_PAGE * sizeof(vhost_log_chunk_t));
+ DPRINT("Largest guest address: 0x%016"PRIx64"\n", last_addr);
+ DPRINT("Log size: %"PRId64"\n", log_size);
+
+ rc = mmap(0, log_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+ if (rc == MAP_FAILED) {
+ vubr_die("mmap");
+ }
+ dev->log_table = (vhost_log_chunk_t *) rc;
+ dev->log_size = log_size;
+
+ vmsg->size = sizeof(vmsg->payload.u64);
+ /* Reply */
+ return 1;
}
static int
@@ -803,8 +928,14 @@ vubr_set_vring_base_exec(VubrDev *dev, VhostUserMsg *vmsg)
static int
vubr_get_vring_base_exec(VubrDev *dev, VhostUserMsg *vmsg)
{
- DPRINT("Function %s() not implemented yet.\n", __func__);
- return 0;
+ unsigned int index = vmsg->payload.state.index;
+
+ DPRINT("State.index: %d\n", index);
+ vmsg->payload.state.num = dev->vq[index].last_avail_index;
+ vmsg->size = sizeof(vmsg->payload.state);
+
+ /* reply */
+ return 1;
}
static int
@@ -829,6 +960,10 @@ vubr_set_vring_kick_exec(VubrDev *dev, VhostUserMsg *vmsg)
DPRINT("Waiting for kicks on fd: %d for vq: %d\n",
dev->vq[index].kick_fd, index);
}
+ if (dev->vq[0].kick_fd != -1 &&
+ dev->vq[1].kick_fd != -1) {
+ dev->ready = 1;
+ }
return 0;
}
@@ -858,9 +993,12 @@ vubr_set_vring_err_exec(VubrDev *dev, VhostUserMsg *vmsg)
static int
vubr_get_protocol_features_exec(VubrDev *dev, VhostUserMsg *vmsg)
{
- /* FIXME: unimplented */
+ vmsg->payload.u64 = 1ULL << VHOST_USER_PROTOCOL_F_LOG_SHMFD;
DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64);
- return 0;
+ vmsg->size = sizeof(vmsg->payload.u64);
+
+ /* Reply */
+ return 1;
}
static int
@@ -1012,6 +1150,12 @@ vubr_new(const char *path)
};
}
+ /* Init log */
+ dev->log_call_fd = -1;
+ dev->log_size = 0;
+ dev->log_table = 0;
+ dev->ready = 0;
+
/* Get a UNIX socket. */
dev->sock = socket(AF_UNIX, SOCK_STREAM, 0);
if (dev->sock == -1) {
--
--Victor
