From: Liu Ping Fan <pingf...@linux.vnet.ibm.com>
virtio-blk will reference to RAM's memoryRegion when the req has been
done. So we can avoid to call bdrv_drain_all() when RAM hot unplug.
Signed-off-by: Liu Ping Fan <pingf...@linux.vnet.ibm.com>
---
hw/dataplane/virtio-blk.c | 52 ++++++++++++++++++++++++++++++++++----------
1 files changed, 40 insertions(+), 12 deletions(-)
diff --git a/hw/dataplane/virtio-blk.c b/hw/dataplane/virtio-blk.c
index 1242d61..437174d 100644
--- a/hw/dataplane/virtio-blk.c
+++ b/hw/dataplane/virtio-blk.c
@@ -34,6 +34,8 @@ enum {
typedef struct {
struct iocb iocb; /* Linux AIO control block */
+ MemoryRegion *mrs[VRING_MAX];
+ int mrs_cnt;
QEMUIOVector *inhdr; /* iovecs for virtio_blk_inhdr */
unsigned int head; /* vring descriptor index */
struct iovec *bounce_iov; /* used if guest buffers are unaligned */
@@ -120,6 +122,9 @@ static void complete_request(struct iocb *iocb, ssize_t
ret, void *opaque)
* transferred plus the status bytes.
*/
vring_push(&s->vring, req->head, len + sizeof(hdr));
+ while (--req->mrs_cnt >= 0) {
+ memory_region_unref(req->mrs[req->mrs_cnt]);
+ }
s->num_reqs--;
}
@@ -155,7 +160,8 @@ static void do_get_id_cmd(VirtIOBlockDataPlane *s,
static int do_rdwr_cmd(VirtIOBlockDataPlane *s, bool read,
struct iovec *iov, unsigned int iov_cnt,
long long offset, unsigned int head,
- QEMUIOVector *inhdr)
+ QEMUIOVector *inhdr,
+ MemoryRegion **mrs, int cnt)
{
struct iocb *iocb;
QEMUIOVector qiov;
@@ -187,6 +193,8 @@ static int do_rdwr_cmd(VirtIOBlockDataPlane *s, bool read,
/* Fill in virtio block metadata needed for completion */
VirtIOBlockRequest *req = container_of(iocb, VirtIOBlockRequest, iocb);
+ memcpy(req->mrs, mrs, cnt*sizeof(MemoryRegion *));
+ req->mrs_cnt = cnt;
req->head = head;
req->inhdr = inhdr;
req->bounce_iov = bounce_iov;
@@ -196,19 +204,22 @@ static int do_rdwr_cmd(VirtIOBlockDataPlane *s, bool read,
static int process_request(IOQueue *ioq, struct iovec iov[],
unsigned int out_num, unsigned int in_num,
- unsigned int head)
+ unsigned int head, MemoryRegion **mrs)
{
VirtIOBlockDataPlane *s = container_of(ioq, VirtIOBlockDataPlane, ioqueue);
struct iovec *in_iov = &iov[out_num];
struct virtio_blk_outhdr outhdr;
QEMUIOVector *inhdr;
size_t in_size;
+ unsigned int i, cnt = out_num+in_num;
+ int ret;
/* Copy in outhdr */
if (unlikely(iov_to_buf(iov, out_num, 0, &outhdr,
sizeof(outhdr)) != sizeof(outhdr))) {
error_report("virtio-blk request outhdr too short");
- return -EFAULT;
+ ret = -EFAULT;
+ goto free_mrs;
}
iov_discard_front(&iov, &out_num, sizeof(outhdr));
@@ -216,7 +227,8 @@ static int process_request(IOQueue *ioq, struct iovec iov[],
in_size = iov_size(in_iov, in_num);
if (in_size < sizeof(struct virtio_blk_inhdr)) {
error_report("virtio_blk request inhdr too short");
- return -EFAULT;
+ ret = -EFAULT;
+ goto free_mrs;
}
inhdr = g_slice_new(QEMUIOVector);
qemu_iovec_init(inhdr, 1);
@@ -229,18 +241,22 @@ static int process_request(IOQueue *ioq, struct iovec
iov[],
outhdr.type &= ~VIRTIO_BLK_T_BARRIER;
switch (outhdr.type) {
+ /* For VIRTIO_BLK_T_IN/OUT, MemoryRegion will be release when cb */
case VIRTIO_BLK_T_IN:
- do_rdwr_cmd(s, true, in_iov, in_num, outhdr.sector * 512, head, inhdr);
+ do_rdwr_cmd(s, true, in_iov, in_num, outhdr.sector * 512, head, inhdr,
+ mrs, cnt);
return 0;
case VIRTIO_BLK_T_OUT:
- do_rdwr_cmd(s, false, iov, out_num, outhdr.sector * 512, head, inhdr);
+ do_rdwr_cmd(s, false, iov, out_num, outhdr.sector * 512, head, inhdr,
+ mrs, cnt);
return 0;
case VIRTIO_BLK_T_SCSI_CMD:
/* TODO support SCSI commands */
complete_request_early(s, head, inhdr, VIRTIO_BLK_S_UNSUPP);
- return 0;
+ ret = 0;
+ goto free_mrs;
case VIRTIO_BLK_T_FLUSH:
/* TODO fdsync not supported by Linux AIO, do it synchronously here! */
@@ -249,18 +265,27 @@ static int process_request(IOQueue *ioq, struct iovec
iov[],
} else {
complete_request_early(s, head, inhdr, VIRTIO_BLK_S_OK);
}
- return 0;
+ ret = 0;
+ goto free_mrs;
case VIRTIO_BLK_T_GET_ID:
do_get_id_cmd(s, in_iov, in_num, head, inhdr);
- return 0;
+ ret = 0;
+ goto free_mrs;
default:
error_report("virtio-blk unsupported request type %#x", outhdr.type);
qemu_iovec_destroy(inhdr);
g_slice_free(QEMUIOVector, inhdr);
- return -EFAULT;
+ ret = -EFAULT;
+ goto free_mrs;
+ }
+
+free_mrs:
+ for (i = 0; i < cnt; i++) {
+ memory_region_unref(mrs[i]);
}
+ return ret;
}
static int flush_true(EventNotifier *e)
@@ -286,6 +311,7 @@ static void handle_notify(EventNotifier *e)
struct iovec iovec[VRING_MAX];
struct iovec *end = &iovec[VRING_MAX];
struct iovec *iov = iovec;
+ MemoryRegion *mrs[VRING_MAX];
/* When a request is read from the vring, the index of the first descriptor
* (aka head) is returned so that the completed request can be pushed onto
@@ -304,7 +330,8 @@ static void handle_notify(EventNotifier *e)
vring_disable_notification(s->vdev, &s->vring);
for (;;) {
- head = vring_pop(s->vdev, &s->vring, iov, end, &out_num, &in_num);
+ head = vring_pop(s->vdev, &s->vring, iov, end, &out_num, &in_num,
+ mrs);
if (head < 0) {
break; /* no more requests */
}
@@ -312,7 +339,8 @@ static void handle_notify(EventNotifier *e)
trace_virtio_blk_data_plane_process_request(s, out_num, in_num,
head);
- if (process_request(&s->ioqueue, iov, out_num, in_num, head) < 0) {
+ if (process_request(&s->ioqueue, iov, out_num, in_num, head,
+ mrs) < 0) {
vring_set_broken(&s->vring);
break;
}
--
1.7.4.4
