Allow the guest to negotiate multiple virtqueue pairs by advertising
VIRTIO_NET_F_MQ and VHOST_USER_PROTOCOL_F_MQ feature flags, and
increase VHOST_USER_MAX_VQS from 2 to 32, supporting up to 16 queue
pairs.
Replace the VHOST_USER_RX_QUEUE, VHOST_USER_TX_QUEUE,
VHOST_USER_IS_QUEUE_TX(), and VHOST_USER_IS_QUEUE_RX() macros with a
general set of QPAIR_* macros in passt.h that translate between queue
pair numbers and virtqueue indices. These are needed now that queue
indices are no longer limited to 0 and 1.
Add a queue pair parameter to vu_send_single(), propagating it to the
virtqueue selection. All callers currently pass QPAIR_DEFAULT (0):
only the first RX queue is used for receiving. The guest kernel
selects which TX queue to use for transmission. Full multi-RX-queue
load balancing will be implemented separately.
Signed-off-by: Laurent Vivier
---
passt.h | 10 ++++++++++
tap.c | 9 ++++++---
tcp_vu.c | 6 ++++--
udp_vu.c | 3 ++-
vhost_user.c | 12 +++++++-----
vhost_user.h | 9 ---------
virtio.h | 2 +-
vu_common.c | 15 +++++++++------
vu_common.h | 3 ++-
9 files changed, 41 insertions(+), 28 deletions(-)
diff --git a/passt.h b/passt.h
index 51ccd4ff46a4..ec936c3d3f32 100644
--- a/passt.h
+++ b/passt.h
@@ -28,6 +28,16 @@ union epoll_ref;
#include "udp.h"
#include "vhost_user.h"
+/* Queue pairs consist of one RX queue (even index) and one TX queue (odd index).
+ * Example: pair 0 has RX queue 0 and TX queue 1; pair 1 has RX queue 2 and TX queue 3.
+ */
+#define QPAIR_DEFAULT 0 /* Default queue pair */
+#define QPAIR_FROMGUEST_QUEUE(qpair) ((size_t)(qpair) * 2 + 1) /* TX queue index from pair */
+#define QPAIR_TOGUEST_QUEUE(qpair) ((size_t)(qpair) * 2) /* RX queue index from pair */
+#define QPAIR_FROM_QUEUE(queue) ((queue) / 2) /* Extract pair from queue */
+#define QPAIR_IS_FROMGUEST(queue) (!!(queue % 2)) /* Can receive data from guest */
+#define QPAIR_IS_TOGUEST(queue) (!(queue % 2)) /* Can send data to guest */
+
/* Default address for our end on the tap interface. Bit 0 of byte 0 must be 0
* (unicast) and bit 1 of byte 1 must be 1 (locally administered). Otherwise
* it's arbitrary.
diff --git a/tap.c b/tap.c
index dca53b9ec511..4956e4dc2589 100644
--- a/tap.c
+++ b/tap.c
@@ -155,7 +155,7 @@ void tap_send_single(const struct ctx *c, const void *data, size_t l2len)
tap_send_frames(c, iov, iovcnt, 1);
break;
case MODE_VU:
- vu_send_single(c, data, l2len);
+ vu_send_single(c, QPAIR_DEFAULT, data, l2len);
break;
}
}
@@ -1376,8 +1376,11 @@ static void tap_backend_show_hints(const struct ctx *c)
break;
case MODE_VU:
info("You can start qemu with:");
- info(" kvm ... -chardev socket,id=chr0,path=%s -netdev vhost-user,id=netdev0,chardev=chr0 -device virtio-net,netdev=netdev0 -object memory-backend-memfd,id=memfd0,share=on,size=$RAMSIZE -numa node,memdev=memfd0\n",
- c->sock_path);
+ info(" kvm ... -chardev socket,id=chr0,path=%s "
+ "-netdev vhost-user,id=netdev0,chardev=chr0,queues=$QUEUES "
+ "-device virtio-net,netdev=netdev0,mq=true "
+ "-object memory-backend-memfd,id=memfd0,share=on,size=$RAMSIZE "
+ "-numa node,memdev=memfd0\n", c->sock_path);
break;
}
}
diff --git a/tcp_vu.c b/tcp_vu.c
index 868a35b968e1..d2950dcc99e6 100644
--- a/tcp_vu.c
+++ b/tcp_vu.c
@@ -126,7 +126,8 @@ int tcp_vu_send_flag(const struct ctx *c, struct tcp_tap_conn *conn, int flags,
const struct timespec *now)
{
struct vu_dev *vdev = c->vdev;
- struct vu_virtq *vq = &vdev->vq[VHOST_USER_RX_QUEUE];
+ int toguest = QPAIR_TOGUEST_QUEUE(QPAIR_DEFAULT);
+ struct vu_virtq *vq = &vdev->vq[toguest];
size_t optlen, hdrlen, iov_cnt, iov_used;
struct vu_virtq_element flags_elem[2];
struct iov_tail payload, l2frame;
@@ -434,8 +435,9 @@ int tcp_vu_data_from_sock(const struct ctx *c, struct tcp_tap_conn *conn,
uint32_t already_sent, const struct timespec *now)
{
uint32_t wnd_scaled = conn->wnd_from_tap << conn->ws_from_tap;
+ int toguest = QPAIR_TOGUEST_QUEUE(QPAIR_DEFAULT);
struct vu_dev *vdev = c->vdev;
- struct vu_virtq *vq = &vdev->vq[VHOST_USER_RX_QUEUE];
+ struct vu_virtq *vq = &vdev->vq[toguest];
ssize_t len, previous_dlen;
int i, elem_cnt, frame_cnt;
size_t hdrlen, fillsize;
diff --git a/udp_vu.c b/udp_vu.c
index edd9cae734a8..4003f5b42b56 100644
--- a/udp_vu.c
+++ b/udp_vu.c
@@ -150,9 +150,10 @@ void udp_vu_sock_to_tap(const struct ctx *c, int s, int n, flow_sidx_t tosidx)
const struct flowside *toside = flowside_at_sidx(tosidx);
bool v6 = !(inany_v4(&toside->eaddr) && inany_v4(&toside->oaddr));
static struct vu_virtq_element elem[VIRTQUEUE_MAX_SIZE];
+ int toguest = QPAIR_TOGUEST_QUEUE(QPAIR_DEFAULT);
static struct iovec iov_vu[VIRTQUEUE_MAX_SIZE];
struct vu_dev *vdev = c->vdev;
- struct vu_virtq *vq = &vdev->vq[VHOST_USER_RX_QUEUE];
+ struct vu_virtq *vq = &vdev->vq[toguest];
size_t hdrlen = udp_vu_hdrlen(v6);
int i;
diff --git a/vhost_user.c b/vhost_user.c
index a1259c2624c0..9e382c21f963 100644
--- a/vhost_user.c
+++ b/vhost_user.c
@@ -324,6 +324,7 @@ static bool vu_get_features_exec(struct vu_dev *vdev,
1ULL << VIRTIO_F_VERSION_1 |
1ULL << VIRTIO_NET_F_GUEST_CSUM |
1ULL << VIRTIO_NET_F_MRG_RXBUF |
+ 1ULL << VIRTIO_NET_F_MQ |
1ULL << VHOST_F_LOG_ALL |
1ULL << VHOST_USER_F_PROTOCOL_FEATURES;
@@ -770,7 +771,8 @@ static void vu_check_queue_msg_file(struct vhost_user_msg *vmsg)
bool nofd = vmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK;
if (idx >= VHOST_USER_MAX_VQS)
- die("Invalid vhost-user queue index: %u", idx);
+ die("Invalid vhost-user queue index: %u (maximum %u)", idx,
+ VHOST_USER_MAX_VQS - 1);
if (nofd) {
vmsg_close_fds(vmsg);
@@ -812,7 +814,7 @@ static bool vu_set_vring_kick_exec(struct vu_dev *vdev,
vdev->vq[idx].started = true;
- if (vdev->vq[idx].kick_fd != -1 && VHOST_USER_IS_QUEUE_TX(idx)) {
+ if (vdev->vq[idx].kick_fd != -1 && QPAIR_IS_FROMGUEST(idx)) {
vu_set_watch(vdev, idx);
debug("Waiting for kicks on fd: %d for vq: %d",
vdev->vq[idx].kick_fd, idx);
@@ -899,7 +901,8 @@ static bool vu_get_protocol_features_exec(struct vu_dev *vdev,
uint64_t features = 1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK |
1ULL << VHOST_USER_PROTOCOL_F_LOG_SHMFD |
1ULL << VHOST_USER_PROTOCOL_F_DEVICE_STATE |
- 1ULL << VHOST_USER_PROTOCOL_F_RARP;
+ 1ULL << VHOST_USER_PROTOCOL_F_RARP |
+ 1ULL << VHOST_USER_PROTOCOL_F_MQ;
(void)vdev;
vmsg_set_reply_u64(vmsg, features);
@@ -938,10 +941,9 @@ static bool vu_get_queue_num_exec(struct vu_dev *vdev,
{
(void)vdev;
- /* NOLINTNEXTLINE(misc-redundant-expression) */
vmsg_set_reply_u64(vmsg, VHOST_USER_MAX_VQS / 2);
- debug("VHOST_USER_MAX_VQS %u", VHOST_USER_MAX_VQS / 2);
+ debug("Using up to %u vhost-user queue pairs", VHOST_USER_MAX_VQS / 2);
return true;
}
diff --git a/vhost_user.h b/vhost_user.h
index e806a9e54e00..d2e51d3e86c3 100644
--- a/vhost_user.h
+++ b/vhost_user.h
@@ -201,15 +201,6 @@ struct vhost_user_msg {
} __attribute__ ((__packed__));
#define VHOST_USER_HDR_SIZE sizeof(struct vhost_user_header)
-/* index of the RX virtqueue */
-#define VHOST_USER_RX_QUEUE 0
-/* index of the TX virtqueue */
-#define VHOST_USER_TX_QUEUE 1
-
-/* in case of multiqueue, the RX and TX queues are interleaved */
-#define VHOST_USER_IS_QUEUE_TX(n) (n % 2)
-#define VHOST_USER_IS_QUEUE_RX(n) (!(n % 2))
-
/* Default virtio-net header for passt */
#define VU_HEADER ((struct virtio_net_hdr){ \
.flags = VIRTIO_NET_HDR_F_DATA_VALID, \
diff --git a/virtio.h b/virtio.h
index 8f2ae068d5ba..eb7570e63cd7 100644
--- a/virtio.h
+++ b/virtio.h
@@ -90,7 +90,7 @@ struct vu_dev_region {
uint64_t mmap_addr;
};
-#define VHOST_USER_MAX_VQS 2U
+#define VHOST_USER_MAX_VQS 32U
/*
* Set a reasonable maximum number of ram slots, which will be supported by
diff --git a/vu_common.c b/vu_common.c
index d07f584f228a..8adcf42b954b 100644
--- a/vu_common.c
+++ b/vu_common.c
@@ -175,7 +175,7 @@ static void vu_handle_tx(struct vu_dev *vdev, int index,
int out_sg_count;
int count;
- assert(VHOST_USER_IS_QUEUE_TX(index));
+ assert(QPAIR_IS_FROMGUEST(index));
tap_flush_pools();
@@ -233,28 +233,31 @@ void vu_kick_cb(struct vu_dev *vdev, union epoll_ref ref,
trace("vhost-user: got kick_data: %016"PRIx64" idx: %d",
kick_data, ref.queue);
- if (VHOST_USER_IS_QUEUE_TX(ref.queue))
+ if (QPAIR_IS_FROMGUEST(ref.queue))
vu_handle_tx(vdev, ref.queue, now);
}
/**
- * vu_send_single() - Send a buffer to the front-end using the RX virtqueue
- * @c: execution context
+ * vu_send_single() - Send a buffer to the front-end using a specified virtqueue
+ * @c: Execution context
+ * @qpair: Queue pair on which to send the buffer
* @buf: address of the buffer
* @size: size of the buffer
*
* Return: number of bytes sent, -1 if there is an error
*/
-int vu_send_single(const struct ctx *c, const void *buf, size_t size)
+int vu_send_single(const struct ctx *c, unsigned int qpair, const void *buf, size_t size)
{
struct vu_dev *vdev = c->vdev;
- struct vu_virtq *vq = &vdev->vq[VHOST_USER_RX_QUEUE];
struct vu_virtq_element elem[VIRTQUEUE_MAX_SIZE];
struct iovec in_sg[VIRTQUEUE_MAX_SIZE];
+ struct vu_virtq *vq;
size_t total, in_total;
int elem_cnt;
int i;
+ vq = &vdev->vq[QPAIR_TOGUEST_QUEUE(qpair)];
+
trace("vu_send_single size %zu", size);
if (!vu_queue_enabled(vq) || !vu_queue_started(vq)) {
diff --git a/vu_common.h b/vu_common.h
index 817384175a1d..f5603d9ddeb6 100644
--- a/vu_common.h
+++ b/vu_common.h
@@ -23,7 +23,8 @@ void vu_flush(const struct vu_dev *vdev, struct vu_virtq *vq,
struct vu_virtq_element *elem, int elem_cnt, size_t frame_len);
void vu_kick_cb(struct vu_dev *vdev, union epoll_ref ref,
const struct timespec *now);
-int vu_send_single(const struct ctx *c, const void *buf, size_t size);
+int vu_send_single(const struct ctx *c, unsigned int qpair, const void *buf,
+ size_t size);
void vu_pad(const struct iovec *iov, size_t cnt, size_t frame_len);
#endif /* VU_COMMON_H */
--
2.54.0