From 70c72316c26e95cd18b4d46b83e78ba3a148212c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= <eperezma@redhat.com>
Date: Tue, 23 Aug 2022 20:30:33 +0200
Subject: [PATCH 18/23] vdpa: Move command buffers map to start of net device
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RH-Author: Eugenio Pérez <eperezma@redhat.com>
RH-MergeRequest: 116: vdpa: Restore device state on destination
RH-Bugzilla: 2114060
RH-Acked-by: Cindy Lu <lulu@redhat.com>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Commit: [17/21] 7a9824fa618f5c2904648b50e3078474cd3987aa (eperezmartin/qemu-kvm)
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2114060
Upstream status: git@github.com:jasowang/qemu.git net-next
As this series will reuse them to restore the device state at the end of
a migration (or a device start), let's allocate only once at the device
start so we don't duplicate their map and unmap.
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
(cherry picked from commit d7d73dec14cebcebd8de774424795aeb821236c1)
---
net/vhost-vdpa.c | 123 ++++++++++++++++++++++-------------------------
1 file changed, 58 insertions(+), 65 deletions(-)
diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index 03e4cf1abc..17626feb8d 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -263,29 +263,20 @@ static size_t vhost_vdpa_net_cvq_cmd_page_len(void)
return ROUND_UP(vhost_vdpa_net_cvq_cmd_len(), qemu_real_host_page_size);
}
-/** Copy and map a guest buffer. */
-static bool vhost_vdpa_cvq_map_buf(struct vhost_vdpa *v,
- const struct iovec *out_data,
- size_t out_num, size_t data_len, void *buf,
- size_t *written, bool write)
+/** Map CVQ buffer. */
+static int vhost_vdpa_cvq_map_buf(struct vhost_vdpa *v, void *buf, size_t size,
+ bool write)
{
DMAMap map = {};
int r;
- if (unlikely(!data_len)) {
- qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid legnth of %s buffer\n",
- __func__, write ? "in" : "out");
- return false;
- }
-
- *written = iov_to_buf(out_data, out_num, 0, buf, data_len);
map.translated_addr = (hwaddr)(uintptr_t)buf;
- map.size = vhost_vdpa_net_cvq_cmd_page_len() - 1;
+ map.size = size - 1;
map.perm = write ? IOMMU_RW : IOMMU_RO,
r = vhost_iova_tree_map_alloc(v->iova_tree, &map);
if (unlikely(r != IOVA_OK)) {
error_report("Cannot map injected element");
- return false;
+ return r;
}
r = vhost_vdpa_dma_map(v, map.iova, vhost_vdpa_net_cvq_cmd_page_len(), buf,
@@ -294,50 +285,58 @@ static bool vhost_vdpa_cvq_map_buf(struct vhost_vdpa *v,
goto dma_map_err;
}
- return true;
+ return 0;
dma_map_err:
vhost_iova_tree_remove(v->iova_tree, map);
- return false;
+ return r;
}
-/**
- * Copy the guest element into a dedicated buffer suitable to be sent to NIC
- *
- * @iov: [0] is the out buffer, [1] is the in one
- */
-static bool vhost_vdpa_net_cvq_map_elem(VhostVDPAState *s,
- VirtQueueElement *elem,
- struct iovec *iov)
+static int vhost_vdpa_net_cvq_start(NetClientState *nc)
{
- size_t in_copied;
- bool ok;
+ VhostVDPAState *s;
+ int r;
- iov[0].iov_base = s->cvq_cmd_out_buffer;
- ok = vhost_vdpa_cvq_map_buf(&s->vhost_vdpa, elem->out_sg, elem->out_num,
- vhost_vdpa_net_cvq_cmd_len(), iov[0].iov_base,
- &iov[0].iov_len, false);
- if (unlikely(!ok)) {
- return false;
+ assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
+
+ s = DO_UPCAST(VhostVDPAState, nc, nc);
+ if (!s->vhost_vdpa.shadow_vqs_enabled) {
+ return 0;
}
- iov[1].iov_base = s->cvq_cmd_in_buffer;
- ok = vhost_vdpa_cvq_map_buf(&s->vhost_vdpa, NULL, 0,
- sizeof(virtio_net_ctrl_ack), iov[1].iov_base,
- &in_copied, true);
- if (unlikely(!ok)) {
+ r = vhost_vdpa_cvq_map_buf(&s->vhost_vdpa, s->cvq_cmd_out_buffer,
+ vhost_vdpa_net_cvq_cmd_page_len(), false);
+ if (unlikely(r < 0)) {
+ return r;
+ }
+
+ r = vhost_vdpa_cvq_map_buf(&s->vhost_vdpa, s->cvq_cmd_in_buffer,
+ vhost_vdpa_net_cvq_cmd_page_len(), true);
+ if (unlikely(r < 0)) {
vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, s->cvq_cmd_out_buffer);
- return false;
}
- iov[1].iov_len = sizeof(virtio_net_ctrl_ack);
- return true;
+ return r;
+}
+
+static void vhost_vdpa_net_cvq_stop(NetClientState *nc)
+{
+ VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
+
+ assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
+
+ if (s->vhost_vdpa.shadow_vqs_enabled) {
+ vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, s->cvq_cmd_out_buffer);
+ vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, s->cvq_cmd_in_buffer);
+ }
}
static NetClientInfo net_vhost_vdpa_cvq_info = {
.type = NET_CLIENT_DRIVER_VHOST_VDPA,
.size = sizeof(VhostVDPAState),
.receive = vhost_vdpa_receive,
+ .start = vhost_vdpa_net_cvq_start,
+ .stop = vhost_vdpa_net_cvq_stop,
.cleanup = vhost_vdpa_cleanup,
.has_vnet_hdr = vhost_vdpa_has_vnet_hdr,
.has_ufo = vhost_vdpa_has_ufo,
@@ -348,19 +347,17 @@ static NetClientInfo net_vhost_vdpa_cvq_info = {
* Do not forward commands not supported by SVQ. Otherwise, the device could
* accept it and qemu would not know how to update the device model.
*/
-static bool vhost_vdpa_net_cvq_validate_cmd(const struct iovec *out,
- size_t out_num)
+static bool vhost_vdpa_net_cvq_validate_cmd(const void *out_buf, size_t len)
{
struct virtio_net_ctrl_hdr ctrl;
- size_t n;
- n = iov_to_buf(out, out_num, 0, &ctrl, sizeof(ctrl));
- if (unlikely(n < sizeof(ctrl))) {
+ if (unlikely(len < sizeof(ctrl))) {
qemu_log_mask(LOG_GUEST_ERROR,
- "%s: invalid legnth of out buffer %zu\n", __func__, n);
+ "%s: invalid legnth of out buffer %zu\n", __func__, len);
return false;
}
+ memcpy(&ctrl, out_buf, sizeof(ctrl));
switch (ctrl.class) {
case VIRTIO_NET_CTRL_MAC:
switch (ctrl.cmd) {
@@ -392,10 +389,14 @@ static int vhost_vdpa_net_handle_ctrl_avail(VhostShadowVirtqueue *svq,
VhostVDPAState *s = opaque;
size_t in_len, dev_written;
virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
- /* out and in buffers sent to the device */
- struct iovec dev_buffers[2] = {
- { .iov_base = s->cvq_cmd_out_buffer },
- { .iov_base = s->cvq_cmd_in_buffer },
+ /* Out buffer sent to both the vdpa device and the device model */
+ struct iovec out = {
+ .iov_base = s->cvq_cmd_out_buffer,
+ };
+ /* In buffer sent to the device */
+ const struct iovec dev_in = {
+ .iov_base = s->cvq_cmd_in_buffer,
+ .iov_len = sizeof(virtio_net_ctrl_ack),
};
/* in buffer used for device model */
const struct iovec in = {
@@ -405,17 +406,15 @@ static int vhost_vdpa_net_handle_ctrl_avail(VhostShadowVirtqueue *svq,
int r = -EINVAL;
bool ok;
- ok = vhost_vdpa_net_cvq_map_elem(s, elem, dev_buffers);
- if (unlikely(!ok)) {
- goto out;
- }
-
- ok = vhost_vdpa_net_cvq_validate_cmd(&dev_buffers[0], 1);
+ out.iov_len = iov_to_buf(elem->out_sg, elem->out_num, 0,
+ s->cvq_cmd_out_buffer,
+ vhost_vdpa_net_cvq_cmd_len());
+ ok = vhost_vdpa_net_cvq_validate_cmd(s->cvq_cmd_out_buffer, out.iov_len);
if (unlikely(!ok)) {
goto out;
}
- r = vhost_svq_add(svq, &dev_buffers[0], 1, &dev_buffers[1], 1, elem);
+ r = vhost_svq_add(svq, &out, 1, &dev_in, 1, elem);
if (unlikely(r != 0)) {
if (unlikely(r == -ENOSPC)) {
qemu_log_mask(LOG_GUEST_ERROR, "%s: No space on device queue\n",
@@ -435,13 +434,13 @@ static int vhost_vdpa_net_handle_ctrl_avail(VhostShadowVirtqueue *svq,
goto out;
}
- memcpy(&status, dev_buffers[1].iov_base, sizeof(status));
+ memcpy(&status, s->cvq_cmd_in_buffer, sizeof(status));
if (status != VIRTIO_NET_OK) {
goto out;
}
status = VIRTIO_NET_ERR;
- virtio_net_handle_ctrl_iov(svq->vdev, &in, 1, dev_buffers, 1);
+ virtio_net_handle_ctrl_iov(svq->vdev, &in, 1, &out, 1);
if (status != VIRTIO_NET_OK) {
error_report("Bad CVQ processing in model");
}
@@ -454,12 +453,6 @@ out:
}
vhost_svq_push_elem(svq, elem, MIN(in_len, sizeof(status)));
g_free(elem);
- if (dev_buffers[0].iov_base) {
- vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, dev_buffers[0].iov_base);
- }
- if (dev_buffers[1].iov_base) {
- vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, dev_buffers[1].iov_base);
- }
return r;
}
--
2.31.1