[PULL 0/5] Net patches

[PULL 0/5] Net patches

[Jason Wang]

The following changes since commit 5012e522aca161be5c141596c66e5cc6082538a9:

  Update version for v9.0.0-rc1 release (2024-03-26 19:46:55 +0000)

are available in the Git repository at:

  https://github.com/jasowang/qemu.git tags/net-pull-request

for you to fetch changes up to d9b33018a0da51eddceb48c42345cfb351065f3e:

  Revert "tap: setting error appropriately when calling net_init_tap_one()" (2024-03-29 14:59:07 +0800)

----------------------------------------------------------------
-----BEGIN PGP SIGNATURE-----

iQEzBAABCAAdFiEEIV1G9IJGaJ7HfzVi7wSWWzmNYhEFAmYGZ7EACgkQ7wSWWzmN
YhHvxgf/SDEYYMlxU7PA1SfwlIYtUG8K1zQnwLXNY6ySCJuCn1IdVoITaUt3BtE5
OtrhKI8cW5WwL4qzkElWlL431vyqomGdmJQedF8agwoR2aIo24i/Ue09MHxJxXUB
ONEOv3bizDCYWUjz+PMHRdIbo0AiSNaUDnB8iY59yD6HZqSLVMDx8Ia2KVrzUKwc
nMuqkDsVIc3gwqFNPbTl3yqVt6k1x+vBCGQUg9BiKE3pkUcONhsJpBYYj4hlY9mn
/BPlQBcRUoLHQD7KGSUKVFSODHPYzDg7BsSz2+EpuZucRRI3VEyHlcB5A6LIVhrK
fpqd+80Fb7VE9CAxA2gFj7gh5uPJ1A==
=shO6
-----END PGP SIGNATURE-----

----------------------------------------------------------------
Akihiko Odaki (5):
      virtio-net: Fix vhost virtqueue notifiers for RSS
      ebpf: Fix indirections table setting
      hw/net/net_tx_pkt: Fix virtio header without checksum offloading
      tap-win32: Remove unnecessary stubs
      Revert "tap: setting error appropriately when calling net_init_tap_one()"

 ebpf/ebpf_rss.c         |  9 +++++++--
 hw/net/net_tx_pkt.c     |  1 +
 hw/net/virtio-net.c     |  4 ++--
 include/net/vhost_net.h |  3 ---
 net/tap-win32.c         | 54 -------------------------------------------------
 net/tap.c               | 22 +++++---------------
 6 files changed, 15 insertions(+), 78 deletions(-)

[PULL 1/5] virtio-net: Fix vhost virtqueue notifiers for RSS

[Jason Wang]

From: Akihiko Odaki <akihiko.odaki@daynix.com>

virtio_net_guest_notifier_pending() and virtio_net_guest_notifier_mask()
checked VIRTIO_NET_F_MQ to know there are multiple queues, but
VIRTIO_NET_F_RSS also enables multiple queues. Refer to n->multiqueue,
which is set to true either of VIRTIO_NET_F_MQ or VIRTIO_NET_F_RSS is
enabled.

Fixes: 68b0a6395f36 ("virtio-net: align ctrl_vq index for non-mq guest for vhost_vdpa")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 hw/net/virtio-net.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 9959f1932b..a6ff000cd9 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -3426,7 +3426,7 @@ static bool virtio_net_guest_notifier_pending(VirtIODevice *vdev, int idx)
     VirtIONet *n = VIRTIO_NET(vdev);
     NetClientState *nc;
     assert(n->vhost_started);
-    if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_MQ) && idx == 2) {
+    if (!n->multiqueue && idx == 2) {
         /* Must guard against invalid features and bogus queue index
          * from being set by malicious guest, or penetrated through
          * buggy migration stream.
@@ -3458,7 +3458,7 @@ static void virtio_net_guest_notifier_mask(VirtIODevice *vdev, int idx,
     VirtIONet *n = VIRTIO_NET(vdev);
     NetClientState *nc;
     assert(n->vhost_started);
-    if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_MQ) && idx == 2) {
+    if (!n->multiqueue && idx == 2) {
         /* Must guard against invalid features and bogus queue index
          * from being set by malicious guest, or penetrated through
          * buggy migration stream.
-- 
2.42.0

[PULL 2/5] ebpf: Fix indirections table setting

[Jason Wang]

From: Akihiko Odaki <akihiko.odaki@daynix.com>

The kernel documentation says:
> The value stored can be of any size, however, all array elements are
> aligned to 8 bytes.
https://www.kernel.org/doc/html/v6.8/bpf/map_array.html

Fixes: 333b3e5fab75 ("ebpf: Added eBPF map update through mmap.")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Acked-by: Andrew Melnychenko <andrew@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 ebpf/ebpf_rss.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/ebpf/ebpf_rss.c b/ebpf/ebpf_rss.c
index 2e506f9743..d102f3dd09 100644
--- a/ebpf/ebpf_rss.c
+++ b/ebpf/ebpf_rss.c
@@ -185,13 +185,18 @@ static bool ebpf_rss_set_indirections_table(struct EBPFRSSContext *ctx,
                                             uint16_t *indirections_table,
                                             size_t len)
 {
+    char *cursor = ctx->mmap_indirections_table;
+
     if (!ebpf_rss_is_loaded(ctx) || indirections_table == NULL ||
        len > VIRTIO_NET_RSS_MAX_TABLE_LEN) {
         return false;
     }
 
-    memcpy(ctx->mmap_indirections_table, indirections_table,
-            sizeof(*indirections_table) * len);
+    for (size_t i = 0; i < len; i++) {
+        *(uint16_t *)cursor = indirections_table[i];
+        cursor += 8;
+    }
+
     return true;
 }
 
-- 
2.42.0

[PULL 3/5] hw/net/net_tx_pkt: Fix virtio header without checksum offloading

[Jason Wang]

From: Akihiko Odaki <akihiko.odaki@daynix.com>

It is incorrect to have the VIRTIO_NET_HDR_F_NEEDS_CSUM set when
checksum offloading is disabled so clear the bit.

TCP/UDP checksum is usually offloaded when the peer requires virtio
headers because they can instruct the peer to compute checksum. However,
igb disables TX checksum offloading when a VF is enabled whether the
peer requires virtio headers because a transmitted packet can be routed
to it and it expects the packet has a proper checksum. Therefore, it
is necessary to have a correct virtio header even when checksum
offloading is disabled.

A real TCP/UDP checksum will be computed and saved in the buffer when
checksum offloading is disabled. The virtio specification requires to
set the packet checksum stored in the buffer to the TCP/UDP pseudo
header when the VIRTIO_NET_HDR_F_NEEDS_CSUM bit is set so the bit must
be cleared in that case.

Fixes: ffbd2dbd8e64 ("e1000e: Perform software segmentation for loopback")
Buglink: https://issues.redhat.com/browse/RHEL-23067
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 hw/net/net_tx_pkt.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/net/net_tx_pkt.c b/hw/net/net_tx_pkt.c
index 2e5f58b3c9..2134a18c4c 100644
--- a/hw/net/net_tx_pkt.c
+++ b/hw/net/net_tx_pkt.c
@@ -833,6 +833,7 @@ bool net_tx_pkt_send_custom(struct NetTxPkt *pkt, bool offload,
 
     if (offload || gso_type == VIRTIO_NET_HDR_GSO_NONE) {
         if (!offload && pkt->virt_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
+            pkt->virt_hdr.flags &= ~VIRTIO_NET_HDR_F_NEEDS_CSUM;
             net_tx_pkt_do_sw_csum(pkt, &pkt->vec[NET_TX_PKT_L2HDR_FRAG],
                                   pkt->payload_frags + NET_TX_PKT_PL_START_FRAG - 1,
                                   pkt->payload_len);
-- 
2.42.0

[PULL 4/5] tap-win32: Remove unnecessary stubs

[Jason Wang]

From: Akihiko Odaki <akihiko.odaki@daynix.com>

Some of them are only necessary for POSIX systems. The others are
assigned to function pointers in NetClientInfo that can actually be
NULL.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 net/tap-win32.c | 54 -------------------------------------------------
 1 file changed, 54 deletions(-)

diff --git a/net/tap-win32.c b/net/tap-win32.c
index 7b8b4be02c..7edbd71633 100644
--- a/net/tap-win32.c
+++ b/net/tap-win32.c
@@ -707,70 +707,16 @@ static void tap_win32_send(void *opaque)
     }
 }
 
-static bool tap_has_ufo(NetClientState *nc)
-{
-    return false;
-}
-
-static bool tap_has_vnet_hdr(NetClientState *nc)
-{
-    return false;
-}
-
-int tap_probe_vnet_hdr_len(int fd, int len)
-{
-    return 0;
-}
-
-void tap_fd_set_vnet_hdr_len(int fd, int len)
-{
-}
-
-int tap_fd_set_vnet_le(int fd, int is_le)
-{
-    return -EINVAL;
-}
-
-int tap_fd_set_vnet_be(int fd, int is_be)
-{
-    return -EINVAL;
-}
-
-static void tap_using_vnet_hdr(NetClientState *nc, bool using_vnet_hdr)
-{
-}
-
-static void tap_set_offload(NetClientState *nc, int csum, int tso4,
-                     int tso6, int ecn, int ufo, int uso4, int uso6)
-{
-}
-
 struct vhost_net *tap_get_vhost_net(NetClientState *nc)
 {
     return NULL;
 }
 
-static bool tap_has_vnet_hdr_len(NetClientState *nc, int len)
-{
-    return false;
-}
-
-static void tap_set_vnet_hdr_len(NetClientState *nc, int len)
-{
-    abort();
-}
-
 static NetClientInfo net_tap_win32_info = {
     .type = NET_CLIENT_DRIVER_TAP,
     .size = sizeof(TAPState),
     .receive = tap_receive,
     .cleanup = tap_cleanup,
-    .has_ufo = tap_has_ufo,
-    .has_vnet_hdr = tap_has_vnet_hdr,
-    .has_vnet_hdr_len = tap_has_vnet_hdr_len,
-    .using_vnet_hdr = tap_using_vnet_hdr,
-    .set_offload = tap_set_offload,
-    .set_vnet_hdr_len = tap_set_vnet_hdr_len,
 };
 
 static int tap_win32_init(NetClientState *peer, const char *model,
-- 
2.42.0

[PULL 5/5] Revert "tap: setting error appropriately when calling net_init_tap_one()"

[Jason Wang]

From: Akihiko Odaki <akihiko.odaki@daynix.com>

This reverts commit 46d4d36d0bf2b24b205f2f604f0905db80264eef.

The reverted commit changed to emit warnings instead of errors when
vhost is requested but vhost initialization fails if vhostforce option
is not set.

However, vhostforce is not meant to ignore vhost errors. It was once
introduced as an option to commit 5430a28fe4 ("vhost: force vhost off
for non-MSI guests") to force enabling vhost for non-MSI guests, which
will have worse performance with vhost. The option was deprecated with
commit 1e7398a140 ("vhost: enable vhost without without MSI-X") and
changed to behave identical with the vhost option for compatibility.

Worse, commit bf769f742c ("virtio: del net client if net_init_tap_one
failed") changed to delete the client when vhost fails even when the
failure only results in a warning. The leads to an assertion failure
for the -netdev command line option.

The reverted commit was intended to avoid that the vhost initialization
failure won't result in a corrupted netdev. This problem should have
been fixed by deleting netdev when the initialization fails instead of
ignoring the failure with an arbitrary option. Fortunately, commit
bf769f742c ("virtio: del net client if net_init_tap_one failed"),
mentioned earlier, implements this behavior.

Restore the correct semantics and fix the assertion failure for the
-netdev command line option by reverting the problematic commit.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 include/net/vhost_net.h |  3 ---
 net/tap.c               | 22 +++++-----------------
 2 files changed, 5 insertions(+), 20 deletions(-)

diff --git a/include/net/vhost_net.h b/include/net/vhost_net.h
index c37aba35e6..c6a5361a2a 100644
--- a/include/net/vhost_net.h
+++ b/include/net/vhost_net.h
@@ -4,9 +4,6 @@
 #include "net/net.h"
 #include "hw/virtio/vhost-backend.h"
 
-#define VHOST_NET_INIT_FAILED \
-    "vhost-net requested but could not be initialized"
-
 struct vhost_net;
 typedef struct vhost_net VHostNetState;
 
diff --git a/net/tap.c b/net/tap.c
index c698b70475..baaa2f7a9a 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -743,11 +743,7 @@ static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer,
         if (vhostfdname) {
             vhostfd = monitor_fd_param(monitor_cur(), vhostfdname, &err);
             if (vhostfd == -1) {
-                if (tap->has_vhostforce && tap->vhostforce) {
-                    error_propagate(errp, err);
-                } else {
-                    warn_report_err(err);
-                }
+                error_propagate(errp, err);
                 goto failed;
             }
             if (!g_unix_set_fd_nonblocking(vhostfd, true, NULL)) {
@@ -758,13 +754,8 @@ static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer,
         } else {
             vhostfd = open("/dev/vhost-net", O_RDWR);
             if (vhostfd < 0) {
-                if (tap->has_vhostforce && tap->vhostforce) {
-                    error_setg_errno(errp, errno,
-                                     "tap: open vhost char device failed");
-                } else {
-                    warn_report("tap: open vhost char device failed: %s",
-                                strerror(errno));
-                }
+                error_setg_errno(errp, errno,
+                                 "tap: open vhost char device failed");
                 goto failed;
             }
             if (!g_unix_set_fd_nonblocking(vhostfd, true, NULL)) {
@@ -777,11 +768,8 @@ static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer,
 
         s->vhost_net = vhost_net_init(&options);
         if (!s->vhost_net) {
-            if (tap->has_vhostforce && tap->vhostforce) {
-                error_setg(errp, VHOST_NET_INIT_FAILED);
-            } else {
-                warn_report(VHOST_NET_INIT_FAILED);
-            }
+            error_setg(errp,
+                       "vhost-net requested but could not be initialized");
             goto failed;
         }
     } else if (vhostfdname) {
-- 
2.42.0

Re: [PULL 0/5] Net patches

[Peter Maydell]

On Fri, 29 Mar 2024 at 07:11, Jason Wang <jasowang@redhat.com> wrote:
>
> The following changes since commit 5012e522aca161be5c141596c66e5cc6082538a9:
>
>   Update version for v9.0.0-rc1 release (2024-03-26 19:46:55 +0000)
>
> are available in the Git repository at:
>
>   https://github.com/jasowang/qemu.git tags/net-pull-request
>
> for you to fetch changes up to d9b33018a0da51eddceb48c42345cfb351065f3e:
>
>   Revert "tap: setting error appropriately when calling net_init_tap_one()" (2024-03-29 14:59:07 +0800)
>

Applied, thanks.

Please update the changelog at https://wiki.qemu.org/ChangeLog/9.0
for any user-visible changes.

-- PMM

Re: [PULL 0/5] Net patches

[Michael Tokarev]

29.03.2024 10:10, Jason Wang:

> Akihiko Odaki (5):
>        virtio-net: Fix vhost virtqueue notifiers for RSS
>        ebpf: Fix indirections table setting
>        hw/net/net_tx_pkt: Fix virtio header without checksum offloading
>        tap-win32: Remove unnecessary stubs
>        Revert "tap: setting error appropriately when calling net_init_tap_one()"

 From the above, I'm picking up

   virtio-net: Fix vhost virtqueue notifiers for RSS
   hw/net/net_tx_pkt: Fix virtio header without checksum offloading

for stable.  Not yet sure about

   Revert "tap: setting error appropriately when calling net_init_tap_one()"

as it's been with us for a long time.

Please Cc: qemu-stable@ for changes which should be picked for stable
series.

Thanks,

/mjt

Re: [PULL 0/5] Net patches

[Jason Wang]

On Mon, Apr 1, 2024 at 3:21 AM Michael Tokarev <mjt@tls.msk.ru> wrote:
>
> 29.03.2024 10:10, Jason Wang:
>
> > Akihiko Odaki (5):
> >        virtio-net: Fix vhost virtqueue notifiers for RSS
> >        ebpf: Fix indirections table setting
> >        hw/net/net_tx_pkt: Fix virtio header without checksum offloading
> >        tap-win32: Remove unnecessary stubs
> >        Revert "tap: setting error appropriately when calling net_init_tap_one()"
>
>  From the above, I'm picking up
>
>    virtio-net: Fix vhost virtqueue notifiers for RSS
>    hw/net/net_tx_pkt: Fix virtio header without checksum offloading

Yes.

>
> for stable.  Not yet sure about
>
>    Revert "tap: setting error appropriately when calling net_init_tap_one()"
>
> as it's been with us for a long time.

It probably isn't worth bothering.

>
> Please Cc: qemu-stable@ for changes which should be picked for stable
> series.
>

Right.

Thanks

> Thanks,
>
> /mjt
>