On Friday 07 August 2009, Mark McLoughlin wrote:
> slirp has started using VLANClientState::opaque and this has caused the
> kvm specific tap_has_vnet_hdr() hack to break because we blindly use
> this opaque pointer even if it is not a tap client.
>
> Add yet another hack to check that we're actually getting called with a
> tap client.
>
> [Needed on stable-0.11 too]
>
> Signed-off-by: Mark McLoughlin <markmc@xxxxxxxxxx>
Jens and I discovered the same bug before, but then we forgot about
sending a fix (sorry). Your patch should work fine as a workaround,
but I wonder if it is the right solution.
The abstraction of struct VLANClientState is otherwise done through
function pointers taking the VLANClientState pointer as their
first argument. IMHO a cleaner abstraction would be to do the same
for tap_has_vnet_hdr(), like the patch below, and similar for
other functions passing 'opaque' pointers.
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
diff --git a/hw/virtio-net.c b/hw/virtio-net.c
index 6dfe758..6b34e82 100644
--- a/hw/virtio-net.c
+++ b/hw/virtio-net.c
@@ -123,7 +123,7 @@ static uint32_t virtio_net_get_features(VirtIODevice *vdev)
VirtIONet *n = to_virtio_net(vdev);
VLANClientState *host = n->vc->vlan->first_client;
- if (tap_has_vnet_hdr(host)) {
+ if (host->has_vnet_hdr && host->has_vnet_hdr(host)) {
tap_using_vnet_hdr(host, 1);
features |= (1 << VIRTIO_NET_F_CSUM);
features |= (1 << VIRTIO_NET_F_GUEST_CSUM);
@@ -166,7 +166,7 @@ static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)
n->mergeable_rx_bufs = !!(features & (1 << VIRTIO_NET_F_MRG_RXBUF));
#ifdef TAP_VNET_HDR
- if (!tap_has_vnet_hdr(host) || !host->set_offload)
+ if (!(host->has_vnet_hdr && host->has_vnet_hdr(host)) || !host->set_offload)
return;
host->set_offload(host,
@@ -398,7 +398,7 @@ static int receive_header(VirtIONet *n, struct iovec *iov, int iovcnt,
hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
#ifdef TAP_VNET_HDR
- if (tap_has_vnet_hdr(n->vc->vlan->first_client)) {
+ if ((host->has_vnet_hdr && host->has_vnet_hdr(n->vc->vlan->first_client))) {
memcpy(hdr, buf, sizeof(*hdr));
offset = sizeof(*hdr);
work_around_broken_dhclient(hdr, buf + offset, size - offset);
@@ -425,7 +425,8 @@ static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
return 1;
#ifdef TAP_VNET_HDR
- if (tap_has_vnet_hdr(n->vc->vlan->first_client))
+ if ((host->has_vnet_hdr &&
+ host->has_vnet_hdr(n->vc->vlan->first_client)))
ptr += sizeof(struct virtio_net_hdr);
#endif
@@ -529,7 +530,8 @@ static void virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
{
VirtQueueElement elem;
#ifdef TAP_VNET_HDR
- int has_vnet_hdr = tap_has_vnet_hdr(n->vc->vlan->first_client);
+ int has_vnet_hdr = (host->has_vnet_hdr &&
+ host->has_vnet_hdr(n->vc->vlan->first_client));
#else
int has_vnet_hdr = 0;
#endif
@@ -620,7 +622,7 @@ static void virtio_net_save(QEMUFile *f, void *opaque)
qemu_put_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
#ifdef TAP_VNET_HDR
- qemu_put_be32(f, tap_has_vnet_hdr(n->vc->vlan->first_client));
+ qemu_put_be32(f, (host->has_vnet_hdr && host->has_vnet_hdr(n->vc->vlan->first_client)));
#else
qemu_put_be32(f, 0);
#endif
diff --git a/net.c b/net.c
index 931def1..b56ae78 100644
--- a/net.c
+++ b/net.c
@@ -754,7 +754,7 @@ static void vmchannel_read(void *opaque, const uint8_t *buf, int size)
#ifdef _WIN32
-int tap_has_vnet_hdr(void *opaque)
+static int tap_has_vnet_hdr(struct VLANClientState *vc)
{
return 0;
}
@@ -906,9 +906,8 @@ static void tap_send(void *opaque)
} while (s->size > 0);
}
-int tap_has_vnet_hdr(void *opaque)
+static int tap_has_vnet_hdr(struct VLANClientState *vc)
{
- VLANClientState *vc = opaque;
TAPState *s = vc->opaque;
return s ? s->has_vnet_hdr : 0;
@@ -991,6 +990,7 @@ static TAPState *net_tap_fd_init(VLANState *vlan,
s->has_vnet_hdr = vnet_hdr != 0;
s->vc = qemu_new_vlan_client(vlan, model, name, tap_receive,
NULL, tap_cleanup, s);
+ s->vc->has_vnet_hdr = tap_has_vnet_hdr;
s->vc->fd_readv = tap_receive_iov;
#ifdef TUNSETOFFLOAD
s->vc->set_offload = tap_set_offload;
diff --git a/net.h b/net.h
index bc42428..7c79734 100644
--- a/net.h
+++ b/net.h
@@ -21,6 +21,7 @@ struct VLANClientState {
IOCanRWHandler *fd_can_read;
NetCleanup *cleanup;
LinkStatusChanged *link_status_changed;
+ int (*has_vnet_hdr)(struct VLANClientState *);
int link_down;
SetOffload *set_offload;
void *opaque;
@@ -72,7 +73,6 @@ void qemu_handler_true(void *opaque);
void do_info_network(Monitor *mon);
int do_set_link(Monitor *mon, const char *name, const char *up_or_down);
-int tap_has_vnet_hdr(void *opaque);
void tap_using_vnet_hdr(void *opaque, int using_vnet_hdr);
/* NIC info */
--
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