| Message ID | 1434650744-6585-1-git-send-email-marcel@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Thu, Jun 18, 2015 at 09:05:44PM +0300, Marcel Apfelbaum wrote: > Clear host multi-queue related features if the peer > doesn't support it. > > Signed-off-by: Marcel Apfelbaum <marcel@redhat.com> > --- > Notes: > This fixes a guest CPU soft lock, however the virtio-net > device will not work correctly. It seems that is > peer's "fault", not knowing how to handle the situation. > However, I submit this patch since it corrects the negotiation > and saves us from a guest crash (!). > > Any ideas from the virtio/multi-queue developers on how to debug > this further are welcomed. > > hw/net/virtio-net.c | 13 ++++++++++++- > 1 file changed, 12 insertions(+), 1 deletion(-) > > diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c > index 9281aa1..63e59e8 100644 > --- a/hw/net/virtio-net.c > +++ b/hw/net/virtio-net.c > @@ -367,6 +367,11 @@ static int peer_has_ufo(VirtIONet *n) > return n->has_ufo; > } > > +static int peer_has_multiqueue(VirtIONet *n) > +{ > + return n->multiqueue; > +} > + > static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs, > int version_1) > { > @@ -469,6 +474,13 @@ static uint64_t virtio_net_get_features(VirtIODevice *vdev, uint64_t features) > virtio_clear_feature(&features, VIRTIO_NET_F_HOST_UFO); > } > > + if (!peer_has_multiqueue(n)) { > + virtio_clear_feature(&features, VIRTIO_NET_F_MQ); > + virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_ANNOUNCE); > + virtio_clear_feature(&features, VIRTIO_NET_F_CTRL_VQ); > + virtio_clear_feature(&features, VIRTIO_NET_F_CTRL_RX); > + } > + > if (!get_vhost_net(nc->peer)) { > virtio_add_feature(&features, VIRTIO_F_VERSION_1); > return features; _MQ makes sense but what about the rest? Why clear them? > @@ -1314,7 +1326,6 @@ static void virtio_net_tx_bh(void *opaque) > static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue) > { > n->multiqueue = multiqueue; > - > virtio_net_set_queues(n); > } > > -- > 2.1.0
On 06/23/2015 12:57 PM, Michael S. Tsirkin wrote: > On Thu, Jun 18, 2015 at 09:05:44PM +0300, Marcel Apfelbaum wrote: >> Clear host multi-queue related features if the peer >> doesn't support it. >> >> Signed-off-by: Marcel Apfelbaum <marcel@redhat.com> >> --- >> Notes: >> This fixes a guest CPU soft lock, however the virtio-net >> device will not work correctly. It seems that is >> peer's "fault", not knowing how to handle the situation. >> However, I submit this patch since it corrects the negotiation >> and saves us from a guest crash (!). >> >> Any ideas from the virtio/multi-queue developers on how to debug >> this further are welcomed. >> >> hw/net/virtio-net.c | 13 ++++++++++++- >> 1 file changed, 12 insertions(+), 1 deletion(-) >> >> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c >> index 9281aa1..63e59e8 100644 >> --- a/hw/net/virtio-net.c >> +++ b/hw/net/virtio-net.c >> @@ -367,6 +367,11 @@ static int peer_has_ufo(VirtIONet *n) >> return n->has_ufo; >> } >> >> +static int peer_has_multiqueue(VirtIONet *n) >> +{ >> + return n->multiqueue; >> +} >> + >> static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs, >> int version_1) >> { >> @@ -469,6 +474,13 @@ static uint64_t virtio_net_get_features(VirtIODevice *vdev, uint64_t features) >> virtio_clear_feature(&features, VIRTIO_NET_F_HOST_UFO); >> } >> >> + if (!peer_has_multiqueue(n)) { >> + virtio_clear_feature(&features, VIRTIO_NET_F_MQ); >> + virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_ANNOUNCE); >> + virtio_clear_feature(&features, VIRTIO_NET_F_CTRL_VQ); >> + virtio_clear_feature(&features, VIRTIO_NET_F_CTRL_RX); >> + } >> + >> if (!get_vhost_net(nc->peer)) { >> virtio_add_feature(&features, VIRTIO_F_VERSION_1); >> return features; > > _MQ makes sense but what about the rest? Why clear them? Guest's virtio driver doesn't like if MQ is off and any of the other flags remains ON. It has a specific check for each of them and fails the loading if not all are off. Thanks, Marcel > >> @@ -1314,7 +1326,6 @@ static void virtio_net_tx_bh(void *opaque) >> static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue) >> { >> n->multiqueue = multiqueue; >> - >> virtio_net_set_queues(n); >> } >> >> -- >> 2.1.0
On Tue, Jun 23, 2015 at 01:23:10PM +0300, Marcel Apfelbaum wrote: > On 06/23/2015 12:57 PM, Michael S. Tsirkin wrote: > >On Thu, Jun 18, 2015 at 09:05:44PM +0300, Marcel Apfelbaum wrote: > >>Clear host multi-queue related features if the peer > >>doesn't support it. > >> > >>Signed-off-by: Marcel Apfelbaum <marcel@redhat.com> > >>--- > >>Notes: > >> This fixes a guest CPU soft lock, however the virtio-net > >> device will not work correctly. It seems that is > >> peer's "fault", not knowing how to handle the situation. > >> However, I submit this patch since it corrects the negotiation > >> and saves us from a guest crash (!). > >> > >> Any ideas from the virtio/multi-queue developers on how to debug > >> this further are welcomed. > >> > >> hw/net/virtio-net.c | 13 ++++++++++++- > >> 1 file changed, 12 insertions(+), 1 deletion(-) > >> > >>diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c > >>index 9281aa1..63e59e8 100644 > >>--- a/hw/net/virtio-net.c > >>+++ b/hw/net/virtio-net.c > >>@@ -367,6 +367,11 @@ static int peer_has_ufo(VirtIONet *n) > >> return n->has_ufo; > >> } > >> > >>+static int peer_has_multiqueue(VirtIONet *n) > >>+{ > >>+ return n->multiqueue; > >>+} > >>+ > >> static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs, > >> int version_1) > >> { > >>@@ -469,6 +474,13 @@ static uint64_t virtio_net_get_features(VirtIODevice *vdev, uint64_t features) > >> virtio_clear_feature(&features, VIRTIO_NET_F_HOST_UFO); > >> } > >> > >>+ if (!peer_has_multiqueue(n)) { > >>+ virtio_clear_feature(&features, VIRTIO_NET_F_MQ); > >>+ virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_ANNOUNCE); > >>+ virtio_clear_feature(&features, VIRTIO_NET_F_CTRL_VQ); > >>+ virtio_clear_feature(&features, VIRTIO_NET_F_CTRL_RX); > >>+ } > >>+ > >> if (!get_vhost_net(nc->peer)) { > >> virtio_add_feature(&features, VIRTIO_F_VERSION_1); > >> return features; > > > >_MQ makes sense but what about the rest? Why clear them? > Guest's virtio driver doesn't like if MQ is off and any of the other flags remains ON. > It has a specific check for each of them and fails the loading if not all are off. > > Thanks, > Marcel I think you are mistaken. if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) && (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX, "VIRTIO_NET_F_CTRL_VQ") || VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN, "VIRTIO_NET_F_CTRL_VQ") || VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE, "VIRTIO_NET_F_CTRL_VQ") || VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") || VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR, "VIRTIO_NET_F_CTRL_VQ"))) { return false; } return true; So if CTRL VQ is not set, you can not have MQ or any of the others. > > > >>@@ -1314,7 +1326,6 @@ static void virtio_net_tx_bh(void *opaque) > >> static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue) > >> { > >> n->multiqueue = multiqueue; > >>- > >> virtio_net_set_queues(n); > >> } > >> > >>-- > >>2.1.0
On 06/19/2015 02:05 AM, Marcel Apfelbaum wrote: > Clear host multi-queue related features if the peer > doesn't support it. > > Signed-off-by: Marcel Apfelbaum <marcel@redhat.com> > --- > Notes: > This fixes a guest CPU soft lock, however the virtio-net > device will not work correctly. It seems that is > peer's "fault", not knowing how to handle the situation. > However, I submit this patch since it corrects the negotiation > and saves us from a guest crash (!). Could you please describe how to reproduce this issue? > > Any ideas from the virtio/multi-queue developers on how to debug > this further are welcomed. > > hw/net/virtio-net.c | 13 ++++++++++++- > 1 file changed, 12 insertions(+), 1 deletion(-) > > diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c > index 9281aa1..63e59e8 100644 > --- a/hw/net/virtio-net.c > +++ b/hw/net/virtio-net.c > @@ -367,6 +367,11 @@ static int peer_has_ufo(VirtIONet *n) > return n->has_ufo; > } > > +static int peer_has_multiqueue(VirtIONet *n) > +{ > + return n->multiqueue; > +} The name is confusing, this is in fact whether or not guest support multiqueue. To check peer's ability, you need check n->nic_conf.peers.queues instead. > + > static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs, > int version_1) > { > @@ -469,6 +474,13 @@ static uint64_t virtio_net_get_features(VirtIODevice *vdev, uint64_t features) > virtio_clear_feature(&features, VIRTIO_NET_F_HOST_UFO); > } > > + if (!peer_has_multiqueue(n)) { > + virtio_clear_feature(&features, VIRTIO_NET_F_MQ); I'm not quite understand this, VIRTIO_NET_F_MQ should work if peer has only 1 queue. > + virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_ANNOUNCE); > + virtio_clear_feature(&features, VIRTIO_NET_F_CTRL_VQ); > + virtio_clear_feature(&features, VIRTIO_NET_F_CTRL_RX); > + } > + Those features don't depend on multiqueue, why clear them? > if (!get_vhost_net(nc->peer)) { > virtio_add_feature(&features, VIRTIO_F_VERSION_1); > return features; > @@ -1314,7 +1326,6 @@ static void virtio_net_tx_bh(void *opaque) > static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue) > { > n->multiqueue = multiqueue; > - > virtio_net_set_queues(n); > } >
On 06/24/2015 11:00 AM, Jason Wang wrote: > > > On 06/19/2015 02:05 AM, Marcel Apfelbaum wrote: >> Clear host multi-queue related features if the peer >> doesn't support it. >> >> Signed-off-by: Marcel Apfelbaum <marcel@redhat.com> >> --- >> Notes: >> This fixes a guest CPU soft lock, however the virtio-net >> device will not work correctly. It seems that is >> peer's "fault", not knowing how to handle the situation. >> However, I submit this patch since it corrects the negotiation >> and saves us from a guest crash (!). > > Could you please describe how to reproduce this issue? Hi Jason, Sorry for the late reply. I was hoping that a vhost-user multi-queue "insider" will ask questions :) This happens when we have OVS as backend without multi-queue support and qemu/guest with multi-queue-support. > >> >> Any ideas from the virtio/multi-queue developers on how to debug >> this further are welcomed. >> >> hw/net/virtio-net.c | 13 ++++++++++++- >> 1 file changed, 12 insertions(+), 1 deletion(-) >> >> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c >> index 9281aa1..63e59e8 100644 >> --- a/hw/net/virtio-net.c >> +++ b/hw/net/virtio-net.c >> @@ -367,6 +367,11 @@ static int peer_has_ufo(VirtIONet *n) >> return n->has_ufo; >> } >> >> +static int peer_has_multiqueue(VirtIONet *n) >> +{ >> + return n->multiqueue; >> +} > > The name is confusing, this is in fact whether or not guest support > multiqueue. To check peer's ability, you need check > n->nic_conf.peers.queues instead. I just wanted to mimic similar code, I have no issue against this approach. > >> + >> static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs, >> int version_1) >> { >> @@ -469,6 +474,13 @@ static uint64_t virtio_net_get_features(VirtIODevice *vdev, uint64_t features) >> virtio_clear_feature(&features, VIRTIO_NET_F_HOST_UFO); >> } >> >> + if (!peer_has_multiqueue(n)) { >> + virtio_clear_feature(&features, VIRTIO_NET_F_MQ); > > I'm not quite understand this, VIRTIO_NET_F_MQ should work if peer has > only 1 queue. Please explain, I thought VIRTIO_NET_F_MQ flag *enables* multi-queue, and in our case we pass queue=2 to vhost. > >> + virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_ANNOUNCE); >> + virtio_clear_feature(&features, VIRTIO_NET_F_CTRL_VQ); >> + virtio_clear_feature(&features, VIRTIO_NET_F_CTRL_RX); >> + } >> + > > Those features don't depend on multiqueue, why clear them? Once VIRTIO_NET_F_MQ is cleared, the virtio driver from guest is complaining about those other flags too. Any explanations about how *it should* work are welcomed. Again, the scenario is: backend doesn't support multi-queue, QEMU/guest do, and queues=2 is passed on command line. Thanks, Marcel > >> if (!get_vhost_net(nc->peer)) { >> virtio_add_feature(&features, VIRTIO_F_VERSION_1); >> return features; >> @@ -1314,7 +1326,6 @@ static void virtio_net_tx_bh(void *opaque) >> static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue) >> { >> n->multiqueue = multiqueue; >> - >> virtio_net_set_queues(n); >> } >> >
On 06/23/2015 01:56 PM, Michael S. Tsirkin wrote: > On Tue, Jun 23, 2015 at 01:23:10PM +0300, Marcel Apfelbaum wrote: >> On 06/23/2015 12:57 PM, Michael S. Tsirkin wrote: >>> On Thu, Jun 18, 2015 at 09:05:44PM +0300, Marcel Apfelbaum wrote: >>>> Clear host multi-queue related features if the peer >>>> doesn't support it. >>>> >>>> Signed-off-by: Marcel Apfelbaum <marcel@redhat.com> >>>> --- >>>> Notes: >>>> This fixes a guest CPU soft lock, however the virtio-net >>>> device will not work correctly. It seems that is >>>> peer's "fault", not knowing how to handle the situation. >>>> However, I submit this patch since it corrects the negotiation >>>> and saves us from a guest crash (!). >>>> >>>> Any ideas from the virtio/multi-queue developers on how to debug >>>> this further are welcomed. >>>> >>>> hw/net/virtio-net.c | 13 ++++++++++++- >>>> 1 file changed, 12 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c >>>> index 9281aa1..63e59e8 100644 >>>> --- a/hw/net/virtio-net.c >>>> +++ b/hw/net/virtio-net.c >>>> @@ -367,6 +367,11 @@ static int peer_has_ufo(VirtIONet *n) >>>> return n->has_ufo; >>>> } >>>> >>>> +static int peer_has_multiqueue(VirtIONet *n) >>>> +{ >>>> + return n->multiqueue; >>>> +} >>>> + >>>> static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs, >>>> int version_1) >>>> { >>>> @@ -469,6 +474,13 @@ static uint64_t virtio_net_get_features(VirtIODevice *vdev, uint64_t features) >>>> virtio_clear_feature(&features, VIRTIO_NET_F_HOST_UFO); >>>> } >>>> >>>> + if (!peer_has_multiqueue(n)) { >>>> + virtio_clear_feature(&features, VIRTIO_NET_F_MQ); >>>> + virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_ANNOUNCE); >>>> + virtio_clear_feature(&features, VIRTIO_NET_F_CTRL_VQ); >>>> + virtio_clear_feature(&features, VIRTIO_NET_F_CTRL_RX); >>>> + } >>>> + >>>> if (!get_vhost_net(nc->peer)) { >>>> virtio_add_feature(&features, VIRTIO_F_VERSION_1); >>>> return features; >>> >>> _MQ makes sense but what about the rest? Why clear them? >> Guest's virtio driver doesn't like if MQ is off and any of the other flags remains ON. >> It has a specific check for each of them and fails the loading if not all are off. >> >> Thanks, >> Marcel > > > I think you are mistaken. > > if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) && > (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX, > "VIRTIO_NET_F_CTRL_VQ") || > VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN, > "VIRTIO_NET_F_CTRL_VQ") || > VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE, > "VIRTIO_NET_F_CTRL_VQ") || > VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") || > VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR, > "VIRTIO_NET_F_CTRL_VQ"))) { > return false; > } > > return true; > > So if CTRL VQ is not set, you can not have MQ or any of the others. > Hmm, I know what saw, but I don't fully understand why is happening. I'll give another try and I'll return with more info. Thanks, Marcel > > >>> >>>> @@ -1314,7 +1326,6 @@ static void virtio_net_tx_bh(void *opaque) >>>> static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue) >>>> { >>>> n->multiqueue = multiqueue; >>>> - >>>> virtio_net_set_queues(n); >>>> } >>>> >>>> -- >>>> 2.1.0 >
On 06/26/2015 12:54 AM, Marcel Apfelbaum wrote: > On 06/24/2015 11:00 AM, Jason Wang wrote: >> >> >> On 06/19/2015 02:05 AM, Marcel Apfelbaum wrote: >>> Clear host multi-queue related features if the peer >>> doesn't support it. >>> >>> Signed-off-by: Marcel Apfelbaum <marcel@redhat.com> >>> --- >>> Notes: >>> This fixes a guest CPU soft lock, however the virtio-net >>> device will not work correctly. It seems that is >>> peer's "fault", not knowing how to handle the situation. >>> However, I submit this patch since it corrects the negotiation >>> and saves us from a guest crash (!). >> >> Could you please describe how to reproduce this issue? > Hi Jason, > Sorry for the late reply. > I was hoping that a vhost-user multi-queue "insider" will ask > questions :) > > This happens when we have OVS as backend without multi-queue support > and qemu/guest with multi-queue-support. > > >> >>> >>> Any ideas from the virtio/multi-queue developers on how to debug >>> this further are welcomed. >>> >>> hw/net/virtio-net.c | 13 ++++++++++++- >>> 1 file changed, 12 insertions(+), 1 deletion(-) >>> >>> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c >>> index 9281aa1..63e59e8 100644 >>> --- a/hw/net/virtio-net.c >>> +++ b/hw/net/virtio-net.c >>> @@ -367,6 +367,11 @@ static int peer_has_ufo(VirtIONet *n) >>> return n->has_ufo; >>> } >>> >>> +static int peer_has_multiqueue(VirtIONet *n) >>> +{ >>> + return n->multiqueue; >>> +} >> >> The name is confusing, this is in fact whether or not guest support >> multiqueue. To check peer's ability, you need check >> n->nic_conf.peers.queues instead. > I just wanted to mimic similar code, I have no issue against > this approach. > >> >>> + >>> static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int >>> mergeable_rx_bufs, >>> int version_1) >>> { >>> @@ -469,6 +474,13 @@ static uint64_t >>> virtio_net_get_features(VirtIODevice *vdev, uint64_t features) >>> virtio_clear_feature(&features, VIRTIO_NET_F_HOST_UFO); >>> } >>> >>> + if (!peer_has_multiqueue(n)) { >>> + virtio_clear_feature(&features, VIRTIO_NET_F_MQ); >> >> I'm not quite understand this, VIRTIO_NET_F_MQ should work if peer has >> only 1 queue. > Please explain, I thought VIRTIO_NET_F_MQ flag *enables* > multi-queue, and in our case we pass queue=2 to vhost. > >> >>> + virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_ANNOUNCE); >>> + virtio_clear_feature(&features, VIRTIO_NET_F_CTRL_VQ); >>> + virtio_clear_feature(&features, VIRTIO_NET_F_CTRL_RX); >>> + } >>> + >> >> Those features don't depend on multiqueue, why clear them? > Once VIRTIO_NET_F_MQ is cleared, the virtio driver from guest is > complaining > about those other flags too. > > Any explanations about how *it should* work are welcomed. > Again, the scenario is: backend doesn't support multi-queue, > QEMU/guest do, > and queues=2 is passed on command line. > In this case, backend should just fail the initialization like what we've done for tap. I believe vhost-user should check whether or not its backend can support up to 2 queues and fail if not. Thanks > > Thanks, > Marcel >> >>> if (!get_vhost_net(nc->peer)) { >>> virtio_add_feature(&features, VIRTIO_F_VERSION_1); >>> return features; >>> @@ -1314,7 +1326,6 @@ static void virtio_net_tx_bh(void *opaque) >>> static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue) >>> { >>> n->multiqueue = multiqueue; >>> - >>> virtio_net_set_queues(n); >>> } >>> >> >
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index 9281aa1..63e59e8 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -367,6 +367,11 @@ static int peer_has_ufo(VirtIONet *n) return n->has_ufo; } +static int peer_has_multiqueue(VirtIONet *n) +{ + return n->multiqueue; +} + static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs, int version_1) { @@ -469,6 +474,13 @@ static uint64_t virtio_net_get_features(VirtIODevice *vdev, uint64_t features) virtio_clear_feature(&features, VIRTIO_NET_F_HOST_UFO); } + if (!peer_has_multiqueue(n)) { + virtio_clear_feature(&features, VIRTIO_NET_F_MQ); + virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_ANNOUNCE); + virtio_clear_feature(&features, VIRTIO_NET_F_CTRL_VQ); + virtio_clear_feature(&features, VIRTIO_NET_F_CTRL_RX); + } + if (!get_vhost_net(nc->peer)) { virtio_add_feature(&features, VIRTIO_F_VERSION_1); return features; @@ -1314,7 +1326,6 @@ static void virtio_net_tx_bh(void *opaque) static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue) { n->multiqueue = multiqueue; - virtio_net_set_queues(n); }
Clear host multi-queue related features if the peer doesn't support it. Signed-off-by: Marcel Apfelbaum <marcel@redhat.com> --- Notes: This fixes a guest CPU soft lock, however the virtio-net device will not work correctly. It seems that is peer's "fault", not knowing how to handle the situation. However, I submit this patch since it corrects the negotiation and saves us from a guest crash (!). Any ideas from the virtio/multi-queue developers on how to debug this further are welcomed. hw/net/virtio-net.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)