| Message ID | 1437459483-24535-3-git-send-email-fan.du@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On 21/07/15 07:18, Fan Du wrote: > vhost kernel driver does not support mutiple queue yet, > Tweak queue number will fail with "--net mode=tap,vhost=1,mq=2" > as below when lkvm trying to set ring kick fd for queue 2: > > VHOST_SET_VRING_KICK failed: No buffer space available > > Error on this scenario, and overide with the default one queue > configuration. I don't like the idea of overriding an explicitly given command line parameter (mq=2). So why do you provide mq=2 in the first place if you know that the kernel does not support it? I'd rather see the error message to be more descriptive in that case. That would help the user to understand what's going on, also it would still work should the kernel ever support multiple queues in the future. Cheers, Andre. > > Signed-off-by: Fan Du <fan.du@intel.com> > --- > virtio/net.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/virtio/net.c b/virtio/net.c > index d343615..21a80f3 100644 > --- a/virtio/net.c > +++ b/virtio/net.c > @@ -730,6 +730,10 @@ static int set_net_param(struct kvm *kvm, struct virtio_net_params *p, > p->mq = atoi(val); > } else > die("Unknown network parameter %s", param); > + if (p->vhost && p->mq > 1) { > + p->mq = 1; > + pr_err("vhost does not support mq yet, overide mq to 1."); > + } > > return 0; > } > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
>-----Original Message----- >From: Andre Przywara [mailto:andre.przywara@arm.com] >Sent: Tuesday, July 21, 2015 5:45 PM >To: Du, Fan; Will Deacon >Cc: kvm@vger.kernel.org; Marc Zyngier >Subject: Re: [PATCHv3 2/2] kvmtool: Restrict virtio queue number to 1 when >vhost on > >Hi, > >On 21/07/15 07:18, Fan Du wrote: >> vhost kernel driver does not support mutiple queue yet, >> Tweak queue number will fail with "--net mode=tap,vhost=1,mq=2" >> as below when lkvm trying to set ring kick fd for queue 2: >> >> VHOST_SET_VRING_KICK failed: No buffer space available >> >> Error on this scenario, and overide with the default one queue >> configuration. > >I don't like the idea of overriding an explicitly given command line >parameter (mq=2). >So why do you provide mq=2 in the first place if you know that the >kernel does not support it? On the contrary, the help message doesn't explicitly state mq is not supported when vhost=1, what's the insanity to supply with mq option?! >I'd rather see the error message to be more descriptive in that case. >That would help the user to understand what's going on, also it would >still work should the kernel ever support multiple queues in the future. I will check how it could be support, either in user land or kernel. So let's drop this patch. >Cheers, >Andre. > >> >> Signed-off-by: Fan Du <fan.du@intel.com> >> --- >> virtio/net.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/virtio/net.c b/virtio/net.c >> index d343615..21a80f3 100644 >> --- a/virtio/net.c >> +++ b/virtio/net.c >> @@ -730,6 +730,10 @@ static int set_net_param(struct kvm *kvm, struct >virtio_net_params *p, >> p->mq = atoi(val); >> } else >> die("Unknown network parameter %s", param); >> + if (p->vhost && p->mq > 1) { >> + p->mq = 1; >> + pr_err("vhost does not support mq yet, overide mq to 1."); >> + } >> >> return 0; >> } >> -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/virtio/net.c b/virtio/net.c index d343615..21a80f3 100644 --- a/virtio/net.c +++ b/virtio/net.c @@ -730,6 +730,10 @@ static int set_net_param(struct kvm *kvm, struct virtio_net_params *p, p->mq = atoi(val); } else die("Unknown network parameter %s", param); + if (p->vhost && p->mq > 1) { + p->mq = 1; + pr_err("vhost does not support mq yet, overide mq to 1."); + } return 0; }
vhost kernel driver does not support mutiple queue yet, Tweak queue number will fail with "--net mode=tap,vhost=1,mq=2" as below when lkvm trying to set ring kick fd for queue 2: VHOST_SET_VRING_KICK failed: No buffer space available Error on this scenario, and overide with the default one queue configuration. Signed-off-by: Fan Du <fan.du@intel.com> --- virtio/net.c | 4 ++++ 1 file changed, 4 insertions(+)