Hi, Could you please help/guide me here. As suggested by Jason I did other changes also. But when I did testing still virtio-net.c functions like 'receive()' gets called when vhost is 'ON'.
I want to know is there anything I am missing here or is this expected behaviour? I was also searching for "kvm eventfd support for injecting level-triggered interrupts", For non-MSIX guests, can we remove vhost-force unless we have this feature? Best regards, Pankaj ----- Original Message ----- > From: "Jason Wang" <jasow...@redhat.com> > To: "Pankaj Gupta" <pagu...@redhat.com> > Cc: "Michael S. Tsirkin" <m...@redhat.com>, qemu-devel@nongnu.org, > stefa...@redhat.com, aligu...@amazon.com > Sent: Sunday, February 15, 2015 8:11:29 AM > Subject: Re: [Qemu-devel] [RFC] net: 'Remove vhostforce option in > addition to vhost param' > > > > On Thu, Feb 12, 2015 at 11:41 PM, Pankaj Gupta <pagu...@redhat.com> > wrote: > > > >> > >> > On Thu, Feb 12, 2015 at 11:50:05AM +0530, Pankaj Gupta wrote: > >> > > vhostforce was added to enable use of vhost when > >> > > guest don't have MSI-X support. > >> > > Now, we have scenarios which dont use interrupts > >> > > like DPDK and still use vhost. Also, performance of > >> > > guests without MSI-X support is getting less popular. > >> > > > >> > > Its ok to remove this extra option and enable vhost > >> > > on the basis of vhost=ON/OFF. > >> > > > >> > > Signed-off-by: Pankaj Gupta <pagu...@redhat.com> > >> > > >> > The patch doesn't seem to do what it says. > >> > Did you try with a non MSIX guest and vhost=on, to check that > >> > it actually runs vhost and not userspace virtio? > >> > >> No, I have not. I just did basic tested a new guest without > >> vhostforce. > >> I will test non-MSIX guest and share the result. > > > > I tested this with RHEL 4 guest which don't have MSI-X. Though vhost > > gets > > created but still userspace virtio-net code executes. > > > > So, vhostforce was added to disable vhost for non-MSI guest? > > In fact to enable vhost. > > > > I took the idea from KVM/Networking todo list. > > > > Do we have some other dependency before we want to remove vhostforce? > > > > You may want to take a look at the vhost_dev->force and > vhost_dev_query(). > > > >> > >> > > >> > > --- > >> > > net/tap.c | 4 +--- > >> > > net/vhost-user.c | 16 ++-------------- > >> > > 2 files changed, 3 insertions(+), 17 deletions(-) > >> > > > >> > > diff --git a/net/tap.c b/net/tap.c > >> > > index 1fe0edf..bd2efa9 100644 > >> > > --- a/net/tap.c > >> > > +++ b/net/tap.c > >> > > @@ -634,13 +634,11 @@ static int net_init_tap_one(const > >> NetdevTapOptions > >> > > *tap, NetClientState *peer, > >> > > } > >> > > } > >> > > > >> > > - if (tap->has_vhost ? tap->vhost : > >> > > - vhostfdname || (tap->has_vhostforce && > >> tap->vhostforce)) { > >> > > + if (tap->has_vhost ? tap->vhost : vhostfdname) { > >> > > VhostNetOptions options; > >> > > > >> > > options.backend_type = VHOST_BACKEND_TYPE_KERNEL; > >> > > options.net_backend = &s->nc; > >> > > - options.force = tap->has_vhostforce && tap->vhostforce; > >> > > > >> > > if (tap->has_vhostfd || tap->has_vhostfds) { > >> > > vhostfd = monitor_handle_fd_param(cur_mon, > >> vhostfdname); > >> > > diff --git a/net/vhost-user.c b/net/vhost-user.c > >> > > index 24e050c..d2d7bf2 100644 > >> > > --- a/net/vhost-user.c > >> > > +++ b/net/vhost-user.c > >> > > @@ -18,7 +18,6 @@ > >> > > typedef struct VhostUserState { > >> > > NetClientState nc; > >> > > CharDriverState *chr; > >> > > - bool vhostforce; > >> > > VHostNetState *vhost_net; > >> > > } VhostUserState; > >> > > > >> > > @@ -51,7 +50,6 @@ static int vhost_user_start(VhostUserState *s) > >> > > options.backend_type = VHOST_BACKEND_TYPE_USER; > >> > > options.net_backend = &s->nc; > >> > > options.opaque = s->chr; > >> > > - options.force = s->vhostforce; > >> > > > >> > > s->vhost_net = vhost_net_init(&options); > >> > > > >> > > @@ -133,8 +131,7 @@ static void net_vhost_user_event(void > >> *opaque, int > >> > > event) > >> > > } > >> > > > >> > > static int net_vhost_user_init(NetClientState *peer, const > >> char *device, > >> > > - const char *name, > >> CharDriverState *chr, > >> > > - bool vhostforce) > >> > > + const char *name, > >> CharDriverState *chr) > >> > > { > >> > > NetClientState *nc; > >> > > VhostUserState *s; > >> > > @@ -149,7 +146,6 @@ static int > >> net_vhost_user_init(NetClientState *peer, > >> > > const char *device, > >> > > /* We don't provide a receive callback */ > >> > > s->nc.receive_disabled = 1; > >> > > s->chr = chr; > >> > > - s->vhostforce = vhostforce; > >> > > > >> > > qemu_chr_add_handlers(s->chr, NULL, NULL, > >> net_vhost_user_event, s); > >> > > > >> > > @@ -230,7 +226,6 @@ int net_init_vhost_user(const > >> NetClientOptions *opts, > >> > > const char *name, > >> > > { > >> > > const NetdevVhostUserOptions *vhost_user_opts; > >> > > CharDriverState *chr; > >> > > - bool vhostforce; > >> > > > >> > > assert(opts->kind == NET_CLIENT_OPTIONS_KIND_VHOST_USER); > >> > > vhost_user_opts = opts->vhost_user; > >> > > @@ -247,12 +242,5 @@ int net_init_vhost_user(const > >> NetClientOptions > >> > > *opts, > >> > > const char *name, > >> > > return -1; > >> > > } > >> > > > >> > > - /* vhostforce for non-MSIX */ > >> > > - if (vhost_user_opts->has_vhostforce) { > >> > > - vhostforce = vhost_user_opts->vhostforce; > >> > > - } else { > >> > > - vhostforce = false; > >> > > - } > >> > > - > >> > > - return net_vhost_user_init(peer, "vhost_user", name, chr, > >> > > vhostforce); > >> > > + return net_vhost_user_init(peer, "vhost_user", name, chr); > >> > > } > >> > > -- > >> > > 1.8.3.1 > >> > > >> > > >> > > > >