From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40017) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZdwkN-0008PG-CL for qemu-devel@nongnu.org; Mon, 21 Sep 2015 04:46:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZdwkK-0008KX-5K for qemu-devel@nongnu.org; Mon, 21 Sep 2015 04:46:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45627) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZdwkJ-0008KR-UI for qemu-devel@nongnu.org; Mon, 21 Sep 2015 04:46:48 -0400 Date: Mon, 21 Sep 2015 11:46:43 +0300 From: "Michael S. Tsirkin" Message-ID: <20150921114601-mutt-send-email-mst@redhat.com> References: <1442657533-13030-1-git-send-email-marcandre.lureau@redhat.com> <1442657533-13030-13-git-send-email-marcandre.lureau@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <1442657533-13030-13-git-send-email-marcandre.lureau@redhat.com> Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v4 12/22] vhost: only use shared log if in use by backend List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: marcandre.lureau@redhat.com Cc: haifeng.lin@huawei.com, thibaut.collet@6wind.com, jasowang@redhat.com, qemu-devel@nongnu.org, pbonzini@redhat.com On Sat, Sep 19, 2015 at 12:12:03PM +0200, marcandre.lureau@redhat.com wro= te: > From: Marc-Andr=E9 Lureau >=20 > Do not allocate a shared log if the backend doesn't support it. >=20 > Signed-off-by: Marc-Andr=E9 Lureau If not there, we probably want to block live migration, correct? > --- > hw/virtio/vhost-user.c | 9 +++++++++ > hw/virtio/vhost.c | 15 ++++++++++----- > include/hw/virtio/vhost-backend.h | 4 ++++ > 3 files changed, 23 insertions(+), 5 deletions(-) >=20 > diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c > index 3cb5559..d12cd66 100644 > --- a/hw/virtio/vhost-user.c > +++ b/hw/virtio/vhost-user.c > @@ -508,10 +508,19 @@ static int vhost_user_cleanup(struct vhost_dev *d= ev) > return 0; > } > =20 > +static bool vhost_user_want_shm_log(struct vhost_dev *dev) > +{ > + assert(dev->vhost_ops->backend_type =3D=3D VHOST_BACKEND_TYPE_USER= ); > + > + return virtio_has_feature(dev->protocol_features, > + VHOST_USER_PROTOCOL_F_LOG_SHMFD); > +} > + > const VhostOps user_ops =3D { > .backend_type =3D VHOST_BACKEND_TYPE_USER, > .vhost_backend_init =3D vhost_user_init, > .vhost_backend_cleanup =3D vhost_user_cleanup, > + .vhost_backend_want_shm_log =3D vhost_user_want_shm_log, > =20 > .vhost_net_set_backend =3D vhost_net_set_backend, > .vhost_scsi_set_endpoint =3D vhost_scsi_set_endpoint, > diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c > index 0fa7b69..d5070fb 100644 > --- a/hw/virtio/vhost.c > +++ b/hw/virtio/vhost.c > @@ -350,10 +350,15 @@ static void vhost_log_put(struct vhost_dev *dev, = bool sync) > } > } > =20 > -static inline void vhost_dev_log_resize(struct vhost_dev* dev, uint64_= t size) > +static bool vhost_dev_log_is_shared(struct vhost_dev *dev) > { > - bool share =3D dev->vhost_ops->backend_type =3D=3D VHOST_BACKEND_T= YPE_USER; > - struct vhost_log *log =3D vhost_log_get(size, share); > + return dev->vhost_ops->vhost_backend_want_shm_log && > + dev->vhost_ops->vhost_backend_want_shm_log(dev); > +} > + > +static inline void vhost_dev_log_resize(struct vhost_dev *dev, uint64_= t size) > +{ > + struct vhost_log *log =3D vhost_log_get(size, vhost_dev_log_is_sha= red(dev)); > uint64_t log_base =3D (uintptr_t)log->log; > int r; > =20 > @@ -1161,10 +1166,10 @@ int vhost_dev_start(struct vhost_dev *hdev, Vir= tIODevice *vdev) > =20 > if (hdev->log_enabled) { > uint64_t log_base; > - bool share =3D hdev->vhost_ops->backend_type =3D=3D VHOST_BACK= END_TYPE_USER; > =20 > hdev->log_size =3D vhost_get_log_size(hdev); > - hdev->log =3D vhost_log_get(hdev->log_size, share); > + hdev->log =3D vhost_log_get(hdev->log_size, > + vhost_dev_log_is_shared(hdev)); > log_base =3D (uintptr_t)hdev->log->log; > r =3D hdev->vhost_ops->vhost_set_log_base(hdev, > hdev->log_size ? log_b= ase : 0, > diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhos= t-backend.h > index a87f0b3..44bf200 100644 > --- a/include/hw/virtio/vhost-backend.h > +++ b/include/hw/virtio/vhost-backend.h > @@ -11,6 +11,8 @@ > #ifndef VHOST_BACKEND_H_ > #define VHOST_BACKEND_H_ > =20 > +#include > + > typedef enum VhostBackendType { > VHOST_BACKEND_TYPE_NONE =3D 0, > VHOST_BACKEND_TYPE_KERNEL =3D 1, > @@ -28,6 +30,7 @@ struct vhost_scsi_target; > =20 > typedef int (*vhost_backend_init)(struct vhost_dev *dev, void *opaque)= ; > typedef int (*vhost_backend_cleanup)(struct vhost_dev *dev); > +typedef bool (*vhost_backend_want_shm_log)(struct vhost_dev *dev); > =20 > typedef int (*vhost_net_set_backend_op)(struct vhost_dev *dev, > struct vhost_vring_file *file)= ; > @@ -67,6 +70,7 @@ typedef struct VhostOps { > =20 > vhost_backend_init vhost_backend_init; > vhost_backend_cleanup vhost_backend_cleanup; > + vhost_backend_want_shm_log vhost_backend_want_shm_log; > =20 > vhost_net_set_backend_op vhost_net_set_backend; > vhost_scsi_set_endpoint_op vhost_scsi_set_endpoint; > --=20 > 2.4.3