> -----Original Message----- > From: dev <dev-boun...@dpdk.org> On Behalf Of Maxime Coquelin > Sent: Thursday, May 28, 2020 5:04 PM > To: dev@dpdk.org; Ye, Xiaolong <xiaolong...@intel.com>; > amore...@redhat.com; david.march...@redhat.com; tho...@monjalon.net > Cc: Maxime Coquelin <maxime.coque...@redhat.com> > Subject: [dpdk-dev] [PATCH v2] vhost: enable reply-ack systematically > > As announced during v20.05 release cycle, this patch makes reply-ack protocol > feature to be enabled unconditionally. > > This protocol feature makes the communication between the master and the > slave more robust, avoiding for example possible undefined behaviour with > VHOST_USER_SET_MEM_TABLE. > > Also, reply-ack support will be required for upcoming VHOST_USER_SET_STATUS > request. > > Note that this protocol feature was disabled by default because Qemu version > 2.7.0 to 2.9.0 had a bug causing a deadlock when reply-ack was negotiated and > multiqueue enabled. These Qemu version are now very old and no more > maintained, so we can resonnably consider we no more support them. > > Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com> > --- > > v2: > - Fix commit message > - Remove mention to the workaround in the doc > > doc/guides/prog_guide/vhost_lib.rst | 5 ----- > lib/librte_vhost/vhost_user.c | 9 --------- > 2 files changed, 14 deletions(-) > > diff --git a/doc/guides/prog_guide/vhost_lib.rst > b/doc/guides/prog_guide/vhost_lib.rst > index 07e40e3c5e..db921f922b 100644 > --- a/doc/guides/prog_guide/vhost_lib.rst > +++ b/doc/guides/prog_guide/vhost_lib.rst > @@ -104,11 +104,6 @@ The following is an overview of some key Vhost API > functions: > from accessing memory the virtio device isn't allowed to, when the > feature > is negotiated and an IOMMU device is declared. > > - However, this feature enables vhost-user's reply-ack protocol feature, > - which implementation is buggy in Qemu v2.7.0-v2.9.0 when doing > multiqueue. > - Enabling this flag with these Qemu version results in Qemu being blocked > - when multiple queue pairs are declared. > - > - ``RTE_VHOST_USER_POSTCOPY_SUPPORT`` > > Postcopy live-migration support will be enabled when this flag is set. > diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c > index > 84bebad792..ea9cd107b9 100644 > --- a/lib/librte_vhost/vhost_user.c > +++ b/lib/librte_vhost/vhost_user.c > @@ -2012,15 +2012,6 @@ vhost_user_get_protocol_features(struct virtio_net > **pdev, > rte_vhost_driver_get_features(dev->ifname, &features); > rte_vhost_driver_get_protocol_features(dev->ifname, > &protocol_features); > > - /* > - * REPLY_ACK protocol feature is only mandatory for now > - * for IOMMU feature. If IOMMU is explicitly disabled by the > - * application, disable also REPLY_ACK feature for older buggy > - * Qemu versions (from v2.7.0 to v2.9.0). > - */ > - if (!(features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))) > - protocol_features &= ~(1ULL << > VHOST_USER_PROTOCOL_F_REPLY_ACK); > - > msg->payload.u64 = protocol_features; > msg->size = sizeof(msg->payload.u64); > msg->fd_num = 0; > -- > 2.26.2
Reviewed-by: Chenbo Xia <chenbo....@intel.com>
