From: Maxime Coquelin Date: Thu, 28 May 2020 09:03:47 +0000 (+0200) Subject: vhost: enable reply-ack systematically X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=d1c074bd7663b3eb009eff30aff3306d242f4a61;p=dpdk.git 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 reasonably consider we no more support them. Signed-off-by: Maxime Coquelin Reviewed-by: Chenbo Xia --- 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;