From 6ea069651e72e6ee282e79e59ea0367d3f2f90e2 Mon Sep 17 00:00:00 2001 From: Maxime Coquelin Date: Mon, 6 Nov 2017 21:38:10 +0100 Subject: [PATCH] vhost: disable reply-ack feature if IOMMU disabled If the application has disabled VIRTIO_F_IOMMU_PLATFORM, disable VHOST_USER_PROTOCOL_F_REPLY_ACK protocol feature that is only mandatory with IOMMU for now. This is done to provide a way for the application to support multiqueue with old Qemu versions (v2.7.0 to v2.9.0) that have reply-ack feature broken. Signed-off-by: Maxime Coquelin Acked-by: Yuanhan Liu Tested-by: Mark Kavanagh Acked-by: Mark Kavanagh --- lib/librte_vhost/vhost_user.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c index 6fbdac5979..f4c7ce462f 100644 --- a/lib/librte_vhost/vhost_user.c +++ b/lib/librte_vhost/vhost_user.c @@ -860,6 +860,27 @@ vhost_user_set_vring_enable(struct virtio_net *dev, return 0; } +static void +vhost_user_get_protocol_features(struct virtio_net *dev, + struct VhostUserMsg *msg) +{ + uint64_t features, protocol_features = VHOST_USER_PROTOCOL_FEATURES; + + rte_vhost_driver_get_features(dev->ifname, &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); +} + static void vhost_user_set_protocol_features(struct virtio_net *dev, uint64_t protocol_features) @@ -1231,8 +1252,7 @@ vhost_user_msg_handler(int vid, int fd) break; case VHOST_USER_GET_PROTOCOL_FEATURES: - msg.payload.u64 = VHOST_USER_PROTOCOL_FEATURES; - msg.size = sizeof(msg.payload.u64); + vhost_user_get_protocol_features(dev, &msg); send_vhost_reply(fd, &msg); break; case VHOST_USER_SET_PROTOCOL_FEATURES: -- 2.20.1