From 04ceb61a4075fadbf374ef89662c41999da83489 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 29 Apr 2021 19:13:15 +0200 Subject: [PATCH] virtio: Fail if iommu_platform is requested, but unsupported Commit 2943b53f6 (' virtio: force VIRTIO_F_IOMMU_PLATFORM') made sure that vhost can't just reject VIRTIO_F_IOMMU_PLATFORM when it was requested. However, just adding it back to the negotiated flags isn't right either because it promises support to the guest that the device actually doesn't support. One example of a vhost-user device that doesn't have support for the flag is the vhost-user-blk export of QEMU. Instead of successfully creating a device that doesn't work, just fail to plug the device when it doesn't support the feature, but it was requested. This results in much clearer error messages. Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1935019 Signed-off-by: Kevin Wolf Reviewed-by: Raphael Norwitz Message-Id: <20210429171316.162022-6-kwolf@redhat.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Kevin Wolf --- hw/virtio/virtio-bus.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/hw/virtio/virtio-bus.c b/hw/virtio/virtio-bus.c index d6332d45c3..859978d248 100644 --- a/hw/virtio/virtio-bus.c +++ b/hw/virtio/virtio-bus.c @@ -69,6 +69,11 @@ void virtio_bus_device_plugged(VirtIODevice *vdev, Error **errp) return; } + if (has_iommu && !virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM)) { + error_setg(errp, "iommu_platform=true is not supported by the device"); + return; + } + if (klass->device_plugged != NULL) { klass->device_plugged(qbus->parent, &local_err); }