From d6a9378f47515c6d70dbff4912c5740c98709880 Mon Sep 17 00:00:00 2001 From: Stefano Garzarella Date: Tue, 21 Sep 2021 18:16:41 +0200 Subject: [PATCH] vhost-vsock: fix migration issue when seqpacket is supported Commit 1e08fd0a46 ("vhost-vsock: SOCK_SEQPACKET feature bit support") enabled the SEQPACKET feature bit. This commit is released with QEMU 6.1, so if we try to migrate a VM where the host kernel supports SEQPACKET but machine type version is less than 6.1, we get the following errors: Features 0x130000002 unsupported. Allowed features: 0x179000000 Failed to load virtio-vhost_vsock:virtio error while loading state for instance 0x0 of device '0000:00:05.0/virtio-vhost_vsock' load of migration failed: Operation not permitted Let's disable the feature bit for machine types < 6.1. We add a new OnOffAuto property for this, called `seqpacket`. When it is `auto` (default), QEMU behaves as before, trying to enable the feature, when it is `on` QEMU will fail if the backend (vhost-vsock kernel module) doesn't support it. Fixes: 1e08fd0a46 ("vhost-vsock: SOCK_SEQPACKET feature bit support") Cc: qemu-stable@nongnu.org Reported-by: Jiang Wang Signed-off-by: Stefano Garzarella Message-Id: <20210921161642.206461-2-sgarzare@redhat.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/core/machine.c | 1 + hw/virtio/vhost-vsock.c | 19 ++++++++++++++++--- include/hw/virtio/vhost-vsock.h | 3 +++ 3 files changed, 20 insertions(+), 3 deletions(-) diff --git a/hw/core/machine.c b/hw/core/machine.c index 3920a2f2af..74f2a9a984 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -46,6 +46,7 @@ GlobalProperty hw_compat_6_0[] = { { "nvme-ns", "eui64-default", "off"}, { "e1000", "init-vet", "off" }, { "e1000e", "init-vet", "off" }, + { "vhost-vsock-device", "seqpacket", "off" }, }; const size_t hw_compat_6_0_len = G_N_ELEMENTS(hw_compat_6_0); diff --git a/hw/virtio/vhost-vsock.c b/hw/virtio/vhost-vsock.c index 1b1a5c70ed..dade0da031 100644 --- a/hw/virtio/vhost-vsock.c +++ b/hw/virtio/vhost-vsock.c @@ -114,10 +114,21 @@ static uint64_t vhost_vsock_get_features(VirtIODevice *vdev, Error **errp) { VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev); + VHostVSock *vsock = VHOST_VSOCK(vdev); - virtio_add_feature(&requested_features, VIRTIO_VSOCK_F_SEQPACKET); - return vhost_get_features(&vvc->vhost_dev, feature_bits, - requested_features); + if (vsock->seqpacket != ON_OFF_AUTO_OFF) { + virtio_add_feature(&requested_features, VIRTIO_VSOCK_F_SEQPACKET); + } + + requested_features = vhost_get_features(&vvc->vhost_dev, feature_bits, + requested_features); + + if (vsock->seqpacket == ON_OFF_AUTO_ON && + !virtio_has_feature(requested_features, VIRTIO_VSOCK_F_SEQPACKET)) { + error_setg(errp, "vhost-vsock backend doesn't support seqpacket"); + } + + return requested_features; } static const VMStateDescription vmstate_virtio_vhost_vsock = { @@ -218,6 +229,8 @@ static void vhost_vsock_device_unrealize(DeviceState *dev) static Property vhost_vsock_properties[] = { DEFINE_PROP_UINT64("guest-cid", VHostVSock, conf.guest_cid, 0), DEFINE_PROP_STRING("vhostfd", VHostVSock, conf.vhostfd), + DEFINE_PROP_ON_OFF_AUTO("seqpacket", VHostVSock, seqpacket, + ON_OFF_AUTO_AUTO), DEFINE_PROP_END_OF_LIST(), }; diff --git a/include/hw/virtio/vhost-vsock.h b/include/hw/virtio/vhost-vsock.h index 84f4e727c7..3f121a624f 100644 --- a/include/hw/virtio/vhost-vsock.h +++ b/include/hw/virtio/vhost-vsock.h @@ -30,6 +30,9 @@ struct VHostVSock { VHostVSockCommon parent; VHostVSockConf conf; + /* features */ + OnOffAuto seqpacket; + /*< public >*/ };