From 316b73277de233c7a9b6917077c00d7012060944 Mon Sep 17 00:00:00 2001 From: Si-Wei Liu Date: Fri, 6 May 2022 19:28:13 -0700 Subject: [PATCH 09/16] virtio-net: align ctrl_vq index for non-mq guest for vhost_vdpa MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Jason Wang RH-MergeRequest: 98: Multiqueue fixes for vhost-vDPA RH-Commit: [2/7] 7f764bbb579c7b473ad67fc25b46e698d277e781 (jasowang/qemu-kvm-cs) RH-Bugzilla: 2070804 RH-Acked-by: Eugenio Pérez RH-Acked-by: Laurent Vivier RH-Acked-by: Cindy Lu With MQ enabled vdpa device and non-MQ supporting guest e.g. booting vdpa with mq=on over OVMF of single vqp, below assert failure is seen: ../hw/virtio/vhost-vdpa.c:560: vhost_vdpa_get_vq_index: Assertion `idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs' failed. 0 0x00007f8ce3ff3387 in raise () at /lib64/libc.so.6 1 0x00007f8ce3ff4a78 in abort () at /lib64/libc.so.6 2 0x00007f8ce3fec1a6 in __assert_fail_base () at /lib64/libc.so.6 3 0x00007f8ce3fec252 in () at /lib64/libc.so.6 4 0x0000558f52d79421 in vhost_vdpa_get_vq_index (dev=, idx=) at ../hw/virtio/vhost-vdpa.c:563 5 0x0000558f52d79421 in vhost_vdpa_get_vq_index (dev=, idx=) at ../hw/virtio/vhost-vdpa.c:558 6 0x0000558f52d7329a in vhost_virtqueue_mask (hdev=0x558f55c01800, vdev=0x558f568f91f0, n=2, mask=) at ../hw/virtio/vhost.c:1557 7 0x0000558f52c6b89a in virtio_pci_set_guest_notifier (d=d@entry=0x558f568f0f60, n=n@entry=2, assign=assign@entry=true, with_irqfd=with_irqfd@entry=false) at ../hw/virtio/virtio-pci.c:974 8 0x0000558f52c6c0d8 in virtio_pci_set_guest_notifiers (d=0x558f568f0f60, nvqs=3, assign=true) at ../hw/virtio/virtio-pci.c:1019 9 0x0000558f52bf091d in vhost_net_start (dev=dev@entry=0x558f568f91f0, ncs=0x558f56937cd0, data_queue_pairs=data_queue_pairs@entry=1, cvq=cvq@entry=1) at ../hw/net/vhost_net.c:361 10 0x0000558f52d4e5e7 in virtio_net_set_status (status=, n=0x558f568f91f0) at ../hw/net/virtio-net.c:289 11 0x0000558f52d4e5e7 in virtio_net_set_status (vdev=0x558f568f91f0, status=15 '\017') at ../hw/net/virtio-net.c:370 12 0x0000558f52d6c4b2 in virtio_set_status (vdev=vdev@entry=0x558f568f91f0, val=val@entry=15 '\017') at ../hw/virtio/virtio.c:1945 13 0x0000558f52c69eff in virtio_pci_common_write (opaque=0x558f568f0f60, addr=, val=, size=) at ../hw/virtio/virtio-pci.c:1292 14 0x0000558f52d15d6e in memory_region_write_accessor (mr=0x558f568f19d0, addr=20, value=, size=1, shift=, mask=, attrs=...) at ../softmmu/memory.c:492 15 0x0000558f52d127de in access_with_adjusted_size (addr=addr@entry=20, value=value@entry=0x7f8cdbffe748, size=size@entry=1, access_size_min=, access_size_max=, access_fn=0x558f52d15cf0 , mr=0x558f568f19d0, attrs=...) at ../softmmu/memory.c:554 16 0x0000558f52d157ef in memory_region_dispatch_write (mr=mr@entry=0x558f568f19d0, addr=20, data=, op=, attrs=attrs@entry=...) at ../softmmu/memory.c:1504 17 0x0000558f52d078e7 in flatview_write_continue (fv=fv@entry=0x7f8accbc3b90, addr=addr@entry=103079215124, attrs=..., ptr=ptr@entry=0x7f8ce6300028, len=len@entry=1, addr1=, l=, mr=0x558f568f19d0) at /home/opc/qemu-upstream/include/qemu/host-utils.h:165 18 0x0000558f52d07b06 in flatview_write (fv=0x7f8accbc3b90, addr=103079215124, attrs=..., buf=0x7f8ce6300028, len=1) at ../softmmu/physmem.c:2822 19 0x0000558f52d0b36b in address_space_write (as=, addr=, attrs=..., buf=buf@entry=0x7f8ce6300028, len=) at ../softmmu/physmem.c:2914 20 0x0000558f52d0b3da in address_space_rw (as=, addr=, attrs=..., attrs@entry=..., buf=buf@entry=0x7f8ce6300028, len=, is_write=) at ../softmmu/physmem.c:2924 21 0x0000558f52dced09 in kvm_cpu_exec (cpu=cpu@entry=0x558f55c2da60) at ../accel/kvm/kvm-all.c:2903 22 0x0000558f52dcfabd in kvm_vcpu_thread_fn (arg=arg@entry=0x558f55c2da60) at ../accel/kvm/kvm-accel-ops.c:49 23 0x0000558f52f9f04a in qemu_thread_start (args=) at ../util/qemu-thread-posix.c:556 24 0x00007f8ce4392ea5 in start_thread () at /lib64/libpthread.so.0 25 0x00007f8ce40bb9fd in clone () at /lib64/libc.so.6 The cause for the assert failure is due to that the vhost_dev index for the ctrl vq was not aligned with actual one in use by the guest. Upon multiqueue feature negotiation in virtio_net_set_multiqueue(), if guest doesn't support multiqueue, the guest vq layout would shrink to a single queue pair, consisting of 3 vqs in total (rx, tx and ctrl). This results in ctrl_vq taking a different vhost_dev group index than the default. We can map vq to the correct vhost_dev group by checking if MQ is supported by guest and successfully negotiated. Since the MQ feature is only present along with CTRL_VQ, we ensure the index 2 is only meant for the control vq while MQ is not supported by guest. Fixes: 22288fe ("virtio-net: vhost control virtqueue support") Suggested-by: Jason Wang Signed-off-by: Si-Wei Liu Acked-by: Jason Wang Message-Id: <1651890498-24478-3-git-send-email-si-wei.liu@oracle.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin (cherry picked from commit 68b0a6395f36a8f48f56f46d05f30be2067598b0) Signed-off-by: Jason Wang --- hw/net/virtio-net.c | 33 +++++++++++++++++++++++++++++++-- 1 file changed, 31 insertions(+), 2 deletions(-) diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index ffb3475201..f0bb29c741 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -14,6 +14,7 @@ #include "qemu/osdep.h" #include "qemu/atomic.h" #include "qemu/iov.h" +#include "qemu/log.h" #include "qemu/main-loop.h" #include "qemu/module.h" #include "hw/virtio/virtio.h" @@ -3171,8 +3172,22 @@ static NetClientInfo net_virtio_info = { static bool virtio_net_guest_notifier_pending(VirtIODevice *vdev, int idx) { VirtIONet *n = VIRTIO_NET(vdev); - NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(idx)); + NetClientState *nc; assert(n->vhost_started); + if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_MQ) && idx == 2) { + /* Must guard against invalid features and bogus queue index + * from being set by malicious guest, or penetrated through + * buggy migration stream. + */ + if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) { + qemu_log_mask(LOG_GUEST_ERROR, + "%s: bogus vq index ignored\n", __func__); + return false; + } + nc = qemu_get_subqueue(n->nic, n->max_queue_pairs); + } else { + nc = qemu_get_subqueue(n->nic, vq2q(idx)); + } return vhost_net_virtqueue_pending(get_vhost_net(nc->peer), idx); } @@ -3180,8 +3195,22 @@ static void virtio_net_guest_notifier_mask(VirtIODevice *vdev, int idx, bool mask) { VirtIONet *n = VIRTIO_NET(vdev); - NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(idx)); + NetClientState *nc; assert(n->vhost_started); + if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_MQ) && idx == 2) { + /* Must guard against invalid features and bogus queue index + * from being set by malicious guest, or penetrated through + * buggy migration stream. + */ + if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) { + qemu_log_mask(LOG_GUEST_ERROR, + "%s: bogus vq index ignored\n", __func__); + return; + } + nc = qemu_get_subqueue(n->nic, n->max_queue_pairs); + } else { + nc = qemu_get_subqueue(n->nic, vq2q(idx)); + } vhost_net_virtqueue_mask(get_vhost_net(nc->peer), vdev, idx, mask); } -- 2.31.1