[v1] pc,pci,virtio: bugfixes, improvements

[PULL 04/13] virtio-pci: Added check for virtio device presence in mm callbacks.

Michael S. Tsirkin posted 13 patches 4 years, 7 months ago

Diff against v1
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Maintainers: Eduardo Habkost <ehabkost@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, Kevin Wolf <kwolf@redhat.com>, Igor Mammedov <imammedo@redhat.com>, Stefan Hajnoczi <stefanha@redhat.com>, Thomas Huth <thuth@redhat.com>, Cornelia Huck <cohuck@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, David Hildenbrand <david@redhat.com>, Fam Zheng <fam@euphon.net>, Christian Borntraeger <borntraeger@de.ibm.com>, Max Reitz <mreitz@redhat.com>, "Michael S. Tsirkin" <mst@redhat.com>, Halil Pasic <pasic@linux.ibm.com>, Jason Wang <jasowang@redhat.com>

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[PULL 04/13] virtio-pci: Added check for virtio device presence in mm callbacks.

Posted by Michael S. Tsirkin 4 years, 7 months ago

From: Andrew Melnychenko <andrew@daynix.com>

During unplug the virtio device is unplugged from virtio-bus on pci. In some cases,
requests to virtio-pci mm may acquire during/after unplug. Added check that virtio
device is on the bus, for "common" memory region.

Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Message-Id: <20210609095843.141378-2-andrew@daynix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/virtio/virtio-pci.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index f1e105fa52..1bef7a2be8 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1147,6 +1147,10 @@ static uint64_t virtio_pci_common_read(void *opaque, hwaddr addr,
     uint32_t val = 0;
     int i;
 
+    if (vdev == NULL) {
+        return UINT64_MAX;
+    }
+
     switch (addr) {
     case VIRTIO_PCI_COMMON_DFSELECT:
         val = proxy->dfselect;
@@ -1230,6 +1234,10 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr,
     VirtIOPCIProxy *proxy = opaque;
     VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
 
+    if (vdev == NULL) {
+        return;
+    }
+
     switch (addr) {
     case VIRTIO_PCI_COMMON_DFSELECT:
         proxy->dfselect = val;
-- 
MST