4.9-stable review patch. If anyone has any objections, please let me know.
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From: Suzuki K Poulose suzuki.poulose@arm.com
[ Upstream commit 69599206ea9a3f8f2e94d46580579cbf9d08ad6c ]
Legacy PCI over virtio uses a 32bit PFN for the queue. If the queue pfn is too large to fit in 32bits, which we could hit on arm64 systems with 52bit physical addresses (even with 64K page size), we simply miss out a proper link to the other side of the queue.
Add a check to validate the PFN, rather than silently breaking the devices.
Cc: "Michael S. Tsirkin" mst@redhat.com Cc: Jason Wang jasowang@redhat.com Cc: Marc Zyngier marc.zyngier@arm.com Cc: Christoffer Dall cdall@kernel.org Cc: Peter Maydel peter.maydell@linaro.org Cc: Jean-Philippe Brucker jean-philippe.brucker@arm.com Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com Signed-off-by: Michael S. Tsirkin mst@redhat.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/virtio/virtio_pci_legacy.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)
--- a/drivers/virtio/virtio_pci_legacy.c +++ b/drivers/virtio/virtio_pci_legacy.c @@ -121,6 +121,7 @@ static struct virtqueue *setup_vq(struct struct virtqueue *vq; u16 num; int err; + u64 q_pfn;
/* Select the queue we're interested in */ iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL); @@ -139,9 +140,17 @@ static struct virtqueue *setup_vq(struct if (!vq) return ERR_PTR(-ENOMEM);
+ q_pfn = virtqueue_get_desc_addr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT; + if (q_pfn >> 32) { + dev_err(&vp_dev->pci_dev->dev, + "platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n", + 0x1ULL << (32 + PAGE_SHIFT - 30)); + err = -E2BIG; + goto out_del_vq; + } + /* activate the queue */ - iowrite32(virtqueue_get_desc_addr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT, - vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN); + iowrite32(q_pfn, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
vq->priv = (void __force *)vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY;
@@ -158,6 +167,7 @@ static struct virtqueue *setup_vq(struct
out_deactivate: iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN); +out_del_vq: vring_del_virtqueue(vq); return ERR_PTR(err); }