4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Suzuki K Poulose <[email protected]> [ 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" <[email protected]> Cc: Jason Wang <[email protected]> Cc: Marc Zyngier <[email protected]> Cc: Christoffer Dall <[email protected]> Cc: Peter Maydel <[email protected]> Cc: Jean-Philippe Brucker <[email protected]> Signed-off-by: Suzuki K Poulose <[email protected]> Signed-off-by: Michael S. Tsirkin <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- 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); }
