From 826eb17271d3c647516d9944c47b0779afedea25 Mon Sep 17 00:00:00 2001 From: Ian Jackson Date: Mon, 1 Jul 2013 15:20:28 +0100 Subject: libxl: suppress device assignment to HVM guest when there is no IOMMU This in effect copies similar logic from xend: While there's no way to check whether a device is assigned to a particular guest, XEN_DOMCTL_test_assign_device at least allows checking whether an IOMMU is there and whether a device has been assign to _some_ guest. For the time being, this should be enough to cover for the missing error checking/recovery in other parts of libxl's device assignment paths. There remains a (functionality-, but not security-related) race in that the iommu should be set up earlier, but this is too risky a change for this stage of the 4.3 release. This is a security issue, XSA-61. Signed-off-by: Jan Beulich Tested-by: George Dunlap Acked-by: George Dunlap Acked-by: Ian Jackson --- tools/libxl/libxl_pci.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'tools/libxl') diff --git a/tools/libxl/libxl_pci.c b/tools/libxl/libxl_pci.c index 2f9f010cb3..88bf91ebbf 100644 --- a/tools/libxl/libxl_pci.c +++ b/tools/libxl/libxl_pci.c @@ -1036,6 +1036,18 @@ int libxl__device_pci_add(libxl__gc *gc, uint32_t domid, libxl_device_pci *pcide int num_assigned, i, rc; int stubdomid = 0; + if (libxl__domain_type(gc, domid) == LIBXL_DOMAIN_TYPE_HVM) { + rc = xc_test_assign_device(ctx->xch, domid, pcidev_encode_bdf(pcidev)); + if (rc) { + LIBXL__LOG(ctx, LIBXL__LOG_ERROR, + "PCI device %04x:%02x:%02x.%u %s?", + pcidev->domain, pcidev->bus, pcidev->dev, pcidev->func, + errno == ENOSYS ? "cannot be assigned - no IOMMU" + : "already assigned to a different guest"); + goto out; + } + } + rc = libxl__device_pci_setdefault(gc, pcidev); if (rc) goto out; -- cgit v1.2.3