From d6cb14b34ffc2a830022d059f1aa22bf19dcf55f Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Fri, 25 Apr 2014 12:12:38 +0200 Subject: [PATCH] VT-d: suppress UR signaling for desktop chipsets Unsupported Requests can be signaled for malformed writes to the MSI address region, e.g. due to buggy or malicious DMA set up to that region. These should normally result in IOMMU faults, but don't on the desktop chipsets dealt with here. This is CVE-2013-3495 / XSA-59. Signed-off-by: Jan Beulich Reviewed-by: Andrew Cooper Acked-by: Don Dugger Acked-by: Tim Deegan Acked-by: Xiantao Zhang --- xen/drivers/passthrough/vtd/quirks.c | 30 ++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/xen/drivers/passthrough/vtd/quirks.c b/xen/drivers/passthrough/vtd/quirks.c index 464e1c1841..56ffd6bf35 100644 --- a/xen/drivers/passthrough/vtd/quirks.c +++ b/xen/drivers/passthrough/vtd/quirks.c @@ -393,6 +393,8 @@ void __hwdom_init pci_vtd_quirk(struct pci_dev *pdev) int func = PCI_FUNC(pdev->devfn); int pos; u32 val; + u64 bar; + paddr_t pa; if ( pci_conf_read16(seg, bus, dev, func, PCI_VENDOR_ID) != PCI_VENDOR_ID_INTEL ) @@ -454,5 +456,33 @@ void __hwdom_init pci_vtd_quirk(struct pci_dev *pdev) printk(XENLOG_INFO "Masked UR signaling on %04x:%02x:%02x.%u\n", seg, bus, dev, func); break; + + case 0x100: case 0x104: case 0x108: /* Sandybridge */ + case 0x150: case 0x154: case 0x158: /* Ivybridge */ + case 0xa04: /* Haswell ULT */ + case 0xc00: case 0xc04: case 0xc08: /* Haswell */ + bar = pci_conf_read32(seg, bus, dev, func, 0x6c); + bar = (bar << 32) | pci_conf_read32(seg, bus, dev, func, 0x68); + pa = bar & 0x7fffff000; /* bits 12...38 */ + if ( (bar & 1) && pa && + page_is_ram_type(paddr_to_pfn(pa), RAM_TYPE_RESERVED) ) + { + u32 __iomem *va = ioremap(pa, PAGE_SIZE); + + if ( va ) + { + __set_bit(0x1c8 * 8 + 20, va); + iounmap(va); + printk(XENLOG_INFO "Masked UR signaling on %04x:%02x:%02x.%u\n", + seg, bus, dev, func); + } + else + printk(XENLOG_ERR "Could not map %"PRIpaddr" for %04x:%02x:%02x.%u\n", + pa, seg, bus, dev, func); + } + else + printk(XENLOG_WARNING "Bogus DMIBAR %#"PRIx64" on %04x:%02x:%02x.%u\n", + bar, seg, bus, dev, func); + break; } } -- 2.39.5