VT-d: apply quirks at device setup time rather than only at boot

Accessing extended config space may not be possible at boot time, e.g.
when the memory space used by MMCFG is reserved only via ACPI tables,
but not in the E820/UEFI memory maps (which we need Dom0 to tell us
about). Consequently the change here still leaves the issue unaddressed
for systems where the extended config space remains inaccessible (due
to firmware bugs, i.e. not properly reserving the address space of
those regions).

With the respective messages now potentially getting logged more than
once, we ought to consider whether we should issue them only if we in
fact were required to do any masking (i.e. if the relevant mask bits
weren't already set).

This is CVE-2013-3495 / XSA-59.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Xiantao Zhang <xiantao.zhang@intel.com>
Acked-by: Yang Zhang <yang.z.zhang@intel.com>
master commit: 5786718fbaafbe47d72cc1512cd93de79b8fc2fa
master date: 2014-05-20 15:53:20 +0200

diff --git a/xen/drivers/passthrough/vtd/extern.h b/xen/drivers/passthrough/vtd/extern.h
index 14cd90ee982a9085ff4a6ac48b089a3162c1922b..afe7fafa73100ff84b75a33709092545f6dc05bf 100644 (file)
--- a/xen/drivers/passthrough/vtd/extern.h
+++ b/xen/drivers/passthrough/vtd/extern.h
@@ -99,7 +99,7 @@ void platform_quirks_init(void);
 void vtd_ops_preamble_quirk(struct iommu* iommu);
 void vtd_ops_postamble_quirk(struct iommu* iommu);
 void me_wifi_quirk(struct domain *domain, u8 bus, u8 devfn, int map);
-void pci_vtd_quirk(struct pci_dev *pdev);
+void pci_vtd_quirk(const struct pci_dev *);
 int platform_supports_intremap(void);
 int platform_supports_x2apic(void);
 

diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c
index 7ba1be789fee72a57df1d6f5197c250a67c84966..61740d25ba8ec67a32456795f57b36c73b6bda23 100644 (file)
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -1475,6 +1475,9 @@ static int domain_context_mapping(
         break;
     }
 
+    if ( !ret && devfn == pdev->devfn )
+        pci_vtd_quirk(pdev);
+
     return ret;
 }
 
@@ -1905,6 +1908,8 @@ static int intel_iommu_enable_device(struct pci_dev *pdev)
     struct acpi_drhd_unit *drhd = acpi_find_matched_drhd_unit(pdev);
     int ret = drhd ? ats_device(pdev, drhd) : -ENODEV;
 
+    pci_vtd_quirk(pdev);
+
     if ( ret <= 0 )
         return ret;
 
@@ -1976,12 +1981,7 @@ static int intel_iommu_remove_device(u8 devfn, struct pci_dev *pdev)
 
 static int __init setup_dom0_device(u8 devfn, struct pci_dev *pdev)
 {
-    int err;
-
-    err = domain_context_mapping(pdev->domain, devfn, pdev);
-    if ( !err && devfn == pdev->devfn )
-        pci_vtd_quirk(pdev);
-    return err;
+    return domain_context_mapping(pdev->domain, devfn, pdev);
 }
 
 void clear_fault_bits(struct iommu *iommu)

diff --git a/xen/drivers/passthrough/vtd/quirks.c b/xen/drivers/passthrough/vtd/quirks.c
index 2bbcc21c9fa876807202d69f3375ff3d4d06de7e..7cbe0ad8ec5ded5d842d9c313cf5430779b21958 100644 (file)
--- a/xen/drivers/passthrough/vtd/quirks.c
+++ b/xen/drivers/passthrough/vtd/quirks.c
@@ -385,7 +385,7 @@ void me_wifi_quirk(struct domain *domain, u8 bus, u8 devfn, int map)
  *   - This can cause system failure upon non-fatal VT-d faults
  *   - Potential security issue if malicious guest trigger VT-d faults
  */
-void __init pci_vtd_quirk(struct pci_dev *pdev)
+void pci_vtd_quirk(const struct pci_dev *pdev)
 {
     int seg = pdev->seg;
     int bus = pdev->bus;