[Xen-changelog] [xen-unstable] Intel VTD: Ignore USB RMRR for HVM guest

[Xen patchbot-unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1205922169 0
# Node ID 70f9a2110421cc6f4ce066eb80d4c639a28643bd
# Parent  b8e3dbca1677e3fffeb8bf8baedc895c90d4e619
Intel VTD: Ignore USB RMRR for HVM guest

USB controller RMRR (0xed000 - 0xeffff) conflicts with HVM guest bios
region. Setting identity mapping for it will cover the guest bios
region in p2m table. This causes system crash.

As VT-d spec says, USB controller RMRR is used in case of DMA
performed by a USB controller under BIOS SMM control for legacy
keyboard emulation. Whereas, current guest BIOS doesn't support
emulating stardand Keyboard/mouse, and it also doesn't support SMM
mode. Actually it is no chance to use USB controller RMRR now.

This patch ignores the USB controller RMRR for HVM guest.

Signed-off-by: Weidong Han <weidong.han@xxxxxxxxx>
---
 xen/drivers/passthrough/vtd/dmar.h  |    1 +
 xen/drivers/passthrough/vtd/iommu.c |    6 ++++++
 xen/drivers/passthrough/vtd/utils.c |    9 +++++++++
 3 files changed, 16 insertions(+)

diff -r b8e3dbca1677 -r 70f9a2110421 xen/drivers/passthrough/vtd/dmar.h
--- a/xen/drivers/passthrough/vtd/dmar.h        Wed Mar 19 10:21:01 2008 +0000
+++ b/xen/drivers/passthrough/vtd/dmar.h        Wed Mar 19 10:22:49 2008 +0000
@@ -100,5 +100,6 @@ struct acpi_rmrr_unit * acpi_find_matche
 
 int vtd_hw_check(void);
 void disable_pmr(struct iommu *iommu);
+int is_usb_device(struct pci_dev *pdev);
 
 #endif // _DMAR_H_
diff -r b8e3dbca1677 -r 70f9a2110421 xen/drivers/passthrough/vtd/iommu.c
--- a/xen/drivers/passthrough/vtd/iommu.c       Wed Mar 19 10:21:01 2008 +0000
+++ b/xen/drivers/passthrough/vtd/iommu.c       Wed Mar 19 10:22:49 2008 +0000
@@ -2019,6 +2019,12 @@ int intel_iommu_assign_device(struct dom
     for_each_rmrr_device( rmrr, pdev )
         if ( pdev->bus == bus && pdev->devfn == devfn )
         {
+            /* FIXME: Because USB RMRR conflicts with guest bios region,
+             * ignore USB RMRR temporarily.
+             */
+            if ( is_usb_device(pdev) )
+                return 0;
+
             ret = iommu_prepare_rmrr_dev(d, rmrr, pdev);
             if ( ret )
             {
diff -r b8e3dbca1677 -r 70f9a2110421 xen/drivers/passthrough/vtd/utils.c
--- a/xen/drivers/passthrough/vtd/utils.c       Wed Mar 19 10:21:01 2008 +0000
+++ b/xen/drivers/passthrough/vtd/utils.c       Wed Mar 19 10:22:49 2008 +0000
@@ -29,6 +29,15 @@
 #define INTEL   0x8086
 #define SEABURG 0x4000
 #define C_STEP  2
+
+int is_usb_device(struct pci_dev *pdev)
+{
+    u8 bus = pdev->bus;
+    u8 dev = PCI_SLOT(pdev->devfn);
+    u8 func = PCI_FUNC(pdev->devfn);
+    u16 class = read_pci_config_16(bus, dev, func, PCI_CLASS_DEVICE);
+    return (class == 0xc03);
+}
 
 int vtd_hw_check(void)
 {

_______________________________________________
Xen-changelog mailing list
Xen-changelog@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-changelog