[v7][RFC][PATCH 12/13] xen/vtd: re-enable USB device assignment

[Tiejun Chen <tiejun.chen@intel.com>]

Before we refine RMRR mechanism, USB RMRR may conflict with guest bios
region so we always ignore USB RMRR. Now this can be gone.

Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
---
 xen/drivers/passthrough/vtd/dmar.h  |  1 -
 xen/drivers/passthrough/vtd/iommu.c | 11 ++---------
 xen/drivers/passthrough/vtd/utils.c |  7 -------
 3 files changed, 2 insertions(+), 17 deletions(-)

diff --git a/xen/drivers/passthrough/vtd/dmar.h b/xen/drivers/passthrough/vtd/dmar.h
index af1feef..af205f5 100644
--- a/xen/drivers/passthrough/vtd/dmar.h
+++ b/xen/drivers/passthrough/vtd/dmar.h
@@ -129,7 +129,6 @@ do {                                                \
 
 int vtd_hw_check(void);
 void disable_pmr(struct iommu *iommu);
-int is_usb_device(u16 seg, u8 bus, u8 devfn);
 int is_igd_drhd(struct acpi_drhd_unit *drhd);
 
 #endif /* _DMAR_H_ */
diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c
index 07136df..298d458 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -2232,11 +2232,9 @@ static int reassign_device_ownership(
     /*
      * If the device belongs to the hardware domain, and it has RMRR, don't
      * remove it from the hardware domain, because BIOS may use RMRR at
-     * booting time. Also account for the special casing of USB below (in
-     * intel_iommu_assign_device()).
+     * booting time.
      */
-    if ( !is_hardware_domain(source) &&
-         !is_usb_device(pdev->seg, pdev->bus, pdev->devfn) )
+    if ( !is_hardware_domain(source) )
     {
         const struct acpi_rmrr_unit *rmrr;
         u16 bdf;
@@ -2285,13 +2283,8 @@ static int intel_iommu_assign_device(
     if ( ret )
         return ret;
 
-    /* FIXME: Because USB RMRR conflicts with guest bios region,
-     * ignore USB RMRR temporarily.
-     */
     seg = pdev->seg;
     bus = pdev->bus;
-    if ( is_usb_device(seg, bus, pdev->devfn) )
-        return 0;
 
     /* Setup rmrr identity mapping */
     for_each_rmrr_device( rmrr, bdf, i )
diff --git a/xen/drivers/passthrough/vtd/utils.c b/xen/drivers/passthrough/vtd/utils.c
index a33564b..0d7bfe9 100644
--- a/xen/drivers/passthrough/vtd/utils.c
+++ b/xen/drivers/passthrough/vtd/utils.c
@@ -29,13 +29,6 @@
 #include "extern.h"
 #include <asm/io_apic.h>
 
-int is_usb_device(u16 seg, u8 bus, u8 devfn)
-{
-    u16 class = pci_conf_read16(seg, bus, PCI_SLOT(devfn), PCI_FUNC(devfn),
-                                PCI_CLASS_DEVICE);
-    return (class == 0xc03);
-}
-
 /* Disable vt-d protected memory registers. */
 void disable_pmr(struct iommu *iommu)
 {
-- 
1.9.1