[v8][PATCH 17/17] xen/vtd: re-enable USB device assignment if enable pci_force

[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 when we enable
pci_force to check/reserve RMRR.

Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
---
 xen/drivers/passthrough/vtd/dmar.h  |  1 +
 xen/drivers/passthrough/vtd/iommu.c | 12 ++++++++----
 xen/drivers/passthrough/vtd/utils.c | 18 ++++++++++++++++++
 3 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/xen/drivers/passthrough/vtd/dmar.h b/xen/drivers/passthrough/vtd/dmar.h
index a57c0d4..832dc32 100644
--- a/xen/drivers/passthrough/vtd/dmar.h
+++ b/xen/drivers/passthrough/vtd/dmar.h
@@ -132,6 +132,7 @@ do {                                                \
 int vtd_hw_check(void);
 void disable_pmr(struct iommu *iommu);
 int is_usb_device(u16 seg, u8 bus, u8 devfn);
+int is_reserve_device_memory(struct domain *d, 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 ba40209..1f1ceb7 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -2264,9 +2264,11 @@ static int reassign_device_ownership(
      * 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()).
+     * But if we already check to reserve RMRR, this should be fine.
      */
     if ( !is_hardware_domain(source) &&
-         !is_usb_device(pdev->seg, pdev->bus, pdev->devfn) )
+         !is_usb_device(pdev->seg, pdev->bus, pdev->devfn) &&
+         !is_reserve_device_memory(source, pdev->bus, pdev->devfn) )
     {
         const struct acpi_rmrr_unit *rmrr;
         u16 bdf;
@@ -2315,12 +2317,14 @@ static int intel_iommu_assign_device(
     if ( ret )
         return ret;
 
-    /* FIXME: Because USB RMRR conflicts with guest bios region,
-     * ignore USB RMRR temporarily.
+    /*
+     * Because USB RMRR conflicts with guest bios region,
+     * ignore USB RMRR temporarily in case of non-reserving-RMRR.
      */
     seg = pdev->seg;
     bus = pdev->bus;
-    if ( is_usb_device(seg, bus, pdev->devfn) )
+    if ( is_usb_device(seg, bus, pdev->devfn) &&
+         !is_reserve_device_memory(d, bus, pdev->devfn) )
         return 0;
 
     /* Setup rmrr identity mapping */
diff --git a/xen/drivers/passthrough/vtd/utils.c b/xen/drivers/passthrough/vtd/utils.c
index a33564b..1045ac1 100644
--- a/xen/drivers/passthrough/vtd/utils.c
+++ b/xen/drivers/passthrough/vtd/utils.c
@@ -36,6 +36,24 @@ int is_usb_device(u16 seg, u8 bus, u8 devfn)
     return (class == 0xc03);
 }
 
+int is_reserve_device_memory(struct domain *d, u8 bus, u8 devfn)
+{
+    int i = 0;
+
+    if ( d->arch.hvm_domain.pci_force == PCI_DEV_RDM_CHECK )
+        return 1;
+
+    for ( i = 0; i < d->arch.hvm_domain.num_pcidevs; i++ )
+    {
+        if ( d->arch.hvm_domain.pcidevs[i].bus == bus &&
+             d->arch.hvm_domain.pcidevs[i].devfn == devfn &&
+             d->arch.hvm_domain.pcidevs[i].flags == PCI_DEV_RDM_CHECK )
+        return 1;
+    }
+
+    return 0;
+}
+
 /* Disable vt-d protected memory registers. */
 void disable_pmr(struct iommu *iommu)
 {
-- 
1.9.1