Intel-IOMMU, intr-remap: source-id checking

To support domain-isolation usages, the platform hardware must be
capable of uniquely identifying the requestor (source-id) for each
interrupt message. Without source-id checking for interrupt remapping
, a rouge guest/VM with assigned devices can launch interrupt attacks
to bring down anothe guest/VM or the VMM itself.

This patch adds source-id checking for interrupt remapping, and then
really isolates interrupts for guests/VMs with assigned devices.

Because PCI subsystem is not initialized yet when set up IOAPIC
entries, use read_pci_config_byte to access PCI config space directly.

Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/include/linux/dmar.h b/include/linux/dmar.h
index 1731fb5fd775..4a2b162c256a 100644
--- a/include/linux/dmar.h
+++ b/include/linux/dmar.h
@@ -126,6 +126,8 @@ extern int free_irte(int irq);
 extern int irq_remapped(int irq);
 extern struct intel_iommu *map_dev_to_ir(struct pci_dev *dev);
 extern struct intel_iommu *map_ioapic_to_ir(int apic);
+extern int set_ioapic_sid(struct irte *irte, int apic);
+extern int set_msi_sid(struct irte *irte, struct pci_dev *dev);
 #else
 static inline int alloc_irte(struct intel_iommu *iommu, int irq, u16 count)
 {
@@ -156,6 +158,15 @@ static inline struct intel_iommu *map_ioapic_to_ir(int apic)
 {
         return NULL;
 }
+static inline int set_ioapic_sid(struct irte *irte, int apic)
+{
+        return 0;
+}
+static inline int set_msi_sid(struct irte *irte, struct pci_dev *dev)
+{
+        return 0;
+}
+
 #define irq_remapped(irq)               (0)
 #define enable_intr_remapping(mode)     (-1)
 #define disable_intr_remapping()        (0)