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, 6 insertions, 0 deletions

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index b7a79207295e..4d0216fcb36c 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -1414,6 +1414,9 @@ int setup_ioapic_entry(int apic_id, int irq,
                 irte.vector = vector;
                 irte.dest_id = IRTE_DEST(destination);
 
+                /* Set source-id of interrupt request */
+                set_ioapic_sid(&irte, apic_id);
+
                 modify_irte(irq, &irte);
 
                 ir_entry->index2 = (index >> 15) & 0x1;
@@ -3290,6 +3293,9 @@ static int msi_compose_msg(struct pci_dev *pdev, unsigned int irq, struct msi_ms
                 irte.vector = cfg->vector;
                 irte.dest_id = IRTE_DEST(dest);
 
+                /* Set source-id of interrupt request */
+                set_msi_sid(&irte, pdev);
+
                 modify_irte(irq, &irte);
 
                 msg->address_hi = MSI_ADDR_BASE_HI;