[Qemu-devel] [RFC PATCH 02/13] intel_iommu: simplify irq region translation

[Peter Xu <peterx@redhat.com>]

Before we have int-remap, we need to bypass interrupt write requests.
That's not necessary now - we have supported int-remap, and all the irq
region requests should be redirected there. Cleaning up the block with
an assertion instead.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 hw/i386/intel_iommu.c | 29 ++++++-----------------------
 1 file changed, 6 insertions(+), 23 deletions(-)

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 92e4064..f19a8b3 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -842,29 +842,12 @@ static void vtd_do_iommu_translate(VTDAddressSpace *vtd_as, PCIBus *bus,
     bool writes = true;
     VTDIOTLBEntry *iotlb_entry;
 
-    /* Check if the request is in interrupt address range */
-    if (vtd_is_interrupt_addr(addr)) {
-        if (flags & IOMMU_WO) {
-            /* FIXME: since we don't know the length of the access here, we
-             * treat Non-DWORD length write requests without PASID as
-             * interrupt requests, too. Withoud interrupt remapping support,
-             * we just use 1:1 mapping.
-             */
-            VTD_DPRINTF(MMU, "write request to interrupt address "
-                        "gpa 0x%"PRIx64, addr);
-            entry->iova = addr & VTD_PAGE_MASK_4K;
-            entry->translated_addr = addr & VTD_PAGE_MASK_4K;
-            entry->addr_mask = ~VTD_PAGE_MASK_4K;
-            entry->perm = IOMMU_WO;
-            return;
-        } else {
-            VTD_DPRINTF(GENERAL, "error: read request from interrupt address "
-                        "gpa 0x%"PRIx64, addr);
-            vtd_report_dmar_fault(s, source_id, addr, VTD_FR_READ,
-                    flags & IOMMU_WO);
-            return;
-        }
-    }
+    /*
+     * We have standalone memory region for interrupt addresses, we
+     * should never receive translation requests in this region.
+     */
+    assert(!vtd_is_interrupt_addr(addr));
+
     /* Try to fetch slpte form IOTLB */
     iotlb_entry = vtd_lookup_iotlb(s, source_id, addr);
     if (iotlb_entry) {
-- 
2.7.4