intel_iommu: enable remote IOTLB

This patch is based on Aviv Ben-David (<bd.aviv@gmail.com>)'s patch
upstream:

  "IOMMU: enable intel_iommu map and unmap notifiers"
  https://lists.gnu.org/archive/html/qemu-devel/2016-11/msg01453.html

However I removed/fixed some content, and added my own codes.

Instead of translate() every page for iotlb invalidations (which is
slower), we walk the pages when needed and notify in a hook function.

This patch enables vfio devices for VT-d emulation.

And, since we already have vhost DMAR support via device-iotlb, a
natural benefit that this patch brings is that vt-d enabled vhost can
live even without ATS capability now. Though more tests are needed.

Signed-off-by: Aviv Ben-David <bdaviv@cs.technion.ac.il>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: \"Michael S. Tsirkin\" <mst@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <1491562755-23867-10-git-send-email-peterx@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
index 8f212a1198..3e51876b75 100644
--- a/include/hw/i386/intel_iommu.h
+++ b/include/hw/i386/intel_iommu.h
@@ -63,6 +63,7 @@ typedef union VTD_IR_TableEntry VTD_IR_TableEntry;
 typedef union VTD_IR_MSIAddress VTD_IR_MSIAddress;
 typedef struct VTDIrq VTDIrq;
 typedef struct VTD_MSIMessage VTD_MSIMessage;
+typedef struct IntelIOMMUNotifierNode IntelIOMMUNotifierNode;
 
 /* Context-Entry */
 struct VTDContextEntry {
@@ -249,6 +250,11 @@ struct VTD_MSIMessage {
 /* When IR is enabled, all MSI/MSI-X data bits should be zero */
 #define VTD_IR_MSI_DATA          (0)
 
+struct IntelIOMMUNotifierNode {
+    VTDAddressSpace *vtd_as;
+    QLIST_ENTRY(IntelIOMMUNotifierNode) next;
+};
+
 /* The iommu (DMAR) device state struct */
 struct IntelIOMMUState {
     X86IOMMUState x86_iommu;
@@ -286,6 +292,8 @@ struct IntelIOMMUState {
     MemoryRegionIOMMUOps iommu_ops;
     GHashTable *vtd_as_by_busptr;   /* VTDBus objects indexed by PCIBus* reference */
     VTDBus *vtd_as_by_bus_num[VTD_PCI_BUS_MAX]; /* VTDBus objects indexed by bus number */
+    /* list of registered notifiers */
+    QLIST_HEAD(, IntelIOMMUNotifierNode) notifiers_list;
 
     /* interrupt remapping */
     bool intr_enabled;              /* Whether guest enabled IR */