diff mbox series

[RFC,v6,12/13] intel_iommu: Do not notify regular iotlb to device-iotlb notifiers

Message ID 20200826143651.7915-13-eperezma@redhat.com
State New
Headers show
Series [RFC,1/1] memory: Delete assertion in memory_region_unregister_iommu_notifier | expand

Commit Message

Eugenio Perez Martin Aug. 26, 2020, 2:36 p.m. UTC 
This improves performance in case of netperf with vhost-net:
* TCP_STREAM: From 9049.59Mbit/s to 9049.59Mbit/s (13%)
* TCP_RR: From 8464.73 trans/s to 8932.703333 trans/s (5.5%)
* UDP_RR: From 8562.08 trans/s to 9005.62/s (5.1%)
* UDP_STREAM: No change observed (insignificant 0.1% improvement)

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
 hw/i386/intel_iommu.c | 6 ++++++
 1 file changed, 6 insertions(+)
diff mbox series

Patch

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index ddb828da1f..7620a1abbf 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -1960,6 +1960,12 @@  static void vtd_iotlb_domain_invalidate(IntelIOMMUState *s, uint16_t domain_id)
     vtd_iommu_unlock(s);
 
     QLIST_FOREACH(vtd_as, &s->vtd_as_with_notifiers, next) {
+        if (vtd_as->iommu.iommu_notify_flags & IOMMU_NOTIFIER_DEVIOTLB) {
+            /* If IOMMU memory region is DEVICE IOTLB type, it does not make
+             * sense to send regular IOMMU notifications. */
+            continue;
+        }
+
         if (!vtd_dev_to_context_entry(s, pci_bus_num(vtd_as->bus),
                                       vtd_as->devfn, &ce) &&
             domain_id == vtd_get_domain_id(s, &ce)) {