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| author | Eugenio Pérez | 2020-11-16 17:55:05 +0100 |
|---|---|---|
| committer | Michael S. Tsirkin | 2020-12-08 19:48:57 +0100 |
| commit | f7701e2c7983b680790af47117577b285b6a1aed (patch) | |
| tree | 06d41748f97c15b85d71d2b9fdadd723c5ff9674 /hw/i386 | |
| parent | memory: Add IOMMU_NOTIFIER_DEVIOTLB_UNMAP IOMMUTLBNotificationType (diff) | |
| download | qemu-f7701e2c7983b680790af47117577b285b6a1aed.tar.gz qemu-f7701e2c7983b680790af47117577b285b6a1aed.tar.xz qemu-f7701e2c7983b680790af47117577b285b6a1aed.zip | |
intel_iommu: Skip page walking on device iotlb invalidations
Although they didn't reach the notifier because of the filtering in
memory_region_notify_iommu_one, the vt-d was still splitting huge
memory invalidations in chunks. Skipping it.
This improves performance in case of netperf with vhost-net:
* TCP_STREAM: From 1923.6Mbit/s to 2175.13Mbit/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>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20201116165506.31315-5-eperezma@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'hw/i386')
| -rw-r--r-- | hw/i386/intel_iommu.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c index edc3090f91..0cc71e4057 100644 --- a/hw/i386/intel_iommu.c +++ b/hw/i386/intel_iommu.c @@ -1478,6 +1478,10 @@ static int vtd_sync_shadow_page_table(VTDAddressSpace *vtd_as) VTDContextEntry ce; IOMMUNotifier *n; + if (!(vtd_as->iommu.iommu_notify_flags & IOMMU_NOTIFIER_IOTLB_EVENTS)) { + return 0; + } + ret = vtd_dev_to_context_entry(vtd_as->iommu_state, pci_bus_num(vtd_as->bus), vtd_as->devfn, &ce); |