Re: [PATCH] vhost: use large iotlb entry if no IOMMU translation is needed

On Wed, Aug 4, 2021 at 5:11 AM Peter Xu wrote: > > On Tue, Aug 03, 2021 at 04:14:57PM +0800, Jason Wang wrote: > > > > 在 2021/8/3 下午1:51, Chao Gao 写道: > > > On Tue, Aug 03, 2021 at 12:43:58PM +0800, Jason Wang wrote: > > > > 在 2021/8/3 下午12:29, Chao Gao 写道: > > > > > Ping. Could someone help to re

Re: [PATCH] vhost: use large iotlb entry if no IOMMU translation is needed

On Tue, Aug 03, 2021 at 04:14:57PM +0800, Jason Wang wrote: > > 在 2021/8/3 下午1:51, Chao Gao 写道: > > On Tue, Aug 03, 2021 at 12:43:58PM +0800, Jason Wang wrote: > > > 在 2021/8/3 下午12:29, Chao Gao 写道: > > > > Ping. Could someone help to review this patch? > > > > > > > > Thanks > > > > Chao > > > >

Re: [PATCH] vhost: use large iotlb entry if no IOMMU translation is needed

在 2021/8/3 下午1:51, Chao Gao 写道: On Tue, Aug 03, 2021 at 12:43:58PM +0800, Jason Wang wrote: 在 2021/8/3 下午12:29, Chao Gao 写道: Ping. Could someone help to review this patch? Thanks Chao On Wed, Jul 21, 2021 at 03:54:02PM +0800, Chao Gao wrote: If guest enables IOMMU_PLATFORM for virtio-net,

Re: [PATCH] vhost: use large iotlb entry if no IOMMU translation is needed

On Tue, Aug 03, 2021 at 12:43:58PM +0800, Jason Wang wrote: > >在 2021/8/3 下午12:29, Chao Gao 写道: >> Ping. Could someone help to review this patch? >> >> Thanks >> Chao >> >> On Wed, Jul 21, 2021 at 03:54:02PM +0800, Chao Gao wrote: >> > If guest enables IOMMU_PLATFORM for virtio-net, severe networ

Re: [PATCH] vhost: use large iotlb entry if no IOMMU translation is needed

在 2021/8/3 下午12:29, Chao Gao 写道: Ping. Could someone help to review this patch? Thanks Chao On Wed, Jul 21, 2021 at 03:54:02PM +0800, Chao Gao wrote: If guest enables IOMMU_PLATFORM for virtio-net, severe network performance drop is observed even if there is no IOMMU. We see such reports

Re: [PATCH] vhost: use large iotlb entry if no IOMMU translation is needed

Ping. Could someone help to review this patch? Thanks Chao On Wed, Jul 21, 2021 at 03:54:02PM +0800, Chao Gao wrote: >If guest enables IOMMU_PLATFORM for virtio-net, severe network >performance drop is observed even if there is no IOMMU. And disabling >vhost can mitigate the perf issue. Finally,

[PATCH] vhost: use large iotlb entry if no IOMMU translation is needed

If guest enables IOMMU_PLATFORM for virtio-net, severe network performance drop is observed even if there is no IOMMU. And disabling vhost can mitigate the perf issue. Finally, we found the culprit is frequent iotlb misses: kernel vhost-net has 2048 entries and each entry is 4K (qemu uses 4K for i3