Re: [RFC 0/4] Virtio uses DMA API for all devices

2018-08-03 Thread Benjamin Herrenschmidt
On Fri, 2018-08-03 at 22:08 +0300, Michael S. Tsirkin wrote: > > > > Please go through these patches and review whether this approach broadly > > > > makes sense. I will appreciate suggestions, inputs, comments regarding > > > > the patches or the approach in general. Thank you. > > > > > > Jason

Re: [RFC 0/4] Virtio uses DMA API for all devices

2018-08-03 Thread Benjamin Herrenschmidt
On Fri, 2018-08-03 at 22:07 +0300, Michael S. Tsirkin wrote: > On Fri, Aug 03, 2018 at 10:58:36AM -0500, Benjamin Herrenschmidt wrote: > > On Fri, 2018-08-03 at 00:05 -0700, Christoph Hellwig wrote: > > > > 2- Make virtio use the DMA API with our custom platform-provided > > > > swiotlb callbacks

Re: [RFC 0/4] Virtio uses DMA API for all devices

2018-08-03 Thread Benjamin Herrenschmidt
On Fri, 2018-08-03 at 22:07 +0300, Michael S. Tsirkin wrote: > On Fri, Aug 03, 2018 at 10:58:36AM -0500, Benjamin Herrenschmidt wrote: > > On Fri, 2018-08-03 at 00:05 -0700, Christoph Hellwig wrote: > > > > 2- Make virtio use the DMA API with our custom platform-provided > > > > swiotlb callbacks

Re: [RFC 0/4] Virtio uses DMA API for all devices

2018-08-03 Thread Benjamin Herrenschmidt
On Fri, 2018-08-03 at 22:07 +0300, Michael S. Tsirkin wrote: > On Fri, Aug 03, 2018 at 10:58:36AM -0500, Benjamin Herrenschmidt wrote: > > On Fri, 2018-08-03 at 00:05 -0700, Christoph Hellwig wrote: > > > > 2- Make virtio use the DMA API with our custom platform-provided > > > > swiotlb callbacks

Re: [RFC 0/4] Virtio uses DMA API for all devices

2018-08-03 Thread Benjamin Herrenschmidt
On Fri, 2018-08-03 at 22:07 +0300, Michael S. Tsirkin wrote: > On Fri, Aug 03, 2018 at 10:58:36AM -0500, Benjamin Herrenschmidt wrote: > > On Fri, 2018-08-03 at 00:05 -0700, Christoph Hellwig wrote: > > > > 2- Make virtio use the DMA API with our custom platform-provided > > > > swiotlb callbacks

Re: [RFC 0/4] Virtio uses DMA API for all devices

2018-08-03 Thread Michael S. Tsirkin
On Fri, Aug 03, 2018 at 12:05:07AM -0700, Christoph Hellwig wrote: > On Thu, Aug 02, 2018 at 04:13:09PM -0500, Benjamin Herrenschmidt wrote: > > So let's differenciate the two problems of having an IOMMU (real or > > emulated) which indeeds adds overhead etc... and using the DMA API. > > > > At th

Re: [PATCH v3 2/2] virtio_balloon: replace oom notifier with shrinker

2018-08-03 Thread Michael S. Tsirkin
On Fri, Aug 03, 2018 at 04:32:26PM +0800, Wei Wang wrote: > The OOM notifier is getting deprecated to use for the reasons: > - As a callout from the oom context, it is too subtle and easy to > generate bugs and corner cases which are hard to track; > - It is called too late (after the reclaiming

Re: [net-next, v6, 6/7] net-sysfs: Add interface for Rx queue(s) map per Tx queue

2018-08-03 Thread Michael S. Tsirkin
On Fri, Aug 03, 2018 at 12:06:51PM -0700, Andrei Vagin wrote: > On Fri, Aug 03, 2018 at 12:08:05AM +0300, Michael S. Tsirkin wrote: > > On Thu, Aug 02, 2018 at 02:04:12PM -0700, Nambiar, Amritha wrote: > > > On 8/1/2018 5:11 PM, Andrei Vagin wrote: > > > > On Tue, Jul 10, 2018 at 07:28:49PM -0700,

Re: [RFC 0/4] Virtio uses DMA API for all devices

2018-08-03 Thread Michael S. Tsirkin
On Fri, Aug 03, 2018 at 10:41:41AM +0800, Jason Wang wrote: > > > On 2018年08月03日 04:55, Michael S. Tsirkin wrote: > > On Fri, Jul 20, 2018 at 09:29:37AM +0530, Anshuman Khandual wrote: > > > This patch series is the follow up on the discussions we had before about > > > the RFC titled [RFC,V2] vi

Re: [RFC 0/4] Virtio uses DMA API for all devices

2018-08-03 Thread Michael S. Tsirkin
On Fri, Aug 03, 2018 at 10:58:36AM -0500, Benjamin Herrenschmidt wrote: > On Fri, 2018-08-03 at 00:05 -0700, Christoph Hellwig wrote: > > > 2- Make virtio use the DMA API with our custom platform-provided > > > swiotlb callbacks when needed, that is when not using IOMMU *and* > > > running on a s

Re: [RFC 0/4] Virtio uses DMA API for all devices

2018-08-03 Thread Benjamin Herrenschmidt
On Fri, 2018-08-03 at 09:02 -0700, Christoph Hellwig wrote: > On Fri, Aug 03, 2018 at 10:58:36AM -0500, Benjamin Herrenschmidt wrote: > > On Fri, 2018-08-03 at 00:05 -0700, Christoph Hellwig wrote: > > > > 2- Make virtio use the DMA API with our custom platform-provided > > > > swiotlb callbacks

Re: [RFC 0/4] Virtio uses DMA API for all devices

2018-08-03 Thread Christoph Hellwig
On Fri, Aug 03, 2018 at 10:58:36AM -0500, Benjamin Herrenschmidt wrote: > On Fri, 2018-08-03 at 00:05 -0700, Christoph Hellwig wrote: > > > 2- Make virtio use the DMA API with our custom platform-provided > > > swiotlb callbacks when needed, that is when not using IOMMU *and* > > > running on a s

Re: [RFC 0/4] Virtio uses DMA API for all devices

2018-08-03 Thread Benjamin Herrenschmidt
On Fri, 2018-08-03 at 00:05 -0700, Christoph Hellwig wrote: > > 2- Make virtio use the DMA API with our custom platform-provided > > swiotlb callbacks when needed, that is when not using IOMMU *and* > > running on a secure VM in our case. > > And total NAK the customer platform-provided part of

Re: [PATCH] crypto: virtio: Replace GFP_ATOMIC with GFP_KERNEL in __virtio_crypto_ablkcipher_do_req()

2018-08-03 Thread Herbert Xu
On Mon, Jul 23, 2018 at 04:43:46PM +0800, Jia-Ju Bai wrote: > __virtio_crypto_ablkcipher_do_req() is never called in atomic context. > > __virtio_crypto_ablkcipher_do_req() is only called by > virtio_crypto_ablkcipher_crypt_req(), which is only called by > virtcrypto_find_vqs() that is never cal

Re: [PATCH v3 2/2] virtio_balloon: replace oom notifier with shrinker

2018-08-03 Thread Tetsuo Handa
On 2018/08/03 17:32, Wei Wang wrote: > +static int virtio_balloon_register_shrinker(struct virtio_balloon *vb) > +{ > + vb->shrinker.scan_objects = virtio_balloon_shrinker_scan; > + vb->shrinker.count_objects = virtio_balloon_shrinker_count; > + vb->shrinker.batch = 0; > + vb->shrin

[PATCH v3 2/2] virtio_balloon: replace oom notifier with shrinker

2018-08-03 Thread Wei Wang
The OOM notifier is getting deprecated to use for the reasons: - As a callout from the oom context, it is too subtle and easy to generate bugs and corner cases which are hard to track; - It is called too late (after the reclaiming has been performed). Drivers with large amuont of reclaimable me

[PATCH v3 1/2] virtio-balloon: remove BUG() in init_vqs

2018-08-03 Thread Wei Wang
It's a bit overkill to use BUG when failing to add an entry to the stats_vq in init_vqs. So remove it and just return the error to the caller to bail out nicely. Signed-off-by: Wei Wang Cc: Michael S. Tsirkin --- drivers/virtio/virtio_balloon.c | 10 +++--- 1 file changed, 7 insertions(+),

[PATCH v3 0/2] virtio-balloon: some improvements

2018-08-03 Thread Wei Wang
This series is split from the "Virtio-balloon: support free page reporting" series to make some improvements. ChangeLog: v2->v3: - shrink the balloon pages according to the amount requested by the claimer, instead of using a user specified number; v1->v2: - register the shrinker when VIRTIO_BALL

Re: [PATCH net-next] vhost: switch to use new message format

2018-08-03 Thread Michael S. Tsirkin
On Fri, Aug 03, 2018 at 03:04:51PM +0800, Jason Wang wrote: > We use to have message like: > > struct vhost_msg { > int type; > union { > struct vhost_iotlb_msg iotlb; > __u8 padding[64]; > }; > }; > > Unfortunately, there will be a hole of 32bit in 6

Re: [RFC 0/4] Virtio uses DMA API for all devices

2018-08-03 Thread Christoph Hellwig
On Thu, Aug 02, 2018 at 11:53:08PM +0300, Michael S. Tsirkin wrote: > > We don't need cache flushing tricks. > > You don't but do real devices on same platform need them? IBMs power plaforms are always cache coherent. There are some powerpc platforms have not cache coherent DMA, but I guess this

Re: [RFC 0/4] Virtio uses DMA API for all devices

2018-08-03 Thread Christoph Hellwig
On Thu, Aug 02, 2018 at 04:13:09PM -0500, Benjamin Herrenschmidt wrote: > So let's differenciate the two problems of having an IOMMU (real or > emulated) which indeeds adds overhead etc... and using the DMA API. > > At the moment, virtio does this all over the place: > > if (use_dma_api) >

[PATCH net-next] vhost: switch to use new message format

2018-08-03 Thread Jason Wang
We use to have message like: struct vhost_msg { int type; union { struct vhost_iotlb_msg iotlb; __u8 padding[64]; }; }; Unfortunately, there will be a hole of 32bit in 64bit machine because of the alignment. This leads a different formats be