search for: virtio_balloon_f_page_chunks

Add a new feature, VIRTIO_BALLOON_F_PAGE_CHUNKS, which enables the transfer of the ballooned (i.e. inflated/deflated) pages in chunks to the host. The implementation of the previous virtio-balloon is not very efficient, because the ballooned pages are transferred to the host one by one. Here is the breakdown of the time in percentage spent on e...

On Thu, May 04, 2017 at 04:50:12PM +0800, Wei Wang wrote: > Add a new feature, VIRTIO_BALLOON_F_PAGE_CHUNKS, which enables > the transfer of the ballooned (i.e. inflated/deflated) pages in > chunks to the host. > > The implementation of the previous virtio-balloon is not very > efficient, because the ballooned pages are transferred to the > host one by one. Here is the breakdown of the...

On Thu, May 04, 2017 at 04:50:12PM +0800, Wei Wang wrote: > Add a new feature, VIRTIO_BALLOON_F_PAGE_CHUNKS, which enables > the transfer of the ballooned (i.e. inflated/deflated) pages in > chunks to the host. > > The implementation of the previous virtio-balloon is not very > efficient, because the ballooned pages are transferred to the > host one by one. Here is the breakdown of the...

On 06/13/2017 10:56 AM, Michael S. Tsirkin wrote: >> +/* The size of one page_bmap used to record inflated/deflated pages. */ >> +#define VIRTIO_BALLOON_PAGE_BMAP_SIZE (8 * PAGE_SIZE) > At this size, you probably want alloc_pages to avoid kmalloc > overhead. For slub, at least, kmalloc() just calls alloc_pages() basically directly. There's virtually no overhead.

Hi Matthew, On 06/28/2017 11:04 PM, Matthew Wilcox wrote: > On Thu, Jun 15, 2017 at 04:10:17PM +0800, Wei Wang wrote: >>> So you still have a home-grown bitmap. I'd like to know why >>> isn't xbitmap suggested for this purpose by Matthew Wilcox >>> appropriate. Please add a comment explaining the requirements >>> from the data structure. >> I

On 06/14/2017 01:56 AM, Michael S. Tsirkin wrote: > On Fri, Jun 09, 2017 at 06:41:38PM +0800, Wei Wang wrote: >> Add a new feature, VIRTIO_BALLOON_F_PAGE_CHUNKS, which enables >> the transfer of the ballooned (i.e. inflated/deflated) pages in >> chunks to the host. > so now these chunks are just s/g list entry. > So let's rename this VIRTIO_BALLOON_F_SG with a comment: > * Use standard virtio s/g instead of PFN lists * Actually, i...

Add a new feature, VIRTIO_BALLOON_F_PAGE_CHUNKS, which enables the transfer of the ballooned (i.e. inflated/deflated) pages in chunks to the host. The implementation of the previous virtio-balloon is not very efficient, because the ballooned pages are transferred to the host one by one. Here is the breakdown of the time in percentage spent on e...

On Fri, Jun 09, 2017 at 06:41:38PM +0800, Wei Wang wrote: > Add a new feature, VIRTIO_BALLOON_F_PAGE_CHUNKS, which enables > the transfer of the ballooned (i.e. inflated/deflated) pages in > chunks to the host. so now these chunks are just s/g list entry. So let's rename this VIRTIO_BALLOON_F_SG with a comment: * Use standard virtio s/g instead of PFN lists * > The implementation of the pr...

On Fri, Jun 09, 2017 at 06:41:38PM +0800, Wei Wang wrote: > Add a new feature, VIRTIO_BALLOON_F_PAGE_CHUNKS, which enables > the transfer of the ballooned (i.e. inflated/deflated) pages in > chunks to the host. so now these chunks are just s/g list entry. So let's rename this VIRTIO_BALLOON_F_SG with a comment: * Use standard virtio s/g instead of PFN lists * > The implementation of the pr...

...get the free page block. v7->v8: 1) Use only one chunk format, instead of two. 2) re-write the virtio-balloon implementation patch. 3) commit changes 4) patch re-org Liang Li (1): virtio-balloon: deflate via a page list Wei Wang (5): virtio-balloon: coding format cleanup virtio-balloon: VIRTIO_BALLOON_F_PAGE_CHUNKS mm: function to offer a page block on the free list mm: export symbol of next_zone and first_online_pgdat virtio-balloon: VIRTIO_BALLOON_F_MISC_VQ drivers/virtio/virtio_balloon.c | 696 +++++++++++++++++++++++++++++++++--- include/linux/mm.h | 5 + include/uapi/linux/...

...get the free page block. v7->v8: 1) Use only one chunk format, instead of two. 2) re-write the virtio-balloon implementation patch. 3) commit changes 4) patch re-org Liang Li (1): virtio-balloon: deflate via a page list Wei Wang (5): virtio-balloon: coding format cleanup virtio-balloon: VIRTIO_BALLOON_F_PAGE_CHUNKS mm: function to offer a page block on the free list mm: export symbol of next_zone and first_online_pgdat virtio-balloon: VIRTIO_BALLOON_F_MISC_VQ drivers/virtio/virtio_balloon.c | 696 +++++++++++++++++++++++++++++++++--- include/linux/mm.h | 5 + include/uapi/linux/...

...e to send commands between the device and driver. Currently, it supports commands to report memory stats (replace the old statq mechanism) and report guest unused pages. Liang Li (1): virtio-balloon: deflate via a page list Wei Wang (5): virtio-balloon: coding format cleanup virtio-balloon: VIRTIO_BALLOON_F_PAGE_CHUNKS mm: function to offer a page block on the free list mm: export symbol of next_zone and first_online_pgdat virtio-balloon: VIRTIO_BALLOON_F_CMD_VQ drivers/virtio/virtio_balloon.c | 781 ++++++++++++++++++++++++++++++++---- drivers/virtio/virtio_ring.c | 120 +++++- include/linux/m...

...e to send commands between the device and driver. Currently, it supports commands to report memory stats (replace the old statq mechanism) and report guest unused pages. Liang Li (1): virtio-balloon: deflate via a page list Wei Wang (5): virtio-balloon: coding format cleanup virtio-balloon: VIRTIO_BALLOON_F_PAGE_CHUNKS mm: function to offer a page block on the free list mm: export symbol of next_zone and first_online_pgdat virtio-balloon: VIRTIO_BALLOON_F_CMD_VQ drivers/virtio/virtio_balloon.c | 781 ++++++++++++++++++++++++++++++++---- drivers/virtio/virtio_ring.c | 120 +++++- include/linux/m...

...hat fast! :) In general, what this section is all about: Why to not simply host enforce virtio-balloon. > >> Q: Why not reuse virtio-balloon? >> >> A: virtio-balloon is for cooperative memory management. It has a fixed >> page size > > We are fixing that with VIRTIO_BALLOON_F_PAGE_CHUNKS btw. > I would appreciate you looking into that patchset. Will do, thanks. Problem is that there is no "enforcement" on the page size. VIRTIO_BALLOON_F_PAGE_CHUNKS simply allows to send bigger chunks. Nobody hinders the guest (especially legacy virtio-balloon drivers) from sending 4k...

...hat fast! :) In general, what this section is all about: Why to not simply host enforce virtio-balloon. > >> Q: Why not reuse virtio-balloon? >> >> A: virtio-balloon is for cooperative memory management. It has a fixed >> page size > > We are fixing that with VIRTIO_BALLOON_F_PAGE_CHUNKS btw. > I would appreciate you looking into that patchset. Will do, thanks. Problem is that there is no "enforcement" on the page size. VIRTIO_BALLOON_F_PAGE_CHUNKS simply allows to send bigger chunks. Nobody hinders the guest (especially legacy virtio-balloon drivers) from sending 4k...

...tion is all about: Why to not simply host > enforce virtio-balloon. > > > >> Q: Why not reuse virtio-balloon? > >> > >> A: virtio-balloon is for cooperative memory management. It has a fixed > >> page size > > > > We are fixing that with VIRTIO_BALLOON_F_PAGE_CHUNKS btw. > > I would appreciate you looking into that patchset. > > Will do, thanks. Problem is that there is no "enforcement" on the page > size. VIRTIO_BALLOON_F_PAGE_CHUNKS simply allows to send bigger chunks. > Nobody hinders the guest (especially legacy virtio-balloon...

...s! I went over this quickly, will read some more in the coming days. I would like to ask for some clarifications on one part meanwhile: > Q: Why not reuse virtio-balloon? > > A: virtio-balloon is for cooperative memory management. It has a fixed > page size We are fixing that with VIRTIO_BALLOON_F_PAGE_CHUNKS btw. I would appreciate you looking into that patchset. > and will deflate in certain situations. What does this refer to? > Any change we > introduce will break backwards compatibility. Why does this have to be the case? > virtio-balloon was not > designed to give guarant...

...te_balloon_size_work); cancel_work_sync(&vb->update_balloon_stats_work); + cancel_work_sync(&vb->cmdq_handle_work); remove_common(vb); free_page_bmap(vb); @@ -1029,6 +1313,7 @@ static unsigned int features[] = { VIRTIO_BALLOON_F_STATS_VQ, VIRTIO_BALLOON_F_DEFLATE_ON_OOM, VIRTIO_BALLOON_F_PAGE_CHUNKS, + VIRTIO_BALLOON_F_CMD_VQ, }; static struct virtio_driver virtio_balloon_driver = { diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h index 5ed3c7b..cb66c1a 100644 --- a/include/uapi/linux/virtio_balloon.h +++ b/include/uapi/linux/virtio_balloon.h @@ -35,6...

Hi, this is an idea that is based on Andrea Arcangeli's original idea to host enforce guest access to memory given up using virtio-balloon using userfaultfd in the hypervisor. While looking into the details, I realized that host-enforcing virtio-balloon would result in way too many problems (mainly backwards compatibility) and would also have some conceptual restrictions that I want to avoid.

Hi, this is an idea that is based on Andrea Arcangeli's original idea to host enforce guest access to memory given up using virtio-balloon using userfaultfd in the hypervisor. While looking into the details, I realized that host-enforcing virtio-balloon would result in way too many problems (mainly backwards compatibility) and would also have some conceptual restrictions that I want to avoid.