similar to: [PATCH] virtio_balloon: fix towards_target when deflating balloon

On 29.08.23 03:54, Gavin Shan wrote: > The deflation request to the target, which isn't unaligned to the > guest page size causes endless deflation and inflation actions. For > example, we receive the flooding QMP events for the changes on memory > balloon's size after a deflation request to the unaligned target is > sent for the ARM64 guest, where we have 64KB base page

The deflation request to the target, which isn't unaligned to the guest page size causes endless deflation and inflation actions. For example, we receive the flooding QMP events for the changes on memory balloon's size after a deflation request to the unaligned target is sent for the ARM64 guest, where we have 64KB base page size. /home/gavin/sandbox/qemu.main/build/qemu-system-aarch64

The deflation request to the target, which isn't unaligned to the guest page size causes endless deflation and inflation actions. For example, we receive the flooding QMP events for the changes on memory balloon's size after a deflation request to the unaligned target is sent for the ARM64 guest, where we have 64KB base page size. /home/gavin/sandbox/qemu.main/build/qemu-system-aarch64

Virtio 1.0 doesn't include a modern balloon device. But it's not a big change to support a transitional balloon device: this has the advantage of supporting existing drivers, transparently. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- include/uapi/linux/virtio_balloon.h | 11 +++++++++-- drivers/virtio/virtio_balloon.c | 29 +++++++++++++++++++++-------- 2 files

Virtio 1.0 doesn't include a modern balloon device. But it's not a big change to support a transitional balloon device: this has the advantage of supporting existing drivers, transparently. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- include/uapi/linux/virtio_balloon.h | 11 +++++++++-- drivers/virtio/virtio_balloon.c | 29 +++++++++++++++++++++-------- 2 files

"Michael S. Tsirkin" <mst at redhat.com> writes: > On Tue, Apr 14, 2015 at 11:50:53AM +0200, Cornelia Huck wrote: >> On Tue, 14 Apr 2015 11:21:11 +0200 >> "Michael S. Tsirkin" <mst at redhat.com> wrote: >> >> > diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h >> > index f81b220..164e0c2

"Michael S. Tsirkin" <mst at redhat.com> writes: > On Tue, Apr 14, 2015 at 11:50:53AM +0200, Cornelia Huck wrote: >> On Tue, 14 Apr 2015 11:21:11 +0200 >> "Michael S. Tsirkin" <mst at redhat.com> wrote: >> >> > diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h >> > index f81b220..164e0c2

> > Negotiation of the VIRTIO_BALLOON_F_FREE_PAGE_VQ feature indicates the > support of reporting hints of guest free pages to host via virtio-balloon. > > Host requests the guest to report free pages by sending a new cmd > id to the guest via the free_page_report_cmd_id configuration register. > > When the guest starts to report, the first element added to the free page

> > Negotiation of the VIRTIO_BALLOON_F_FREE_PAGE_VQ feature indicates the > support of reporting hints of guest free pages to host via virtio-balloon. > > Host requests the guest to report free pages by sending a new cmd > id to the guest via the free_page_report_cmd_id configuration register. > > When the guest starts to report, the first element added to the free page

On Mon, Jun 25, 2018 at 08:05:10PM +0800, Wei Wang wrote: > Negotiation of the VIRTIO_BALLOON_F_FREE_PAGE_HINT feature indicates the > support of reporting hints of guest free pages to host via virtio-balloon. > > Host requests the guest to report free page hints by sending a new cmd id > to the guest via the free_page_report_cmd_id configuration register. > > As the first

On Mon, Jun 25, 2018 at 08:05:10PM +0800, Wei Wang wrote: > Negotiation of the VIRTIO_BALLOON_F_FREE_PAGE_HINT feature indicates the > support of reporting hints of guest free pages to host via virtio-balloon. > > Host requests the guest to report free page hints by sending a new cmd id > to the guest via the free_page_report_cmd_id configuration register. > > As the first

Workqueues have clean and rich API for all basic operations. The code is usually easier and better readable. It can be easily tuned for the given purpose. In many cases, it allows to avoid an extra kernel thread. It helps to stop the growing number of them. Also there will be less thread-specific hacks all over the kernel code. It forces making the task selfcontained. There is no longer an

Workqueues have clean and rich API for all basic operations. The code is usually easier and better readable. It can be easily tuned for the given purpose. In many cases, it allows to avoid an extra kernel thread. It helps to stop the growing number of them. Also there will be less thread-specific hacks all over the kernel code. It forces making the task selfcontained. There is no longer an

Negotiation of the VIRTIO_BALLOON_F_FREE_PAGE_HINT feature indicates the support of reporting hints of guest free pages to host via virtio-balloon. Host requests the guest to report free page hints by sending a new cmd id to the guest via the free_page_report_cmd_id configuration register. When the guest starts to report, the first element added to the free page vq is the cmd id given by host.

Negotiation of the VIRTIO_BALLOON_F_FREE_PAGE_HINT feature indicates the support of reporting hints of guest free pages to host via virtio-balloon. Host requests the guest to report free page hints by sending a new cmd id to the guest via the free_page_report_cmd_id configuration register. When the guest starts to report, the first element added to the free page vq is the cmd id given by host.

Unless the host requires that requested pages won't be used until he us notified (VIRTIO_BALLOON_F_MUST_TELL_HOST), only notify after deflating the balloon. This will avoid having to take an exit before actually using the pages. Cc: Rusty Russell <rusty at rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst at redhat.com> Cc: virtualization at lists.linux-foundation.org Cc:

Unless the host requires that requested pages won't be used until he us notified (VIRTIO_BALLOON_F_MUST_TELL_HOST), only notify after deflating the balloon. This will avoid having to take an exit before actually using the pages. Cc: Rusty Russell <rusty at rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst at redhat.com> Cc: virtualization at lists.linux-foundation.org Cc:

[Christian, Hollis, how much is this ABI breakage going to hurt you?] A recent proposed feature addition to the virtio block driver revealed some flaws in the API, in particular how easy it is to break big endian machines. The virtio config space was originally chosen to be little-endian, because we thought the config might be part of the PCI config space for virtio_pci. It's actually a

[Christian, Hollis, how much is this ABI breakage going to hurt you?] A recent proposed feature addition to the virtio block driver revealed some flaws in the API, in particular how easy it is to break big endian machines. The virtio config space was originally chosen to be little-endian, because we thought the config might be part of the PCI config space for virtio_pci. It's actually a

Workqueues have clean and rich API for all basic operations. The code is usually easier and better readable. It can be easily tuned for the given purpose. In many cases, it allows to avoid an extra kernel thread. It helps to stop the growing number of them. Also there will be less thread-specific hacks all over the kernel code. It forces making the task selfcontained. There is no longer an