similar to: [PATCH v4 00/15] virtio-mem: paravirtualized memory

This series is based on latest linux-next. The patches are located at: https://github.com/davidhildenbrand/linux.git virtio-mem-v3 Patch #1 - #10 where contained in v2 and only contain minor modifications (mostly smaller fixes). The remaining patches are new and contain smaller optimizations. Details about virtio-mem can be found in the cover letter of v2 [1]. A basic QEMU implementation was

This series is based on latest linux-next. The patches are located at: https://github.com/davidhildenbrand/linux.git virtio-mem-v3 Patch #1 - #10 where contained in v2 and only contain minor modifications (mostly smaller fixes). The remaining patches are new and contain smaller optimizations. Details about virtio-mem can be found in the cover letter of v2 [1]. A basic QEMU implementation was

This series is based on latest linux-next. The patches are located at: https://github.com/davidhildenbrand/linux.git virtio-mem-v2 I now have acks for all !virtio-mem changes. I'll be happy to get review feedback, testing reports, etc. for the virtio-mem changes. If there are no further comments, I guess this is good to go as a v1 soon. The basic idea of virtio-mem is to provide a

This series is based on latest linux-next. The patches are located at: https://github.com/davidhildenbrand/linux.git virtio-mem-rfc-v4 The basic idea of virtio-mem is to provide a flexible, cross-architecture memory hot(un)plug solution that avoids many limitations imposed by existing technologies, architectures, and interfaces. More details can be found below and in linked material. This

This series is based on latest linux-next. The patches are located at: https://github.com/davidhildenbrand/linux.git virtio-mem-rfc-v4 The basic idea of virtio-mem is to provide a flexible, cross-architecture memory hot(un)plug solution that avoids many limitations imposed by existing technologies, architectures, and interfaces. More details can be found below and in linked material. This

Long time no RFC! I finally had time to get the next version of the Linux driver side of virtio-mem into shape, incorporating ideas and feedback from previous discussions. This RFC is based on the series currently on the mm list: - [PATCH 0/3] Remove __online_page_set_limits() - [PATCH v1 0/3] mm/memory_hotplug: Export generic_online_page() - [PATCH v4 0/8] mm/memory_hotplug: Shrink zones before

This series is based on latest linux-next. The patches are located at: https://github.com/davidhildenbrand/linux.git virtio-mem-v1 The basic idea of virtio-mem is to provide a flexible, cross-architecture memory hot(un)plug solution that avoids many limitations imposed by existing technologies, architectures, and interfaces. More details can be found below and in linked material. It's

This series is based on latest linux-next. The patches are located at: https://github.com/davidhildenbrand/linux.git virtio-mem-v1 The basic idea of virtio-mem is to provide a flexible, cross-architecture memory hot(un)plug solution that avoids many limitations imposed by existing technologies, architectures, and interfaces. More details can be found below and in linked material. It's

On Mon 02-03-20 14:49:37, David Hildenbrand wrote: [...] > +static void virtio_mem_notify_going_offline(struct virtio_mem *vm, > + unsigned long mb_id) > +{ > + const unsigned long nr_pages = PFN_DOWN(vm->subblock_size); > + unsigned long pfn; > + int sb_id, i; > + > + for (sb_id = 0; sb_id < vm->nb_sb_per_mb; sb_id++) { > + if

On Mon 02-03-20 14:49:37, David Hildenbrand wrote: [...] > +static void virtio_mem_notify_going_offline(struct virtio_mem *vm, > + unsigned long mb_id) > +{ > + const unsigned long nr_pages = PFN_DOWN(vm->subblock_size); > + unsigned long pfn; > + int sb_id, i; > + > + for (sb_id = 0; sb_id < vm->nb_sb_per_mb; sb_id++) { > + if

If subblock size is large (e.g. 1G) 32 bit math involving it can overflow. Rather than try to catch all instances of that, let's tweak block size to 64 bit. It ripples through UAPI which is an ABI change, but it's not too late to make it, and it will allow supporting >4Gbyte blocks while might become necessary down the road. Fixes: 5f1f79bbc9e26 ("virtio-mem: Paravirtualized

If subblock size is large (e.g. 1G) 32 bit math involving it can overflow. Rather than try to catch all instances of that, let's tweak block size to 64 bit. It ripples through UAPI which is an ABI change, but it's not too late to make it, and it will allow supporting >4Gbyte blocks while might become necessary down the road. Fixes: 5f1f79bbc9e26 ("virtio-mem: Paravirtualized

Each virtio-mem device owns exactly one memory region. It is responsible for adding/removing memory from that memory region on request. When the device driver starts up, the requested amount of memory is queried and then plugged to Linux. On request, further memory can be plugged or unplugged. This patch only implements the plugging part. On x86-64, memory can currently be plugged in 4MB

On Tue 10-03-20 12:46:05, David Hildenbrand wrote: > On 10.03.20 12:43, Michal Hocko wrote: > > On Mon 02-03-20 14:49:37, David Hildenbrand wrote: > > [...] > >> +static void virtio_mem_notify_going_offline(struct virtio_mem *vm, > >> + unsigned long mb_id) > >> +{ > >> + const unsigned long nr_pages = PFN_DOWN(vm->subblock_size); >

On Mon, Jun 08, 2020 at 08:58:31AM +0200, David Hildenbrand wrote: > On 08.06.20 08:14, Michael S. Tsirkin wrote: > > If subblock size is large (e.g. 1G) 32 bit math involving it > > can overflow. Rather than try to catch all instances of that, > > let's tweak block size to 64 bit. > > I fail to see where we could actually trigger an overflow. The reported >

On Mon, Jun 08, 2020 at 08:58:31AM +0200, David Hildenbrand wrote: > On 08.06.20 08:14, Michael S. Tsirkin wrote: > > If subblock size is large (e.g. 1G) 32 bit math involving it > > can overflow. Rather than try to catch all instances of that, > > let's tweak block size to 64 bit. > > I fail to see where we could actually trigger an overflow. The reported >

Dropping the reference count of PageOffline() pages allows offlining code to skip them. However, we also have to convert PG_reserved to another flag - let's use PG_dirty - so has_unmovable_pages() will properly handle them. PG_reserved pages get detected as unmovable right away. We need the flag to see if we are onlining pages the first time, or if we allocated them via alloc_contig_range().

Fixes: 676fa9ba893e ("virtio_mem: convert device block size into 64bit") Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/virtio/virtio_mem.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c index 7b1bece8a331..50c689f25045 100644 --- a/drivers/virtio/virtio_mem.c +++

@Andrew, @Mst, I suggest the whole series (including the virtio-mem change) goes via the -mm tree. Currently, virtio-mem does not really support ZONE_MOVABLE. While it allows to online fully plugged memory blocks to ZONE_MOVABLE, it does not allow to online partially-plugged memory blocks to ZONE_MOVABLE and will never consider such memory blocks when unplugging memory. This might be surprising

For 5.10. Patch #1-#4,#6 have RBs or ACKs, patch #5 is virtio-mem stuff maintained by me. This should go via the -mm tree. --- When introducing virtio-mem, the semantics of ZONE_MOVABLE were rather unclear, which is why we special-cased ZONE_MOVABLE such that partially plugged blocks would never end up in ZONE_MOVABLE. Now that the semantics are much clearer (and are documented in patch #6),