linux.git/drivers/virtio, branch v5.8-rc2

treewide: replace '---help---' in Kconfig files with 'help'

2020-06-13T16:57:21+00:00

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

  a) 4 spaces + '---help---'
  b) 7 spaces + '---help---'
  c) 8 spaces + '---help---'
  d) 1 space + 1 tab + '---help---'
  e) 1 tab + '---help---'    (correct indentation)
  f) 1 tab + 1 space + '---help---'
  g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

  $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada

virtio_mem: convert device block size into 64bit

2020-06-09T10:42:06+00:00

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 memory hotplug")
Signed-off-by: Michael S. Tsirkin 
Acked-by: David Hildenbrand

virtio-mem: drop unnecessary initialization

2020-06-08T09:12:52+00:00

rc is initialized to -ENIVAL but that's never used. Drop it.

Fixes: 5f1f79bbc9e2 ("virtio-mem: Paravirtualized memory hotplug")
Reported-by: kernel test robot 
Signed-off-by: Michael S. Tsirkin 
Acked-by: David Hildenbrand

virtio-mem: Don't rely on implicit compiler padding for requests

2020-06-04T19:36:52+00:00

The compiler will add padding after the last member, make that explicit.
The size of a request is always 24 bytes. The size of a response always
10 bytes. Add compile-time checks.

Cc: "Michael S. Tsirkin" 
Cc: Pankaj Gupta 
Cc: teawater 
Signed-off-by: David Hildenbrand 
Link: https://lore.kernel.org/r/20200515101402.16597-1-david@redhat.com
Signed-off-by: Michael S. Tsirkin

virtio-mem: Try to unplug the complete online memory block first

2020-06-04T19:36:52+00:00

Right now, we always try to unplug single subblocks when processing an
online memory block. Let's try to unplug the complete online memory block
first, in case it is fully plugged and the unplug request is large
enough. Fallback to single subblocks in case the memory block cannot get
unplugged as a whole.

Cc: "Michael S. Tsirkin" 
Cc: Pankaj Gupta 
Signed-off-by: David Hildenbrand 
Link: https://lore.kernel.org/r/20200507140139.17083-16-david@redhat.com
Signed-off-by: Michael S. Tsirkin

virtio-mem: Use -ETXTBSY as error code if the device is busy

2020-06-04T19:36:52+00:00

Let's be able to distinguish if the device or if memory is busy.

Cc: "Michael S. Tsirkin" 
Cc: Pankaj Gupta 
Signed-off-by: David Hildenbrand 
Link: https://lore.kernel.org/r/20200507140139.17083-15-david@redhat.com
Signed-off-by: Michael S. Tsirkin

virtio-mem: Unplug subblocks right-to-left

2020-06-04T19:36:52+00:00

We unplug blocks right-to-left, let's also unplug subblocks within a block
right-to-left.

Cc: "Michael S. Tsirkin" 
Cc: Pankaj Gupta 
Signed-off-by: David Hildenbrand 
Link: https://lore.kernel.org/r/20200507140139.17083-14-david@redhat.com
Signed-off-by: Michael S. Tsirkin

virtio-mem: Drop manual check for already present memory

2020-06-04T19:36:52+00:00

Registering our parent resource will fail if any memory is still present
(e.g., because somebody unloaded the driver and tries to reload it). No
need for the manual check.

Move our "unplug all" handling to after registering the resource.

Cc: "Michael S. Tsirkin" 
Cc: Pankaj Gupta 
Signed-off-by: David Hildenbrand 
Link: https://lore.kernel.org/r/20200507140139.17083-13-david@redhat.com
Signed-off-by: Michael S. Tsirkin

virtio-mem: Add parent resource for all added "System RAM"

2020-06-04T19:36:52+00:00

Let's add a parent resource, named after the virtio device (inspired by
drivers/dax/kmem.c). This allows user space to identify which memory
belongs to which virtio-mem device.

With this change and two virtio-mem devices:
	:/# cat /proc/iomem
	00000000-00000fff : Reserved
	00001000-0009fbff : System RAM
	[...]
	140000000-333ffffff : virtio0
	  140000000-147ffffff : System RAM
	  148000000-14fffffff : System RAM
	  150000000-157ffffff : System RAM
	[...]
	334000000-3033ffffff : virtio1
	  338000000-33fffffff : System RAM
	  340000000-347ffffff : System RAM
	  348000000-34fffffff : System RAM
	[...]

Cc: "Michael S. Tsirkin" 
Cc: Pankaj Gupta 
Signed-off-by: David Hildenbrand 
Link: https://lore.kernel.org/r/20200507140139.17083-12-david@redhat.com
Signed-off-by: Michael S. Tsirkin 
Reviewed-by: Pankaj Gupta

virtio-mem: Better retry handling

2020-06-04T19:36:52+00:00

Let's start with a retry interval of 5 seconds and double the time until
we reach 5 minutes, in case we keep getting errors. Reset the retry
interval in case we succeeded.

The two main reasons for having to retry are
- The hypervisor is busy and cannot process our request
- We cannot reach the desired requested_size (esp., not enough memory can
  get unplugged because we can't allocate any subblocks).

Tested-by: Pankaj Gupta 
Cc: "Michael S. Tsirkin" 
Cc: Jason Wang 
Cc: Oscar Salvador 
Cc: Michal Hocko 
Cc: Igor Mammedov 
Cc: Dave Young 
Cc: Andrew Morton 
Cc: Dan Williams 
Cc: Pavel Tatashin 
Cc: Stefan Hajnoczi 
Cc: Vlastimil Babka 
Signed-off-by: David Hildenbrand 
Link: https://lore.kernel.org/r/20200507140139.17083-11-david@redhat.com
Signed-off-by: Michael S. Tsirkin