The get_config callback can be used by the device to fill the
config structure.
The callback will be invoked in vdpasim_get_config() before copying
bytes into caller buffer.
Move vDPA-net config updates from vdpasim_set_features() in the
new vdpasim_net_get_config() callback.
This is safe since in vdpa_get_config() we already check that
.set_features() callback is called before .get_config().
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/20201215144256.155342-13-sgarzare@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Let's try to unplug completely offline big blocks first. Then, (if
enabled via unplug_offline) try to offline and remove whole big blocks.
No locking necessary - we can deal with concurrent onlining/offlining
just fine.
Note1: This is sub-optimal and might be dangerous in some environments: we
could end up in an infinite loop when offlining (e.g., long-term pinnings),
similar as with DIMMs. We'll introduce safe memory hotunplug via
fake-offlining next, and use this basic mode only when explicitly enabled.
Note2: Without ZONE_MOVABLE, memory unplug will be extremely unreliable
with bigger block sizes.
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20201112133815.13332-29-david@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
virtio-mem soon wants to use offline_and_remove_memory() memory that
exceeds a single Linux memory block (memory_block_size_bytes()). Let's
remove that restriction.
Let's remember the old state and try to restore that if anything goes
wrong. While re-onlining can, in general, fail, it's highly unlikely to
happen (usually only when a notifier fails to allocate memory, and these
are rather rare).
This will be used by virtio-mem to offline+remove memory ranges that are
bigger than a single memory block - for example, with a device block
size of 1 GiB (e.g., gigantic pages in the hypervisor) and a Linux memory
block size of 128MB.
While we could compress the state into 2 bit, using 8 bit is much
easier.
This handling is similar, but different to acpi_scan_try_to_offline():
a) We don't try to offline twice. I am not sure if this CONFIG_MEMCG
optimization is still relevant - it should only apply to ZONE_NORMAL
(where we have no guarantees). If relevant, we can always add it.
b) acpi_scan_try_to_offline() simply onlines all memory in case
something goes wrong. It doesn't restore previous online type. Let's do
that, so we won't overwrite what e.g., user space configured.
Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20201112133815.13332-28-david@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Currently, we do not support device block sizes that exceed the Linux
memory block size. For example, having a device block size of 1 GiB (e.g.,
gigantic pages in the hypervisor) won't work with 128 MiB Linux memory
blocks.
Let's implement Big Block Mode (BBM), whereby we add/remove at least
one Linux memory block at a time. With a 1 GiB device block size, a Big
Block (BB) will cover 8 Linux memory blocks.
We'll keep registering the online_page_callback machinery, it will be used
for safe memory hotunplug in BBM next.
Note: BBM is properly prepared for variable-sized Linux memory
blocks that we might see in the future. So we won't care how many Linux
memory blocks a big block actually spans, and how the memory notifier is
called.
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20201112133815.13332-26-david@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Let's use wrappers for the low-level functions that dev_dbg/dev_warn
and work on addr + size, such that we can reuse them for adding/removing
in other granularity.
We only warn when adding memory failed, because that's something to pay
attention to. We won't warn when removing failed, we'll reuse that in
racy context soon (and we do have proper BUG_ON() statements in the
current cases where it must never happen).
Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20201112133815.13332-25-david@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
We don't want to add too much memory when it's not getting onlined
immediately, to avoid running OOM. Generalize the handling, to avoid
making use of memory block states. Use a threshold of 1 GiB for now.
Properly adjust the offline size when adding/removing memory. As we are
not always protected by a lock when touching the offline size, use an
atomic64_t. We don't care about races (e.g., someone offlining memory
while we are adding more), only about consistent values.
(1 GiB needs a memmap of ~16MiB - which sounds reasonable even for
setups with little boot memory and (possibly) one virtio-mem device per
node)
We don't want to retrigger when onlining is caused immediately by our
action (e.g., adding memory which immediately gets onlined), so use a
flag to indicate if the workqueue is active and use that as an
indicator whether to trigger a retry. This will also be especially relevant
for Big Block Mode (BBM), whereby we might re-online memory in case
offlining of another memory block failed.
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20201112133815.13332-17-david@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Let's trigger from offlining code only when we're not allowed to unplug
online memory. Handle the other case (memmap possibly freeing up another
memory block) when actually removing memory. We now also properly handle
the case when removing already offline memory blocks via
virtio_mem_mb_remove(). When removing via virtio_mem_remove(), when
unloading the driver, virtio_mem_retry() is a NOP and safe to use.
While at it, move retry handling when offlining out of
virtio_mem_notify_offline(), to share it with Big Block Mode (BBM)
soon.
This is a preparation for Big Block Mode (BBM), whereby we can see some
temporary offlining of memory blocks without actually making progress.
Imagine you have a Big Block that spans to Linux memory blocks. Assume
the first Linux memory blocks has no unmovable data on it. When we would
call offline_and_remove_memory() on the big block, we would
1. Try to offline the first block. Works, notifiers triggered.
virtio_mem_retry() called.
2. Try to offline the second block. Does not work.
3. Re-online first block.
4. Exit to main loop, exit workqueue.
5. Retry immediately (due to virtio_mem_retry()), go to 1.
The result are endless retries.
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20201112133815.13332-16-david@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Pull x86 fixes from Thomas Gleixner:
"A set of x86 and membarrier fixes:
- Correct a few problems in the x86 and the generic membarrier
implementation. Small corrections for assumptions about visibility
which have turned out not to be true.
- Make the PAT bits for memory encryption correct vs 4K and 2M/1G
page table entries as they are at a different location.
- Fix a concurrency issue in the the local bandwidth readout of
resource control leading to incorrect values
- Fix the ordering of allocating a vector for an interrupt. The order
missed to respect the provided cpumask when the first attempt of
allocating node local in the mask fails. It then tries the node
instead of trying the full provided mask first. This leads to
erroneous error messages and breaking the (user) supplied affinity
request. Reorder it.
- Make the INT3 padding detection in optprobe work correctly"
* tag 'x86-urgent-2020-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/kprobes: Fix optprobe to detect INT3 padding correctly
x86/apic/vector: Fix ordering in vector assignment
x86/resctrl: Fix incorrect local bandwidth when mba_sc is enabled
x86/mm/mem_encrypt: Fix definition of PMD_FLAGS_DEC_WP
membarrier: Execute SYNC_CORE on the calling thread
membarrier: Explicitly sync remote cores when SYNC_CORE is requested
membarrier: Add an actual barrier before rseq_preempt()
x86/membarrier: Get rid of a dubious optimization
Pull block fixes from Jens Axboe:
"This should be it for 5.10.
Mike and Song looked into the warning case, and thankfully it appears
the fix was pretty trivial - we can just change the md device chunk
type to unsigned int to get rid of it. They cannot currently be < 0,
and nobody is checking for that either.
We're reverting the discard changes as the corruption reports came in
very late, and there's just no time to attempt to deal with it at this
point. Reverting the changes in question is the right call for 5.10"
* tag 'block-5.10-2020-12-12' of git://git.kernel.dk/linux-block:
md: change mddev 'chunk_sectors' from int to unsigned
Revert "md: add md_submit_discard_bio() for submitting discard bio"
Revert "md/raid10: extend r10bio devs to raid disks"
Revert "md/raid10: pull codes that wait for blocked dev into one function"
Revert "md/raid10: improve raid10 discard request"
Revert "md/raid10: improve discard request for far layout"
Revert "dm raid: remove unnecessary discard limits for raid10"
Pull SCSI fixes from James Bottomley:
"Five small fixes. Four in drivers:
- hisi_sas: fix internal queue timeout
- be2iscsi: revert a prior fix causing problems
- bnx2i: add missing dependency
- storvsc: late arriving revert of a problem fix
and one in the core.
The core one is a minor change to stop paying attention to the busy
count when returning out of resources because there's a race window
where the queue might not restart due to missing returning I/O"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
Revert "scsi: storvsc: Validate length of incoming packet in storvsc_on_channel_callback()"
scsi: hisi_sas: Select a suitable queue for internal I/Os
scsi: core: Fix race between handling STS_RESOURCE and completion
scsi: be2iscsi: Revert "Fix a theoretical leak in beiscsi_create_eqs()"
scsi: bnx2i: Requires MMU
Pull i2c fix from Wolfram Sang:
"Bugfix for the AT24 EEPROM driver"
* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
misc: eeprom: at24: fix NVMEM name with custom AT24 device name
