On 31.10.24 17:47, Sumanth Korikkar wrote:
On Thu, Oct 31, 2024 at 05:27:06PM +0100, Sumanth Korikkar wrote:
On Fri, Oct 25, 2024 at 04:14:45PM +0200, David Hildenbrand wrote:
Let's finally add s390 support for virtio-mem; my last RFC was sent
4 years ago, and a lot changed in the meantime.
The latest QEMU series is available at [1], which contains some more
details and a usage example on s390 (last patch).
There is not too much in here: The biggest part is querying a new diag(500)
STORAGE_LIMIT hypercall to obtain the proper "max_physmem_end".
The last three patches are not strictly required but certainly nice-to-have.
Note that -- in contrast to standby memory -- virtio-mem memory must be
configured to be automatically onlined as soon as hotplugged. The easiest
approach is using the "memhp_default_state=" kernel parameter or by using
proper udev rules. More details can be found at [2].
I have reviving+upstreaming a systemd service to handle configuring
that on my todo list, but for some reason I keep getting distracted ...
I tested various things, including:
* Various memory hotplug/hotunplug combinations
* Device hotplug/hotunplug
* /proc/iomem output
* reboot
* kexec
* kdump: make sure we properly enter the "kdump mode" in the virtio-mem
driver
kdump support for virtio-mem memory on s390 will be sent out separately.
v2 -> v3
* "s390/kdump: make is_kdump_kernel() consistently return "true" in kdump
environments only"
-> Sent out separately [3]
* "s390/physmem_info: query diag500(STORAGE LIMIT) to support QEMU/KVM memory
devices"
-> No query function for diag500 for now.
-> Update comment above setup_ident_map_size().
-> Optimize/rewrite diag500_storage_limit() [Heiko]
-> Change handling in detect_physmem_online_ranges [Alexander]
-> Improve documentation.
* "s390/sparsemem: provide memory_add_physaddr_to_nid() with CONFIG_NUMA"
-> Added after testing on systems with CONFIG_NUMA=y
v1 -> v2:
* Document the new diag500 subfunction
* Use "s390" instead of "s390x" consistently
[1] https://lkml.kernel.org/r/[email protected]
[2] https://virtio-mem.gitlab.io/user-guide/user-guide-linux.html
[3] https://lkml.kernel.org/r/[email protected]
Cc: Heiko Carstens <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Thomas Huth <[email protected]>
Cc: Cornelia Huck <[email protected]>
Cc: Janosch Frank <[email protected]>
Cc: Claudio Imbrenda <[email protected]>
Cc: "Michael S. Tsirkin" <[email protected]>
Cc: Jason Wang <[email protected]>
Cc: Xuan Zhuo <[email protected]>
Cc: "Eugenio P?rez" <[email protected]>
Cc: Eric Farman <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Jonathan Corbet <[email protected]>
David Hildenbrand (7):
Documentation: s390-diag.rst: make diag500 a generic KVM hypercall
Documentation: s390-diag.rst: document diag500(STORAGE LIMIT)
subfunction
s390/physmem_info: query diag500(STORAGE LIMIT) to support QEMU/KVM
memory devices
virtio-mem: s390 support
lib/Kconfig.debug: default STRICT_DEVMEM to "y" on s390
s390/sparsemem: reduce section size to 128 MiB
s390/sparsemem: provide memory_add_physaddr_to_nid() with CONFIG_NUMA
Documentation/virt/kvm/s390/s390-diag.rst | 35 +++++++++++++----
arch/s390/boot/physmem_info.c | 47 ++++++++++++++++++++++-
arch/s390/boot/startup.c | 7 +++-
arch/s390/include/asm/physmem_info.h | 3 ++
arch/s390/include/asm/sparsemem.h | 10 ++++-
drivers/virtio/Kconfig | 12 +++---
lib/Kconfig.debug | 2 +-
7 files changed, 98 insertions(+), 18 deletions(-)
base-commit: ae90f6a6170d7a7a1aa4fddf664fbd093e3023bc
--
2.46.1
Tested successfully various memory hotplug operations on lpar.
Just to be more precise, tested memory hotplug/hotunplug combinations +
Device hotplug/hotunplug operations on guest.
Thanks a bunch!
--
Cheers,
David / dhildenb
