All of lore.kernel.org
 help / color / mirror / Atom feed
From: Claudio Imbrenda <imbrenda@linux.ibm.com>
To: linux-kernel@vger.kernel.org
Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org,
	borntraeger@de.ibm.com, frankja@linux.ibm.com, nrb@linux.ibm.com,
	seiden@linux.ibm.com, schlameuss@linux.ibm.com,
	gra@linux.ibm.com, david@kernel.org
Subject: [PATCH v3 0/6] KVM: s390: Enable 4k granularity for memslots
Date: Thu,  2 Apr 2026 17:01:29 +0200	[thread overview]
Message-ID: <20260402150135.196943-1-imbrenda@linux.ibm.com> (raw)

Currently the memslot granularity for s390 VMs is 1M. Both the s390
core architecture and virtio-mem only support a 1M granularity for
guest memory.

Notwithstanding the official architectural limits, it can be beneficial
to support memslots with 4k granularity. With the new gmap code, this
is a quite simple change. This allows us to enable more existing
selftests and makes KVM on s390 more future proof.


v2->v3
* Remove more 1M-alignment #ifdefs in the kvm selftests.
* Do not remove the common tests from loongarch, since loongarch does
  not include the common tests by default.
* Opportunistically fix a potential NULL pointer dereference when
  memslots for UCONTROL guests are attempted to be removed (does not
  actually happen in practice).

v1->v2
* Fixed the first patch (thanks Christian)


Claudio Imbrenda (6):
  KVM: s390: Add some useful mask macros
  KVM: s390: Add alignment checks for hugepages
  KVM: s390: Allow 4k granularity for memslots
  KVM: selftests: Remove 1M alignment requirement for s390
  KVM: s390: selftests: enable some common memory-related tests
  KVM: s390: ucontrol: Fix memslot handling

 arch/s390/kvm/dat.h                           |  5 +++
 arch/s390/kvm/faultin.c                       |  2 +-
 arch/s390/kvm/gaccess.c                       |  2 +-
 arch/s390/kvm/gmap.c                          | 32 +++++++++++++++----
 arch/s390/kvm/gmap.h                          |  3 +-
 arch/s390/kvm/kvm-s390.c                      | 22 ++++---------
 tools/testing/selftests/kvm/Makefile.kvm      |  9 ++----
 tools/testing/selftests/kvm/dirty_log_test.c  |  3 --
 .../testing/selftests/kvm/include/kvm_util.h  |  4 ---
 .../selftests/kvm/kvm_page_table_test.c       |  3 --
 tools/testing/selftests/kvm/lib/kvm_util.c    |  9 +-----
 tools/testing/selftests/kvm/lib/memstress.c   |  4 ---
 .../selftests/kvm/pre_fault_memory_test.c     |  4 ---
 .../selftests/kvm/set_memory_region_test.c    |  9 +-----
 14 files changed, 47 insertions(+), 64 deletions(-)

-- 
2.53.0


             reply	other threads:[~2026-04-02 15:01 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-02 15:01 Claudio Imbrenda [this message]
2026-04-02 15:01 ` [PATCH v3 1/6] KVM: s390: Add some useful mask macros Claudio Imbrenda
2026-04-07 12:13   ` Steffen Eiden
2026-04-09 13:41   ` Christoph Schlameuss
2026-04-02 15:01 ` [PATCH v3 2/6] KVM: s390: Add alignment checks for hugepages Claudio Imbrenda
2026-04-07 12:30   ` Steffen Eiden
2026-04-10  9:15   ` Christoph Schlameuss
2026-04-02 15:01 ` [PATCH v3 3/6] KVM: s390: Allow 4k granularity for memslots Claudio Imbrenda
2026-04-07 12:33   ` Steffen Eiden
2026-04-10 10:02   ` Christoph Schlameuss
2026-04-02 15:01 ` [PATCH v3 4/6] KVM: selftests: Remove 1M alignment requirement for s390 Claudio Imbrenda
2026-04-07 12:44   ` Steffen Eiden
2026-04-10 11:28   ` Christoph Schlameuss
2026-04-02 15:01 ` [PATCH v3 5/6] KVM: s390: selftests: enable some common memory-related tests Claudio Imbrenda
2026-04-07 12:47   ` Steffen Eiden
2026-04-07 13:04     ` Claudio Imbrenda
2026-04-07 13:41       ` Steffen Eiden
2026-04-07 15:19   ` Steffen Eiden
2026-04-09  8:50   ` Claudio Imbrenda
2026-04-10 12:02   ` Christoph Schlameuss
2026-04-02 15:01 ` [PATCH v3 6/6] KVM: s390: ucontrol: Fix memslot handling Claudio Imbrenda
2026-04-07 12:55   ` Steffen Eiden
2026-04-07 13:05     ` Claudio Imbrenda
2026-04-10  9:25   ` Christoph Schlameuss

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20260402150135.196943-1-imbrenda@linux.ibm.com \
    --to=imbrenda@linux.ibm.com \
    --cc=borntraeger@de.ibm.com \
    --cc=david@kernel.org \
    --cc=frankja@linux.ibm.com \
    --cc=gra@linux.ibm.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-s390@vger.kernel.org \
    --cc=nrb@linux.ibm.com \
    --cc=schlameuss@linux.ibm.com \
    --cc=seiden@linux.ibm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.