Re: [libvirt] [PATCH v3 0/3] Add "memfd" memory backing type (resend)
On 11/15/2018 12:55 PM, marcandre.lureau(a)redhat.com wrote:
From: Marc-André Lureau <marcandre.lureau(a)redhat.com>
Hi,
This is an alternative series from "[PATCH 0/5] Use memfd if
possible". Instead of automatically using memfd for anonymous memory
when available (as suggested by Daniel), it introduces the "memfd"
memory backing type.
Although using memfd transparently when possible is a good idea, it is
a source of various complications for migration & save/restore. This
could eventually be challenged in a different series.
*please*:
The first two patches have been modified and reviewed by John
Ferlan. Hopefully they can be merged early, regardless of the last
patch outcome, to avoid the painful rebase conflicts due to
capabilities checks introduction.
Thanks :)
v3:
- rebased, to fix capabilities check and ping the series
Marc-André Lureau (3):
qemu: add memory-backend-memfd capability check
qemu: check memory-backend-memfd.hugetlb capability
qemu: add memfd source type
docs/formatdomain.html.in | 9 +-
docs/schemas/domaincommon.rng | 1 +
src/conf/domain_conf.c | 3 +-
src/conf/domain_conf.h | 1 +
src/qemu/qemu_capabilities.c | 10 ++
src/qemu/qemu_capabilities.h | 2 +
src/qemu/qemu_command.c | 69 +++++++----
src/qemu/qemu_domain.c | 12 +-
.../caps_2.12.0.aarch64.replies | 94 ++++++++++++---
.../caps_2.12.0.aarch64.xml | 4 +-
.../caps_2.12.0.ppc64.replies | 90 +++++++++++---
.../caps_2.12.0.ppc64.xml | 4 +-
.../caps_2.12.0.s390x.replies | 98 ++++++++++++----
.../caps_2.12.0.s390x.xml | 4 +-
.../caps_2.12.0.x86_64.replies | 110 +++++++++++++-----
.../caps_2.12.0.x86_64.xml | 4 +-
.../caps_3.0.0.ppc64.replies | 90 +++++++++++---
.../qemucapabilitiesdata/caps_3.0.0.ppc64.xml | 4 +-
.../caps_3.0.0.riscv32.replies | 86 +++++++++++---
.../caps_3.0.0.riscv32.xml | 2 +
.../caps_3.0.0.riscv64.replies | 86 +++++++++++---
.../caps_3.0.0.riscv64.xml | 2 +
.../caps_3.0.0.s390x.replies | 98 ++++++++++++----
.../qemucapabilitiesdata/caps_3.0.0.s390x.xml | 4 +-
.../caps_3.0.0.x86_64.replies | 110 +++++++++++++-----
.../caps_3.0.0.x86_64.xml | 4 +-
.../memfd-memory-numa.x86_64-latest.args | 34 ++++++
tests/qemuxml2argvdata/memfd-memory-numa.xml | 36 ++++++
tests/qemuxml2argvtest.c | 2 +
29 files changed, 869 insertions(+), 204 deletions(-)
create mode 100644 tests/qemuxml2argvdata/memfd-memory-numa.x86_64-latest.args
create mode 100644 tests/qemuxml2argvdata/memfd-memory-numa.xml
I've did the review and all three patches look good to me. I've fixed
all the issues I've found and I'm keeping them in a local branch of mine
to give others some time to raise their concerns should they have some.
My main concern was that we would be exposing memory backend to users by
giving them a config knob that could be set to enforce memfd usage. But
I don't think there is any other way, esp. since memory backends are not
real backends (one can't migrate a domain that was started with one to
another one).
ACK series
Michal