On Thu, Apr 25, 2024 at 02:21:11AM +0000, Hao Xiang wrote: > Intel DSA offloading is an optional feature that turns on if > proper hardware and software stack is available. To turn on > DSA offloading in multifd live migration: > > multifd-dsa-accel="[dsa_dev_path1] [dsa_dev_path2] ... [dsa_dev_pathX]" > > This feature is turned off by default. > > Signed-off-by: Hao Xiang <hao.xi...@linux.dev> > --- > migration/migration-hmp-cmds.c | 8 ++++++++ > migration/options.c | 30 ++++++++++++++++++++++++++++++ > migration/options.h | 1 + > qapi/migration.json | 26 +++++++++++++++++++++++--- > 4 files changed, 62 insertions(+), 3 deletions(-)
> diff --git a/qapi/migration.json b/qapi/migration.json > index 8c65b90328..934fa8839e 100644 > --- a/qapi/migration.json > +++ b/qapi/migration.json > @@ -914,6 +914,12 @@ > # See description in @ZeroPageDetection. Default is 'multifd'. > # (since 9.0) > # > +# @multifd-dsa-accel: If enabled, use DSA accelerator offloading for > +# certain memory operations. Enable DSA accelerator offloading by > +# setting this string to a list of DSA device path separated by space > +# characters. Setting this string to an empty string means disabling > +# DSA accelerator offloading. Defaults to an empty string. (since 9.2) Passing a list of paths as a single space separate string is a design anti-pattern. This needs to use a list type at the QAPI level. Also I don't think we need add 'multifd' on the name - all new features are for multifd. Overall it should be called 'dsa-accel-path' I thjink > @@ -1122,6 +1128,12 @@ > # See description in @ZeroPageDetection. Default is 'multifd'. > # (since 9.0) > # > +# @multifd-dsa-accel: If enabled, use DSA accelerator offloading for > +# certain memory operations. Enable DSA accelerator offloading by > +# setting this string to a list of DSA device path separated by space > +# characters. Setting this string to an empty string means disabling > +# DSA accelerator offloading. Defaults to an empty string. (since 9.2) > +# > # Features: > # > # @deprecated: Member @block-incremental is deprecated. Use > @@ -1176,7 +1188,8 @@ > 'features': [ 'unstable' ] }, > '*vcpu-dirty-limit': 'uint64', > '*mode': 'MigMode', > - '*zero-page-detection': 'ZeroPageDetection'} } > + '*zero-page-detection': 'ZeroPageDetection', > + '*multifd-dsa-accel': 'StrOrNull'} } This needs to be ['str'] not 'StrOrNull' > > ## > # @migrate-set-parameters: > @@ -1354,6 +1367,12 @@ > # See description in @ZeroPageDetection. Default is 'multifd'. > # (since 9.0) > # > +# @multifd-dsa-accel: If enabled, use DSA accelerator offloading for > +# certain memory operations. Enable DSA accelerator offloading by > +# setting this string to a list of DSA device path separated by space > +# characters. Setting this string to an empty string means disabling > +# DSA accelerator offloading. Defaults to an empty string. (since 9.2) > +# > # Features: > # > # @deprecated: Member @block-incremental is deprecated. Use > @@ -1405,7 +1424,8 @@ > 'features': [ 'unstable' ] }, > '*vcpu-dirty-limit': 'uint64', > '*mode': 'MigMode', > - '*zero-page-detection': 'ZeroPageDetection'} } > + '*zero-page-detection': 'ZeroPageDetection', > + '*multifd-dsa-accel': 'str'} } Liekewise needs to be ['str'] Having mgmt apps pass in the path every time though, feels like overkill. Surely there's a standard path that QEMU should use by default, and should only require flag to turn on its usage. IOW, why not extend the ZeroPageDetection enum, to have a further entry for 'dsa' to request ue of dsa accel. Passing paths could be optional. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
