Re: [libvirt] [PATCH v2] qemu: Support copy on read for disk

The new introduced optional attribute "copy_on_read</code> controls wether to copy read backing file into the image file. The value can

be either "on" or "off". Copy-on-read avoids accessing the same backing file sectors repeatedly and is useful when the backing file is over a slow network. By default copy-on-read is off. --- docs/formatdomain.html.in | 9 ++++ docs/schemas/domaincommon.rng | 11 ++++ src/conf/domain_conf.c | 24 +++++++++- src/conf/domain_conf.h | 10 ++++ src/libvirt_private.syms | 2 + src/qemu/qemu_capabilities.c | 3 + src/qemu/qemu_capabilities.h | 1 + src/qemu/qemu_command.c | 11 ++++ tests/qemuhelptest.c | 3 +- .../qemuxml2argv-disk-copy_on_read.args | 11 ++++ .../qemuxml2argv-disk-copy_on_read.xml | 50 ++++++++++++++++++++ tests/qemuxml2argvtest.c | 4 ++ 12 files changed, 137 insertions(+), 2 deletions(-) create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-disk-copy_on_read.args create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-disk-copy_on_read.xml diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index 42e23a1..3a42ebb 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -1202,6 +1202,15 @@ <b>In general you should leave this option alone, unless you are very certain you know what you are doing.</b> </li> + <li> + The optional <code>copy_on_read</code> attribute controls + wether to copy read backing file into the image file. The + value can be either "on" or "off". + Copy-on-read avoids accessing the same backing file sectors + repeatedly and is useful when the backing file is over a slow + network. By default copy-on-read is off. + <span class='since'>Since 0.9.9 (QEMU and KVM only)</span>

+++ b/docs/schemas/domaincommon.rng @@ -958,6 +958,9 @@ <optional> <ref name="event_idx"/> </optional> + <optional> + <ref name="copy_on_read"/> + </optional>