QEMU supports detect-zeroes option since version 2.1, but we never added support for it in libvirt. If was requested by Vasiliy Tolstov in the list, so I just added it. There are two discussions to be had, optionally. One is to decide whether we should disable detect_zeros='unmap' if discard is not set to 'unmap', but this is getting very hypervisor-specific, so I just documented the behaviour. The other one is the naming. I described why I made the decision for "zeros" instead of "zeroes" the decision in the patch, but I have no problem changing it to what others like better. v2: - format detect_zeroes on the command line instead of detect_zeros v1: - https://www.redhat.com/archives/libvir-list/2015-December/msg00484.html Martin Kletzander (2): conf: Add support of zero-detection for disks qemu: Add support for zero-detection writes docs/formatdomain.html.in | 10 ++++++ docs/schemas/domaincommon.rng | 12 +++++++ src/conf/domain_conf.c | 23 +++++++++++++- src/conf/domain_conf.h | 11 +++++++ src/libvirt_private.syms | 2 ++ src/qemu/qemu_capabilities.c | 2 ++ src/qemu/qemu_capabilities.h | 1 + src/qemu/qemu_command.c | 11 +++++++ tests/qemucapabilitiesdata/caps_2.1.1-1.caps | 1 + tests/qemucapabilitiesdata/caps_2.4.0-1.caps | 1 + tests/qemucapabilitiesdata/caps_2.5.0-1.caps | 1 + .../qemuxml2argv-disk-drive-detect-zeros.args | 27 ++++++++++++++++ .../qemuxml2argv-disk-drive-detect-zeros.xml | 37 ++++++++++++++++++++++ tests/qemuxml2argvtest.c | 4 +++ tests/qemuxml2xmltest.c | 1 + 15 files changed, 143 insertions(+), 1 deletion(-) create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-disk-drive-detect-zeros.args create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-disk-drive-detect-zeros.xml -- 2.6.4 -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list