On Fri, Sep 02, 2011 at 03:38:38PM +0800, Osier Yang wrote: > Newer QEMU introduced cache=directsync for -drive, this patchset > is to expose it in libvirt layer. > > * Introduced a new QEMU capability flag ($prefix_CACHE_DIRECTSYNC), > As even $prefix_CACHE_V2 is set, we can't known if directsync > is supported. > --- > docs/formatdomain.html.in | 2 +- > docs/schemas/domain.rng | 1 + > src/conf/domain_conf.c | 3 ++- > src/conf/domain_conf.h | 1 + > src/qemu/qemu_capabilities.c | 6 +++++- > src/qemu/qemu_capabilities.h | 1 + > src/qemu/qemu_command.c | 29 ++++++++++++++++++++++------- > tests/qemuargv2xmltest.c | 1 + > tests/qemuxml2argvtest.c | 3 +++ > tools/virsh.pod | 3 ++- > 10 files changed, 39 insertions(+), 11 deletions(-) > > diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in > index f46771d..6cb36d3 100644 > --- a/docs/formatdomain.html.in > +++ b/docs/formatdomain.html.in > @@ -976,7 +976,7 @@ > <li> > The optional<code>cache</code> attribute controls the > cache mechanism, possible values are "default", "none", > - "writethrough" and "writeback". > + "writethrough", "writeback", and "directsync". > <span class="since">Since 0.6.0</span> > </li> > <li> > diff --git a/docs/schemas/domain.rng b/docs/schemas/domain.rng > index dd8c41a..e43b17d 100644 > --- a/docs/schemas/domain.rng > +++ b/docs/schemas/domain.rng > @@ -829,6 +829,7 @@ > <value>none</value> > <value>writeback</value> > <value>writethrough</value> > +<value>directsync</value> > </choice> > </attribute> > </define> > diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c > index 00212db..a2de8df 100644 > --- a/src/conf/domain_conf.c > +++ b/src/conf/domain_conf.c > @@ -160,7 +160,8 @@ VIR_ENUM_IMPL(virDomainDiskCache, VIR_DOMAIN_DISK_CACHE_LAST, > "default", > "none", > "writethrough", > - "writeback") > + "writeback", > + "directsync") > > VIR_ENUM_IMPL(virDomainDiskErrorPolicy, VIR_DOMAIN_DISK_ERROR_POLICY_LAST, > "default", > diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h > index 8382d28..0abb75e 100644 > --- a/src/conf/domain_conf.h > +++ b/src/conf/domain_conf.h > @@ -165,6 +165,7 @@ enum virDomainDiskCache { > VIR_DOMAIN_DISK_CACHE_DISABLE, > VIR_DOMAIN_DISK_CACHE_WRITETHRU, > VIR_DOMAIN_DISK_CACHE_WRITEBACK, > + VIR_DOMAIN_DISK_CACHE_DIRECTSYNC, > > VIR_DOMAIN_DISK_CACHE_LAST > }; > diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c > index f665de4..631d683 100644 > --- a/src/qemu/qemu_capabilities.c > +++ b/src/qemu/qemu_capabilities.c > @@ -125,6 +125,7 @@ VIR_ENUM_IMPL(qemuCaps, QEMU_CAPS_LAST, > "sga", > "virtio-blk-pci.event_idx", > "virtio-net-pci.event_idx", > + "cache-directsync", > ); > > struct qemu_feature_flags { > @@ -902,8 +903,11 @@ qemuCapsComputeCmdFlags(const char *help, > if (strstr(help, "-drive")) { > qemuCapsSet(flags, QEMU_CAPS_DRIVE); > if (strstr(help, "cache=")&& > - !strstr(help, "cache=on|off")) > + !strstr(help, "cache=on|off")) { > qemuCapsSet(flags, QEMU_CAPS_DRIVE_CACHE_V2); > + if (strstr(help, "directsync")) > + qemuCapsSet(flags, QEMU_CAPS_DRIVE_CACHE_DIRECTSYNC); > + } > if (strstr(help, "format=")) > qemuCapsSet(flags, QEMU_CAPS_DRIVE_FORMAT); > if (strstr(help, "readonly=")) > diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h > index 13af0b9..c01d438 100644 > --- a/src/qemu/qemu_capabilities.h > +++ b/src/qemu/qemu_capabilities.h > @@ -100,6 +100,7 @@ enum qemuCapsFlags { > QEMU_CAPS_SGA = 62, /* Serial Graphics Adapter */ > QEMU_CAPS_VIRTIO_BLK_EVENT_IDX = 63, /* virtio-blk-pci.event_idx */ > QEMU_CAPS_VIRTIO_NET_EVENT_IDX = 64, /* virtio-net-pci.event_idx */ > + QEMU_CAPS_DRIVE_CACHE_DIRECTSYNC = 65, /* Is cache=directsync supported? */ > > QEMU_CAPS_LAST, /* this must always be the last item */ > }; > diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c > index 44a553b..fa52dc0 100644 > --- a/src/qemu/qemu_command.c > +++ b/src/qemu/qemu_command.c > @@ -64,14 +64,16 @@ VIR_ENUM_DECL(qemuDiskCacheV2) > VIR_ENUM_IMPL(qemuDiskCacheV1, VIR_DOMAIN_DISK_CACHE_LAST, > "default", > "off", > - "off", /* writethrough not supported, so for safety, disable */ > - "on"); /* Old 'on' was equivalent to 'writeback' */ > + "off", /* writethrough not supported, so for safety, disable */ > + "on", /* Old 'on' was equivalent to 'writeback' */ > + "off"); /* directsync not supported, for safety, disable */ > > VIR_ENUM_IMPL(qemuDiskCacheV2, VIR_DOMAIN_DISK_CACHE_LAST, > "default", > "none", > "writethrough", > - "writeback"); > + "writeback", > + "directsync"); > > VIR_ENUM_DECL(qemuVideo) > > @@ -1516,10 +1518,21 @@ qemuBuildDriveStr(virDomainDiskDefPtr disk, > } > > if (disk->cachemode) { > - const char *mode = > - qemuCapsGet(qemuCaps, QEMU_CAPS_DRIVE_CACHE_V2) ? > - qemuDiskCacheV2TypeToString(disk->cachemode) : > - qemuDiskCacheV1TypeToString(disk->cachemode); > + const char *mode = NULL; > + > + if (qemuCapsGet(qemuCaps, QEMU_CAPS_DRIVE_CACHE_V2)) { > + mode = qemuDiskCacheV2TypeToString(disk->cachemode); > + > + if (disk->cachemode == VIR_DOMAIN_DISK_CACHE_DIRECTSYNC&& > + !qemuCapsGet(qemuCaps, QEMU_CAPS_DRIVE_CACHE_DIRECTSYNC)) { > + qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", > + _("disk cache mode 'directsync' is not " > + "supported by this QEMU")); > + goto error; > + } > + } else { > + mode = qemuDiskCacheV1TypeToString(disk->cachemode); > + } > > virBufferAsprintf(&opt, ",cache=%s", mode); > } else if (disk->shared&& !disk->readonly) { > @@ -5211,6 +5224,8 @@ qemuParseCommandLineDisk(virCapsPtr caps, > def->cachemode = VIR_DOMAIN_DISK_CACHE_WRITEBACK; > else if (STREQ(values[i], "writethrough")) > def->cachemode = VIR_DOMAIN_DISK_CACHE_WRITETHRU; > + else if (STREQ(values[i], "directsync")) > + def->cachemode = VIR_DOMAIN_DISK_CACHE_DIRECTSYNC; > } else if (STREQ(keywords[i], "werror") || > STREQ(keywords[i], "rerror")) { > if (STREQ(values[i], "stop")) > diff --git a/tests/qemuargv2xmltest.c b/tests/qemuargv2xmltest.c > index c2b6cf2..91f15af 100644 > --- a/tests/qemuargv2xmltest.c > +++ b/tests/qemuargv2xmltest.c > @@ -168,6 +168,7 @@ mymain(void) > DO_TEST("disk-drive-cache-v2-wt"); > DO_TEST("disk-drive-cache-v2-wb"); > DO_TEST("disk-drive-cache-v2-none"); > + DO_TEST("disk-drive-cache-directsync"); > DO_TEST("disk-drive-network-nbd"); > DO_TEST("disk-drive-network-rbd"); > DO_TEST("disk-drive-network-sheepdog"); > diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c > index 6e8da5e..b009bf3 100644 > --- a/tests/qemuxml2argvtest.c > +++ b/tests/qemuxml2argvtest.c > @@ -338,6 +338,9 @@ mymain(void) > QEMU_CAPS_DRIVE, QEMU_CAPS_DRIVE_CACHE_V2, QEMU_CAPS_DRIVE_FORMAT); > DO_TEST("disk-drive-cache-v2-none", false, > QEMU_CAPS_DRIVE, QEMU_CAPS_DRIVE_CACHE_V2, QEMU_CAPS_DRIVE_FORMAT); > + DO_TEST("disk-drive-cache-directsync", false, > + QEMU_CAPS_DRIVE, QEMU_CAPS_DRIVE_CACHE_V2, > + QEMU_CAPS_DRIVE_CACHE_DIRECTSYNC, QEMU_CAPS_DRIVE_FORMAT); > DO_TEST("disk-drive-network-nbd", false, > QEMU_CAPS_DRIVE, QEMU_CAPS_DRIVE_FORMAT); > DO_TEST("disk-drive-network-rbd", false, > diff --git a/tools/virsh.pod b/tools/virsh.pod > index b90c26e..5ac2c5c 100644 > --- a/tools/virsh.pod > +++ b/tools/virsh.pod > @@ -1099,7 +1099,8 @@ floppy device; consider using B<update-device> for this usage instead. > I<mode> can specify the two specific mode I<readonly> or I<shareable>. > I<persistent> indicates the changes will affect the next boot of the domain. > I<sourcetype> can indicate the type of source (block|file) > -I<cache> can be one of "default", "none", "writethrough" or "writeback". > +I<cache> can be one of "default", "none", "writethrough", "writeback", or > +"directsync". > I<serial> is the serial of disk device. I<shareable> indicates the disk device > is shareable between domains. > I<address> is the address of disk device in the form of pci:domain.bus.slot.function, ACK, though I would prefer if docs/formatdomain.html.in was expanded to explain the semantic of that new flag ! Daniel