From f887334dcf0c0e4b883d6afed5c5b580552ecc01 Mon Sep 17 00:00:00 2001 From: Oskari Saarenmaa Date: Thu, 22 Sep 2011 22:33:47 +0300 Subject: [PATCH] Add unsafe cache mode support for disk driver QEMU 0.13 introduced cache=unsafe for -drive, this patch exposes it in the libvirt layer. * Introduced a new QEMU capability flag ($prefix_CACHE_UNSAFE), as even if $prefix_CACHE_V2 is set, we can't know if unsafe is supported. * Improved the reliability of qemu cache type detection. --- docs/formatdomain.html.in | 13 +++++--- docs/schemas/domaincommon.rng | 1 + src/conf/domain_conf.c | 3 +- src/conf/domain_conf.h | 1 + src/qemu/qemu_capabilities.c | 14 +++++--- src/qemu/qemu_capabilities.h | 2 ++ src/qemu/qemu_command.c | 14 ++++++-- tests/qemuargv2xmltest.c | 1 + tests/qemuhelptest.c | 3 ++ .../qemuxml2argv-disk-drive-cache-unsafe.args | 5 +++ .../qemuxml2argv-disk-drive-cache-unsafe.xml | 33 +++++++++++++++++++ tests/qemuxml2argvtest.c | 3 ++ tools/virsh.pod | 4 +-- 13 files changed, 84 insertions(+), 13 deletions(-) create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-unsafe.args create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-unsafe.xml diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index 0a7abafac4..3087d016e3 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -996,10 +996,15 @@
  • The optional cache attribute controls the cache mechanism, possible values are "default", "none", - "writethrough", "writeback", and "directsync". "directsync" - is like "writethrough", but it bypasses the host page - cache. - Since 0.6.0 + "writethrough", "writeback", "directsync" (like + "writethrough", but it bypasses the host page cache) and + "unsafe" (host may cache all disk io, and sync requests from + guest are ignored). + + Since 0.6.0, + "directsync" since 0.9.5, + "unsafe" since 0.9.7 +
  • The optional error_policy attribute controls diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng index d0da41c583..be98be03d6 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng @@ -848,6 +848,7 @@ writeback writethrough directsync + unsafe diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 7463d7c3c2..a91867915a 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -164,7 +164,8 @@ VIR_ENUM_IMPL(virDomainDiskCache, VIR_DOMAIN_DISK_CACHE_LAST, "none", "writethrough", "writeback", - "directsync") + "directsync", + "unsafe") 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 371f2701f9..86b4c799f7 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -192,6 +192,7 @@ enum virDomainDiskCache { VIR_DOMAIN_DISK_CACHE_WRITETHRU, VIR_DOMAIN_DISK_CACHE_WRITEBACK, VIR_DOMAIN_DISK_CACHE_DIRECTSYNC, + VIR_DOMAIN_DISK_CACHE_UNSAFE, VIR_DOMAIN_DISK_CACHE_LAST }; diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index 850d46e766..8e20e3f32c 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -137,6 +137,8 @@ VIR_ENUM_IMPL(qemuCaps, QEMU_CAPS_LAST, "usb-redir", "usb-hub", "no-shutdown", + + "cache-unsafe", /* 75 */ ); struct qemu_feature_flags { @@ -912,12 +914,16 @@ qemuCapsComputeCmdFlags(const char *help, else if (strstr(help, "-domid")) qemuCapsSet(flags, QEMU_CAPS_DOMID); if (strstr(help, "-drive")) { + const char *cache = strstr(help, "cache="); + qemuCapsSet(flags, QEMU_CAPS_DRIVE); - if (strstr(help, "cache=") && - !strstr(help, "cache=on|off")) { - qemuCapsSet(flags, QEMU_CAPS_DRIVE_CACHE_V2); - if (strstr(help, "directsync")) + if (cache && (p = strchr(cache, ']'))) { + if (memmem(cache, p - cache, "on|off", sizeof("on|off") - 1) == NULL) + qemuCapsSet(flags, QEMU_CAPS_DRIVE_CACHE_V2); + if (memmem(cache, p - cache, "directsync", sizeof("directsync") - 1)) qemuCapsSet(flags, QEMU_CAPS_DRIVE_CACHE_DIRECTSYNC); + if (memmem(cache, p - cache, "unsafe", sizeof("unsafe") - 1)) + qemuCapsSet(flags, QEMU_CAPS_DRIVE_CACHE_UNSAFE); } if (strstr(help, "format=")) qemuCapsSet(flags, QEMU_CAPS_DRIVE_FORMAT); diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h index 74d3ab2422..ae3de90ac9 100644 --- a/src/qemu/qemu_capabilities.h +++ b/src/qemu/qemu_capabilities.h @@ -112,6 +112,8 @@ enum qemuCapsFlags { QEMU_CAPS_USB_HUB = 73, /* -device usb-hub */ QEMU_CAPS_NO_SHUTDOWN = 74, /* usable -no-shutdown */ + QEMU_CAPS_DRIVE_CACHE_UNSAFE = 75, /* Is cache=unsafe 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 0adc56a5f9..9174a5f4ef 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -66,14 +66,16 @@ VIR_ENUM_IMPL(qemuDiskCacheV1, VIR_DOMAIN_DISK_CACHE_LAST, "off", "off", /* writethrough not supported, so for safety, disable */ "on", /* Old 'on' was equivalent to 'writeback' */ - "off"); /* directsync not supported, for safety, disable */ + "off", /* directsync not supported, for safety, disable */ + "off"); /* unsafe not supported, for safety, disable */ VIR_ENUM_IMPL(qemuDiskCacheV2, VIR_DOMAIN_DISK_CACHE_LAST, "default", "none", "writethrough", "writeback", - "directsync"); + "directsync", + "unsafe"); VIR_ENUM_DECL(qemuVideo) @@ -1622,6 +1624,12 @@ qemuBuildDriveStr(virDomainDiskDefPtr disk, _("disk cache mode 'directsync' is not " "supported by this QEMU")); goto error; + } else if (disk->cachemode == VIR_DOMAIN_DISK_CACHE_UNSAFE && + !qemuCapsGet(qemuCaps, QEMU_CAPS_DRIVE_CACHE_UNSAFE)) { + qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("disk cache mode 'unsafe' is not " + "supported by this QEMU")); + goto error; } } else { mode = qemuDiskCacheV1TypeToString(disk->cachemode); @@ -5536,6 +5544,8 @@ qemuParseCommandLineDisk(virCapsPtr caps, def->cachemode = VIR_DOMAIN_DISK_CACHE_WRITETHRU; else if (STREQ(values[i], "directsync")) def->cachemode = VIR_DOMAIN_DISK_CACHE_DIRECTSYNC; + else if (STREQ(values[i], "unsafe")) + def->cachemode = VIR_DOMAIN_DISK_CACHE_UNSAFE; } 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 91f15af6bb..6a79630865 100644 --- a/tests/qemuargv2xmltest.c +++ b/tests/qemuargv2xmltest.c @@ -169,6 +169,7 @@ mymain(void) DO_TEST("disk-drive-cache-v2-wb"); DO_TEST("disk-drive-cache-v2-none"); DO_TEST("disk-drive-cache-directsync"); + DO_TEST("disk-drive-cache-unsafe"); DO_TEST("disk-drive-network-nbd"); DO_TEST("disk-drive-network-rbd"); DO_TEST("disk-drive-network-sheepdog"); diff --git a/tests/qemuhelptest.c b/tests/qemuhelptest.c index 933d556304..0ff8236582 100644 --- a/tests/qemuhelptest.c +++ b/tests/qemuhelptest.c @@ -165,6 +165,7 @@ mymain(void) QEMU_CAPS_MIGRATE_QEMU_TCP, QEMU_CAPS_MIGRATE_QEMU_EXEC, QEMU_CAPS_DRIVE_CACHE_V2, + QEMU_CAPS_DRIVE_CACHE_UNSAFE, QEMU_CAPS_KVM, QEMU_CAPS_DRIVE_FORMAT, QEMU_CAPS_DRIVE_SERIAL, @@ -408,6 +409,7 @@ mymain(void) QEMU_CAPS_MIGRATE_QEMU_TCP, QEMU_CAPS_MIGRATE_QEMU_EXEC, QEMU_CAPS_DRIVE_CACHE_V2, + QEMU_CAPS_DRIVE_CACHE_UNSAFE, QEMU_CAPS_KVM, QEMU_CAPS_DRIVE_FORMAT, QEMU_CAPS_DRIVE_SERIAL, @@ -460,6 +462,7 @@ mymain(void) QEMU_CAPS_MIGRATE_QEMU_TCP, QEMU_CAPS_MIGRATE_QEMU_EXEC, QEMU_CAPS_DRIVE_CACHE_V2, + QEMU_CAPS_DRIVE_CACHE_UNSAFE, QEMU_CAPS_KVM, QEMU_CAPS_DRIVE_FORMAT, QEMU_CAPS_DRIVE_SERIAL, diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-unsafe.args b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-unsafe.args new file mode 100644 index 0000000000..f8ddcd8494 --- /dev/null +++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-unsafe.args @@ -0,0 +1,5 @@ +LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test /usr/bin/qemu -S -M \ +pc -m 214 -smp 1 -nographic -monitor unix:/tmp/test-monitor,server,nowait \ +-no-acpi -boot c -drive file=/dev/HostVG/QEMUGuest1,if=ide,bus=0,unit=0,\ +format=qcow2,cache=unsafe -drive file=/dev/HostVG/QEMUGuest2,if=ide,\ +media=cdrom,bus=1,unit=0,format=raw -net none -serial none -parallel none -usb diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-unsafe.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-unsafe.xml new file mode 100644 index 0000000000..37185f64d8 --- /dev/null +++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-unsafe.xml @@ -0,0 +1,33 @@ + + QEMUGuest1 + c7a5fdbd-edaf-9455-926a-d65c16db1809 + 219136 + 219136 + 1 + + hvm + + + + destroy + restart + destroy + + /usr/bin/qemu + + + + +
    + + + + + + +
    + + + + + diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c index 1dc6a01759..9e174b378f 100644 --- a/tests/qemuxml2argvtest.c +++ b/tests/qemuxml2argvtest.c @@ -341,6 +341,9 @@ mymain(void) 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-cache-unsafe", false, + QEMU_CAPS_DRIVE, QEMU_CAPS_DRIVE_CACHE_V2, + QEMU_CAPS_DRIVE_CACHE_UNSAFE, 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 086fe93c8c..43ed1eae0d 100644 --- a/tools/virsh.pod +++ b/tools/virsh.pod @@ -1195,8 +1195,8 @@ floppy device; consider using B for this usage instead. I can specify the two specific mode I or I. I indicates the changes will affect the next boot of the domain. I can indicate the type of source (block|file) -I can be one of "default", "none", "writethrough", "writeback", or -"directsync". +I can be one of "default", "none", "writethrough", "writeback", +"directsync" or "unsafe". I is the serial of disk device. I indicates the disk device is shareable between domains. I
    is the address of disk device in the form of pci:domain.bus.slot.function, -- GitLab