Re: [libvirt] [PATCH v3 20/20] Add support for detecting capablities using QMP commands

From: "Daniel P. Berrange" <berrange(a)redhat.com&gt; Start a QEMU process using $QEMU -S -no-user-config -nodefconfig -nodefaults \ -nographic -M none -qmp stdio

and talk QMP over stdio to discover what capabilities the binary supports. This works for QEMU 1.2.0 or later and for older QEMU automatically fallback to the old approach of parsing -help and related command line args. Signed-off-by: Daniel P. Berrange <berrange(a)redhat.com&gt; --- src/qemu/qemu_capabilities.c | 413 +++++++++++++++++++++++++++++++++++++++---- src/qemu/qemu_capabilities.h | 2 +- 2 files changed, 377 insertions(+), 38 deletions(-) diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index c4d36f9..b4e824a 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -35,6 +35,7 @@ #include "command.h" #include "bitmap.h" #include "virnodesuspend.h" +#include "qemu_monitor.h" #include <sys/stat.h> #include <unistd.h> @@ -188,6 +189,8 @@ VIR_ENUM_IMPL(qemuCaps, QEMU_CAPS_LAST, struct _qemuCaps { virObject object; + bool usedQMP; + char *binary; time_t mtime; @@ -1282,6 +1285,7 @@ static struct qemuCapsStringFlags qemuCapsObjectPropsVirtioNet[] = { }; static struct qemuCapsStringFlags qemuCapsObjectPropsPciAssign[] = { + { "rombar", QEMU_CAPS_PCI_ROMBAR }, { "configfd", QEMU_CAPS_PCI_CONFIGFD }, { "bootindex", QEMU_CAPS_PCI_BOOTINDEX }, }; @@ -1857,6 +1861,10 @@ qemuCapsProbeQMPCommands(qemuCapsPtr caps, qemuCapsSet(caps, QEMU_CAPS_BLOCKJOB_ASYNC); else if (STREQ(name, "dump-guest-memory")) qemuCapsSet(caps, QEMU_CAPS_DUMP_GUEST_MEMORY); + else if (STREQ(name, "query-spice")) + qemuCapsSet(caps, QEMU_CAPS_SPICE); + else if (STREQ(name, "query-kvm")) + qemuCapsSet(caps, QEMU_CAPS_KVM); VIR_FREE(name); } VIR_FREE(commands);

@@ -1979,18 +2078,252 @@ qemuCapsPtr qemuCapsNewForBinary(const char *binary) * understands the 0.13.0+ notion of "-device driver,". */ if (qemuCapsGet(caps, QEMU_CAPS_DEVICE) && strstr(help, "-device driver,?") && - qemuCapsExtractDeviceStr(binary, caps) < 0) - goto error; + qemuCapsExtractDeviceStr(caps->binary, caps) < 0) + goto cleanup; if (qemuCapsProbeCPUModels(caps) < 0) - goto error; + goto cleanup; if (qemuCapsProbeMachineTypes(caps) < 0) - goto error; + goto cleanup; + + ret = 0; +cleanup: + virCommandFree(cmd); + return ret; +}

+ + +

+static void qemuCapsMonitorEOFNotify(qemuMonitorPtr mon ATTRIBUTE_UNUSED, + virDomainObjPtr vm ATTRIBUTE_UNUSED)

+{ +} + +static void qemuCapsMonitorErrorNotify(qemuMonitorPtr mon ATTRIBUTE_UNUSED, + virDomainObjPtr vm ATTRIBUTE_UNUSED)

+{ +} + +static qemuMonitorCallbacks callbacks = { + .eofNotify = qemuCapsMonitorEOFNotify, + .errorNotify = qemuCapsMonitorErrorNotify, +};

+ + +/* Capabilities that we assume are always enabled + * for QEMU >= 1.2.0 + */ +static void +qemuCapsInitQMPBasic(qemuCapsPtr caps) +{ + qemuCapsSet(caps, QEMU_CAPS_VNC_COLON); + qemuCapsSet(caps, QEMU_CAPS_NO_REBOOT); + qemuCapsSet(caps, QEMU_CAPS_DRIVE); + qemuCapsSet(caps, QEMU_CAPS_NAME); + qemuCapsSet(caps, QEMU_CAPS_UUID); + qemuCapsSet(caps, QEMU_CAPS_VNET_HDR); + qemuCapsSet(caps, QEMU_CAPS_MIGRATE_QEMU_TCP); + qemuCapsSet(caps, QEMU_CAPS_MIGRATE_QEMU_EXEC); + qemuCapsSet(caps, QEMU_CAPS_DRIVE_CACHE_V2); + qemuCapsSet(caps, QEMU_CAPS_DRIVE_FORMAT); + qemuCapsSet(caps, QEMU_CAPS_VGA); + qemuCapsSet(caps, QEMU_CAPS_0_10); + qemuCapsSet(caps, QEMU_CAPS_MEM_PATH); + qemuCapsSet(caps, QEMU_CAPS_DRIVE_SERIAL); + qemuCapsSet(caps, QEMU_CAPS_MIGRATE_QEMU_UNIX); + qemuCapsSet(caps, QEMU_CAPS_CHARDEV); + qemuCapsSet(caps, QEMU_CAPS_ENABLE_KVM); + qemuCapsSet(caps, QEMU_CAPS_MONITOR_JSON); + qemuCapsSet(caps, QEMU_CAPS_BALLOON); + qemuCapsSet(caps, QEMU_CAPS_DEVICE); + qemuCapsSet(caps, QEMU_CAPS_SDL); + qemuCapsSet(caps, QEMU_CAPS_SMP_TOPOLOGY); + qemuCapsSet(caps, QEMU_CAPS_NETDEV); + qemuCapsSet(caps, QEMU_CAPS_RTC); + qemuCapsSet(caps, QEMU_CAPS_VHOST_NET); + qemuCapsSet(caps, QEMU_CAPS_NO_HPET); + qemuCapsSet(caps, QEMU_CAPS_NODEFCONFIG); + qemuCapsSet(caps, QEMU_CAPS_BOOT_MENU); + qemuCapsSet(caps, QEMU_CAPS_FSDEV); + qemuCapsSet(caps, QEMU_CAPS_NESTING); + qemuCapsSet(caps, QEMU_CAPS_NAME_PROCESS); + qemuCapsSet(caps, QEMU_CAPS_DRIVE_READONLY); + qemuCapsSet(caps, QEMU_CAPS_SMBIOS_TYPE); + qemuCapsSet(caps, QEMU_CAPS_VGA_NONE); + qemuCapsSet(caps, QEMU_CAPS_MIGRATE_QEMU_FD); + qemuCapsSet(caps, QEMU_CAPS_DRIVE_AIO); + qemuCapsSet(caps, QEMU_CAPS_CHARDEV_SPICEVMC); + qemuCapsSet(caps, QEMU_CAPS_DEVICE_QXL_VGA); + qemuCapsSet(caps, QEMU_CAPS_DRIVE_CACHE_DIRECTSYNC); + qemuCapsSet(caps, QEMU_CAPS_NO_SHUTDOWN); + qemuCapsSet(caps, QEMU_CAPS_DRIVE_CACHE_UNSAFE); + qemuCapsSet(caps, QEMU_CAPS_NO_ACPI); + qemuCapsSet(caps, QEMU_CAPS_FSDEV_READONLY); + qemuCapsSet(caps, QEMU_CAPS_VIRTIO_BLK_SG_IO); + qemuCapsSet(caps, QEMU_CAPS_DRIVE_COPY_ON_READ); + qemuCapsSet(caps, QEMU_CAPS_CPU_HOST); + qemuCapsSet(caps, QEMU_CAPS_FSDEV_WRITEOUT); + qemuCapsSet(caps, QEMU_CAPS_DRIVE_IOTUNE); + qemuCapsSet(caps, QEMU_CAPS_WAKEUP); + qemuCapsSet(caps, QEMU_CAPS_NO_USER_CONFIG); + qemuCapsSet(caps, QEMU_CAPS_NETDEV_BRIDGE); +} + +/* + * Returns -1 on fatal error, 0 on success + */

+static int +qemuCapsInitQMP(qemuCapsPtr caps) +{ + int ret = -1; + virCommandPtr cmd = NULL; + virDomainObjPtr vm = NULL; + int socks[2] = { -1, -1 }; + qemuMonitorPtr mon = NULL; + int major, minor, micro; + char *package; + + VIR_DEBUG("caps=%p", caps); + + if (socketpair(PF_UNIX, SOCK_STREAM, 0, socks) < 0) { + virReportSystemError(errno, "%s", + _("unable to create socket pair")); + goto cleanup; + } + + if (!(vm = virDomainObjNew(NULL))) + goto cleanup;

+ + cmd = virCommandNewArgList(caps->binary, + "-S", + "-no-user-config", + "-nodefconfig",

+ "-nodefaults", + "-nographic", + "-M", "none", + "-qmp", "stdio", + NULL); + virCommandAddEnvPassCommon(cmd); + virCommandSetInputFD(cmd, socks[1]); + virCommandSetOutputFD(cmd, &socks[1]); + virCommandClearCaps(cmd); + + if (virCommandRunAsync(cmd, NULL) < 0) + goto cleanup;