Re: [Qemu-devel] [PATCH v7 1/3] qmp: adding 'wakeup-suspend-support' in query-target

Daniel Henrique Barboza <danielhb@xxxxxxxxxxxxx> · Tue, 19 Jun 2018 17:29:26 -0300

    Hi,

      Sorry for the delay. I'll summarize what I've understood from the
      discussion

      so far:

      - query-target is the wrong place for this flag. query-machines is
      (less) wrong

      because it is not a static property of the machine object

      - a new "query-current-machine" can be created to host these
      dynamic

      properties that belongs to the current instance of the VM

      - there are machines in which the suspend support may vary with a

      "-no-acpi" option that would disable both the suspend and wake-up

      support. In this case, I see no problem into counting this flag
      into

      the logic (assuming it is possible, of course) and setting it as
      "false"

      if there is -no-acpi present (or even making the API returning "yes",

      "no" or "acpi" like Markus suggested) somewhere.

      Based on the last email from Eduardo, apparently there is a
      handful

      of other machine properties that can be hosted in either this new

      query-current-machine API or query-machines. I believe that this
      is

      more of a long term goal, but this new query-current-machine API

      would be a good kick-off and we should go for it.

      Is this a fair understanding? Did I miss something?

      Thanks,

      Daniel

    On 05/29/2018 11:55 AM, Eduardo Habkost
      wrote:

      On Mon, May 28, 2018 at 09:23:54AM +0200, Markus Armbruster wrote:

        Eduardo Habkost <ehabkost@xxxxxxxxxx> writes:

      [...]

          [1] Doing a:
  $ git grep 'STR.*machine, "'
on libvirt source is enough to find some code demonstrating where
query-machines is already lacking today:

      [...]

        How can we get from this grep to a list of static or dynamic machine
type capabilties?

      Let's look at the code:

$ git grep -W 'STR.*machine, "'
src/libxl/libxl_capabilities.c=libxlMakeDomainOSCaps(const char *machine,
src/libxl/libxl_capabilities.c-                      virDomainCapsOSPtr os,
src/libxl/libxl_capabilities.c-                      virFirmwarePtr *firmwares,
src/libxl/libxl_capabilities.c-                      size_t nfirmwares)
src/libxl/libxl_capabilities.c-{
src/libxl/libxl_capabilities.c-    virDomainCapsLoaderPtr capsLoader = &os->loader;
src/libxl/libxl_capabilities.c-    size_t i;
src/libxl/libxl_capabilities.c-
src/libxl/libxl_capabilities.c-    os->supported = true;
src/libxl/libxl_capabilities.c-
src/libxl/libxl_capabilities.c:    if (STREQ(machine, "xenpv"))
src/libxl/libxl_capabilities.c-        return 0;

I don't understand why this one is here, but we can find out what
we could add to query-machines to make this unnecessary.

[...]
--
src/libxl/libxl_capabilities.c=libxlMakeDomainCapabilities(virDomainCapsPtr domCaps,
src/libxl/libxl_capabilities.c-                            virFirmwarePtr *firmwares,
src/libxl/libxl_capabilities.c-                            size_t nfirmwares)
src/libxl/libxl_capabilities.c-{
src/libxl/libxl_capabilities.c-    virDomainCapsOSPtr os = &domCaps->os;
src/libxl/libxl_capabilities.c-    virDomainCapsDeviceDiskPtr disk = &domCaps->disk;
src/libxl/libxl_capabilities.c-    virDomainCapsDeviceGraphicsPtr graphics = &domCaps->graphics;
src/libxl/libxl_capabilities.c-    virDomainCapsDeviceVideoPtr video = &domCaps->video;
src/libxl/libxl_capabilities.c-    virDomainCapsDeviceHostdevPtr hostdev = &domCaps->hostdev;
src/libxl/libxl_capabilities.c-
src/libxl/libxl_capabilities.c:    if (STREQ(domCaps->machine, "xenfv"))
src/libxl/libxl_capabilities.c-        domCaps->maxvcpus = HVM_MAX_VCPUS;
src/libxl/libxl_capabilities.c-    else
src/libxl/libxl_capabilities.c-        domCaps->maxvcpus = PV_MAX_VCPUS;

Looks like libvirt isn't using MachineInfo::cpu-max.  libvirt
bug, or workaround for QEMU limitation?

[...]
--
src/libxl/libxl_driver.c=libxlConnectGetDomainCapabilities(virConnectPtr conn,
src/libxl/libxl_driver.c-                                  const char *emulatorbin,
src/libxl/libxl_driver.c-                                  const char *arch_str,
src/libxl/libxl_driver.c-                                  const char *machine,
src/libxl/libxl_driver.c-                                  const char *virttype_str,
src/libxl/libxl_driver.c-                                  unsigned int flags)
src/libxl/libxl_driver.c-{
[...]
src/libxl/libxl_driver.c-    if (machine) {
src/libxl/libxl_driver.c:        if (STRNEQ(machine, "xenpv") && STRNEQ(machine, "xenfv")) {
src/libxl/libxl_driver.c-            virReportError(VIR_ERR_INVALID_ARG, "%s",
src/libxl/libxl_driver.c-                           _("Xen only supports 'xenpv' and 'xenfv' machines"));

Not sure if this should be encoded in QEMU.  accel=xen works with
other PC machines, doesn't it?

[...]
--
src/qemu/qemu_capabilities.c=bool virQEMUCapsHasPCIMultiBus(virQEMUCapsPtr qemuCaps,
src/qemu/qemu_capabilities.c-                               const virDomainDef *def)
src/qemu/qemu_capabilities.c-{
src/qemu/qemu_capabilities.c-    /* x86_64 and i686 support PCI-multibus on all machine types
src/qemu/qemu_capabilities.c-     * since forever */
src/qemu/qemu_capabilities.c-    if (ARCH_IS_X86(def->os.arch))
src/qemu/qemu_capabilities.c-        return true;
src/qemu/qemu_capabilities.c-
src/qemu/qemu_capabilities.c-    if (def->os.arch == VIR_ARCH_PPC ||
src/qemu/qemu_capabilities.c-        ARCH_IS_PPC64(def->os.arch)) {
src/qemu/qemu_capabilities.c-        /*
src/qemu/qemu_capabilities.c-         * Usage of pci.0 naming:
src/qemu/qemu_capabilities.c-         *
src/qemu/qemu_capabilities.c-         *    ref405ep: no pci
src/qemu/qemu_capabilities.c-         *       taihu: no pci
src/qemu/qemu_capabilities.c-         *      bamboo: 1.1.0
src/qemu/qemu_capabilities.c-         *       mac99: 2.0.0
src/qemu/qemu_capabilities.c-         *     g3beige: 2.0.0
src/qemu/qemu_capabilities.c-         *        prep: 1.4.0
src/qemu/qemu_capabilities.c-         *     pseries: 2.0.0
src/qemu/qemu_capabilities.c-         *   mpc8544ds: forever
src/qemu/qemu_capabilities.c-         * virtex-m507: no pci
src/qemu/qemu_capabilities.c-         *     ppce500: 1.6.0
src/qemu/qemu_capabilities.c-         */
src/qemu/qemu_capabilities.c-
src/qemu/qemu_capabilities.c-        /* We do not store the qemu version in domain status XML.
src/qemu/qemu_capabilities.c-         * Hope the user is using a QEMU new enough to use 'pci.0',
src/qemu/qemu_capabilities.c-         * otherwise the results of this function will be wrong
src/qemu/qemu_capabilities.c-         * for domains already running at the time of daemon
src/qemu/qemu_capabilities.c-         * restart */
src/qemu/qemu_capabilities.c-        if (qemuCaps->version == 0)
src/qemu/qemu_capabilities.c-            return true;
src/qemu/qemu_capabilities.c-
src/qemu/qemu_capabilities.c-        if (qemuCaps->version >= 2000000)
src/qemu/qemu_capabilities.c-            return true;
src/qemu/qemu_capabilities.c-
src/qemu/qemu_capabilities.c-        if (qemuCaps->version >= 1006000 &&
src/qemu/qemu_capabilities.c:            STREQ(def->os.machine, "ppce500"))
src/qemu/qemu_capabilities.c-            return true;
src/qemu/qemu_capabilities.c-
src/qemu/qemu_capabilities.c-        if (qemuCaps->version >= 1004000 &&
src/qemu/qemu_capabilities.c:            STREQ(def->os.machine, "prep"))
src/qemu/qemu_capabilities.c-            return true;
src/qemu/qemu_capabilities.c-
src/qemu/qemu_capabilities.c-        if (qemuCaps->version >= 1001000 &&
src/qemu/qemu_capabilities.c:            STREQ(def->os.machine, "bamboo"))
src/qemu/qemu_capabilities.c-            return true;
src/qemu/qemu_capabilities.c-
src/qemu/qemu_capabilities.c:        if (STREQ(def->os.machine, "mpc8544ds"))
src/qemu/qemu_capabilities.c-            return true;

This is due to the lack of bus information on query-machines.

[...]
src/qemu/qemu_capabilities.c-
src/qemu/qemu_capabilities.c-        return false;
src/qemu/qemu_capabilities.c-    }
src/qemu/qemu_capabilities.c-
src/qemu/qemu_capabilities.c-    /* If 'virt' supports PCI, it supports multibus.
src/qemu/qemu_capabilities.c-     * No extra conditions here for simplicity.
src/qemu/qemu_capabilities.c-     */
src/qemu/qemu_capabilities.c-    if (qemuDomainIsVirt(def))
src/qemu/qemu_capabilities.c-        return true;
src/qemu/qemu_capabilities.c-
src/qemu/qemu_capabilities.c-    return false;
src/qemu/qemu_capabilities.c-}
--
src/qemu/qemu_capabilities.c=virQEMUCapsSupportsVmport(virQEMUCapsPtr qemuCaps,
src/qemu/qemu_capabilities.c-                          const virDomainDef *def)
src/qemu/qemu_capabilities.c-{
src/qemu/qemu_capabilities.c-    if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_MACHINE_VMPORT_OPT))
src/qemu/qemu_capabilities.c-        return false;
src/qemu/qemu_capabilities.c-
src/qemu/qemu_capabilities.c-    return qemuDomainIsI440FX(def) ||
src/qemu/qemu_capabilities.c-        qemuDomainIsQ35(def) ||
src/qemu/qemu_capabilities.c:        STREQ(def->os.machine, "isapc");
src/qemu/qemu_capabilities.c-}

Lack of bus information on query-machines?

--
src/qemu/qemu_command.c=qemuBuildMemballoonCommandLine(virCommandPtr cmd,
src/qemu/qemu_command.c-                               const virDomainDef *def,
src/qemu/qemu_command.c-                               virQEMUCapsPtr qemuCaps)
src/qemu/qemu_command.c-{
src/qemu/qemu_command.c-    virBuffer buf = VIR_BUFFER_INITIALIZER;
src/qemu/qemu_command.c-
src/qemu/qemu_command.c:    if (STRPREFIX(def->os.machine, "s390-virtio") &&
src/qemu/qemu_command.c-        virQEMUCapsGet(qemuCaps, QEMU_CAPS_VIRTIO_S390) && def->memballoon)
src/qemu/qemu_command.c-        def->memballoon->model = VIR_DOMAIN_MEMBALLOON_MODEL_NONE;

Lack of bus information on query-machines?

[...]
--
src/qemu/qemu_domain.c=qemuDomainDefAddDefaultDevices(virDomainDefPtr def,
src/qemu/qemu_domain.c-                               virQEMUCapsPtr qemuCaps)
src/qemu/qemu_domain.c-{
[...]
src/qemu/qemu_domain.c:        if (STREQ(def->os.machine, "isapc")) {
src/qemu/qemu_domain.c-            addDefaultUSB = false;

Lack of bus/defaults information on query-machines?

This whole function is a collection of cases where
bus/device/defaults information is missing on query-machines:

src/qemu/qemu_domain.c-            break;
src/qemu/qemu_domain.c-        }
src/qemu/qemu_domain.c-        if (qemuDomainIsQ35(def)) {
src/qemu/qemu_domain.c-            addPCIeRoot = true;
src/qemu/qemu_domain.c-            addImplicitSATA = true;
[...]
src/qemu/qemu_domain.c-        if (qemuDomainIsI440FX(def))
src/qemu/qemu_domain.c-            addPCIRoot = true;
[...]
src/qemu/qemu_domain.c-        break;
src/qemu/qemu_domain.c-
src/qemu/qemu_domain.c-    case VIR_ARCH_ARMV7L:
src/qemu/qemu_domain.c-    case VIR_ARCH_AARCH64:
src/qemu/qemu_domain.c-        addDefaultUSB = false;
src/qemu/qemu_domain.c-        addDefaultMemballoon = false;
src/qemu/qemu_domain.c-        if (qemuDomainIsVirt(def))
src/qemu/qemu_domain.c-            addPCIeRoot = virQEMUCapsGet(qemuCaps, QEMU_CAPS_OBJECT_GPEX);
src/qemu/qemu_domain.c-        break;
src/qemu/qemu_domain.c-
src/qemu/qemu_domain.c-    case VIR_ARCH_PPC64:
src/qemu/qemu_domain.c-    case VIR_ARCH_PPC64LE:
src/qemu/qemu_domain.c-        addPCIRoot = true;
src/qemu/qemu_domain.c-        addDefaultUSBKBD = true;
src/qemu/qemu_domain.c-        addDefaultUSBMouse = true;
src/qemu/qemu_domain.c-        /* For pSeries guests, the firmware provides the same
src/qemu/qemu_domain.c-         * functionality as the pvpanic device, so automatically
src/qemu/qemu_domain.c-         * add the definition if not already present */
src/qemu/qemu_domain.c-        if (qemuDomainIsPSeries(def))
src/qemu/qemu_domain.c-            addPanicDevice = true;
src/qemu/qemu_domain.c-        break;
[...]
--
src/qemu/qemu_domain.c=qemuDomainDefaultNetModel(const virDomainDef *def,
src/qemu/qemu_domain.c-                          virQEMUCapsPtr qemuCaps)
src/qemu/qemu_domain.c-{
src/qemu/qemu_domain.c-    if (ARCH_IS_S390(def->os.arch))
src/qemu/qemu_domain.c-        return "virtio";
src/qemu/qemu_domain.c-
src/qemu/qemu_domain.c-    if (def->os.arch == VIR_ARCH_ARMV7L ||
src/qemu/qemu_domain.c-        def->os.arch == VIR_ARCH_AARCH64) {
src/qemu/qemu_domain.c:        if (STREQ(def->os.machine, "versatilepb"))
src/qemu/qemu_domain.c-            return "smc91c111";
src/qemu/qemu_domain.c-
src/qemu/qemu_domain.c-        if (qemuDomainIsVirt(def))
src/qemu/qemu_domain.c-            return "virtio";
src/qemu/qemu_domain.c-
src/qemu/qemu_domain.c-        /* Incomplete. vexpress (and a few others) use this, but not all
src/qemu/qemu_domain.c-         * arm boards */
src/qemu/qemu_domain.c-        return "lan9118";

Lack of bus/defaults information on query-machines?

[...]
--
src/qemu/qemu_domain.c=qemuDomainMachineIsQ35(const char *machine)
src/qemu/qemu_domain.c-{
src/qemu/qemu_domain.c:    return (STRPREFIX(machine, "pc-q35") ||
src/qemu/qemu_domain.c:            STREQ(machine, "q35"));
src/qemu/qemu_domain.c-}