[libvirt] [PATCH 3/5] qemu: Implement individual vcpu hotplug API

[Pavel Hrdina]

On Fri, Feb 10, 2017 at 06:10:20PM +0100, Peter Krempa wrote:
> Add code that validates user's selection of cores and then uses the
> existing code to plug in the vCPU.
> ---
>  src/qemu/qemu_driver.c  |  74 +++++++++++++++++++++++
>  src/qemu/qemu_hotplug.c | 153 ++++++++++++++++++++++++++++++++++++++++++++++++
>  src/qemu/qemu_hotplug.h |   7 +++
>  3 files changed, 234 insertions(+)
> 
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index 89bc833de..2b875b3e9 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -20190,6 +20190,79 @@ qemuDomainSetGuestVcpus(virDomainPtr dom,
>  }
> 
> 
> +static int
> +qemuDomainSetVcpu(virDomainPtr dom,
> +                  const char *cpumap,
> +                  int state,
> +                  unsigned int flags)
> +{
> +    virQEMUDriverPtr driver = dom->conn->privateData;
> +    virDomainObjPtr vm = NULL;
> +    virDomainDefPtr def = NULL;
> +    virDomainDefPtr persistentDef = NULL;
> +    virBitmapPtr map = NULL;
> +    ssize_t lastvcpu;
> +    int ret = -1;
> +
> +    virCheckFlags(VIR_DOMAIN_AFFECT_LIVE |
> +                  VIR_DOMAIN_AFFECT_CONFIG, -1);
> +
> +    if (state != 0 && state != 1) {
> +        virReportInvalidArg(state, "%s", _("unsupported state value"));
> +        return -1;
> +    }
> +
> +    if (virBitmapParse(cpumap, &map, QEMU_GUEST_VCPU_MAX_ID) < 0)
> +        goto cleanup;
> +
> +    if ((lastvcpu = virBitmapLastSetBit(map)) < 0) {
> +        virReportError(VIR_ERR_INVALID_ARG, "%s",
> +                       _("no vcpus selected for modification"));
> +        goto cleanup;
> +    }
> +
> +    if (!(vm = qemuDomObjFromDomain(dom)))
> +        goto cleanup;
> +
> +    if (virDomainSetVcpuEnsureACL(dom->conn, vm->def, flags) < 0)
> +        goto cleanup;
> +
> +    if (qemuDomainObjBeginJob(driver, vm, QEMU_JOB_MODIFY) < 0)
> +        goto cleanup;
> +
> +    if (virDomainObjGetDefs(vm, flags, &def, &persistentDef) < 0)
> +        goto endjob;
> +
> +    if (persistentDef) {
> +        if (lastvcpu >= virDomainDefGetVcpusMax(persistentDef)) {
> +            virReportError(VIR_ERR_INVALID_ARG,
> +                           _("vcpu %zd is not present in persistent config"),
> +                           lastvcpu);
> +            goto endjob;
> +        }
> +    }
> +
> +    if (def) {
> +        if (lastvcpu >= virDomainDefGetVcpusMax(def)) {
> +            virReportError(VIR_ERR_INVALID_ARG,
> +                           _("vcpu %zd is not present in live config"),
> +                           lastvcpu);
> +            goto endjob;
> +        }
> +    }
> +
> +    ret = qemuDomainSetVcpuInternal(driver, vm, def, persistentDef, map, !!state);
> +
> + endjob:
> +    qemuDomainObjEndJob(driver, vm);
> +
> + cleanup:
> +    virBitmapFree(map);
> +    virDomainObjEndAPI(&vm);
> +    return ret;
> +}
> +
> +
>  static virHypervisorDriver qemuHypervisorDriver = {
>      .name = QEMU_DRIVER_NAME,
>      .connectOpen = qemuConnectOpen, /* 0.2.0 */
> @@ -20403,6 +20476,7 @@ static virHypervisorDriver qemuHypervisorDriver = {
>      .domainMigrateStartPostCopy = qemuDomainMigrateStartPostCopy, /* 1.3.3 */
>      .domainGetGuestVcpus = qemuDomainGetGuestVcpus, /* 2.0.0 */
>      .domainSetGuestVcpus = qemuDomainSetGuestVcpus, /* 2.0.0 */
> +    .domainSetVcpu = qemuDomainSetVcpu, /* 3.1.0 */
>  };
> 
> 
> diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
> index 2f209f12b..363d1070b 100644
> --- a/src/qemu/qemu_hotplug.c
> +++ b/src/qemu/qemu_hotplug.c
> @@ -5700,3 +5700,156 @@ qemuDomainSetVcpusInternal(virQEMUDriverPtr driver,
>      virObjectUnref(cfg);
>      return ret;
>  }
> +
> +
> +static void
> +qemuDomainSetVcpuInactive(virDomainDefPtr def,
> +                          virBitmapPtr map,
> +                          bool state)

qemuDomainSetVcpuConfig is probably a better name because we use
*Live vs *Config naming.

> +{
> +    virDomainVcpuDefPtr vcpu;
> +    ssize_t next = -1;
> +
> +    def->individualvcpus = true;
> +
> +    while ((next = virBitmapNextSetBit(map, next)) > 0) {
> +        if (!(vcpu = virDomainDefGetVcpu(def, next)))
> +            continue;
> +
> +        vcpu->online = state;
> +        vcpu->hotpluggable = VIR_TRISTATE_BOOL_YES;
> +        vcpu->order = 0;
> +    }
> +}
> +
> +
> +/**
> + * qemuDomainFilterHotplugVcpuEntities:
> + *
> + * Returns a bitmap of hotpluggable vcpu entities that correspond to the logical
> + * vcpus requested in @vcpus.
> + */
> +static virBitmapPtr
> +qemuDomainFilterHotplugVcpuEntities(virDomainDefPtr def,
> +                                    virBitmapPtr vcpus,
> +                                    bool state)
> +{
> +    qemuDomainVcpuPrivatePtr vcpupriv;
> +    virDomainVcpuDefPtr vcpu;
> +    virBitmapPtr map = NULL;
> +    virBitmapPtr ret = NULL;
> +    ssize_t next = -1;
> +    size_t i;
> +
> +    if (!(map = virBitmapNewCopy(vcpus)))
> +        return NULL;
> +
> +    /* make sure that all selected vcpus are in the correct state */
> +    while ((next = virBitmapNextSetBit(map, next)) > 0) {
> +        if (!(vcpu = virDomainDefGetVcpu(def, next)))
> +            continue;
> +
> +        if (vcpu->online == state) {
> +            virReportError(VIR_ERR_INVALID_ARG,
> +                           _("vcpu '%zu' is already in requested state"), next);
> +            goto cleanup;
> +        }
> +
> +        if (vcpu->online && !vcpu->hotpluggable) {
> +            virReportError(VIR_ERR_INVALID_ARG,
> +                           _("vcpu '%zu' can't be hotunplugged"), next);
> +            goto cleanup;
> +        }
> +    }
> +
> +    /* Make sure that all vCPUs belonging to a single hotpluggable entity were
> +     * selected and then de-select any sub-threads of it. */
> +    next = -1;
> +    while ((next = virBitmapNextSetBit(map, next)) > 0) {
> +        if (!(vcpu = virDomainDefGetVcpu(def, next)))
> +            continue;
> +
> +        vcpupriv =  QEMU_DOMAIN_VCPU_PRIVATE(vcpu);

Remove the extra space :)

ACK with the issues fixed.

Pavel
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: Digital signature
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20170221/88e4316b/attachment-0001.sig>