[libvirt] [PATCH 12/34] qemu: cpu hotplug: Set vcpu state directly in the new structure

[John Ferlan]

On 01/14/2016 11:27 AM, Peter Krempa wrote:
> Avoid using virDomainDefSetVcpus when we can set it directly in the
> structure.
> ---
>  src/qemu/qemu_driver.c | 24 ++++++++++++++++++++++--
>  1 file changed, 22 insertions(+), 2 deletions(-)
> 
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index f3844d6..3aa49f2 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -4680,6 +4680,7 @@ qemuDomainHotplugAddVcpu(virQEMUDriverPtr driver,
>                           unsigned int vcpu)
>  {
>      qemuDomainObjPrivatePtr priv = vm->privateData;
> +    virDomainVcpuInfoPtr vcpuinfo;
>      int ret = -1;
>      int rc;
>      int oldvcpus = virDomainDefGetVcpus(vm->def);
> @@ -4689,6 +4690,15 @@ qemuDomainHotplugAddVcpu(virQEMUDriverPtr driver,
>      char *mem_mask = NULL;
>      virDomainNumatuneMemMode mem_mode;
> 
> +    if (!(vcpuinfo = virDomainDefGetVcpu(vm->def, vcpu)))
> +        return -1;
> +
> +    if (vcpuinfo->online) {
> +        virReportError(VIR_ERR_INVALID_ARG,
> +                       _("vCPU '%u' is already online"), vcpu);
> +        return -1;
> +    }
> +

Yet another construct that could benefit from an OnlineVcpuMap and
virBitmapCountBits would tell us how many bits are set (oldvcpus in this
instance).

>      qemuDomainObjEnterMonitor(driver, vm);
> 
>      rc = qemuMonitorSetCPU(priv->mon, vcpu, true);
> @@ -4704,7 +4714,7 @@ qemuDomainHotplugAddVcpu(virQEMUDriverPtr driver,
>      if (rc < 0)
>          goto cleanup;
> 
> -    ignore_value(virDomainDefSetVcpus(vm->def, oldvcpus + 1));
> +    vcpuinfo->online = true;

Setting online bit directly...

[and repeat for DelVcpu]

John
> 
>      if (ncpupids < 0)
>          goto cleanup;
> @@ -4780,12 +4790,22 @@ qemuDomainHotplugDelVcpu(virQEMUDriverPtr driver,
>                           unsigned int vcpu)
>  {
>      qemuDomainObjPrivatePtr priv = vm->privateData;
> +    virDomainVcpuInfoPtr vcpuinfo;
>      int ret = -1;
>      int rc;
>      int oldvcpus = virDomainDefGetVcpus(vm->def);
>      pid_t *cpupids = NULL;
>      int ncpupids = 0;
> 
> +    if (!(vcpuinfo = virDomainDefGetVcpu(vm->def, vcpu)))
> +        return -1;
> +
> +    if (!vcpuinfo->online) {
> +        virReportError(VIR_ERR_INVALID_ARG,
> +                       _("vCPU '%u' is already offline"), vcpu);
> +        return -1;
> +    }
> +
>      qemuDomainObjEnterMonitor(driver, vm);
> 
>      rc = qemuMonitorSetCPU(priv->mon, vcpu, false);
> @@ -4809,7 +4829,7 @@ qemuDomainHotplugDelVcpu(virQEMUDriverPtr driver,
>          goto cleanup;
>      }
> 
> -    ignore_value(virDomainDefSetVcpus(vm->def, oldvcpus - 1));
> +    vcpuinfo->online = false;
> 
>      if (qemuDomainDelCgroupForThread(priv->cgroup,
>                                       VIR_CGROUP_THREAD_VCPU, vcpu) < 0)
>