[libvirt] [PATCH 11/12] qemu: Implement RNG device hotplug on live level

[Peter Krempa]

On 01/03/15 06:06, Luyao Huang wrote:
> We have enough patches for hotplug RNG device, maybe we can
> implement live hotplug of a RNG device.
> 
> Signed-off-by: Luyao Huang <lhuang at redhat.com>
> ---
>  src/qemu/qemu_driver.c  |  8 ++++-
>  src/qemu/qemu_hotplug.c | 92 +++++++++++++++++++++++++++++++++++++++++++++++++
>  src/qemu/qemu_hotplug.h |  3 ++
>  3 files changed, 102 insertions(+), 1 deletion(-)
> 

> diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
> index f9327b4..7f1e612 100644
> --- a/src/qemu/qemu_hotplug.c
> +++ b/src/qemu/qemu_hotplug.c
> @@ -1523,6 +1523,98 @@ qemuDomainRNGRemove(virDomainDefPtr vmdef,
>      return ret;
>  }
>  
> +int qemuDomainAttachRNGDevice(virQEMUDriverPtr driver,
> +                              virDomainObjPtr vm,
> +                              virDomainRNGDefPtr rng)
> +{
> +    int ret = -1;
> +    qemuDomainObjPrivatePtr priv = vm->privateData;
> +    virDomainDefPtr vmdef = vm->def;
> +    char *devstr = NULL;
> +    char *charAlias = NULL;
> +    char *objAlias = NULL;
> +    bool need_remove = false;
> +    bool releaseaddr = false;
> +
> +    if (!virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_DEVICE)) {
> +        virReportError(VIR_ERR_OPERATION_INVALID, "%s",
> +                       _("qemu does not support -device"));
> +        return ret;
> +    }

Additionally to the -device support, qemu also needs to support chardev
hotplug and the rng device with the appropriate backends, we already
have capability bits for them so you need to check them here.

> +
> +    if (qemuAssignDeviceRNGAlias(vmdef, rng, -1) < 0)
> +        return ret;
> +
> +    if (rng->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE) {
> +        if (STRPREFIX(vm->def->os.machine, "s390-ccw") &&
> +            virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_VIRTIO_CCW)) {
> +            rng->info.type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_CCW;
> +        } else if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_VIRTIO_S390)) {
> +            rng->info.type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_VIRTIO_S390;
> +        }
> +    }
> +
> +    if (rng->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE ||
> +        rng->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI) {
> +        if (virDomainPCIAddressEnsureAddr(priv->pciaddrs, &rng->info) < 0)
> +            return ret;
> +    } else if (rng->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_CCW) {
> +        if (virDomainCCWAddressAssign(&rng->info, priv->ccwaddrs,
> +                                          !rng->info.addr.ccw.assigned) < 0)

Line above is misaligned.

> +            return ret;
> +    }
> +    releaseaddr = true;
> +    if (!(devstr = qemuBuildRNGDevStr(vmdef, rng, priv->qemuCaps)))
> +        return ret;

After you set releaseaddr to true you need to jump to cleanup in case of
error so that the address gets cleared.

> +
> +    if (virAsprintf(&objAlias, "obj%s", rng->info.alias) < 0)
> +        goto cleanup;
> +
> +    if (rng->backend == VIR_DOMAIN_RNG_BACKEND_EGD) {
> +        if (virAsprintf(&charAlias, "char%s", rng->info.alias) < 0)
> +            goto cleanup;
> +
> +        qemuDomainObjEnterMonitor(driver, vm);
> +        if (qemuMonitorAttachCharDev(priv->mon, charAlias, rng->source.chardev) < 0) {
> +            qemuDomainObjExitMonitor(driver, vm);
> +            goto audit;
> +        }
> +        need_remove = true;

This variable should be named "remove_chardev" so that it's clear what
it's used to.

> +    } else {
> +        qemuDomainObjEnterMonitor(driver, vm);
> +    }
> +
> +    if (qemuMonitorAttachRNGDev(priv->mon, charAlias, objAlias, rng) < 0) {
> +        if (need_remove)
> +            qemuMonitorDetachCharDev(priv->mon, charAlias);
> +        qemuDomainObjExitMonitor(driver, vm);
> +        goto audit;
> +    }
> +
> +    if (devstr && qemuMonitorAddDevice(priv->mon, devstr) < 0) {
> +        qemuMonitorDetachRNGDev(priv->mon, objAlias);
> +        if (need_remove)
> +            qemuMonitorDetachCharDev(priv->mon, charAlias);
> +        qemuDomainObjExitMonitor(driver, vm);
> +        goto audit;
> +    }
> +    qemuDomainObjExitMonitor(driver, vm);
> +
> +    if (qemuDomainRNGInsert(vmdef, rng) < 0)
> +        goto cleanup;
> +
> +    ret = 0;
> + audit:
> +    virDomainAuditRNG(vm, NULL, rng, "attach", ret == 0);
> + cleanup:
> +    if (releaseaddr)
> +        qemuDomainReleaseDeviceAddress(vm, &rng->info, NULL);
> +    VIR_FREE(charAlias);
> +    VIR_FREE(objAlias);
> +    VIR_FREE(devstr);
> +    return ret;
> +}
> +
>  
>  static int
>  qemuDomainAttachHostUSBDevice(virQEMUDriverPtr driver,


The rest looks good.

Peter


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