On Tue, Jun 07, 2022 at 14:52:52 +0200, Michal Privoznik wrote:
> Now that we have a capability that reflects whether QEMU is
> capable of setting iothread pool size, let's introduce a
> validator check to make sure users are not trying to use this
> feature with QEMU that doesn't support it.
>
> Signed-off-by: Michal Privoznik <mprivozn@xxxxxxxxxx>
> Reviewed-by: Peter Krempa <pkrempa@xxxxxxxxxx>
> ---
> src/qemu/qemu_validate.c | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/src/qemu/qemu_validate.c b/src/qemu/qemu_validate.c
> index 9b6245e6d7..7d11ae2c92 100644
> --- a/src/qemu/qemu_validate.c
> +++ b/src/qemu/qemu_validate.c
> @@ -384,6 +384,27 @@ qemuValidateDomainDefCpu(virQEMUDriver *driver,
> }
>
>
> +static int
> +qemuValidateDomainDefIOThreads(const virDomainDef *def,
> + virQEMUCaps *qemuCaps)
> +{
> + size_t i;
> +
> + for (i = 0; i < def->niothreadids; i++) {
> + virDomainIOThreadIDDef *iothread = def->iothreadids[i];
> +
> + if ((iothread->thread_pool_min != -1 || iothread->thread_pool_max != -1) &&
> + !virQEMUCapsGet(qemuCaps, QEMU_CAPS_IOTHREAD_THREAD_POOL_MAX)) {
> + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> + _("thread_pool_min and thread_pool_max is not supported by this QEMU binary"));
> + return -1;
> + }
You'll also need a check that 'thread_pool_max', if supplied, must be
more or equal to 'thread_pool_min', otherwise:
$ virsh dumpxml cd | grep thread_pool
<iothread id='3' thread_pool_min='4' thread_pool_max='3'/>
$ virsh start cd
error: Failed to start domain 'cd'
error: internal error: process exited while connecting to monitor: 2022-06-07T14:58:52.420554Z qemu-system-x86_64: bad thread-pool-min/thread-pool-max values
