On Thu, Dec 02, 2021 at 09:53:34 +0100, Michal Privoznik wrote:
> After previous commit it's possible for domains to fine tune TCG
> features (well, just one - tb-cache). Check that domain has TCG
> enabled, otherwise the feature makes no sense.
>
> Signed-off-by: Michal Privoznik <mprivozn@xxxxxxxxxx>
> ---
> docs/formatdomain.rst | 2 +-
> src/qemu/qemu_validate.c | 16 ++++++++++++++++
> 2 files changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst
> index 041dfc699d..98eb7b7481 100644
> --- a/docs/formatdomain.rst
> +++ b/docs/formatdomain.rst
> @@ -2074,7 +2074,7 @@ are:
> =========== ============================================== =================================================== ==============
> Feature Description Value Since
> =========== ============================================== =================================================== ==============
> - tb-cache The size of translation block cache size an integer :since:`8.0.0`
> + tb-cache The size of translation block cache size an integer (a multiple of MiB) :since:`8.0.0`
> =========== ============================================== =================================================== ==============
>
> :anchor:`<a id="elementsTime"/>`
> diff --git a/src/qemu/qemu_validate.c b/src/qemu/qemu_validate.c
> index a7c89f27cf..3a1c279e63 100644
> --- a/src/qemu/qemu_validate.c
> +++ b/src/qemu/qemu_validate.c
> @@ -295,6 +295,22 @@ qemuValidateDomainDefFeatures(const virDomainDef *def,
> break;
>
> case VIR_DOMAIN_FEATURE_TCG:
> + if (def->features[i] == VIR_TRISTATE_SWITCH_ON) {
> + if (def->virtType != VIR_DOMAIN_VIRT_QEMU) {
> + virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
> + _("TCG features are incompatible with domain type '%s'"),
> + virDomainVirtTypeToString(def->virtType));
> + return -1;
> + }
> +
> + if (def->tcg_features->tb_cache & 0xff) {
You are 2 bits off here. This won't catch increments of 0x100 KiB
(256KiB). You'll need 0x3FF as a mask and an explicit comparison with 0.
> + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> + _("tb-cache size must be an integer multiple of MiB"));
> + return -1;
> + }
> + }
> + break;
> +
> case VIR_DOMAIN_FEATURE_SMM:
> case VIR_DOMAIN_FEATURE_KVM:
> case VIR_DOMAIN_FEATURE_XEN:
> --
> 2.32.0
>
