On Thu, 11 Sept 2025 at 15:49, Sebastian Ott <[email protected]> wrote:
>
> Provide a kvm specific vcpu property to override the default
> (as of kernel v6.13 that would be PSCI v1.3) PSCI version emulated
> by kvm. Current valid values are: 0.1, 0.2, 1.0, 1.1, 1.2, and 1.3
>
> Signed-off-by: Sebastian Ott <[email protected]>
> ---
> docs/system/arm/cpu-features.rst | 5 +++
> target/arm/cpu.h | 6 +++
> target/arm/kvm.c | 70 +++++++++++++++++++++++++++++++-
> 3 files changed, 80 insertions(+), 1 deletion(-)
>
> diff --git a/docs/system/arm/cpu-features.rst
> b/docs/system/arm/cpu-features.rst
> index 37d5dfd15b..1d32ce0fee 100644
> --- a/docs/system/arm/cpu-features.rst
> +++ b/docs/system/arm/cpu-features.rst
> @@ -204,6 +204,11 @@ the list of KVM VCPU features and their descriptions.
> the guest scheduler behavior and/or be exposed to the guest
> userspace.
>
> +``kvm-psci-version``
> + Override the default (as of kernel v6.13 that would be PSCI v1.3)
> + PSCI version emulated by the kernel. Current valid values are:
> + 0.1, 0.2, 1.0, 1.1, 1.2, and 1.3
> +
> TCG VCPU Features
> =================
>
> diff --git a/target/arm/cpu.h b/target/arm/cpu.h
> index c15d79a106..44292aab32 100644
> --- a/target/arm/cpu.h
> +++ b/target/arm/cpu.h
> @@ -974,6 +974,12 @@ struct ArchCPU {
> */
> uint32_t psci_version;
>
> + /*
> + * Intermediate value used during property parsing.
> + * Once finalized, the value should be read from psci_version.
> + */
> + uint32_t prop_psci_version;
> +
> /* Current power state, access guarded by BQL */
> ARMPSCIState power_state;
>
> diff --git a/target/arm/kvm.c b/target/arm/kvm.c
> index 6672344855..bc6073f395 100644
> --- a/target/arm/kvm.c
> +++ b/target/arm/kvm.c
> @@ -483,6 +483,59 @@ static void kvm_steal_time_set(Object *obj, bool value,
> Error **errp)
> ARM_CPU(obj)->kvm_steal_time = value ? ON_OFF_AUTO_ON : ON_OFF_AUTO_OFF;
> }
>
> +static char *kvm_get_psci_version(Object *obj, Error **errp)
> +{
> + ARMCPU *cpu = ARM_CPU(obj);
> + const char *val;
> +
> + switch (cpu->prop_psci_version) {
> + case QEMU_PSCI_VERSION_0_1:
> + val = "0.1";
> + break;
> + case QEMU_PSCI_VERSION_0_2:
> + val = "0.2";
> + break;
> + case QEMU_PSCI_VERSION_1_0:
> + val = "1.0";
> + break;
> + case QEMU_PSCI_VERSION_1_1:
> + val = "1.1";
> + break;
> + case QEMU_PSCI_VERSION_1_2:
> + val = "1.2";
> + break;
> + case QEMU_PSCI_VERSION_1_3:
> + val = "1.3";
> + break;
> + default:
> + val = "0.2";
> + break;
> + }
> + return g_strdup(val);
> +}
> +
> +static void kvm_set_psci_version(Object *obj, const char *value, Error
> **errp)
> +{
> + ARMCPU *cpu = ARM_CPU(obj);
> +
> + if (!strcmp(value, "0.1")) {
> + cpu->prop_psci_version = QEMU_PSCI_VERSION_0_1;
> + } else if (!strcmp(value, "0.2")) {
> + cpu->prop_psci_version = QEMU_PSCI_VERSION_0_2;
> + } else if (!strcmp(value, "1.0")) {
> + cpu->prop_psci_version = QEMU_PSCI_VERSION_1_0;
> + } else if (!strcmp(value, "1.1")) {
> + cpu->prop_psci_version = QEMU_PSCI_VERSION_1_1;
> + } else if (!strcmp(value, "1.2")) {
> + cpu->prop_psci_version = QEMU_PSCI_VERSION_1_2;
> + } else if (!strcmp(value, "1.3")) {
> + cpu->prop_psci_version = QEMU_PSCI_VERSION_1_3;
We already have six values here and it's not implausible
we might end up with more in future; maybe we should make the
mapping between string and constant data-driven rather
than having code written out longhand in the get and set
functions?
> + } else {
> + error_setg(errp, "Invalid PSCI-version value");
> + error_append_hint(errp, "Valid values are 0.1, 0.2, 1.0, 1.1, 1.2,
> 1.3\n");
> + }
> +}
thanks
-- PMM
