On 11/13/25 1:05 PM, Sebastian Ott wrote:
> Hi Philippe,
>
> On Wed, 12 Nov 2025, Philippe Mathieu-Daudé wrote:
>> On 12/11/25 19:13, Sebastian Ott 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
>>>
>>> Note: in order to support PSCI v0.1 we need to drop vcpu
>>> initialization with KVM_CAP_ARM_PSCI_0_2 in that case.
>>>
>>> Signed-off-by: Sebastian Ott <[email protected]>
>>> ---
>>> docs/system/arm/cpu-features.rst | 5 +++
>>> target/arm/cpu.h | 6 +++
>>> target/arm/kvm.c | 64
>>> +++++++++++++++++++++++++++++++-
>>> 3 files changed, 74 insertions(+), 1 deletion(-)
>>
>>
>>> diff --git a/target/arm/kvm.c b/target/arm/kvm.c
>>> index 0d57081e69..e91b1abfb8 100644
>>> --- a/target/arm/kvm.c
>>> +++ b/target/arm/kvm.c
>>> @@ -484,6 +484,49 @@ 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;
>>> }
>>>
>>> +struct psci_version {
>>> + uint32_t number;
>>> + const char *str;
>>> +};
>>> +
>>> +static const struct psci_version psci_versions[] = {
>>> + { QEMU_PSCI_VERSION_0_1, "0.1" },
>>> + { QEMU_PSCI_VERSION_0_2, "0.2" },
>>> + { QEMU_PSCI_VERSION_1_0, "1.0" },
>>> + { QEMU_PSCI_VERSION_1_1, "1.1" },
>>> + { QEMU_PSCI_VERSION_1_2, "1.2" },
>>> + { QEMU_PSCI_VERSION_1_3, "1.3" },
>>> + { -1, NULL },
>>> +};
>>
>>
>>> @@ -505,6 +548,12 @@ void kvm_arm_add_vcpu_properties(ARMCPU *cpu)
>>> kvm_steal_time_set);
>>> object_property_set_description(obj, "kvm-steal-time",
>>> "Set off to disable KVM steal
>>> time.");
>>> +
>>> + object_property_add_str(obj, "kvm-psci-version",
>>> kvm_get_psci_version,
>>> + kvm_set_psci_version);
>>> + object_property_set_description(obj, "kvm-psci-version",
>>> + "Set PSCI version. "
>>> + "Valid values are 0.1, 0.2,
>>> 1.0, 1.1,
>>> 1.2, 1.3");
>>
>> Could we enumerate from psci_versions[] here?
>>
>
> Hm, we'd need to concatenate these. Either manually:
> "Valid values are " psci_versions[0].str ", " psci_versions[1].str ",
> " ... which is not pretty and still needs to be touched for a new
> version.
>
> Or by a helper function that puts these in a new array and uses smth like
> g_strjoinv(", ", array);
> But that's quite a bit of extra code that needs to be maintained without
> much gain.
>
> Or we shy away from the issue and rephrase that to:
> "Valid values include 1.0, 1.1, 1.2, 1.3"
Personally I would vote for keeping it as is (by the way why did you
moit 0.1 and 0.2 above?)
Eric
>
> Since the intended use case is via machine types and I don't expect a
> lot of users setting the psci version manually - I vote for option 3.
>
> Opinions?
>
> Sebastian
