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"
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
