Re: [PATCH v5 3/5] KVM: arm64: Add support for PSCI v1.2 and v1.3

Oliver Upton
2024-10-01T15:36:09Z

On Thu, Sep 26, 2024 at 07:37:58PM +0100, David Woodhouse wrote:
> From: David Woodhouse <dwmw@amazon.co.uk>

Please, add changelogs to your patches.

What we really need here is the detail on *why* we can just bump the
PSCI version like this, i.e. no new required ABI. On top of that, you
could mention that KVM has made the implementation choice to provide
SYSTEM_OFF2 unconditionally in its PSCIv1.3 implementation.

> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
> ---
> arch/arm64/kvm/hypercalls.c | 2 ++
> arch/arm64/kvm/psci.c | 6 +++++-
> include/kvm/arm_psci.h | 4 +++-
> 3 files changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c
> index 5763d979d8ca..9c6267ca2b82 100644
> --- a/arch/arm64/kvm/hypercalls.c
> +++ b/arch/arm64/kvm/hypercalls.c
> @@ -575,6 +575,8 @@ int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
> case KVM_ARM_PSCI_0_2:
> case KVM_ARM_PSCI_1_0:
> case KVM_ARM_PSCI_1_1:
> + case KVM_ARM_PSCI_1_2:
> + case KVM_ARM_PSCI_1_3:
> if (!wants_02)
> return -EINVAL;
> vcpu->kvm->arch.psci_version = val;
> diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c
> index fd0f82464f7d..5177dda5a411 100644
> --- a/arch/arm64/kvm/psci.c
> +++ b/arch/arm64/kvm/psci.c
> @@ -328,7 +328,7 @@ static int kvm_psci_1_x_call(struct kvm_vcpu *vcpu, u32 minor)
>
> switch(psci_fn) {
> case PSCI_0_2_FN_PSCI_VERSION:
> - val = minor == 0 ? KVM_ARM_PSCI_1_0 : KVM_ARM_PSCI_1_1;
> + val = PSCI_VERSION(1, minor);
> break;
> case PSCI_1_0_FN_PSCI_FEATURES:
> arg = smccc_get_arg1(vcpu);
> @@ -486,6 +486,10 @@ int kvm_psci_call(struct kvm_vcpu *vcpu)
> }
>
> switch (version) {
> + case KVM_ARM_PSCI_1_3:
> + return kvm_psci_1_x_call(vcpu, 3);
> + case KVM_ARM_PSCI_1_2:
> + return kvm_psci_1_x_call(vcpu, 2);
> case KVM_ARM_PSCI_1_1:
> return kvm_psci_1_x_call(vcpu, 1);
> case KVM_ARM_PSCI_1_0:
> diff --git a/include/kvm/arm_psci.h b/include/kvm/arm_psci.h
> index e8fb624013d1..cbaec804eb83 100644
> --- a/include/kvm/arm_psci.h
> +++ b/include/kvm/arm_psci.h
> @@ -14,8 +14,10 @@
> #define KVM_ARM_PSCI_0_2 PSCI_VERSION(0, 2)
> #define KVM_ARM_PSCI_1_0 PSCI_VERSION(1, 0)
> #define KVM_ARM_PSCI_1_1 PSCI_VERSION(1, 1)
> +#define KVM_ARM_PSCI_1_2 PSCI_VERSION(1, 2)
> +#define KVM_ARM_PSCI_1_3 PSCI_VERSION(1, 3)
>
> -#define KVM_ARM_PSCI_LATEST KVM_ARM_PSCI_1_1
> +#define KVM_ARM_PSCI_LATEST KVM_ARM_PSCI_1_3
>
> static inline int kvm_psci_version(struct kvm_vcpu *vcpu)
> {
> --
> 2.44.0
>

--
Thanks,
Oliver