Hi Clément,
On 2025-01-06 9:48 AM, Clément Léger wrote:
> The FWFT SBI extension will need to dynamically allocate memory and do
> init time specific initialization. Add an init/deinit callbacks that
> allows to do so.
>
> Signed-off-by: Clément Léger <cleger@xxxxxxxxxxxx>
> ---
> arch/riscv/include/asm/kvm_vcpu_sbi.h | 9 ++++++++
> arch/riscv/kvm/vcpu.c | 2 ++
> arch/riscv/kvm/vcpu_sbi.c | 31 ++++++++++++++++++++++++++-
> 3 files changed, 41 insertions(+), 1 deletion(-)
>
> diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h
> index b96705258cf9..8c465ce90e73 100644
> --- a/arch/riscv/include/asm/kvm_vcpu_sbi.h
> +++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h
> @@ -49,6 +49,14 @@ struct kvm_vcpu_sbi_extension {
>
> /* Extension specific probe function */
> unsigned long (*probe)(struct kvm_vcpu *vcpu);
> +
> + /*
> + * Init/deinit function called once during VCPU init/destroy. These
> + * might be use if the SBI extensions need to allocate or do specific
> + * init time only configuration.
> + */
> + int (*init)(struct kvm_vcpu *vcpu);
> + void (*deinit)(struct kvm_vcpu *vcpu);
> };
>
> void kvm_riscv_vcpu_sbi_forward(struct kvm_vcpu *vcpu, struct kvm_run *run);
> @@ -69,6 +77,7 @@ const struct kvm_vcpu_sbi_extension *kvm_vcpu_sbi_find_ext(
> bool riscv_vcpu_supports_sbi_ext(struct kvm_vcpu *vcpu, int idx);
> int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run);
> void kvm_riscv_vcpu_sbi_init(struct kvm_vcpu *vcpu);
> +void kvm_riscv_vcpu_sbi_deinit(struct kvm_vcpu *vcpu);
>
> int kvm_riscv_vcpu_get_reg_sbi_sta(struct kvm_vcpu *vcpu, unsigned long reg_num,
> unsigned long *reg_val);
> diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
> index e048dcc6e65e..3420a4a62c94 100644
> --- a/arch/riscv/kvm/vcpu.c
> +++ b/arch/riscv/kvm/vcpu.c
> @@ -180,6 +180,8 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
>
> void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
> {
> + kvm_riscv_vcpu_sbi_deinit(vcpu);
> +
> /* Cleanup VCPU AIA context */
> kvm_riscv_vcpu_aia_deinit(vcpu);
>
> diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c
> index 6e704ed86a83..d2dbb0762072 100644
> --- a/arch/riscv/kvm/vcpu_sbi.c
> +++ b/arch/riscv/kvm/vcpu_sbi.c
> @@ -486,7 +486,7 @@ void kvm_riscv_vcpu_sbi_init(struct kvm_vcpu *vcpu)
> struct kvm_vcpu_sbi_context *scontext = &vcpu->arch.sbi_context;
> const struct kvm_riscv_sbi_extension_entry *entry;
> const struct kvm_vcpu_sbi_extension *ext;
> - int idx, i;
> + int idx, i, ret;
>
> for (i = 0; i < ARRAY_SIZE(sbi_ext); i++) {
> entry = &sbi_ext[i];
> @@ -501,8 +501,37 @@ void kvm_riscv_vcpu_sbi_init(struct kvm_vcpu *vcpu)
> continue;
> }
>
> + if (ext->init) {
> + ret = ext->init(vcpu);
> + if (ret)
> + scontext->ext_status[idx] =
> + KVM_RISCV_SBI_EXT_STATUS_UNAVAILABLE;
> + }
> +
> scontext->ext_status[idx] = ext->default_disabled ?
> KVM_RISCV_SBI_EXT_STATUS_DISABLED :
> KVM_RISCV_SBI_EXT_STATUS_ENABLED;
This will overwrite the KVM_RISCV_SBI_EXT_STATUS_UNAVAILABLE set above.
> }
> }
> +
> +void kvm_riscv_vcpu_sbi_deinit(struct kvm_vcpu *vcpu)
> +{
> + struct kvm_vcpu_sbi_context *scontext = &vcpu->arch.sbi_context;
> + const struct kvm_riscv_sbi_extension_entry *entry;
> + const struct kvm_vcpu_sbi_extension *ext;
> + int idx, i;
> +
> + for (i = 0; i < ARRAY_SIZE(sbi_ext); i++) {
> + entry = &sbi_ext[i];
> + ext = entry->ext_ptr;
> + idx = entry->ext_idx;
> +
> + if (idx < 0 || idx >= ARRAY_SIZE(scontext->ext_status))
> + continue;
> +
> + if (scontext->ext_status[idx] != KVM_RISCV_SBI_EXT_STATUS_ENABLED || !ext->deinit)
Given that an extension can be enabled/disabled after initialization, this
should only skip deinit if the status is UNAVAILABLE.
Regards,
Samuel
> + continue;
> +
> + ext->deinit(vcpu);
> + }
> +}
