On Fri, May 23, 2025 at 3:53 PM Clément Léger <cleger@xxxxxxxxxxxx> wrote:
>
> SBI_FWFT_MISALIGNED_DELEG needs hedeleg to be modified to delegate
> misaligned load/store exceptions. Save and restore it during CPU
> load/put.
>
> Signed-off-by: Clément Léger <cleger@xxxxxxxxxxxx>
> Reviewed-by: Deepak Gupta <debug@xxxxxxxxxxxx>
> Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>
> Reviewed-by: Atish Patra <atishp@xxxxxxxxxxxx>
Queued this patch for Linux-6.17
Thanks,
Anup
> ---
> arch/riscv/kvm/vcpu_sbi_fwft.c | 41 ++++++++++++++++++++++++++++++++++
> 1 file changed, 41 insertions(+)
>
> diff --git a/arch/riscv/kvm/vcpu_sbi_fwft.c b/arch/riscv/kvm/vcpu_sbi_fwft.c
> index b0f66c7bf010..6770c043bbcb 100644
> --- a/arch/riscv/kvm/vcpu_sbi_fwft.c
> +++ b/arch/riscv/kvm/vcpu_sbi_fwft.c
> @@ -14,6 +14,8 @@
> #include <asm/kvm_vcpu_sbi.h>
> #include <asm/kvm_vcpu_sbi_fwft.h>
>
> +#define MIS_DELEG (BIT_ULL(EXC_LOAD_MISALIGNED) | BIT_ULL(EXC_STORE_MISALIGNED))
> +
> struct kvm_sbi_fwft_feature {
> /**
> * @id: Feature ID
> @@ -68,7 +70,46 @@ static bool kvm_fwft_is_defined_feature(enum sbi_fwft_feature_t feature)
> return false;
> }
>
> +static bool kvm_sbi_fwft_misaligned_delegation_supported(struct kvm_vcpu *vcpu)
> +{
> + return misaligned_traps_can_delegate();
> +}
> +
> +static long kvm_sbi_fwft_set_misaligned_delegation(struct kvm_vcpu *vcpu,
> + struct kvm_sbi_fwft_config *conf,
> + unsigned long value)
> +{
> + struct kvm_vcpu_config *cfg = &vcpu->arch.cfg;
> +
> + if (value == 1) {
> + cfg->hedeleg |= MIS_DELEG;
> + csr_set(CSR_HEDELEG, MIS_DELEG);
> + } else if (value == 0) {
> + cfg->hedeleg &= ~MIS_DELEG;
> + csr_clear(CSR_HEDELEG, MIS_DELEG);
> + } else {
> + return SBI_ERR_INVALID_PARAM;
> + }
> +
> + return SBI_SUCCESS;
> +}
> +
> +static long kvm_sbi_fwft_get_misaligned_delegation(struct kvm_vcpu *vcpu,
> + struct kvm_sbi_fwft_config *conf,
> + unsigned long *value)
> +{
> + *value = (csr_read(CSR_HEDELEG) & MIS_DELEG) == MIS_DELEG;
> +
> + return SBI_SUCCESS;
> +}
> +
> static const struct kvm_sbi_fwft_feature features[] = {
> + {
> + .id = SBI_FWFT_MISALIGNED_EXC_DELEG,
> + .supported = kvm_sbi_fwft_misaligned_delegation_supported,
> + .set = kvm_sbi_fwft_set_misaligned_delegation,
> + .get = kvm_sbi_fwft_get_misaligned_delegation,
> + },
> };
>
> static struct kvm_sbi_fwft_config *
> --
> 2.49.0
>
