On Tue, Feb 1, 2022 at 12:24 AM Anup Patel <apatel@xxxxxxxxxxxxxxxx> wrote:
>
> The wait for interrupt (WFI) instruction emulation can share the VCPU
> halt logic with SBI HSM suspend emulation so this patch adds a common
> kvm_riscv_vcpu_wfi() function for this purpose.
>
> Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx>
> ---
> arch/riscv/include/asm/kvm_host.h | 1 +
> arch/riscv/kvm/vcpu_exit.c | 22 ++++++++++++++++------
> 2 files changed, 17 insertions(+), 6 deletions(-)
>
> diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
> index 99ef6a120617..78da839657e5 100644
> --- a/arch/riscv/include/asm/kvm_host.h
> +++ b/arch/riscv/include/asm/kvm_host.h
> @@ -228,6 +228,7 @@ void kvm_riscv_stage2_vmid_update(struct kvm_vcpu *vcpu);
>
> void __kvm_riscv_unpriv_trap(void);
>
> +void kvm_riscv_vcpu_wfi(struct kvm_vcpu *vcpu);
> unsigned long kvm_riscv_vcpu_unpriv_read(struct kvm_vcpu *vcpu,
> bool read_insn,
> unsigned long guest_addr,
> diff --git a/arch/riscv/kvm/vcpu_exit.c b/arch/riscv/kvm/vcpu_exit.c
> index 571f319e995a..aa8af129e4bb 100644
> --- a/arch/riscv/kvm/vcpu_exit.c
> +++ b/arch/riscv/kvm/vcpu_exit.c
> @@ -144,12 +144,7 @@ static int system_opcode_insn(struct kvm_vcpu *vcpu,
> {
> if ((insn & INSN_MASK_WFI) == INSN_MATCH_WFI) {
> vcpu->stat.wfi_exit_stat++;
> - if (!kvm_arch_vcpu_runnable(vcpu)) {
> - srcu_read_unlock(&vcpu->kvm->srcu, vcpu->arch.srcu_idx);
> - kvm_vcpu_halt(vcpu);
> - vcpu->arch.srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
> - kvm_clear_request(KVM_REQ_UNHALT, vcpu);
> - }
> + kvm_riscv_vcpu_wfi(vcpu);
> vcpu->arch.guest_context.sepc += INSN_LEN(insn);
> return 1;
> }
> @@ -453,6 +448,21 @@ static int stage2_page_fault(struct kvm_vcpu *vcpu, struct kvm_run *run,
> return 1;
> }
>
> +/**
> + * kvm_riscv_vcpu_wfi -- Emulate wait for interrupt (WFI) behaviour
> + *
> + * @vcpu: The VCPU pointer
> + */
> +void kvm_riscv_vcpu_wfi(struct kvm_vcpu *vcpu)
> +{
> + if (!kvm_arch_vcpu_runnable(vcpu)) {
> + srcu_read_unlock(&vcpu->kvm->srcu, vcpu->arch.srcu_idx);
> + kvm_vcpu_halt(vcpu);
> + vcpu->arch.srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
> + kvm_clear_request(KVM_REQ_UNHALT, vcpu);
> + }
> +}
> +
> /**
> * kvm_riscv_vcpu_unpriv_read -- Read machine word from Guest memory
> *
> --
> 2.25.1
>
Reviewed-by: Atish Patra <atishp@xxxxxxxxxxxx>
--
Regards,
Atish
