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[5/6] RISC-V: KVM: Add common kvm_riscv_vcpu_wfi() function

Message ID 20220201082227.361967-6-apatel@ventanamicro.com
State Accepted
Headers show
Series KVM RISC-V SBI v0.3 support | expand

Commit Message

Anup Patel Feb. 1, 2022, 8:22 a.m. UTC
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@ventanamicro.com>
---
 arch/riscv/include/asm/kvm_host.h |  1 +
 arch/riscv/kvm/vcpu_exit.c        | 22 ++++++++++++++++------
 2 files changed, 17 insertions(+), 6 deletions(-)

Comments

Atish Patra Feb. 23, 2022, 12:01 a.m. UTC | #1
On Tue, Feb 1, 2022 at 12:24 AM Anup Patel <apatel@ventanamicro.com> 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@ventanamicro.com>
> ---
>  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@rivosinc.com>

--
Regards,
Atish
diff mbox series

Patch

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
  *