RISC-V: KVM: Add common kvm_riscv_vcpu_wfi() function

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>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
index 99ef6a1..78da839 100644 (file)
--- 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 571f319..aa8af12 100644 (file)
--- 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;
        }
@@ -454,6 +449,21 @@ static int stage2_page_fault(struct kvm_vcpu *vcpu, struct kvm_run *run,
 }
 
 /**
+ * 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
  *
  * @vcpu: The VCPU pointer