RISC-V: KVM: Handle breakpoint exits for VCPU

Exit to userspace for breakpoint traps. Set the exit_reason as
KVM_EXIT_DEBUG before exit.

Signed-off-by: Chao Du <duchao@eswincomputing.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20240402062628.5425-3-duchao@eswincomputing.com
Signed-off-by: Anup Patel <anup@brainfault.org>

Author: Du-Chao

arch/riscv/kvm/vcpu_exit.c

@@ -204,6 +204,10 @@ int kvm_riscv_vcpu_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
 		if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV)
 			ret = kvm_riscv_vcpu_sbi_ecall(vcpu, run);
 		break;
+	case EXC_BREAKPOINT:
+		run->exit_reason = KVM_EXIT_DEBUG;
+		ret = 0;
+		break;
 	default:
 		break;
 	}