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Commit fcd4f3c6 authored by Thomas Huth's avatar Thomas Huth Committed by Paul Mackerras
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KVM: PPC: Book3S PR: Refactor program interrupt related code into separate function 



The function kvmppc_handle_exit_pr() is quite huge and thus hard to read,
and even contains a "spaghetti-code"-like goto between the different case
labels of the big switch statement. This can be made much more readable
by moving the code related to injecting program interrupts / instruction
emulation into a separate function instead.

Signed-off-by: default avatarThomas Huth <thuth@redhat.com>
Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
parent 8464c884

arch/powerpc/kvm/book3s_pr.c

+65 −65
Original line number Diff line number Diff line
@@ -902,6 +902,69 @@ static void kvmppc_clear_debug(struct kvm_vcpu *vcpu) 
	}

}



static int kvmppc_exit_pr_progint(struct kvm_run *run, struct kvm_vcpu *vcpu,

				  unsigned int exit_nr)

{

	enum emulation_result er;

	ulong flags;

	u32 last_inst;

	int emul, r;



	/*

	 * shadow_srr1 only contains valid flags if we came here via a program

	 * exception. The other exceptions (emulation assist, FP unavailable,

	 * etc.) do not provide flags in SRR1, so use an illegal-instruction

	 * exception when injecting a program interrupt into the guest.

	 */

	if (exit_nr == BOOK3S_INTERRUPT_PROGRAM)

		flags = vcpu->arch.shadow_srr1 & 0x1f0000ull;

	else

		flags = SRR1_PROGILL;



	emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst);

	if (emul != EMULATE_DONE)

		return RESUME_GUEST;



	if (kvmppc_get_msr(vcpu) & MSR_PR) {

#ifdef EXIT_DEBUG

		pr_info("Userspace triggered 0x700 exception at\n 0x%lx (0x%x)\n",

			kvmppc_get_pc(vcpu), last_inst);

#endif

		if ((last_inst & 0xff0007ff) != (INS_DCBZ & 0xfffffff7)) {

			kvmppc_core_queue_program(vcpu, flags);

			return RESUME_GUEST;

		}

	}



	vcpu->stat.emulated_inst_exits++;

	er = kvmppc_emulate_instruction(run, vcpu);

	switch (er) {

	case EMULATE_DONE:

		r = RESUME_GUEST_NV;

		break;

	case EMULATE_AGAIN:

		r = RESUME_GUEST;

		break;

	case EMULATE_FAIL:

		pr_crit("%s: emulation at %lx failed (%08x)\n",

			__func__, kvmppc_get_pc(vcpu), last_inst);

		kvmppc_core_queue_program(vcpu, flags);

		r = RESUME_GUEST;

		break;

	case EMULATE_DO_MMIO:

		run->exit_reason = KVM_EXIT_MMIO;

		r = RESUME_HOST_NV;

		break;

	case EMULATE_EXIT_USER:

		r = RESUME_HOST_NV;

		break;

	default:

		BUG();

	}



	return r;

}



int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu,

			  unsigned int exit_nr)

{
@@ -1044,71 +1107,8 @@ int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu, 
		break;

	case BOOK3S_INTERRUPT_PROGRAM:

	case BOOK3S_INTERRUPT_H_EMUL_ASSIST:

	{

		enum emulation_result er;

		ulong flags;

		u32 last_inst;

		int emul;



program_interrupt:

		/*

		 * shadow_srr1 only contains valid flags if we came here via

		 * a program exception. The other exceptions (emulation assist,

		 * FP unavailable, etc.) do not provide flags in SRR1, so use

		 * an illegal-instruction exception when injecting a program

		 * interrupt into the guest.

		 */

		if (exit_nr == BOOK3S_INTERRUPT_PROGRAM)

			flags = vcpu->arch.shadow_srr1 & 0x1f0000ull;

		else

			flags = SRR1_PROGILL;



		emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst);

		if (emul != EMULATE_DONE) {

			r = RESUME_GUEST;

			break;

		}



		if (kvmppc_get_msr(vcpu) & MSR_PR) {

#ifdef EXIT_DEBUG

			pr_info("Userspace triggered 0x700 exception at\n 0x%lx (0x%x)\n",

				kvmppc_get_pc(vcpu), last_inst);

#endif

			if ((last_inst & 0xff0007ff) !=

			    (INS_DCBZ & 0xfffffff7)) {

				kvmppc_core_queue_program(vcpu, flags);

				r = RESUME_GUEST;

				break;

			}

		}



		vcpu->stat.emulated_inst_exits++;

		er = kvmppc_emulate_instruction(run, vcpu);

		switch (er) {

		case EMULATE_DONE:

			r = RESUME_GUEST_NV;

		r = kvmppc_exit_pr_progint(run, vcpu, exit_nr);

		break;

		case EMULATE_AGAIN:

			r = RESUME_GUEST;

			break;

		case EMULATE_FAIL:

			printk(KERN_CRIT "%s: emulation at %lx failed (%08x)\n",

			       __func__, kvmppc_get_pc(vcpu), last_inst);

			kvmppc_core_queue_program(vcpu, flags);

			r = RESUME_GUEST;

			break;

		case EMULATE_DO_MMIO:

			run->exit_reason = KVM_EXIT_MMIO;

			r = RESUME_HOST_NV;

			break;

		case EMULATE_EXIT_USER:

			r = RESUME_HOST_NV;

			break;

		default:

			BUG();

		}

		break;

	}

	case BOOK3S_INTERRUPT_SYSCALL:

	{

		u32 last_sc;
@@ -1185,7 +1185,7 @@ int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu, 
			emul = kvmppc_get_last_inst(vcpu, INST_GENERIC,

						    &last_inst);

			if (emul == EMULATE_DONE)

				goto program_interrupt;

				r = kvmppc_exit_pr_progint(run, vcpu, exit_nr);

			else

				r = RESUME_GUEST;