Commit 9a26af64 authored by Mihai Caraman's avatar Mihai Caraman Committed by Alexander Graf
Browse files

KVM: PPC: Book3s: Remove kvmppc_read_inst() function 



In the context of replacing kvmppc_ld() function calls with a version of
kvmppc_get_last_inst() which allow to fail, Alex Graf suggested this:

"If we get EMULATE_AGAIN, we just have to make sure we go back into the guest.
No need to inject an ISI into  the guest - it'll do that all by itself.
With an error returning kvmppc_get_last_inst we can just use completely
get rid of kvmppc_read_inst() and only use kvmppc_get_last_inst() instead."

As a intermediate step get rid of kvmppc_read_inst() and only use kvmppc_ld()
instead.

Signed-off-by: default avatarMihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
parent 9c0d4e0d

arch/powerpc/kvm/book3s_pr.c

+34 −51
Original line number Diff line number Diff line
@@ -710,42 +710,6 @@ static void kvmppc_giveup_fac(struct kvm_vcpu *vcpu, ulong fac) 
#endif

}



static int kvmppc_read_inst(struct kvm_vcpu *vcpu)

{

	ulong srr0 = kvmppc_get_pc(vcpu);

	u32 last_inst = kvmppc_get_last_inst(vcpu);

	int ret;



	ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false);

	if (ret == -ENOENT) {

		ulong msr = kvmppc_get_msr(vcpu);



		msr = kvmppc_set_field(msr, 33, 33, 1);

		msr = kvmppc_set_field(msr, 34, 36, 0);

		msr = kvmppc_set_field(msr, 42, 47, 0);

		kvmppc_set_msr_fast(vcpu, msr);

		kvmppc_book3s_queue_irqprio(vcpu, BOOK3S_INTERRUPT_INST_STORAGE);

		return EMULATE_AGAIN;

	}



	return EMULATE_DONE;

}



static int kvmppc_check_ext(struct kvm_vcpu *vcpu, unsigned int exit_nr)

{



	/* Need to do paired single emulation? */

	if (!(vcpu->arch.hflags & BOOK3S_HFLAG_PAIRED_SINGLE))

		return EMULATE_DONE;



	/* Read out the instruction */

	if (kvmppc_read_inst(vcpu) == EMULATE_DONE)

		/* Need to emulate */

		return EMULATE_FAIL;



	return EMULATE_AGAIN;

}



/* Handle external providers (FPU, Altivec, VSX) */

static int kvmppc_handle_ext(struct kvm_vcpu *vcpu, unsigned int exit_nr,

			     ulong msr)
@@ -1149,31 +1113,49 @@ program_interrupt: 
	case BOOK3S_INTERRUPT_VSX:

	{

		int ext_msr = 0;

		int emul;

		ulong pc;

		u32 last_inst;



		if (vcpu->arch.hflags & BOOK3S_HFLAG_PAIRED_SINGLE) {

			/* Do paired single instruction emulation */

			pc = kvmppc_get_pc(vcpu);

			last_inst = kvmppc_get_last_inst(vcpu);

			emul = kvmppc_ld(vcpu, &pc, sizeof(u32), &last_inst,

					 false);

			if (emul == EMULATE_DONE)

				goto program_interrupt;

			else

				r = RESUME_GUEST;



		switch (exit_nr) {

		case BOOK3S_INTERRUPT_FP_UNAVAIL: ext_msr = MSR_FP;  break;

		case BOOK3S_INTERRUPT_ALTIVEC:    ext_msr = MSR_VEC; break;

		case BOOK3S_INTERRUPT_VSX:        ext_msr = MSR_VSX; break;

			break;

		}



		switch (kvmppc_check_ext(vcpu, exit_nr)) {

		case EMULATE_DONE:

			/* everything ok - let's enable the ext */

			r = kvmppc_handle_ext(vcpu, exit_nr, ext_msr);

		/* Enable external provider */

		switch (exit_nr) {

		case BOOK3S_INTERRUPT_FP_UNAVAIL:

			ext_msr = MSR_FP;

			break;

		case EMULATE_FAIL:

			/* we need to emulate this instruction */

			goto program_interrupt;



		case BOOK3S_INTERRUPT_ALTIVEC:

			ext_msr = MSR_VEC;

			break;

		default:

			/* nothing to worry about - go again */



		case BOOK3S_INTERRUPT_VSX:

			ext_msr = MSR_VSX;

			break;

		}



		r = kvmppc_handle_ext(vcpu, exit_nr, ext_msr);

		break;

	}

	case BOOK3S_INTERRUPT_ALIGNMENT:

		if (kvmppc_read_inst(vcpu) == EMULATE_DONE) {

	{

		ulong pc = kvmppc_get_pc(vcpu);

		u32 last_inst = kvmppc_get_last_inst(vcpu);

		int emul = kvmppc_ld(vcpu, &pc, sizeof(u32), &last_inst, false);



		if (emul == EMULATE_DONE) {

			u32 dsisr;

			u64 dar;
@@ -1187,6 +1169,7 @@ program_interrupt: 
		}

		r = RESUME_GUEST;

		break;

	}

#ifdef CONFIG_PPC_BOOK3S_64

	case BOOK3S_INTERRUPT_FAC_UNAVAIL:

		kvmppc_handle_fac(vcpu, vcpu->arch.shadow_fscr >> 56);

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