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Commit 13989b65 authored by Simon Guo's avatar Simon Guo Committed by Paul Mackerras
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KVM: PPC: Book3S PR: Add math support for PR KVM HTM 



The math registers will be saved into vcpu->arch.fp/vr and corresponding
vcpu->arch.fp_tm/vr_tm area.

We flush or giveup the math regs into vcpu->arch.fp/vr before saving
transaction. After transaction is restored, the math regs will be loaded
back into regs.

If there is a FP/VEC/VSX unavailable exception during transaction active
state, the math checkpoint content might be incorrect and we need to do
treclaim./load the correct checkpoint val/trechkpt. sequence to retry the
transaction. That will make our solution complicated. To solve this issue,
we always make the hardware guest MSR math bits (shadow_msr) consistent
with the MSR val which guest sees (kvmppc_get_msr()) when guest msr is
with tm enabled. Then all FP/VEC/VSX unavailable exception can be delivered
to guest and guest handles the exception by itself.

Signed-off-by: default avatarSimon Guo <wei.guo.simon@gmail.com>
Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
parent 8d2e2fc5

arch/powerpc/kvm/book3s_pr.c

+35 −0
Original line number Original line Diff line number Diff line
@@ -308,6 +308,28 @@ static inline void kvmppc_restore_tm_sprs(struct kvm_vcpu *vcpu) 
	tm_disable();

	tm_disable();

}

}





/* loadup math bits which is enabled at kvmppc_get_msr() but not enabled at

 * hardware.

 */

static void kvmppc_handle_lost_math_exts(struct kvm_vcpu *vcpu)

{

	ulong exit_nr;

	ulong ext_diff = (kvmppc_get_msr(vcpu) & ~vcpu->arch.guest_owned_ext) &

		(MSR_FP | MSR_VEC | MSR_VSX);



	if (!ext_diff)

		return;



	if (ext_diff == MSR_FP)

		exit_nr = BOOK3S_INTERRUPT_FP_UNAVAIL;

	else if (ext_diff == MSR_VEC)

		exit_nr = BOOK3S_INTERRUPT_ALTIVEC;

	else

		exit_nr = BOOK3S_INTERRUPT_VSX;



	kvmppc_handle_ext(vcpu, exit_nr, ext_diff);

}



void kvmppc_save_tm_pr(struct kvm_vcpu *vcpu)

void kvmppc_save_tm_pr(struct kvm_vcpu *vcpu)

{

{

	if (!(MSR_TM_ACTIVE(kvmppc_get_msr(vcpu)))) {

	if (!(MSR_TM_ACTIVE(kvmppc_get_msr(vcpu)))) {
@@ -315,6 +337,8 @@ void kvmppc_save_tm_pr(struct kvm_vcpu *vcpu) 
		return;

		return;

	}

	}





	kvmppc_giveup_ext(vcpu, MSR_VSX);



	preempt_disable();

	preempt_disable();

	_kvmppc_save_tm_pr(vcpu, mfmsr());

	_kvmppc_save_tm_pr(vcpu, mfmsr());

	preempt_enable();

	preempt_enable();
@@ -324,12 +348,18 @@ void kvmppc_restore_tm_pr(struct kvm_vcpu *vcpu) 
{

{

	if (!MSR_TM_ACTIVE(kvmppc_get_msr(vcpu))) {

	if (!MSR_TM_ACTIVE(kvmppc_get_msr(vcpu))) {

		kvmppc_restore_tm_sprs(vcpu);

		kvmppc_restore_tm_sprs(vcpu);

		if (kvmppc_get_msr(vcpu) & MSR_TM)

			kvmppc_handle_lost_math_exts(vcpu);

		return;

		return;

	}

	}





	preempt_disable();

	preempt_disable();

	_kvmppc_restore_tm_pr(vcpu, kvmppc_get_msr(vcpu));

	_kvmppc_restore_tm_pr(vcpu, kvmppc_get_msr(vcpu));

	preempt_enable();

	preempt_enable();



	if (kvmppc_get_msr(vcpu) & MSR_TM)

		kvmppc_handle_lost_math_exts(vcpu);



}

}

#endif

#endif
@@ -468,6 +498,11 @@ static void kvmppc_set_msr_pr(struct kvm_vcpu *vcpu, u64 msr) 
	/* Preload FPU if it's enabled */

	/* Preload FPU if it's enabled */

	if (kvmppc_get_msr(vcpu) & MSR_FP)

	if (kvmppc_get_msr(vcpu) & MSR_FP)

		kvmppc_handle_ext(vcpu, BOOK3S_INTERRUPT_FP_UNAVAIL, MSR_FP);

		kvmppc_handle_ext(vcpu, BOOK3S_INTERRUPT_FP_UNAVAIL, MSR_FP);



#ifdef CONFIG_PPC_TRANSACTIONAL_MEM

	if (kvmppc_get_msr(vcpu) & MSR_TM)

		kvmppc_handle_lost_math_exts(vcpu);

#endif

}

}





void kvmppc_set_pvr_pr(struct kvm_vcpu *vcpu, u32 pvr)

void kvmppc_set_pvr_pr(struct kvm_vcpu *vcpu, u32 pvr)