Commit 3f9e2966 authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman
Browse files

KVM: PPC: Book3S HV P9: Implement TM fastpath for guest entry/exit 



If TM is not active, only TM register state needs to be saved and
restored, avoiding several mfmsr/mtmsrd instructions and improving
performance.

Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211123095231.1036501-33-npiggin@gmail.com
parent d5f48019

arch/powerpc/kvm/book3s_hv_p9_entry.c

+23 −4
Original line number Diff line number Diff line
@@ -287,11 +287,20 @@ bool load_vcpu_state(struct kvm_vcpu *vcpu, 
{

	bool ret = false;



#ifdef CONFIG_PPC_TRANSACTIONAL_MEM

	if (cpu_has_feature(CPU_FTR_TM) ||

	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) {

		kvmppc_restore_tm_hv(vcpu, vcpu->arch.shregs.msr, true);

		unsigned long guest_msr = vcpu->arch.shregs.msr;

		if (MSR_TM_ACTIVE(guest_msr)) {

			kvmppc_restore_tm_hv(vcpu, guest_msr, true);

			ret = true;

		} else {

			mtspr(SPRN_TEXASR, vcpu->arch.texasr);

			mtspr(SPRN_TFHAR, vcpu->arch.tfhar);

			mtspr(SPRN_TFIAR, vcpu->arch.tfiar);

		}

	}

#endif



	load_spr_state(vcpu, host_os_sprs);
@@ -315,9 +324,19 @@ void store_vcpu_state(struct kvm_vcpu *vcpu) 
#endif

	vcpu->arch.vrsave = mfspr(SPRN_VRSAVE);



#ifdef CONFIG_PPC_TRANSACTIONAL_MEM

	if (cpu_has_feature(CPU_FTR_TM) ||

	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))

		kvmppc_save_tm_hv(vcpu, vcpu->arch.shregs.msr, true);

	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) {

		unsigned long guest_msr = vcpu->arch.shregs.msr;

		if (MSR_TM_ACTIVE(guest_msr)) {

			kvmppc_save_tm_hv(vcpu, guest_msr, true);

		} else {

			vcpu->arch.texasr = mfspr(SPRN_TEXASR);

			vcpu->arch.tfhar = mfspr(SPRN_TFHAR);

			vcpu->arch.tfiar = mfspr(SPRN_TFIAR);

		}

	}

#endif

}

EXPORT_SYMBOL_GPL(store_vcpu_state);