Commit 245ebf8e authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman
Browse files

powerpc/64s: Always set PMU control registers to frozen/disabled when not in use 



KVM PMU management code looks for particular frozen/disabled bits in
the PMU registers so it knows whether it must clear them when coming
out of a guest or not. Setting this up helps KVM make these optimisations
without getting confused. Longer term the better approach might be to
move guest/host PMU switching to the perf subsystem.

Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Reviewed-by: default avatarAthira Jajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211123095231.1036501-12-npiggin@gmail.com
parent d3c8a2d3

arch/powerpc/kernel/cpu_setup_power.c

+2 −2
Original line number Diff line number Diff line
@@ -109,7 +109,7 @@ static void init_PMU_HV_ISA207(void) 
static void init_PMU(void)

{

	mtspr(SPRN_MMCRA, 0);

	mtspr(SPRN_MMCR0, 0);

	mtspr(SPRN_MMCR0, MMCR0_FC);

	mtspr(SPRN_MMCR1, 0);

	mtspr(SPRN_MMCR2, 0);

}
@@ -123,7 +123,7 @@ static void init_PMU_ISA31(void) 
{

	mtspr(SPRN_MMCR3, 0);

	mtspr(SPRN_MMCRA, MMCRA_BHRB_DISABLE);

	mtspr(SPRN_MMCR0, MMCR0_PMCCEXT);

	mtspr(SPRN_MMCR0, MMCR0_FC | MMCR0_PMCCEXT);

}



/*

arch/powerpc/kernel/dt_cpu_ftrs.c

+3 −3
Original line number Diff line number Diff line
@@ -353,7 +353,7 @@ static void init_pmu_power8(void) 
	}



	mtspr(SPRN_MMCRA, 0);

	mtspr(SPRN_MMCR0, 0);

	mtspr(SPRN_MMCR0, MMCR0_FC);

	mtspr(SPRN_MMCR1, 0);

	mtspr(SPRN_MMCR2, 0);

	mtspr(SPRN_MMCRS, 0);
@@ -392,7 +392,7 @@ static void init_pmu_power9(void) 
		mtspr(SPRN_MMCRC, 0);



	mtspr(SPRN_MMCRA, 0);

	mtspr(SPRN_MMCR0, 0);

	mtspr(SPRN_MMCR0, MMCR0_FC);

	mtspr(SPRN_MMCR1, 0);

	mtspr(SPRN_MMCR2, 0);

}
@@ -428,7 +428,7 @@ static void init_pmu_power10(void) 


	mtspr(SPRN_MMCR3, 0);

	mtspr(SPRN_MMCRA, MMCRA_BHRB_DISABLE);

	mtspr(SPRN_MMCR0, MMCR0_PMCCEXT);

	mtspr(SPRN_MMCR0, MMCR0_FC | MMCR0_PMCCEXT);

}



static int __init feat_enable_pmu_power10(struct dt_cpu_feature *f)

arch/powerpc/kvm/book3s_hv.c

+5 −0
Original line number Diff line number Diff line
@@ -2715,6 +2715,11 @@ static int kvmppc_core_vcpu_create_hv(struct kvm_vcpu *vcpu) 
#endif

#endif

	vcpu->arch.mmcr[0] = MMCR0_FC;

	if (cpu_has_feature(CPU_FTR_ARCH_31)) {

		vcpu->arch.mmcr[0] |= MMCR0_PMCCEXT;

		vcpu->arch.mmcra = MMCRA_BHRB_DISABLE;

	}



	vcpu->arch.ctrl = CTRL_RUNLATCH;

	/* default to host PVR, since we can't spoof it */

	kvmppc_set_pvr_hv(vcpu, mfspr(SPRN_PVR));