arch/powerpc/kvm/book3s_hv_p9_perf.c

Source file repositories/reference/linux-study-clean/arch/powerpc/kvm/book3s_hv_p9_perf.c

File Facts

System
Linux kernel
Corpus path
arch/powerpc/kvm/book3s_hv_p9_perf.c
Extension
.c
Size
6224 bytes
Lines
220
Domain
Architecture Layer
Bucket
arch/powerpc
Inferred role
Architecture Layer: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

if (cpu_has_feature(CPU_FTR_ARCH_31)) {
			host_os_sprs->mmcr3 = mfspr(SPRN_MMCR3);
			host_os_sprs->sier2 = mfspr(SPRN_SIER2);
			host_os_sprs->sier3 = mfspr(SPRN_SIER3);
		}
	}

#ifdef CONFIG_PPC_PSERIES
	/* After saving PMU, before loading guest PMU, flip pmcregs_in_use */
	if (kvmhv_on_pseries()) {
		barrier();
		get_lppaca()->pmcregs_in_use = load_pmu;
		barrier();
	}
#endif

	/*
	 * Load guest. If the VPA said the PMCs are not in use but the guest
	 * tried to access them anyway, HFSCR[PM] will be set by the HFAC
	 * fault so we can make forward progress.
	 */
	if (load_pmu || (vcpu->arch.hfscr & HFSCR_PM)) {
		mtspr(SPRN_PMC1, vcpu->arch.pmc[0]);
		mtspr(SPRN_PMC2, vcpu->arch.pmc[1]);
		mtspr(SPRN_PMC3, vcpu->arch.pmc[2]);
		mtspr(SPRN_PMC4, vcpu->arch.pmc[3]);
		mtspr(SPRN_PMC5, vcpu->arch.pmc[4]);
		mtspr(SPRN_PMC6, vcpu->arch.pmc[5]);
		mtspr(SPRN_MMCR1, vcpu->arch.mmcr[1]);
		mtspr(SPRN_MMCR2, vcpu->arch.mmcr[2]);
		mtspr(SPRN_SDAR, vcpu->arch.sdar);
		mtspr(SPRN_SIAR, vcpu->arch.siar);
		mtspr(SPRN_SIER, vcpu->arch.sier[0]);

		if (cpu_has_feature(CPU_FTR_ARCH_31)) {
			mtspr(SPRN_MMCR3, vcpu->arch.mmcr[3]);
			mtspr(SPRN_SIER2, vcpu->arch.sier[1]);
			mtspr(SPRN_SIER3, vcpu->arch.sier[2]);
		}

		/* Set MMCRA then MMCR0 last */
		mtspr(SPRN_MMCRA, vcpu->arch.mmcra);
		mtspr(SPRN_MMCR0, vcpu->arch.mmcr[0]);
		/* No isync necessary because we're starting counters */

		if (!vcpu->arch.nested &&
		    (vcpu->arch.hfscr_permitted & HFSCR_PM))
			vcpu->arch.hfscr |= HFSCR_PM;
	}
}
EXPORT_SYMBOL_GPL(switch_pmu_to_guest);

void switch_pmu_to_host(struct kvm_vcpu *vcpu,
			struct p9_host_os_sprs *host_os_sprs)
{
	struct lppaca *lp;
	int save_pmu = 1;

	lp = vcpu->arch.vpa.pinned_addr;
	if (lp)
		save_pmu = lp->pmcregs_in_use;
	if (IS_ENABLED(CONFIG_KVM_BOOK3S_HV_NESTED_PMU_WORKAROUND)) {
		/*
		 * Save pmu if this guest is capable of running nested guests.
		 * This is option is for old L1s that do not set their
		 * lppaca->pmcregs_in_use properly when entering their L2.
		 */
		save_pmu |= nesting_enabled(vcpu->kvm);
	}

	if (save_pmu) {
		vcpu->arch.mmcr[0] = mfspr(SPRN_MMCR0);
		vcpu->arch.mmcra = mfspr(SPRN_MMCRA);

		freeze_pmu(vcpu->arch.mmcr[0], vcpu->arch.mmcra);

		vcpu->arch.pmc[0] = mfspr(SPRN_PMC1);
		vcpu->arch.pmc[1] = mfspr(SPRN_PMC2);
		vcpu->arch.pmc[2] = mfspr(SPRN_PMC3);
		vcpu->arch.pmc[3] = mfspr(SPRN_PMC4);
		vcpu->arch.pmc[4] = mfspr(SPRN_PMC5);
		vcpu->arch.pmc[5] = mfspr(SPRN_PMC6);
		vcpu->arch.mmcr[1] = mfspr(SPRN_MMCR1);
		vcpu->arch.mmcr[2] = mfspr(SPRN_MMCR2);
		vcpu->arch.sdar = mfspr(SPRN_SDAR);
		vcpu->arch.siar = mfspr(SPRN_SIAR);
		vcpu->arch.sier[0] = mfspr(SPRN_SIER);

		if (cpu_has_feature(CPU_FTR_ARCH_31)) {
			vcpu->arch.mmcr[3] = mfspr(SPRN_MMCR3);

Annotation

Implementation Notes