[PATCH v4 08/53] KVM: PPC: Book3S HV: POWER10 enable HAIL when running radix guests
From: Nicholas Piggin <npiggin@gmail.com>
Date: 2021-11-23 09:58:06
Subsystem:
kernel virtual machine for powerpc (kvm/powerpc), linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
HV interrupts may be taken with the MMU enabled when radix guests are running. Enable LPCR[HAIL] on ISA v3.1 processors for radix guests. Make this depend on the host LPCR[HAIL] being enabled. Currently that is always enabled, but having this test means any issue that might require LPCR[HAIL] to be disabled in the host will not have to be duplicated in KVM. This optimisation takes 1380 cycles off a NULL hcall entry+exit micro benchmark on a POWER10. Reviewed-by: Fabiano Rosas <redacted> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- arch/powerpc/kvm/book3s_hv.c | 29 +++++++++++++++++++++++++---- 1 file changed, 25 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 1b556dbfcfc8..a683ee5f420a 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c@@ -5073,6 +5073,8 @@ static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu) */ int kvmppc_switch_mmu_to_hpt(struct kvm *kvm) { + unsigned long lpcr, lpcr_mask; + if (nesting_enabled(kvm)) kvmhv_release_all_nested(kvm); kvmppc_rmap_reset(kvm);
@@ -5082,8 +5084,13 @@ int kvmppc_switch_mmu_to_hpt(struct kvm *kvm) kvm->arch.radix = 0; spin_unlock(&kvm->mmu_lock); kvmppc_free_radix(kvm); - kvmppc_update_lpcr(kvm, LPCR_VPM1, - LPCR_VPM1 | LPCR_UPRT | LPCR_GTSE | LPCR_HR); + + lpcr = LPCR_VPM1; + lpcr_mask = LPCR_VPM1 | LPCR_UPRT | LPCR_GTSE | LPCR_HR; + if (cpu_has_feature(CPU_FTR_ARCH_31)) + lpcr_mask |= LPCR_HAIL; + kvmppc_update_lpcr(kvm, lpcr, lpcr_mask); + return 0; }
@@ -5093,6 +5100,7 @@ int kvmppc_switch_mmu_to_hpt(struct kvm *kvm) */ int kvmppc_switch_mmu_to_radix(struct kvm *kvm) { + unsigned long lpcr, lpcr_mask; int err; err = kvmppc_init_vm_radix(kvm);
@@ -5104,8 +5112,17 @@ int kvmppc_switch_mmu_to_radix(struct kvm *kvm) kvm->arch.radix = 1; spin_unlock(&kvm->mmu_lock); kvmppc_free_hpt(&kvm->arch.hpt); - kvmppc_update_lpcr(kvm, LPCR_UPRT | LPCR_GTSE | LPCR_HR, - LPCR_VPM1 | LPCR_UPRT | LPCR_GTSE | LPCR_HR); + + lpcr = LPCR_UPRT | LPCR_GTSE | LPCR_HR; + lpcr_mask = LPCR_VPM1 | LPCR_UPRT | LPCR_GTSE | LPCR_HR; + if (cpu_has_feature(CPU_FTR_ARCH_31)) { + lpcr_mask |= LPCR_HAIL; + if (cpu_has_feature(CPU_FTR_HVMODE) && + (kvm->arch.host_lpcr & LPCR_HAIL)) + lpcr |= LPCR_HAIL; + } + kvmppc_update_lpcr(kvm, lpcr, lpcr_mask); + return 0; }
@@ -5269,6 +5286,10 @@ static int kvmppc_core_init_vm_hv(struct kvm *kvm) kvm->arch.mmu_ready = 1; lpcr &= ~LPCR_VPM1; lpcr |= LPCR_UPRT | LPCR_GTSE | LPCR_HR; + if (cpu_has_feature(CPU_FTR_HVMODE) && + cpu_has_feature(CPU_FTR_ARCH_31) && + (kvm->arch.host_lpcr & LPCR_HAIL)) + lpcr |= LPCR_HAIL; ret = kvmppc_init_vm_radix(kvm); if (ret) { kvmppc_free_lpid(kvm->arch.lpid);
--
2.23.0