From 48013cbc504e064d2318f24482cfbe3c53e0a812 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Fri, 28 May 2021 19:07:32 +1000 Subject: [PATCH] KVM: PPC: Book3S HV P9: Move radix MMU switching instructions together Switching the MMU from radix<->radix mode is tricky particularly as the MMU can remain enabled and requires a certain sequence of SPR updates. Move these together into their own functions. This also includes the radix TLB check / flush because it's tied in to MMU switching due to tlbiel getting LPID from LPIDR. Signed-off-by: Nicholas Piggin Reviewed-by: Alexey Kardashevskiy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210528090752.3542186-13-npiggin@gmail.com --- arch/powerpc/kvm/book3s_hv.c | 62 ++++++++++++++++++++++++------------ 1 file changed, 41 insertions(+), 21 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index bb326cfcf173..3ec1dc1bad16 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -3478,12 +3478,49 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc) trace_kvmppc_run_core(vc, 1); } +static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr) +{ + struct kvmppc_vcore *vc = vcpu->arch.vcore; + struct kvm_nested_guest *nested = vcpu->arch.nested; + u32 lpid; + + lpid = nested ? nested->shadow_lpid : kvm->arch.lpid; + + /* + * All the isync()s are overkill but trivially follow the ISA + * requirements. Some can likely be replaced with justification + * comment for why they are not needed. + */ + isync(); + mtspr(SPRN_LPID, lpid); + isync(); + mtspr(SPRN_LPCR, lpcr); + isync(); + mtspr(SPRN_PID, vcpu->arch.pid); + isync(); + + /* TLBIEL must have LPIDR set, so set guest LPID before flushing. */ + kvmppc_check_need_tlb_flush(kvm, vc->pcpu, nested); +} + +static void switch_mmu_to_host_radix(struct kvm *kvm, u32 pid) +{ + isync(); + mtspr(SPRN_PID, pid); + isync(); + mtspr(SPRN_LPID, kvm->arch.host_lpid); + isync(); + mtspr(SPRN_LPCR, kvm->arch.host_lpcr); + isync(); +} + /* * Load up hypervisor-mode registers on P9. */ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr) { + struct kvm *kvm = vcpu->kvm; struct kvmppc_vcore *vc = vcpu->arch.vcore; s64 hdec; u64 tb, purr, spurr; @@ -3535,7 +3572,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit, } mtspr(SPRN_CIABR, vcpu->arch.ciabr); mtspr(SPRN_IC, vcpu->arch.ic); - mtspr(SPRN_PID, vcpu->arch.pid); mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC | (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG)); @@ -3549,8 +3585,7 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit, mtspr(SPRN_AMOR, ~0UL); - mtspr(SPRN_LPCR, lpcr); - isync(); + switch_mmu_to_guest_radix(kvm, vcpu, lpcr); /* * P9 suppresses the HDEC exception when LPCR[HDICE] = 0, @@ -3593,7 +3628,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit, mtspr(SPRN_DAWR1, host_dawr1); mtspr(SPRN_DAWRX1, host_dawrx1); } - mtspr(SPRN_PID, host_pidr); /* * Since this is radix, do a eieio; tlbsync; ptesync sequence in @@ -3608,9 +3642,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit, if (cpu_has_feature(CPU_FTR_ARCH_31)) asm volatile(PPC_CP_ABORT); - mtspr(SPRN_LPID, vcpu->kvm->arch.host_lpid); /* restore host LPID */ - isync(); - vc->dpdes = mfspr(SPRN_DPDES); vc->vtb = mfspr(SPRN_VTB); mtspr(SPRN_DPDES, 0); @@ -3627,7 +3658,8 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit, } mtspr(SPRN_HDEC, 0x7fffffff); - mtspr(SPRN_LPCR, vcpu->kvm->arch.host_lpcr); + + switch_mmu_to_host_radix(kvm, host_pidr); return trap; } @@ -4181,7 +4213,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit, { struct kvm_run *run = vcpu->run; int trap, r, pcpu; - int srcu_idx, lpid; + int srcu_idx; struct kvmppc_vcore *vc; struct kvm *kvm = vcpu->kvm; struct kvm_nested_guest *nested = vcpu->arch.nested; @@ -4255,13 +4287,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit, vc->vcore_state = VCORE_RUNNING; trace_kvmppc_run_core(vc, 0); - if (cpu_has_feature(CPU_FTR_HVMODE)) { - lpid = nested ? nested->shadow_lpid : kvm->arch.lpid; - mtspr(SPRN_LPID, lpid); - isync(); - kvmppc_check_need_tlb_flush(kvm, pcpu, nested); - } - guest_enter_irqoff(); srcu_idx = srcu_read_lock(&kvm->srcu); @@ -4280,11 +4305,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit, srcu_read_unlock(&kvm->srcu, srcu_idx); - if (cpu_has_feature(CPU_FTR_HVMODE)) { - mtspr(SPRN_LPID, kvm->arch.host_lpid); - isync(); - } - set_irq_happened(trap); kvmppc_set_host_core(pcpu);