From f3c99f97a3cda284418af6e242e06b351b83f647 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Mon, 8 Oct 2018 16:31:12 +1100 Subject: KVM: PPC: Book3S HV: Don't access HFSCR, LPIDR or LPCR when running nested When running as a nested hypervisor, this avoids reading hypervisor privileged registers (specifically HFSCR, LPIDR and LPCR) at startup; instead reasonable default values are used. This also avoids writing LPIDR in the single-vcpu entry/exit path. Also, this removes the check for CPU_FTR_HVMODE in kvmppc_mmu_hv_init() since its only caller already checks this. Reviewed-by: David Gibson Signed-off-by: Paul Mackerras Signed-off-by: Michael Ellerman --- arch/powerpc/kvm/book3s_hv.c | 33 +++++++++++++++++++++------------ 1 file changed, 21 insertions(+), 12 deletions(-) (limited to 'arch/powerpc/kvm/book3s_hv.c') diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index f8c14e86a4ab..c90deb5a5219 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -2174,15 +2174,18 @@ static struct kvm_vcpu *kvmppc_core_vcpu_create_hv(struct kvm *kvm, * Set the default HFSCR for the guest from the host value. * This value is only used on POWER9. * On POWER9, we want to virtualize the doorbell facility, so we - * turn off the HFSCR bit, which causes those instructions to trap. + * don't set the HFSCR_MSGP bit, and that causes those instructions + * to trap and then we emulate them. */ - vcpu->arch.hfscr = mfspr(SPRN_HFSCR); - if (cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) + vcpu->arch.hfscr = HFSCR_TAR | HFSCR_EBB | HFSCR_PM | HFSCR_BHRB | + HFSCR_DSCR | HFSCR_VECVSX | HFSCR_FP; + if (cpu_has_feature(CPU_FTR_HVMODE)) { + vcpu->arch.hfscr &= mfspr(SPRN_HFSCR); + if (cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) + vcpu->arch.hfscr |= HFSCR_TM; + } + if (cpu_has_feature(CPU_FTR_TM_COMP)) vcpu->arch.hfscr |= HFSCR_TM; - else if (!cpu_has_feature(CPU_FTR_TM_COMP)) - vcpu->arch.hfscr &= ~HFSCR_TM; - if (cpu_has_feature(CPU_FTR_ARCH_300)) - vcpu->arch.hfscr &= ~HFSCR_MSGP; kvmppc_mmu_book3s_hv_init(vcpu); @@ -4006,8 +4009,10 @@ int kvmhv_run_single_vcpu(struct kvm_run *kvm_run, srcu_read_unlock(&kvm->srcu, srcu_idx); - mtspr(SPRN_LPID, kvm->arch.host_lpid); - isync(); + if (cpu_has_feature(CPU_FTR_HVMODE)) { + mtspr(SPRN_LPID, kvm->arch.host_lpid); + isync(); + } trace_hardirqs_off(); set_irq_happened(trap); @@ -4634,9 +4639,13 @@ static int kvmppc_core_init_vm_hv(struct kvm *kvm) kvm->arch.host_sdr1 = mfspr(SPRN_SDR1); /* Init LPCR for virtual RMA mode */ - kvm->arch.host_lpid = mfspr(SPRN_LPID); - kvm->arch.host_lpcr = lpcr = mfspr(SPRN_LPCR); - lpcr &= LPCR_PECE | LPCR_LPES; + if (cpu_has_feature(CPU_FTR_HVMODE)) { + kvm->arch.host_lpid = mfspr(SPRN_LPID); + kvm->arch.host_lpcr = lpcr = mfspr(SPRN_LPCR); + lpcr &= LPCR_PECE | LPCR_LPES; + } else { + lpcr = 0; + } lpcr |= (4UL << LPCR_DPFD_SH) | LPCR_HDICE | LPCR_VPM0 | LPCR_VPM1; kvm->arch.vrma_slb_v = SLB_VSID_B_1T | -- cgit v1.2.1