On Fri, Sep 21, 2018 at 08:01:59PM +1000, Paul Mackerras wrote:
> 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.
>
> Signed-off-by: Paul Mackerras <paulus@xxxxxxxxxx>
Reviewed-by: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>
> ---
> arch/powerpc/kvm/book3s_64_mmu_hv.c | 7 +++----
> arch/powerpc/kvm/book3s_hv.c | 33 +++++++++++++++++++++------------
> 2 files changed, 24 insertions(+), 16 deletions(-)
>
> diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
> index 68e14af..c615617 100644
> --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
> +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
> @@ -268,14 +268,13 @@ int kvmppc_mmu_hv_init(void)
> {
> unsigned long host_lpid, rsvd_lpid;
>
> - if (!cpu_has_feature(CPU_FTR_HVMODE))
> - return -EINVAL;
> -
> if (!mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE))
> return -EINVAL;
>
> /* POWER7 has 10-bit LPIDs (12-bit in POWER8) */
> - host_lpid = mfspr(SPRN_LPID);
> + host_lpid = 0;
> + if (cpu_has_feature(CPU_FTR_HVMODE))
> + host_lpid = mfspr(SPRN_LPID);
> rsvd_lpid = LPID_RSVD;
>
> kvmppc_init_lpid(rsvd_lpid + 1);
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index 2b66f3f..71ed0cd 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -2191,15 +2191,18 @@ 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);
>
> @@ -4004,8 +4007,10 @@ int kvmhv_run_single_vcpu(struct kvm_run *kvm_run,
>
> srcu_read_unlock(&vc->kvm->srcu, srcu_idx);
>
> - mtspr(SPRN_LPID, vc->kvm->arch.host_lpid);
> - isync();
> + if (cpu_has_feature(CPU_FTR_HVMODE)) {
> + mtspr(SPRN_LPID, vc->kvm->arch.host_lpid);
> + isync();
> + }
>
> trace_hardirqs_off();
> set_irq_happened(trap);
> @@ -4624,9 +4629,13 @@ 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 |
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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