I abandon this patch, I will send a v2 with a minor fix for 85xx. Mike > -----Original Message----- > From: Mihai Caraman [mailto:mihai.caraman@xxxxxxxxxxxxx] > Sent: Friday, August 29, 2014 8:04 PM > To: kvm-ppc@xxxxxxxxxxxxxxx > Cc: kvm@xxxxxxxxxxxxxxx; Caraman Mihai Claudiu-B02008 > Subject: [PATCH 1/2] KVM: PPC: e500mc: Add support for single threaded > vcpus on e6500 core > > ePAPR represents hardware threads as cpu node properties in device tree. > So with existing QEMU, hardware threads are simply exposed as vcpus with > one hardware thread. > > The e6500 core shares TLBs between hardware threads. Without tlb write > conditional instruction, the Linux kernel uses per core mechanisms to > protect against duplicate TLB entries. > > The guest is unable to detect real siblings threads, so it can't use a > TLB protection mechanism. An alternative solution is to use the > hypervisor > to allocate different lpids to guest's vcpus running simultaneous on real > siblings threads. On systems with two threads per core this patch halves > the size of the lpid pool that the allocator sees and use two lpids per > VM. > Use even numbers to speedup vcpu lpid computation with consecutive lpids > per VM: vm1 will use lpids 2 and 3, vm2 lpids 4 and 5, and so on. > > Signed-off-by: Mihai Caraman <mihai.caraman@xxxxxxxxxxxxx> > --- > arch/powerpc/include/asm/kvm_booke.h | 5 +++- > arch/powerpc/kvm/e500.h | 20 ++++++++++++++++ > arch/powerpc/kvm/e500_mmu_host.c | 16 ++++++------- > arch/powerpc/kvm/e500mc.c | 46 ++++++++++++++++++++++++++---- > ------ > 4 files changed, 64 insertions(+), 23 deletions(-) > > diff --git a/arch/powerpc/include/asm/kvm_booke.h > b/arch/powerpc/include/asm/kvm_booke.h > index f7aa5cc..630134d 100644 > --- a/arch/powerpc/include/asm/kvm_booke.h > +++ b/arch/powerpc/include/asm/kvm_booke.h > @@ -23,7 +23,10 @@ > #include <linux/types.h> > #include <linux/kvm_host.h> > > -/* LPIDs we support with this build -- runtime limit may be lower */ > +/* > + * Number of available lpids. Only the low-order 6 bits of LPID rgister > are > + * implemented on e500mc+ cores. > + */ > #define KVMPPC_NR_LPIDS 64 > > #define KVMPPC_INST_EHPRIV 0x7c00021c > diff --git a/arch/powerpc/kvm/e500.h b/arch/powerpc/kvm/e500.h > index a326178..7b74453 100644 > --- a/arch/powerpc/kvm/e500.h > +++ b/arch/powerpc/kvm/e500.h > @@ -22,6 +22,7 @@ > #include <linux/kvm_host.h> > #include <asm/mmu-book3e.h> > #include <asm/tlb.h> > +#include <asm/cputhreads.h> > > enum vcpu_ftr { > VCPU_FTR_MMU_V2 > @@ -289,6 +290,25 @@ void kvmppc_e500_tlbil_all(struct kvmppc_vcpu_e500 > *vcpu_e500); > #define kvmppc_e500_get_tlb_stid(vcpu, gtlbe) get_tlb_tid(gtlbe) > #define get_tlbmiss_tid(vcpu) get_cur_pid(vcpu) > #define get_tlb_sts(gtlbe) (gtlbe->mas1 & MAS1_TS) > + > +/* > + * This functios should be called with preemtion disabled > + * and the returned value is valid only in that context > + */ > +static inline int get_thread_specific_lpid(int vm_lpid) > +{ > + int vcpu_lpid = vm_lpid; > + > + if (threads_per_core == 2) > + vcpu_lpid |= smp_processor_id() & 1; > + > + return vcpu_lpid; > +} > + > +static inline int get_lpid(struct kvm_vcpu *vcpu) > +{ > + return get_thread_specific_lpid(vcpu->kvm->arch.lpid); > +} > #else > unsigned int kvmppc_e500_get_tlb_stid(struct kvm_vcpu *vcpu, > struct kvm_book3e_206_tlb_entry *gtlbe); > diff --git a/arch/powerpc/kvm/e500_mmu_host.c > b/arch/powerpc/kvm/e500_mmu_host.c > index 08f14bb..5759608 100644 > --- a/arch/powerpc/kvm/e500_mmu_host.c > +++ b/arch/powerpc/kvm/e500_mmu_host.c > @@ -69,7 +69,8 @@ static inline u32 e500_shadow_mas3_attrib(u32 mas3, int > usermode) > * writing shadow tlb entry to host TLB > */ > static inline void __write_host_tlbe(struct kvm_book3e_206_tlb_entry > *stlbe, > - uint32_t mas0) > + uint32_t mas0, > + uint32_t lpid) > { > unsigned long flags; > > @@ -80,7 +81,7 @@ static inline void __write_host_tlbe(struct > kvm_book3e_206_tlb_entry *stlbe, > mtspr(SPRN_MAS3, (u32)stlbe->mas7_3); > mtspr(SPRN_MAS7, (u32)(stlbe->mas7_3 >> 32)); > #ifdef CONFIG_KVM_BOOKE_HV > - mtspr(SPRN_MAS8, stlbe->mas8); > + mtspr(SPRN_MAS8, MAS8_TGS | get_thread_specific_lpid(lpid)); > #endif > asm volatile("isync; tlbwe" : : : "memory"); > > @@ -129,11 +130,12 @@ static inline void write_host_tlbe(struct > kvmppc_vcpu_e500 *vcpu_e500, > > if (tlbsel == 0) { > mas0 = get_host_mas0(stlbe->mas2); > - __write_host_tlbe(stlbe, mas0); > + __write_host_tlbe(stlbe, mas0, vcpu_e500->vcpu.kvm- > >arch.lpid); > } else { > __write_host_tlbe(stlbe, > MAS0_TLBSEL(1) | > - MAS0_ESEL(to_htlb1_esel(sesel))); > + MAS0_ESEL(to_htlb1_esel(sesel)), > + vcpu_e500->vcpu.kvm->arch.lpid); > } > } > > @@ -317,10 +319,6 @@ static void kvmppc_e500_setup_stlbe( > stlbe->mas2 = (gvaddr & MAS2_EPN) | (ref->flags & > E500_TLB_MAS2_ATTR); > stlbe->mas7_3 = ((u64)pfn << PAGE_SHIFT) | > e500_shadow_mas3_attrib(gtlbe->mas7_3, pr); > - > -#ifdef CONFIG_KVM_BOOKE_HV > - stlbe->mas8 = MAS8_TGS | vcpu->kvm->arch.lpid; > -#endif > } > > static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 > *vcpu_e500, > @@ -633,7 +631,7 @@ int kvmppc_load_last_inst(struct kvm_vcpu *vcpu, enum > instruction_type type, > > local_irq_save(flags); > mtspr(SPRN_MAS6, (vcpu->arch.pid << MAS6_SPID_SHIFT) | addr_space); > - mtspr(SPRN_MAS5, MAS5_SGS | vcpu->kvm->arch.lpid); > + mtspr(SPRN_MAS5, MAS5_SGS | get_lpid(vcpu)); > asm volatile("tlbsx 0, %[geaddr]\n" : : > [geaddr] "r" (geaddr)); > mtspr(SPRN_MAS5, 0); > diff --git a/arch/powerpc/kvm/e500mc.c b/arch/powerpc/kvm/e500mc.c > index 4549349..bf8f99f 100644 > --- a/arch/powerpc/kvm/e500mc.c > +++ b/arch/powerpc/kvm/e500mc.c > @@ -48,10 +48,11 @@ void kvmppc_set_pending_interrupt(struct kvm_vcpu > *vcpu, enum int_class type) > return; > } > > - > - tag = PPC_DBELL_LPID(vcpu->kvm->arch.lpid) | vcpu->vcpu_id; > + preempt_disable(); > + tag = PPC_DBELL_LPID(get_lpid(vcpu)) | vcpu->vcpu_id; > mb(); > ppc_msgsnd(dbell_type, 0, tag); > + preempt_enable(); > } > > /* gtlbe must not be mapped by more than one host tlb entry */ > @@ -60,12 +61,11 @@ void kvmppc_e500_tlbil_one(struct kvmppc_vcpu_e500 > *vcpu_e500, > { > unsigned int tid, ts; > gva_t eaddr; > - u32 val, lpid; > + u32 val; > unsigned long flags; > > ts = get_tlb_ts(gtlbe); > tid = get_tlb_tid(gtlbe); > - lpid = vcpu_e500->vcpu.kvm->arch.lpid; > > /* We search the host TLB to invalidate its shadow TLB entry */ > val = (tid << 16) | ts; > @@ -74,7 +74,7 @@ void kvmppc_e500_tlbil_one(struct kvmppc_vcpu_e500 > *vcpu_e500, > local_irq_save(flags); > > mtspr(SPRN_MAS6, val); > - mtspr(SPRN_MAS5, MAS5_SGS | lpid); > + mtspr(SPRN_MAS5, MAS5_SGS | get_lpid(&vcpu_e500->vcpu)); > > asm volatile("tlbsx 0, %[eaddr]\n" : : [eaddr] "r" (eaddr)); > val = mfspr(SPRN_MAS1); > @@ -95,7 +95,7 @@ void kvmppc_e500_tlbil_all(struct kvmppc_vcpu_e500 > *vcpu_e500) > unsigned long flags; > > local_irq_save(flags); > - mtspr(SPRN_MAS5, MAS5_SGS | vcpu_e500->vcpu.kvm->arch.lpid); > + mtspr(SPRN_MAS5, MAS5_SGS | get_lpid(&vcpu_e500->vcpu)); > asm volatile("tlbilxlpid"); > mtspr(SPRN_MAS5, 0); > local_irq_restore(flags); > @@ -110,6 +110,7 @@ void kvmppc_mmu_msr_notify(struct kvm_vcpu *vcpu, u32 > old_msr) > { > } > > +/* We use two lpids per VM */ > static DEFINE_PER_CPU(struct kvm_vcpu *[KVMPPC_NR_LPIDS], > last_vcpu_of_lpid); > > static void kvmppc_core_vcpu_load_e500mc(struct kvm_vcpu *vcpu, int cpu) > @@ -118,10 +119,12 @@ static void kvmppc_core_vcpu_load_e500mc(struct > kvm_vcpu *vcpu, int cpu) > > kvmppc_booke_vcpu_load(vcpu, cpu); > > - mtspr(SPRN_LPID, vcpu->kvm->arch.lpid); > + mtspr(SPRN_LPID, get_lpid(vcpu)); > mtspr(SPRN_EPCR, vcpu->arch.shadow_epcr); > mtspr(SPRN_GPIR, vcpu->vcpu_id); > mtspr(SPRN_MSRP, vcpu->arch.shadow_msrp); > + vcpu->arch.eplc = EPC_EGS | (get_lpid(vcpu) << EPC_ELPID_SHIFT); > + vcpu->arch.epsc = vcpu->arch.eplc; > mtspr(SPRN_EPLC, vcpu->arch.eplc); > mtspr(SPRN_EPSC, vcpu->arch.epsc); > > @@ -141,9 +144,9 @@ static void kvmppc_core_vcpu_load_e500mc(struct > kvm_vcpu *vcpu, int cpu) > mtspr(SPRN_GESR, vcpu->arch.shared->esr); > > if (vcpu->arch.oldpir != mfspr(SPRN_PIR) || > - __get_cpu_var(last_vcpu_of_lpid)[vcpu->kvm->arch.lpid] != vcpu) > { > + __get_cpu_var(last_vcpu_of_lpid)[get_lpid(vcpu)] != vcpu) { > kvmppc_e500_tlbil_all(vcpu_e500); > - __get_cpu_var(last_vcpu_of_lpid)[vcpu->kvm->arch.lpid] = > vcpu; > + __get_cpu_var(last_vcpu_of_lpid)[get_lpid(vcpu)] = vcpu; > } > } > > @@ -193,8 +196,6 @@ int kvmppc_core_vcpu_setup(struct kvm_vcpu *vcpu) > vcpu->arch.shadow_epcr |= SPRN_EPCR_ICM; > #endif > vcpu->arch.shadow_msrp = MSRP_UCLEP | MSRP_PMMP; > - vcpu->arch.eplc = EPC_EGS | (vcpu->kvm->arch.lpid << > EPC_ELPID_SHIFT); > - vcpu->arch.epsc = vcpu->arch.eplc; > > vcpu->arch.pvr = mfspr(SPRN_PVR); > vcpu_e500->svr = mfspr(SPRN_SVR); > @@ -354,13 +355,26 @@ static int kvmppc_core_init_vm_e500mc(struct kvm > *kvm) > if (lpid < 0) > return lpid; > > + /* > + * Use two lpids per VM on cores with two threads like e6500. Use > + * even numbers to speedup vcpu lpid computation with consecutive > lpids > + * per VM. vm1 will use lpids 2 and 3, vm2 lpids 4 and 5, and so > on. > + */ > + if (threads_per_core == 2) > + lpid <<= 1; > + > kvm->arch.lpid = lpid; > return 0; > } > > static void kvmppc_core_destroy_vm_e500mc(struct kvm *kvm) > { > - kvmppc_free_lpid(kvm->arch.lpid); > + int lpid = kvm->arch.lpid; > + > + if (threads_per_core == 2) > + lpid >>= 1; > + > + kvmppc_free_lpid(lpid); > } > > static struct kvmppc_ops kvm_ops_e500mc = { > @@ -388,7 +402,13 @@ static int __init kvmppc_e500mc_init(void) > if (r) > goto err_out; > > - kvmppc_init_lpid(64); > + /* > + * Use two lpids per VM on dual threaded processors like e6500 > + * to workarround the lack of tlb write conditional instruction. > + * Expose half the number of available hardware lpids to the lpid > + * allocator. > + */ > + kvmppc_init_lpid(KVMPPC_NR_LPIDS/threads_per_core); > kvmppc_claim_lpid(0); /* host */ > > r = kvm_init(NULL, sizeof(struct kvmppc_vcpu_e500), 0, > THIS_MODULE); > -- > 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
