| Message ID | 1492769385-237420-5-git-send-email-borntraeger@de.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
> diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c > index 025b1f2..4719ecb 100644 > --- a/arch/s390/kvm/vsie.c > +++ b/arch/s390/kvm/vsie.c > @@ -117,6 +117,8 @@ static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) > newflags |= cpuflags & CPUSTAT_SM; > if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IBS)) > newflags |= cpuflags & CPUSTAT_IBS; > + if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_KSS)) > + newflags |= cpuflags & CPUSTAT_KSS; > > atomic_set(&scb_s->cpuflags, newflags); > return 0; > @@ -289,7 +291,9 @@ static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) > * bits. Therefore we cannot provide interpretation and would later > * have to provide own emulation handlers. > */ > - scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE; > + if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_KSS)) > + scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE; > + What would actually happen, if ICTL_ISKE | ICTL_SSKE | ICTL_RRBE remain set? I assume KSS will dominate? Or are there any validity interceptions defined for this?
On 04/21/2017 02:15 PM, David Hildenbrand wrote: > >> diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c >> index 025b1f2..4719ecb 100644 >> --- a/arch/s390/kvm/vsie.c >> +++ b/arch/s390/kvm/vsie.c >> @@ -117,6 +117,8 @@ static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) >> newflags |= cpuflags & CPUSTAT_SM; >> if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IBS)) >> newflags |= cpuflags & CPUSTAT_IBS; >> + if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_KSS)) >> + newflags |= cpuflags & CPUSTAT_KSS; >> >> atomic_set(&scb_s->cpuflags, newflags); >> return 0; >> @@ -289,7 +291,9 @@ static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) >> * bits. Therefore we cannot provide interpretation and would later >> * have to provide own emulation handlers. >> */ >> - scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE; >> + if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_KSS)) >> + scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE; >> + > What would actually happen, if ICTL_ISKE | ICTL_SSKE | ICTL_RRBE remain > set? I assume KSS will dominate? Or are there any validity interceptions > defined for this? While having the same priority, the ICTL would win in this case, which is not what we want. We would need to check for keyless in our storage key emulation and reinject a keyless intercept. By not enabling the ICTL if the nested guest runs keyless we can simply forward the keyless intercept.
On 21.04.2017 14:23, Christian Borntraeger wrote: > On 04/21/2017 02:15 PM, David Hildenbrand wrote: >> >>> diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c >>> index 025b1f2..4719ecb 100644 >>> --- a/arch/s390/kvm/vsie.c >>> +++ b/arch/s390/kvm/vsie.c >>> @@ -117,6 +117,8 @@ static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) >>> newflags |= cpuflags & CPUSTAT_SM; >>> if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IBS)) >>> newflags |= cpuflags & CPUSTAT_IBS; >>> + if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_KSS)) >>> + newflags |= cpuflags & CPUSTAT_KSS; >>> >>> atomic_set(&scb_s->cpuflags, newflags); >>> return 0; >>> @@ -289,7 +291,9 @@ static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) >>> * bits. Therefore we cannot provide interpretation and would later >>> * have to provide own emulation handlers. >>> */ >>> - scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE; >>> + if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_KSS)) >>> + scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE; >>> + >> What would actually happen, if ICTL_ISKE | ICTL_SSKE | ICTL_RRBE remain >> set? I assume KSS will dominate? Or are there any validity interceptions >> defined for this? > > While having the same priority, the ICTL would win in this case, which > is not what we want. We would need to check for keyless in our > storage key emulation and reinject a keyless intercept. > > By not enabling the ICTL if the nested guest runs keyless we can simply > forward the keyless intercept. > Thanks! Sounds and looks good to me :)
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index 552c319..426614a 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -122,6 +122,7 @@ struct esca_block { #define CPUSTAT_SLSR 0x00002000 #define CPUSTAT_ZARCH 0x00000800 #define CPUSTAT_MCDS 0x00000100 +#define CPUSTAT_KSS 0x00000200 #define CPUSTAT_SM 0x00000080 #define CPUSTAT_IBS 0x00000040 #define CPUSTAT_GED2 0x00000010 @@ -185,6 +186,7 @@ struct kvm_s390_sie_block { #define ICPT_OPEREXC 0x2C #define ICPT_PARTEXEC 0x38 #define ICPT_IOINST 0x40 +#define ICPT_KSS 0x5c __u8 icptcode; /* 0x0050 */ __u8 icptstatus; /* 0x0051 */ __u16 ihcpu; /* 0x0052 */ diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h index 2c9ad25..bf92679 100644 --- a/arch/s390/include/uapi/asm/kvm.h +++ b/arch/s390/include/uapi/asm/kvm.h @@ -119,6 +119,7 @@ struct kvm_s390_vm_cpu_machine { #define KVM_S390_VM_CPU_FEAT_CMMA 10 #define KVM_S390_VM_CPU_FEAT_PFMFI 11 #define KVM_S390_VM_CPU_FEAT_SIGPIF 12 +#define KVM_S390_VM_CPU_FEAT_KSS 13 struct kvm_s390_vm_cpu_feat { __u64 feat[16]; }; diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c index f5378f3..a4752bf 100644 --- a/arch/s390/kvm/intercept.c +++ b/arch/s390/kvm/intercept.c @@ -426,6 +426,9 @@ int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu) case ICPT_PARTEXEC: rc = handle_partial_execution(vcpu); break; + case ICPT_KSS: + rc = kvm_s390_skey_check_enable(vcpu); + break; default: return -EOPNOTSUPP; } diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 11b7d66..8771fef 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -300,6 +300,8 @@ static void kvm_s390_cpu_feat_init(void) allow_cpu_feat(KVM_S390_VM_CPU_FEAT_CEI); if (sclp.has_ibs) allow_cpu_feat(KVM_S390_VM_CPU_FEAT_IBS); + if (sclp.has_kss) + allow_cpu_feat(KVM_S390_VM_CPU_FEAT_KSS); /* * KVM_S390_VM_CPU_FEAT_SKEY: Wrong shadow of PTE.I bits will make * all skey handling functions read/set the skey from the PGSTE @@ -2034,7 +2036,11 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu) vcpu->arch.sie_block->sdnxo = ((unsigned long) &vcpu->run->s.regs.sdnx) | SDNXC; vcpu->arch.sie_block->riccbd = (unsigned long) &vcpu->run->s.regs.riccb; - vcpu->arch.sie_block->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE; + + if (sclp.has_kss) + atomic_or(CPUSTAT_KSS, &vcpu->arch.sie_block->cpuflags); + else + vcpu->arch.sie_block->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE; if (vcpu->kvm->arch.use_cmma) { rc = kvm_s390_vcpu_setup_cmma(vcpu); diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h index 455124f..55f5c84 100644 --- a/arch/s390/kvm/kvm-s390.h +++ b/arch/s390/kvm/kvm-s390.h @@ -254,6 +254,7 @@ int kvm_s390_handle_lpsw(struct kvm_vcpu *vcpu); int kvm_s390_handle_stctl(struct kvm_vcpu *vcpu); int kvm_s390_handle_lctl(struct kvm_vcpu *vcpu); int kvm_s390_handle_eb(struct kvm_vcpu *vcpu); +int kvm_s390_skey_check_enable(struct kvm_vcpu *vcpu); /* implemented in vsie.c */ int kvm_s390_handle_vsie(struct kvm_vcpu *vcpu); diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index 0ffe973..c03106c 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -198,18 +198,25 @@ static int handle_store_cpu_address(struct kvm_vcpu *vcpu) return 0; } -static int __skey_check_enable(struct kvm_vcpu *vcpu) +int kvm_s390_skey_check_enable(struct kvm_vcpu *vcpu) { int rc = 0; + struct kvm_s390_sie_block *sie_block = vcpu->arch.sie_block; trace_kvm_s390_skey_related_inst(vcpu); - if (!(vcpu->arch.sie_block->ictl & (ICTL_ISKE | ICTL_SSKE | ICTL_RRBE))) + if (!(sie_block->ictl & (ICTL_ISKE | ICTL_SSKE | ICTL_RRBE)) && + !(atomic_read(&sie_block->cpuflags) & CPUSTAT_KSS)) return rc; rc = s390_enable_skey(); VCPU_EVENT(vcpu, 3, "enabling storage keys for guest: %d", rc); - if (!rc) - vcpu->arch.sie_block->ictl &= ~(ICTL_ISKE | ICTL_SSKE | ICTL_RRBE); + if (!rc) { + if (atomic_read(&sie_block->cpuflags) & CPUSTAT_KSS) + atomic_andnot(CPUSTAT_KSS, &sie_block->cpuflags); + else + sie_block->ictl &= ~(ICTL_ISKE | ICTL_SSKE | + ICTL_RRBE); + } return rc; } @@ -218,7 +225,7 @@ static int try_handle_skey(struct kvm_vcpu *vcpu) int rc; vcpu->stat.instruction_storage_key++; - rc = __skey_check_enable(vcpu); + rc = kvm_s390_skey_check_enable(vcpu); if (rc) return rc; if (sclp.has_skey) { @@ -916,7 +923,7 @@ static int handle_pfmf(struct kvm_vcpu *vcpu) } if (vcpu->run->s.regs.gprs[reg1] & PFMF_SK) { - int rc = __skey_check_enable(vcpu); + int rc = kvm_s390_skey_check_enable(vcpu); if (rc) return rc; diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c index 025b1f2..4719ecb 100644 --- a/arch/s390/kvm/vsie.c +++ b/arch/s390/kvm/vsie.c @@ -117,6 +117,8 @@ static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) newflags |= cpuflags & CPUSTAT_SM; if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IBS)) newflags |= cpuflags & CPUSTAT_IBS; + if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_KSS)) + newflags |= cpuflags & CPUSTAT_KSS; atomic_set(&scb_s->cpuflags, newflags); return 0; @@ -289,7 +291,9 @@ static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) * bits. Therefore we cannot provide interpretation and would later * have to provide own emulation handlers. */ - scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE; + if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_KSS)) + scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE; + scb_s->icpua = scb_o->icpua; if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_SM))