From: Janosch Frank Date: Fri, 20 Jul 2018 12:51:21 +0000 (+0100) Subject: KVM: s390: Beautify skey enable check X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=57cb198cfdd2e666a8dc2b7e5df6d2708191eddb;p=linux.git KVM: s390: Beautify skey enable check Let's introduce an explicit check if skeys have already been enabled for the vcpu, so we don't have to check the mm context if we don't have the storage key facility. This lets us check for enablement without having to take the mm semaphore and thus speedup skey emulation. Signed-off-by: Janosch Frank Reviewed-by: David Hildenbrand Acked-by: Farhan Ali Signed-off-by: Christian Borntraeger --- diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index 1a7b6834797ec..29c940bf8506a 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -656,6 +656,7 @@ struct kvm_vcpu_arch { seqcount_t cputm_seqcount; __u64 cputm_start; bool gs_enabled; + bool skey_enabled; }; struct kvm_vm_stat { diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index c623b6f1dd4e8..63285b14ff312 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -205,13 +205,10 @@ static int handle_store_cpu_address(struct kvm_vcpu *vcpu) int kvm_s390_skey_check_enable(struct kvm_vcpu *vcpu) { int rc; - struct kvm_s390_sie_block *sie_block = vcpu->arch.sie_block; trace_kvm_s390_skey_related_inst(vcpu); /* Already enabled? */ - if (vcpu->kvm->arch.use_skf && - !(sie_block->ictl & (ICTL_ISKE | ICTL_SSKE | ICTL_RRBE)) && - !kvm_s390_test_cpuflags(vcpu, CPUSTAT_KSS)) + if (vcpu->arch.skey_enabled) return 0; rc = s390_enable_skey(); @@ -222,9 +219,10 @@ int kvm_s390_skey_check_enable(struct kvm_vcpu *vcpu) if (kvm_s390_test_cpuflags(vcpu, CPUSTAT_KSS)) kvm_s390_clear_cpuflags(vcpu, CPUSTAT_KSS); if (!vcpu->kvm->arch.use_skf) - sie_block->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE; + vcpu->arch.sie_block->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE; else - sie_block->ictl &= ~(ICTL_ISKE | ICTL_SSKE | ICTL_RRBE); + vcpu->arch.sie_block->ictl &= ~(ICTL_ISKE | ICTL_SSKE | ICTL_RRBE); + vcpu->arch.skey_enabled = true; return 0; }