From 57cb198cfdd2e666a8dc2b7e5df6d2708191eddb Mon Sep 17 00:00:00 2001 From: Janosch Frank Date: Fri, 20 Jul 2018 13:51:21 +0100 Subject: [PATCH] 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 --- arch/s390/include/asm/kvm_host.h | 1 + arch/s390/kvm/priv.c | 10 ++++------ 2 files changed, 5 insertions(+), 6 deletions(-) diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index 1a7b6834797e..29c940bf8506 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 c623b6f1dd4e..63285b14ff31 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; } -- 2.30.2