From 6502a34cfd6695929086187f63fe670cc3050e68 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Tue, 21 Jun 2016 14:19:51 +0200 Subject: KVM: s390: allow user space to handle instr 0x0000 We will use illegal instruction 0x0000 for handling 2 byte sw breakpoints from user space. As it can be enabled dynamically via a capability, let's move setting of ICTL_OPEREXC to the post creation step, so we avoid any races when enabling that capability just while adding new cpus. Acked-by: Janosch Frank Reviewed-by: Cornelia Huck Signed-off-by: David Hildenbrand Signed-off-by: Christian Borntraeger --- arch/s390/kvm/intercept.c | 3 +++ arch/s390/kvm/kvm-s390.c | 26 ++++++++++++++++++++++++-- 2 files changed, 27 insertions(+), 2 deletions(-) (limited to 'arch/s390/kvm') diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c index 850be47c4cc9..7a2f1551bc39 100644 --- a/arch/s390/kvm/intercept.c +++ b/arch/s390/kvm/intercept.c @@ -359,6 +359,9 @@ static int handle_operexc(struct kvm_vcpu *vcpu) test_kvm_facility(vcpu->kvm, 74)) return handle_sthyi(vcpu); + if (vcpu->arch.sie_block->ipa == 0 && vcpu->kvm->arch.user_instr0) + return -EOPNOTSUPP; + return kvm_s390_inject_program_int(vcpu, PGM_OPERATION); } diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index d42428c11794..63ac7c1641a7 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -364,6 +364,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_S390_USER_STSI: case KVM_CAP_S390_SKEYS: case KVM_CAP_S390_IRQ_STATE: + case KVM_CAP_S390_USER_INSTR0: r = 1; break; case KVM_CAP_S390_MEM_OP: @@ -456,6 +457,16 @@ out: return r; } +static void icpt_operexc_on_all_vcpus(struct kvm *kvm) +{ + unsigned int i; + struct kvm_vcpu *vcpu; + + kvm_for_each_vcpu(i, vcpu, kvm) { + kvm_s390_sync_request(KVM_REQ_ICPT_OPEREXC, vcpu); + } +} + static int kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) { int r; @@ -507,6 +518,12 @@ static int kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) kvm->arch.user_stsi = 1; r = 0; break; + case KVM_CAP_S390_USER_INSTR0: + VM_EVENT(kvm, 3, "%s", "ENABLE: CAP_S390_USER_INSTR0"); + kvm->arch.user_instr0 = 1; + icpt_operexc_on_all_vcpus(kvm); + r = 0; + break; default: r = -EINVAL; break; @@ -1836,6 +1853,8 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu) vcpu->arch.gmap = vcpu->kvm->arch.gmap; sca_add_vcpu(vcpu); } + if (test_kvm_facility(vcpu->kvm, 74) || vcpu->kvm->arch.user_instr0) + vcpu->arch.sie_block->ictl |= ICTL_OPEREXC; /* make vcpu_load load the right gmap on the first trigger */ vcpu->arch.enabled_gmap = vcpu->arch.gmap; } @@ -1923,8 +1942,6 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu) } vcpu->arch.sie_block->riccbd = (unsigned long) &vcpu->run->s.regs.riccb; vcpu->arch.sie_block->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE; - if (test_kvm_facility(vcpu->kvm, 74)) - vcpu->arch.sie_block->ictl |= ICTL_OPEREXC; if (vcpu->kvm->arch.use_cmma) { rc = kvm_s390_vcpu_setup_cmma(vcpu); @@ -2369,6 +2386,11 @@ retry: goto retry; } + if (kvm_check_request(KVM_REQ_ICPT_OPEREXC, vcpu)) { + vcpu->arch.sie_block->ictl |= ICTL_OPEREXC; + goto retry; + } + /* nothing to do, just clear the request */ clear_bit(KVM_REQ_UNHALT, &vcpu->requests); -- cgit v1.2.3