From fa6b7fe9928d50444c29b29c8563746c6b0c6299 Mon Sep 17 00:00:00 2001 From: Cornelia Huck Date: Thu, 20 Dec 2012 15:32:12 +0100 Subject: KVM: s390: Add support for channel I/O instructions. Add a new capability, KVM_CAP_S390_CSS_SUPPORT, which will pass intercepts for channel I/O instructions to userspace. Only I/O instructions interacting with I/O interrupts need to be handled in-kernel: - TEST PENDING INTERRUPTION (tpi) dequeues and stores pending interrupts entirely in-kernel. - TEST SUBCHANNEL (tsch) dequeues pending interrupts in-kernel and exits via KVM_EXIT_S390_TSCH to userspace for subchannel- related processing. Reviewed-by: Marcelo Tosatti Reviewed-by: Alexander Graf Signed-off-by: Cornelia Huck Signed-off-by: Marcelo Tosatti --- arch/s390/include/asm/kvm_host.h | 1 + arch/s390/kvm/intercept.c | 1 + arch/s390/kvm/interrupt.c | 37 ++++++++++++++++ arch/s390/kvm/kvm-s390.c | 12 ++++++ arch/s390/kvm/kvm-s390.h | 2 + arch/s390/kvm/priv.c | 91 ++++++++++++++++++++++++++++++++++++++-- arch/s390/kvm/trace-s390.h | 20 +++++++++ 7 files changed, 160 insertions(+), 4 deletions(-) (limited to 'arch/s390') diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index 29363d155cd5..16bd5d169cdb 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -262,6 +262,7 @@ struct kvm_arch{ debug_info_t *dbf; struct kvm_s390_float_interrupt float_int; struct gmap *gmap; + int css_support; }; extern int sie64a(struct kvm_s390_sie_block *, u64 *); diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c index 71af87dbb42c..f26ff1e31bdb 100644 --- a/arch/s390/kvm/intercept.c +++ b/arch/s390/kvm/intercept.c @@ -264,6 +264,7 @@ static const intercept_handler_t intercept_funcs[] = { [0x0C >> 2] = handle_instruction_and_prog, [0x10 >> 2] = handle_noop, [0x14 >> 2] = handle_noop, + [0x18 >> 2] = handle_noop, [0x1C >> 2] = kvm_s390_handle_wait, [0x20 >> 2] = handle_validity, [0x28 >> 2] = handle_stop, diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index b3b4748485ee..9a128357fd15 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -709,6 +709,43 @@ int kvm_s390_inject_program_int(struct kvm_vcpu *vcpu, u16 code) return 0; } +struct kvm_s390_interrupt_info *kvm_s390_get_io_int(struct kvm *kvm, + u64 cr6, u64 schid) +{ + struct kvm_s390_float_interrupt *fi; + struct kvm_s390_interrupt_info *inti, *iter; + + if ((!schid && !cr6) || (schid && cr6)) + return NULL; + mutex_lock(&kvm->lock); + fi = &kvm->arch.float_int; + spin_lock(&fi->lock); + inti = NULL; + list_for_each_entry(iter, &fi->list, list) { + if (!is_ioint(iter->type)) + continue; + if (cr6 && ((cr6 & iter->io.io_int_word) == 0)) + continue; + if (schid) { + if (((schid & 0x00000000ffff0000) >> 16) != + iter->io.subchannel_id) + continue; + if ((schid & 0x000000000000ffff) != + iter->io.subchannel_nr) + continue; + } + inti = iter; + break; + } + if (inti) + list_del_init(&inti->list); + if (list_empty(&fi->list)) + atomic_set(&fi->active, 0); + spin_unlock(&fi->lock); + mutex_unlock(&kvm->lock); + return inti; +} + int kvm_s390_inject_vm(struct kvm *kvm, struct kvm_s390_interrupt *s390int) { diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 5ff26033825c..5b01f0953900 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -141,6 +141,7 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_SYNC_REGS: case KVM_CAP_ONE_REG: case KVM_CAP_ENABLE_CAP: + case KVM_CAP_S390_CSS_SUPPORT: r = 1; break; case KVM_CAP_NR_VCPUS: @@ -235,6 +236,9 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) if (!kvm->arch.gmap) goto out_nogmap; } + + kvm->arch.css_support = 0; + return 0; out_nogmap: debug_unregister(kvm->arch.dbf); @@ -658,6 +662,7 @@ rerun_vcpu: case KVM_EXIT_INTR: case KVM_EXIT_S390_RESET: case KVM_EXIT_S390_UCONTROL: + case KVM_EXIT_S390_TSCH: break; default: BUG(); @@ -818,6 +823,13 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu, return -EINVAL; switch (cap->cap) { + case KVM_CAP_S390_CSS_SUPPORT: + if (!vcpu->kvm->arch.css_support) { + vcpu->kvm->arch.css_support = 1; + trace_kvm_s390_enable_css(vcpu->kvm); + } + r = 0; + break; default: r = -EINVAL; break; diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h index 211b340385a7..3e05deff21b6 100644 --- a/arch/s390/kvm/kvm-s390.h +++ b/arch/s390/kvm/kvm-s390.h @@ -113,6 +113,8 @@ int kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu, struct kvm_s390_interrupt *s390int); int kvm_s390_inject_program_int(struct kvm_vcpu *vcpu, u16 code); int kvm_s390_inject_sigp_stop(struct kvm_vcpu *vcpu, int action); +struct kvm_s390_interrupt_info *kvm_s390_get_io_int(struct kvm *kvm, + u64 cr6, u64 schid); /* implemented in priv.c */ int kvm_s390_handle_b2(struct kvm_vcpu *vcpu); diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index 8ad776f87856..0ef9894606e5 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -127,15 +127,98 @@ static int handle_skey(struct kvm_vcpu *vcpu) return 0; } -static int handle_io_inst(struct kvm_vcpu *vcpu) +static int handle_tpi(struct kvm_vcpu *vcpu) { - VCPU_EVENT(vcpu, 4, "%s", "I/O instruction"); - /* condition code 3 */ + u64 addr; + struct kvm_s390_interrupt_info *inti; + int cc; + + addr = kvm_s390_get_base_disp_s(vcpu); + + inti = kvm_s390_get_io_int(vcpu->kvm, vcpu->run->s.regs.crs[6], 0); + if (inti) { + if (addr) { + /* + * Store the two-word I/O interruption code into the + * provided area. + */ + put_guest_u16(vcpu, addr, inti->io.subchannel_id); + put_guest_u16(vcpu, addr + 2, inti->io.subchannel_nr); + put_guest_u32(vcpu, addr + 4, inti->io.io_int_parm); + } else { + /* + * Store the three-word I/O interruption code into + * the appropriate lowcore area. + */ + put_guest_u16(vcpu, 184, inti->io.subchannel_id); + put_guest_u16(vcpu, 186, inti->io.subchannel_nr); + put_guest_u32(vcpu, 188, inti->io.io_int_parm); + put_guest_u32(vcpu, 192, inti->io.io_int_word); + } + cc = 1; + } else + cc = 0; + kfree(inti); + /* Set condition code and we're done. */ vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44); - vcpu->arch.sie_block->gpsw.mask |= (3 & 3ul) << 44; + vcpu->arch.sie_block->gpsw.mask |= (cc & 3ul) << 44; return 0; } +static int handle_tsch(struct kvm_vcpu *vcpu) +{ + struct kvm_s390_interrupt_info *inti; + + inti = kvm_s390_get_io_int(vcpu->kvm, 0, + vcpu->run->s.regs.gprs[1]); + + /* + * Prepare exit to userspace. + * We indicate whether we dequeued a pending I/O interrupt + * so that userspace can re-inject it if the instruction gets + * a program check. While this may re-order the pending I/O + * interrupts, this is no problem since the priority is kept + * intact. + */ + vcpu->run->exit_reason = KVM_EXIT_S390_TSCH; + vcpu->run->s390_tsch.dequeued = !!inti; + if (inti) { + vcpu->run->s390_tsch.subchannel_id = inti->io.subchannel_id; + vcpu->run->s390_tsch.subchannel_nr = inti->io.subchannel_nr; + vcpu->run->s390_tsch.io_int_parm = inti->io.io_int_parm; + vcpu->run->s390_tsch.io_int_word = inti->io.io_int_word; + } + vcpu->run->s390_tsch.ipb = vcpu->arch.sie_block->ipb; + kfree(inti); + return -EREMOTE; +} + +static int handle_io_inst(struct kvm_vcpu *vcpu) +{ + VCPU_EVENT(vcpu, 4, "%s", "I/O instruction"); + + if (vcpu->kvm->arch.css_support) { + /* + * Most I/O instructions will be handled by userspace. + * Exceptions are tpi and the interrupt portion of tsch. + */ + if (vcpu->arch.sie_block->ipa == 0xb236) + return handle_tpi(vcpu); + if (vcpu->arch.sie_block->ipa == 0xb235) + return handle_tsch(vcpu); + /* Handle in userspace. */ + return -EOPNOTSUPP; + } else { + /* + * Set condition code 3 to stop the guest from issueing channel + * I/O instructions. + */ + vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44); + vcpu->arch.sie_block->gpsw.mask |= (3 & 3ul) << 44; + return 0; + } +} + static int handle_stfl(struct kvm_vcpu *vcpu) { unsigned int facility_list; diff --git a/arch/s390/kvm/trace-s390.h b/arch/s390/kvm/trace-s390.h index 95fbc1ab88dc..13f30f58a2df 100644 --- a/arch/s390/kvm/trace-s390.h +++ b/arch/s390/kvm/trace-s390.h @@ -204,6 +204,26 @@ TRACE_EVENT(kvm_s390_stop_request, ); +/* + * Trace point for enabling channel I/O instruction support. + */ +TRACE_EVENT(kvm_s390_enable_css, + TP_PROTO(void *kvm), + TP_ARGS(kvm), + + TP_STRUCT__entry( + __field(void *, kvm) + ), + + TP_fast_assign( + __entry->kvm = kvm; + ), + + TP_printk("enabling channel I/O support (kvm @ %p)\n", + __entry->kvm) + ); + + #endif /* _TRACE_KVMS390_H */ /* This part must be outside protection */ -- cgit v1.2.3