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author | Cornelia Huck <cornelia.huck@de.ibm.com> | 2012-12-20 15:32:12 +0100 |
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committer | Marcelo Tosatti <mtosatti@redhat.com> | 2013-01-07 19:53:43 -0200 |
commit | fa6b7fe9928d50444c29b29c8563746c6b0c6299 (patch) | |
tree | 0be284cf322eb82eefdb3df2743740e5578ba5c4 /arch/s390/kvm/priv.c | |
parent | d6712df95bcfea597fc3ea2405ec13e8b69a7b8c (diff) | |
download | op-kernel-dev-fa6b7fe9928d50444c29b29c8563746c6b0c6299.zip op-kernel-dev-fa6b7fe9928d50444c29b29c8563746c6b0c6299.tar.gz |
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 <mtosatti@redhat.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/s390/kvm/priv.c')
-rw-r--r-- | arch/s390/kvm/priv.c | 91 |
1 files changed, 87 insertions, 4 deletions
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index 8ad776f..0ef9894 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; |