diff options
| author | Cornelia Huck <cornelia.huck@de.ibm.com> | 2012-12-20 15:32:12 +0100 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2013-01-07 19:53:43 -0200 |
| commit | fa6b7fe9928d50444c29b29c8563746c6b0c6299 (patch) | |
| tree | 0be284cf322eb82eefdb3df2743740e5578ba5c4 /Documentation/virtual | |
| parent | d6712df95bcfea597fc3ea2405ec13e8b69a7b8c (diff) | |
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 'Documentation/virtual')
| -rw-r--r-- | Documentation/virtual/kvm/api.txt | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 73bd159c5559..f2d6391178b9 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2350,6 +2350,22 @@ The possible hypercalls are defined in the Power Architecture Platform Requirements (PAPR) document available from www.power.org (free developer registration required to access it). + /* KVM_EXIT_S390_TSCH */ + struct { + __u16 subchannel_id; + __u16 subchannel_nr; + __u32 io_int_parm; + __u32 io_int_word; + __u32 ipb; + __u8 dequeued; + } s390_tsch; + +s390 specific. This exit occurs when KVM_CAP_S390_CSS_SUPPORT has been enabled +and TEST SUBCHANNEL was intercepted. If dequeued is set, a pending I/O +interrupt for the target subchannel has been dequeued and subchannel_id, +subchannel_nr, io_int_parm and io_int_word contain the parameters for that +interrupt. ipb is needed for instruction parameter decoding. + /* Fix the size of the union. */ char padding[256]; }; @@ -2471,3 +2487,17 @@ For mmu types KVM_MMU_FSL_BOOKE_NOHV and KVM_MMU_FSL_BOOKE_HV: where "num_sets" is the tlb_sizes[] value divided by the tlb_ways[] value. - The tsize field of mas1 shall be set to 4K on TLB0, even though the hardware ignores this value for TLB0. + +6.4 KVM_CAP_S390_CSS_SUPPORT + +Architectures: s390 +Parameters: none +Returns: 0 on success; -1 on error + +This capability enables support for handling of channel I/O instructions. + +TEST PENDING INTERRUPTION and the interrupt portion of TEST SUBCHANNEL are +handled in-kernel, while the other I/O instructions are passed to userspace. + +When this capability is enabled, KVM_EXIT_S390_TSCH will occur on TEST +SUBCHANNEL intercepts. |