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author | Paolo Bonzini <pbonzini@redhat.com> | 2015-01-23 14:33:36 +0100 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2015-01-23 14:33:36 +0100 |
commit | 8fff5e374a2f6047d1bb52288af7da119bc75765 (patch) | |
tree | 723d105441d2bed7a0b6290557a7c89d3787b1fe /Documentation/virtual/kvm/api.txt | |
parent | 1c6007d59a20762052cc92c0a2889ff11030d23a (diff) | |
parent | 0eb135ff9f19b8336e96fa12c599a8f412e7f0c0 (diff) | |
download | linux-rt-8fff5e374a2f6047d1bb52288af7da119bc75765.tar.gz |
Merge tag 'kvm-s390-next-20150122' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-next
KVM: s390: fixes and features for kvm/next (3.20)
1. Generic
- sparse warning (make function static)
- optimize locking
- bugfixes for interrupt injection
- fix MVPG addressing modes
2. hrtimer/wakeup fun
A recent change can cause KVM hangs if adjtime is used in the host.
The hrtimer might wake up too early or too late. Too early is fatal
as vcpu_block will see that the wakeup condition is not met and
sleep again. This CPU might never wake up again.
This series addresses this problem. adjclock slowing down the host
clock will result in too late wakeups. This will require more work.
In addition to that we also change the hrtimer from REALTIME to
MONOTONIC to avoid similar problems with timedatectl set-time.
3. sigp rework
We will move all "slow" sigps to QEMU (protected with a capability that
can be enabled) to avoid several races between concurrent SIGP orders.
4. Optimize the shadow page table
Provide an interface to announce the maximum guest size. The kernel
will use that to make the pagetable 2,3,4 (or theoretically) 5 levels.
5. Provide an interface to set the guest TOD
We now use two vm attributes instead of two oneregs, as oneregs are
vcpu ioctl and we don't want to call them from other threads.
6. Protected key functions
The real HMC allows to enable/disable protected key CPACF functions.
Lets provide an implementation + an interface for QEMU to activate
this the protected key instructions.
Diffstat (limited to 'Documentation/virtual/kvm/api.txt')
-rw-r--r-- | Documentation/virtual/kvm/api.txt | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index f4b19d78782b..b112efc816f1 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2315,7 +2315,7 @@ struct kvm_s390_interrupt { type can be one of the following: -KVM_S390_SIGP_STOP (vcpu) - sigp restart +KVM_S390_SIGP_STOP (vcpu) - sigp stop; optional flags in parm KVM_S390_PROGRAM_INT (vcpu) - program check; code in parm KVM_S390_SIGP_SET_PREFIX (vcpu) - sigp set prefix; prefix address in parm KVM_S390_RESTART (vcpu) - restart @@ -3228,3 +3228,23 @@ userspace from doing that. If the hcall number specified is not one that has an in-kernel implementation, the KVM_ENABLE_CAP ioctl will fail with an EINVAL error. + +7.2 KVM_CAP_S390_USER_SIGP + +Architectures: s390 +Parameters: none + +This capability controls which SIGP orders will be handled completely in user +space. With this capability enabled, all fast orders will be handled completely +in the kernel: +- SENSE +- SENSE RUNNING +- EXTERNAL CALL +- EMERGENCY SIGNAL +- CONDITIONAL EMERGENCY SIGNAL + +All other orders will be handled completely in user space. + +Only privileged operation exceptions will be checked for in the kernel (or even +in the hardware prior to interception). If this capability is not enabled, the +old way of handling SIGP orders is used (partially in kernel and user space). |