On Thu, 5 Dec 2019 07:09:56 -0500 Janosch Frank <frankja@xxxxxxxxxxxxx> wrote: > The architecture states that we need to reset local IRQs for all CPU > resets. Because the old reset interface did not support the normal CPU > reset we never did that. Now that we have a new interface, let's > properly clear out local IRQs and let this commit be a reminder. I'm still confused what this commit is supposed to be a reminder of :) > > Also we add a ioctl for the clear reset to have all resets exposed to > userspace. Currently the clear reset falls back to the initial reset, > but we plan to have clear reset specific code in the future. > > Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx> > Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> > --- > Documentation/virt/kvm/api.txt | 45 ++++++++++++++++++++++++++++++++++ > arch/s390/kvm/kvm-s390.c | 14 +++++++++++ > include/uapi/linux/kvm.h | 5 ++++ > 3 files changed, 64 insertions(+) > > diff --git a/Documentation/virt/kvm/api.txt b/Documentation/virt/kvm/api.txt > index 4833904d32a5..3b62489308e0 100644 > --- a/Documentation/virt/kvm/api.txt > +++ b/Documentation/virt/kvm/api.txt > @@ -4126,6 +4126,44 @@ Valid values for 'action': > #define KVM_PMU_EVENT_ALLOW 0 > #define KVM_PMU_EVENT_DENY 1 > > +4.121 KVM_S390_NORMAL_RESET > + > +Capability: KVM_CAP_S390_VCPU_RESETS > +Architectures: s390 > +Type: vcpu ioctl > +Parameters: none > +Returns: 0 > + > +This ioctl resets VCPU registers and control structures that QEMU s/QEMU/userspace/ (also below) > +can't access via the kvm_run structure. The normal reset clears local > +interrupts, the riccb and PSW bit 24. What about: "It is intended to be called when a normal reset is performed on the vcpu and clears..." > + > +4.122 KVM_S390_INITIAL_RESET Oh, we had never documented it before? > + > +Capability: none > +Architectures: s390 > +Type: vcpu ioctl > +Parameters: none > +Returns: 0 > + > +This ioctl resets VCPU registers and control structures that QEMU > +can't access via the kvm_run structure. The initial reset is a > +superset of the normal reset and additionally clears the psw, prefix, > +timing related registers, as well as setting the control registers to > +their initial value. "It is intended to be called when an initial reset (which is a superset of the normal reset) is performed on the vcpu and additionally clears..." ? > + > +4.123 KVM_S390_CLEAR_RESET > + > +Capability: KVM_CAP_S390_VCPU_RESETS > +Architectures: s390 > +Type: vcpu ioctl > +Parameters: none > +Returns: 0 > + > +This ioctl resets VCPU registers and control structures that QEMU > +can't access via the kvm_run structure. The clear reset is a superset > +of the initial reset and additionally clears general, access, floating > +and vector registers. You can probably guess what I was going to write :) > > 5. The kvm_run structure > ------------------------ > @@ -5322,3 +5360,10 @@ handling by KVM (as some KVM hypercall may be mistakenly treated as TLB > flush hypercalls by Hyper-V) so userspace should disable KVM identification > in CPUID and only exposes Hyper-V identification. In this case, guest > thinks it's running on Hyper-V and only use Hyper-V hypercalls. > + > +8.22 KVM_CAP_S390_VCPU_RESETS > + > +Architectures: s390 > + > +This capability indicates that the KVM_S390_NORMAL_RESET and > +KVM_S390_CLEAR_RESET ioctls are available. (...) The code looks good.
