On Wed, 8 Jan 2020 15:44:57 +0100 Thomas Huth <thuth@xxxxxxxxxx> wrote: > On 08/01/2020 15.38, Christian Borntraeger wrote: > > > > > > On 08.01.20 15:35, Janosch Frank wrote: > >> On 1/8/20 3:28 PM, Christian Borntraeger wrote: > >>> > >>> > >>> On 05.12.19 13:09, Janosch Frank wrote: > >>> [...] > >>>> +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. > >>> > >>> As Thomas outlined, make it more obvious that userspace does the remaining > >>> parts. I do not think that we want the kernel to do the things (unless it > >>> helps you in some way for the ultravisor guests) > >> > >> Ok, will do > > > > I changed my mind (see my other mail) but I would like Thomas, Conny or David > > to ack/nack. > > I don't mind too much as long as it is properly documented, but I also > slightly prefer to be consistent here, i.e. let the kernel clear the > rest here, too, just like we do it already with the initial reset. I definitely agree with the 'properly documented' part :) It's probably enough to just state that the kernel resets the stuff, no need to go into details (and we also don't need to update this for later versions.) Q: Are we sure that we will always be able to reset everything from the kernel?
