On 10.03.20 14:12, Christian Borntraeger wrote: > When we do the initial CPU reset we must not only clear the registers > in the internal data structures but also in kvm_run sync_regs. For > modern userspace sync_regs is the only place that it looks at. > > Cc: stable@xxxxxxxxxxxxxxx # v? > Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx> > --- > arch/s390/kvm/kvm-s390.c | 18 +++++++++++++++++- > 1 file changed, 17 insertions(+), 1 deletion(-) > > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > index d7ff30e45589..c2e6d4ba4e23 100644 > --- a/arch/s390/kvm/kvm-s390.c > +++ b/arch/s390/kvm/kvm-s390.c > @@ -3268,7 +3268,10 @@ static void kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu) > /* Initial reset is a superset of the normal reset */ > kvm_arch_vcpu_ioctl_normal_reset(vcpu); > > - /* this equals initial cpu reset in pop, but we don't switch to ESA */ > + /* > + * This equals initial cpu reset in pop, but we don't switch to ESA. > + * We do not only reset the internal data, but also ... > + */ > vcpu->arch.sie_block->gpsw.mask = 0; > vcpu->arch.sie_block->gpsw.addr = 0; > kvm_s390_set_prefix(vcpu, 0); > @@ -3278,6 +3281,19 @@ static void kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu) > memset(vcpu->arch.sie_block->gcr, 0, sizeof(vcpu->arch.sie_block->gcr)); > vcpu->arch.sie_block->gcr[0] = CR0_INITIAL_MASK; > vcpu->arch.sie_block->gcr[14] = CR14_INITIAL_MASK; > + > + /* ... the data in sync regs */ > + memset(vcpu->run->s.regs.crs, 0, sizeof(vcpu->run->s.regs.crs)); > + vcpu->run->s.regs.ckc = 0; > + vcpu->run->s.regs.crs[0] = CR0_INITIAL_MASK; > + vcpu->run->s.regs.crs[14] = CR14_INITIAL_MASK; > + vcpu->run->psw_addr = 0; > + vcpu->run->psw_mask = 0; > + vcpu->run->s.regs.todpr = 0; > + vcpu->run->s.regs.cputm = 0; > + vcpu->run->s.regs.ckc = 0; > + vcpu->run->s.regs.pp = 0; > + vcpu->run->s.regs.gbea = 1; > vcpu->run->s.regs.fpc = 0; > vcpu->arch.sie_block->gbea = 1; > vcpu->arch.sie_block->pp = 0; > Acked-by: David Hildenbrand <david@xxxxxxxxxx> However, I do wonder if that ioctl *originally* was designed for that - IOW if this is rally a stable patch or just some change that makes sense. IIRC, userspace/QEMU always did the right thing, no? There was no documentation about the guarantees AFAIK. -- Thanks, David / dhildenb
