KVM: s390: correct fprs on SIGP (STOP AND) STORE STATUS
authorDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Tue, 8 Mar 2016 11:24:30 +0000 (12:24 +0100)
committerPaolo Bonzini <pbonzini@redhat.com>
Tue, 8 Mar 2016 11:47:01 +0000 (12:47 +0100)
commit9522b37f5a8c7bfabe46eecadf2e130f1103f337
tree8b8b61f1daa3b5f1732f2d10bc1ce66e5bf62a2f
parent8bb9b9ccff5b7ce5084b5111244a92fd1d0daf16
KVM: s390: correct fprs on SIGP (STOP AND) STORE STATUS

With MACHINE_HAS_VX, we convert the floating point registers from the
vector registeres when storing the status. For other VCPUs, these are
stored to vcpu->run->s.regs.vrs, but we are using current->thread.fpu.vxrs,
which resolves to the currently loaded VCPU.

So kvm_s390_store_status_unloaded() currently writes the wrong floating
point registers (converted from the vector registers) when called from
another VCPU on a z13.

This is only the case for old user space not handling SIGP STORE STATUS and
SIGP STOP AND STORE STATUS, but relying on the kernel implementation. All
other calls come from the loaded VCPU via kvm_s390_store_status().

Fixes: 9abc2a08a7d6 (KVM: s390: fix memory overwrites when vx is disabled)
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: stable@vger.kernel.org # v4.4+
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
arch/s390/kvm/kvm-s390.c