tree 13cde1225820e23d58f598b6b5057651d42bc36b
parent 37abdda9139f98f8fb1d3d2bd9c03addc1e0797b
author Thomas Huth <thuth@redhat.com> 1490681100 +0200
committer Thomas Huth <thuth@redhat.com> 1490681307 +0200

powerpc: Add Special Purpose Register persistency test

This test has two purposes: First, check whether the hypervisor can be
destabilized by writing random values into the SPRs of the PowerPC CPU
(this indeed revealed a bug last year, see CVE-2016-3044).
Second, this test can be used to check whether the SPRs are synchronized
properly between the KVM host CPU and QEMU, e.g. when migrating the VM
from one QEMU instance to another.
The test first fills the various SPRs with some non-zero value, then reads
the values back into a first array. It then either sleeps a short period
of time (for testing without migration, in the hope that we're rescheduled
on another host CPU), or it waits for a key or NMI (with the '-w' option)
so that it is possible to migrate the VM before continuing. The test then
finally reads the values from the SPRs back into another array and then
compares them with the initial values.
Currently the test only supports the SPRs from the PowerISA v2.01
(PowerPC 970) and PowerISA v2.07 specification (i.e. POWER8 CPUs),
but other versions should be pretty easy to add later.

Signed-off-by: Thomas Huth <thuth@redhat.com>