KVM: PPC: Book3S HV: Sanitize special-purpose register values on guest exit

Thomas Huth discovered that a guest could cause a hard hang of a
host CPU by setting the Instruction Authority Mask Register (IAMR)
to a suitable value.  It turns out that this is because when the
code was added to context-switch the new special-purpose registers
(SPRs) that were added in POWER8, we forgot to add code to ensure
that they were restored to a sane value on guest exit.

This adds code to set those registers where a bad value could
compromise the execution of the host kernel to a suitable neutral
value on guest exit.

Cc: [email protected] # v3.14+
Fixes: b005255e12a3
Reported-by: Thomas Huth <[email protected]>
Reviewed-by: David Gibson <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>

0 files changed, 0 insertions, 0 deletions