tree 1ba0103ae377854f10ba7558ced4601c84e051a0
parent a8f2299d1b170b6100b0e9ad00788a7a7e31719b
author David Gibson <david@gibson.dropbear.id.au> 1348593140 +0000
committer Michael Roth <mdroth@linux.vnet.ibm.com> 1350009861 -0500

pseries: Don't test for MSR_PR for hypercalls under KVM

PAPR hypercalls should only be invoked from the guest kernel, not guest
user programs, that is, with MSR[PR]=0.  Currently we check this in
spapr_hypercall, returning H_PRIVILEGE if MSR[PR]=1.

However, under KVM the state of MSR[PR] is already checked by the host
kernel before passing the hypercall to qemu, making this check redundant.
Worse, however, we don't generally synchronize KVM and qemu state on the
hypercall path, meaning that qemu could incorrectly reject a hypercall
because it has a stale MSR value.

This patch fixes the problem by moving the privilege test exclusively to
the TCG hypercall path.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
CC: qemu-stable@nongnu.org
Signed-off-by: Alexander Graf <agraf@suse.de>
(cherry picked from commit efcb9383b974114e5f682e531346006f8f2466c0)

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>