tree 0483176857067675ea31bf4104e8e76a852a3699
parent 65e8d3fbd1c5303b94bb3d82f5979c149fee9950
author Will Deacon <will.deacon@arm.com> 1442243163 +0100
committer chrome-bot <chrome-bot@chromium.org> 1529085236 -0700

UPSTREAM: KVM: arm64: add workaround for Cortex-A57 erratum #852523

When restoring the system register state for an AArch32 guest at EL2,
writes to DACR32_EL2 may not be correctly synchronised by Cortex-A57,
which can lead to the guest effectively running with junk in the DACR
and running into unexpected domain faults.

This patch works around the issue by re-ordering our restoration of the
AArch32 register aliases so that they happen before the AArch64 system
registers. Ensuring that the registers are restored in this order
guarantees that they will be correctly synchronised by the core.

BUG=chromium:846515
TEST=build/boot on hana with USE=kvm_host

Change-Id: I608fa153e49751aaed9f13a6e7addf6ccc1fa98c
Cc: <stable@vger.kernel.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 43297dda0a51e4ffed0888ce727c218cfb7474b6)
Signed-off-by: Sonny Rao <sonnyrao@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1088105