ARM: KVM: arch_timers: zero CNTVOFF upon return to host

To use the virtual counters from the host, we need to ensure that
CNTVOFF doesn't change unexpectedly. When we change to a guest, we
replace the host's CNTVOFF, but we don't restore it when returning to
the host.

As the host sets CNTVOFF to zero, and never changes it, we can simply
zero CNTVOFF when returning to the host. This patch adds said zeroing to
the return to host path.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Christoffer Dall <cdall@cs.columbia.edu>
(cherry picked from commit f793c23ebb)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
This commit is contained in:
Mark Rutland
2013-03-26 13:41:35 +00:00
committed by Christoffer Dall
parent 7ce8a35ca7
commit 9861d210e0

View File

@@ -503,6 +503,10 @@ vcpu .req r0 @ vcpu pointer always in r0
add r5, vcpu, r4
strd r2, r3, [r5]
@ Ensure host CNTVCT == CNTPCT
mov r2, #0
mcrr p15, 4, r2, r2, c14 @ CNTVOFF
1:
#endif
@ Allow physical timer/counter access for the host