arm64: generic timer: use virtual counter instead of physical at EL0

We want to use the virtual counter at EL0, as the physical counter
may not track the current clocksource for guests running under a
hypervisor.

This patch updates the vdso and generic timer driver to use the virtual
counter. The kernel EL2 entry code is also updated to ensure that the
virtual offset is initialised to zero.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index a2f02b63eae9..90dec55b17a2 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -158,6 +158,7 @@ ENTRY(el2_setup)
         mrs     x0, cnthctl_el2
         orr     x0, x0, #3                      // Enable EL1 physical timers
         msr     cnthctl_el2, x0
+        msr     cntvoff_el2, xzr                // Clear virtual offset
 
         /* Populate ID registers. */
         mrs     x0, midr_el1