arm64: Allow EL1 physical timer access when running VHE

To initialise the timer access from EL2 when HCR_EL2.E2H is set,
we must make use the CNTHCTL_EL2 formap used is appropriate.

This amounts to shifting the timer/counter enable bits by 10
to the left.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20230609162200.2024064-7-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>

Author: Marc Zyngier

arch/arm64/include/asm/el2_setup.h

@@ -34,6 +34,11 @@
  */
 .macro __init_el2_timers
 	mov	x0, #3				// Enable EL1 physical timers
+	mrs	x1, hcr_el2
+	and	x1, x1, #HCR_E2H
+	cbz	x1, .LnVHE_\@
+	lsl	x0, x0, #10
+.LnVHE_\@:
 	msr	cnthctl_el2, x0
 	msr	cntvoff_el2, xzr		// Clear virtual offset
 .endm

arch/arm64/kvm/hyp/nvhe/hyp-init.S

@@ -95,6 +95,15 @@ SYM_CODE_START_LOCAL(___kvm_hyp_init)
 	ldr	x1, [x0, #NVHE_INIT_HCR_EL2]
 	msr	hcr_el2, x1
 
+	mov	x2, #HCR_E2H
+	and	x2, x1, x2
+	cbz	x2, 1f
+
+	mrs	x1, cnthctl_el2
+	and	x1, x1, #~(BIT(0) | BIT(1))
+	orr	x1, x1, #(BIT(10) | BIT(11))
+	msr	cnthctl_el2, x1
+1:
 	ldr	x1, [x0, #NVHE_INIT_VTTBR]
 	msr	vttbr_el2, x1