Commit 1e0eec09 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

KVM: arm64: nv: timers: Add a per-timer, per-vcpu offset 



Being able to set a global offset isn't enough.

With NV, we also need to a per-vcpu, per-timer offset (for example,
CNTVCT_EL0 being offset by CNTVOFF_EL2).

Use a similar method as the VM-wide offset to have a timer point
to the shadow register that contains the offset value.

Reviewed-by: default avatarColton Lewis <coltonlewis@google.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230330174800.2677007-17-maz@kernel.org
parent 1935d34a

arch/arm64/kvm/arch_timer.c

+10 −3
Original line number Diff line number Diff line
@@ -89,10 +89,17 @@ u64 timer_get_cval(struct arch_timer_context *ctxt) 


static u64 timer_get_offset(struct arch_timer_context *ctxt)

{

	if (ctxt && ctxt->offset.vm_offset)

		return *ctxt->offset.vm_offset;

	u64 offset = 0;



	if (!ctxt)

		return 0;



	if (ctxt->offset.vm_offset)

		offset += *ctxt->offset.vm_offset;

	if (ctxt->offset.vcpu_offset)

		offset += *ctxt->offset.vcpu_offset;



	return offset;

}



static void timer_set_ctl(struct arch_timer_context *ctxt, u32 ctl)

arch/arm64/kvm/hyp/include/hyp/switch.h

+2 −0
Original line number Diff line number Diff line
@@ -353,6 +353,8 @@ static bool kvm_hyp_handle_cntpct(struct kvm_vcpu *vcpu) 


	if (ctxt->offset.vm_offset)

		val -= *kern_hyp_va(ctxt->offset.vm_offset);

	if (ctxt->offset.vcpu_offset)

		val -= *kern_hyp_va(ctxt->offset.vcpu_offset);



	vcpu_set_reg(vcpu, kvm_vcpu_sys_get_rt(vcpu), val);

	__kvm_skip_instr(vcpu);

include/kvm/arm_arch_timer.h

+5 −0
Original line number Diff line number Diff line
@@ -29,6 +29,11 @@ struct arch_timer_offset { 
	 * structure. If NULL, assume a zero offset.

	 */

	u64	*vm_offset;

	/*

	 * If set, pointer to one of the offsets in the vcpu's sysreg

	 * array. If NULL, assume a zero offset.

	 */

	u64	*vcpu_offset;

};



struct arch_timer_vm_data {