Commit 9b3b2f00 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

KVM: arm64: nv: Accelerate EL0 counter accesses from hypervisor context 



Similarly to handling the physical timer accesses early when FEAT_ECV
causes a trap, we try to handle the physical counter without returning
to the general sysreg handling.

More surprisingly, we introduce something similar for the virtual
counter. Although this isn't necessary yet, it will prove useful on
systems that have a broken CNTVOFF_EL2 implementation. Yes, they exist.

Acked-by: default avatarOliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20241217142321.763801-7-maz@kernel.org


Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent 338f8ea5

arch/arm64/kvm/hyp/vhe/switch.c

+8 −0
Original line number Diff line number Diff line
@@ -324,6 +324,10 @@ static bool kvm_hyp_handle_timer(struct kvm_vcpu *vcpu, u64 *exit_code) 
			val = __vcpu_sys_reg(vcpu, CNTP_CVAL_EL0);

		}

		break;

	case SYS_CNTPCT_EL0:

	case SYS_CNTPCTSS_EL0:

		val = compute_counter_value(vcpu_hptimer(vcpu));

		break;

	case SYS_CNTV_CTL_EL02:

		val = compute_emulated_cntx_ctl_el0(vcpu, CNTV_CTL_EL0);

		break;
@@ -342,6 +346,10 @@ static bool kvm_hyp_handle_timer(struct kvm_vcpu *vcpu, u64 *exit_code) 
		else

			val = __vcpu_sys_reg(vcpu, CNTV_CVAL_EL0);

		break;

	case SYS_CNTVCT_EL0:

	case SYS_CNTVCTSS_EL0:

		val = compute_counter_value(vcpu_hvtimer(vcpu));

		break;

	default:

		return false;

	}