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Commit a07d3b07 authored by Marc Zyngier's avatar Marc Zyngier Committed by Christoffer Dall
Browse files

arm64: KVM: vgic-v2: Enable GICV access from HYP if access from guest is unsafe 



So far, we've been disabling KVM on systems where the GICV region couldn't
be safely given to a guest. Now that we're able to handle this access
safely by emulating it in HYP, we can enable this feature when we detect
an unsafe configuration.

Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
parent bf8feb39

virt/kvm/arm/vgic/vgic-v2.c

+42 −27
Original line number Diff line number Diff line
@@ -278,6 +278,7 @@ int vgic_v2_map_resources(struct kvm *kvm) 
		goto out;

	}



	if (!static_branch_unlikely(&vgic_v2_cpuif_trap)) {

		ret = kvm_phys_addr_ioremap(kvm, dist->vgic_cpu_base,

					    kvm_vgic_global_state.vcpu_base,

					    KVM_VGIC_V2_CPU_SIZE, true);
@@ -285,6 +286,7 @@ int vgic_v2_map_resources(struct kvm *kvm) 
			kvm_err("Unable to remap VGIC CPU to VCPU\n");

			goto out;

		}

	}



	dist->ready = true;
@@ -312,45 +314,51 @@ int vgic_v2_probe(const struct gic_kvm_info *info) 
		return -ENXIO;

	}



	if (!PAGE_ALIGNED(info->vcpu.start)) {

		kvm_err("GICV physical address 0x%llx not page aligned\n",

			(unsigned long long)info->vcpu.start);

		return -ENXIO;

	if (!PAGE_ALIGNED(info->vcpu.start) ||

	    !PAGE_ALIGNED(resource_size(&info->vcpu))) {

		kvm_info("GICV region size/alignment is unsafe, using trapping (reduced performance)\n");

		kvm_vgic_global_state.vcpu_base_va = ioremap(info->vcpu.start,

							     resource_size(&info->vcpu));

		if (!kvm_vgic_global_state.vcpu_base_va) {

			kvm_err("Cannot ioremap GICV\n");

			return -ENOMEM;

		}



	if (!PAGE_ALIGNED(resource_size(&info->vcpu))) {

		kvm_err("GICV size 0x%llx not a multiple of page size 0x%lx\n",

			(unsigned long long)resource_size(&info->vcpu),

			PAGE_SIZE);

		return -ENXIO;

		ret = create_hyp_io_mappings(kvm_vgic_global_state.vcpu_base_va,

					     kvm_vgic_global_state.vcpu_base_va + resource_size(&info->vcpu),

					     info->vcpu.start);

		if (ret) {

			kvm_err("Cannot map GICV into hyp\n");

			goto out;

		}



		static_branch_enable(&vgic_v2_cpuif_trap);

	}



	kvm_vgic_global_state.vctrl_base = ioremap(info->vctrl.start,

						   resource_size(&info->vctrl));

	if (!kvm_vgic_global_state.vctrl_base) {

		kvm_err("Cannot ioremap GICH\n");

		return -ENOMEM;

		ret = -ENOMEM;

		goto out;

	}



	vtr = readl_relaxed(kvm_vgic_global_state.vctrl_base + GICH_VTR);

	kvm_vgic_global_state.nr_lr = (vtr & 0x3f) + 1;



	ret = kvm_register_vgic_device(KVM_DEV_TYPE_ARM_VGIC_V2);

	if (ret) {

		kvm_err("Cannot register GICv2 KVM device\n");

		iounmap(kvm_vgic_global_state.vctrl_base);

		return ret;

	}



	ret = create_hyp_io_mappings(kvm_vgic_global_state.vctrl_base,

				     kvm_vgic_global_state.vctrl_base +

					 resource_size(&info->vctrl),

				     info->vctrl.start);

	if (ret) {

		kvm_err("Cannot map VCTRL into hyp\n");

		kvm_unregister_device_ops(KVM_DEV_TYPE_ARM_VGIC_V2);

		iounmap(kvm_vgic_global_state.vctrl_base);

		return ret;

		goto out;

	}



	ret = kvm_register_vgic_device(KVM_DEV_TYPE_ARM_VGIC_V2);

	if (ret) {

		kvm_err("Cannot register GICv2 KVM device\n");

		goto out;

	}



	kvm_vgic_global_state.can_emulate_gicv2 = true;
@@ -361,4 +369,11 @@ int vgic_v2_probe(const struct gic_kvm_info *info) 
	kvm_info("vgic-v2@%llx\n", info->vctrl.start);



	return 0;

out:

	if (kvm_vgic_global_state.vctrl_base)

		iounmap(kvm_vgic_global_state.vctrl_base);

	if (kvm_vgic_global_state.vcpu_base_va)

		iounmap(kvm_vgic_global_state.vcpu_base_va);



	return ret;

}