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: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
This commit is contained in:
Marc Zyngier 2016-09-06 09:28:47 +01:00 committed by Christoffer Dall
parent bf8feb3964
commit a07d3b07a8

View File

@ -278,12 +278,14 @@ int vgic_v2_map_resources(struct kvm *kvm)
goto out;
}
ret = kvm_phys_addr_ioremap(kvm, dist->vgic_cpu_base,
kvm_vgic_global_state.vcpu_base,
KVM_VGIC_V2_CPU_SIZE, true);
if (ret) {
kvm_err("Unable to remap VGIC CPU to VCPU\n");
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);
if (ret) {
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;
}