From a07d3b07a876d44827e62f3ef55837ebbf61c4e6 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 6 Sep 2016 09:28:47 +0100 Subject: 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 Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall --- virt/kvm/arm/vgic/vgic-v2.c | 69 +++++++++++++++++++++++++++------------------ 1 file changed, 42 insertions(+), 27 deletions(-) (limited to 'virt/kvm') diff --git a/virt/kvm/arm/vgic/vgic-v2.c b/virt/kvm/arm/vgic/vgic-v2.c index b8da9011889d..0a063af40565 100644 --- a/virt/kvm/arm/vgic/vgic-v2.c +++ b/virt/kvm/arm/vgic/vgic-v2.c @@ -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; } -- cgit v1.2.3