diff options
Diffstat (limited to 'virt/kvm/arm/vgic/vgic-mmio-v2.c')
| -rw-r--r-- | virt/kvm/arm/vgic/vgic-mmio-v2.c | 66 |
1 files changed, 59 insertions, 7 deletions
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v2.c b/virt/kvm/arm/vgic/vgic-mmio-v2.c index ffc587bf4742..738b65d2d0e7 100644 --- a/virt/kvm/arm/vgic/vgic-mmio-v2.c +++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c @@ -22,22 +22,33 @@ #include "vgic.h" #include "vgic-mmio.h" +/* + * The Revision field in the IIDR have the following meanings: + * + * Revision 1: Report GICv2 interrupts as group 0 instead of group 1 + * Revision 2: Interrupt groups are guest-configurable and signaled using + * their configured groups. + */ + static unsigned long vgic_mmio_read_v2_misc(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len) { + struct vgic_dist *vgic = &vcpu->kvm->arch.vgic; u32 value; switch (addr & 0x0c) { case GIC_DIST_CTRL: - value = vcpu->kvm->arch.vgic.enabled ? GICD_ENABLE : 0; + value = vgic->enabled ? GICD_ENABLE : 0; break; case GIC_DIST_CTR: - value = vcpu->kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS; + value = vgic->nr_spis + VGIC_NR_PRIVATE_IRQS; value = (value >> 5) - 1; value |= (atomic_read(&vcpu->kvm->online_vcpus) - 1) << 5; break; case GIC_DIST_IIDR: - value = (PRODUCT_ID_KVM << 24) | (IMPLEMENTER_ARM << 0); + value = (PRODUCT_ID_KVM << GICD_IIDR_PRODUCT_ID_SHIFT) | + (vgic->implementation_rev << GICD_IIDR_REVISION_SHIFT) | + (IMPLEMENTER_ARM << GICD_IIDR_IMPLEMENTER_SHIFT); break; default: return 0; @@ -66,6 +77,42 @@ static void vgic_mmio_write_v2_misc(struct kvm_vcpu *vcpu, } } +static int vgic_mmio_uaccess_write_v2_misc(struct kvm_vcpu *vcpu, + gpa_t addr, unsigned int len, + unsigned long val) +{ + switch (addr & 0x0c) { + case GIC_DIST_IIDR: + if (val != vgic_mmio_read_v2_misc(vcpu, addr, len)) + return -EINVAL; + + /* + * If we observe a write to GICD_IIDR we know that userspace + * has been updated and has had a chance to cope with older + * kernels (VGICv2 IIDR.Revision == 0) incorrectly reporting + * interrupts as group 1, and therefore we now allow groups to + * be user writable. Doing this by default would break + * migration from old kernels to new kernels with legacy + * userspace. + */ + vcpu->kvm->arch.vgic.v2_groups_user_writable = true; + return 0; + } + + vgic_mmio_write_v2_misc(vcpu, addr, len, val); + return 0; +} + +static int vgic_mmio_uaccess_write_v2_group(struct kvm_vcpu *vcpu, + gpa_t addr, unsigned int len, + unsigned long val) +{ + if (vcpu->kvm->arch.vgic.v2_groups_user_writable) + vgic_mmio_write_group(vcpu, addr, len, val); + + return 0; +} + static void vgic_mmio_write_sgir(struct kvm_vcpu *source_vcpu, gpa_t addr, unsigned int len, unsigned long val) @@ -352,17 +399,22 @@ static void vgic_mmio_write_apr(struct kvm_vcpu *vcpu, if (n > vgic_v3_max_apr_idx(vcpu)) return; + + n = array_index_nospec(n, 4); + /* GICv3 only uses ICH_AP1Rn for memory mapped (GICv2) guests */ vgicv3->vgic_ap1r[n] = val; } } static const struct vgic_register_region vgic_v2_dist_registers[] = { - REGISTER_DESC_WITH_LENGTH(GIC_DIST_CTRL, - vgic_mmio_read_v2_misc, vgic_mmio_write_v2_misc, 12, - VGIC_ACCESS_32bit), + REGISTER_DESC_WITH_LENGTH_UACCESS(GIC_DIST_CTRL, + vgic_mmio_read_v2_misc, vgic_mmio_write_v2_misc, + NULL, vgic_mmio_uaccess_write_v2_misc, + 12, VGIC_ACCESS_32bit), REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_IGROUP, - vgic_mmio_read_rao, vgic_mmio_write_wi, NULL, NULL, 1, + vgic_mmio_read_group, vgic_mmio_write_group, + NULL, vgic_mmio_uaccess_write_v2_group, 1, VGIC_ACCESS_32bit), REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ENABLE_SET, vgic_mmio_read_enable, vgic_mmio_write_senable, NULL, NULL, 1, |