On Wed, Jan 14, 2015 at 04:31:24PM +0000, Andre Przywara wrote:
> Although the GIC architecture requires us to map the MMIO regions
> only at page aligned addresses, we currently do not enforce this from
> the kernel side.
> Restrict any vGICv2 regions to be 4K aligned and any GICv3 regions
> to be 64K aligned. Document this requirement.
>
> Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
> ---
> Changelog:
> (new in v7)
>
> Documentation/virtual/kvm/devices/arm-vgic.txt | 4 ++++
> virt/kvm/arm/vgic.c | 16 +++++++++++++---
> 2 files changed, 17 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/virtual/kvm/devices/arm-vgic.txt b/Documentation/virtual/kvm/devices/arm-vgic.txt
> index 5d4fd4b..3fb9054 100644
> --- a/Documentation/virtual/kvm/devices/arm-vgic.txt
> +++ b/Documentation/virtual/kvm/devices/arm-vgic.txt
> @@ -20,20 +20,24 @@ Groups:
> KVM_VGIC_V2_ADDR_TYPE_DIST (rw, 64-bit)
> Base address in the guest physical address space of the GIC distributor
> register mappings. Only valid for KVM_DEV_TYPE_ARM_VGIC_V2.
> + This address needs to be 4K aligned and the region covers 4 KByte.
>
> KVM_VGIC_V2_ADDR_TYPE_CPU (rw, 64-bit)
> Base address in the guest physical address space of the GIC virtual cpu
> interface register mappings. Only valid for KVM_DEV_TYPE_ARM_VGIC_V2.
> + This address needs to be 4K aligned and the region covers 4 KByte.
>
> KVM_VGIC_V3_ADDR_TYPE_DIST (rw, 64-bit)
> Base address in the guest physical address space of the GICv3 distributor
> register mappings. Only valid for KVM_DEV_TYPE_ARM_VGIC_V3.
> + This address needs to be 64K aligned and the region covers 64 KByte.
>
> KVM_VGIC_V3_ADDR_TYPE_REDIST (rw, 64-bit)
> Base address in the guest physical address space of the GICv3
> redistributor register mappings. There are two 64K pages for each
> VCPU and all of the redistributor pages are contiguous.
> Only valid for KVM_DEV_TYPE_ARM_VGIC_V3.
> + This address needs to be 64K aligned.
>
>
> KVM_DEV_ARM_VGIC_GRP_DIST_REGS
> diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
> index 184c6db..0cc6ab6 100644
> --- a/virt/kvm/arm/vgic.c
> +++ b/virt/kvm/arm/vgic.c
> @@ -1683,6 +1683,7 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write)
> struct vgic_dist *vgic = &kvm->arch.vgic;
> int type_needed;
> phys_addr_t *addr_ptr, block_size;
> + phys_addr_t alignment;
>
> mutex_lock(&kvm->lock);
> switch (type) {
> @@ -1690,22 +1691,26 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write)
> type_needed = KVM_DEV_TYPE_ARM_VGIC_V2;
> addr_ptr = &vgic->vgic_dist_base;
> block_size = KVM_VGIC_V2_DIST_SIZE;
> + alignment = SZ_4K;
> break;
> case KVM_VGIC_V2_ADDR_TYPE_CPU:
> type_needed = KVM_DEV_TYPE_ARM_VGIC_V2;
> addr_ptr = &vgic->vgic_cpu_base;
> block_size = KVM_VGIC_V2_CPU_SIZE;
> + alignment = SZ_4K;
> break;
> #ifdef CONFIG_ARM_GIC_V3
> case KVM_VGIC_V3_ADDR_TYPE_DIST:
> type_needed = KVM_DEV_TYPE_ARM_VGIC_V3;
> addr_ptr = &vgic->vgic_dist_base;
> block_size = KVM_VGIC_V3_DIST_SIZE;
> + alignment = SZ_64K;
> break;
> case KVM_VGIC_V3_ADDR_TYPE_REDIST:
> type_needed = KVM_DEV_TYPE_ARM_VGIC_V3;
> addr_ptr = &vgic->vgic_redist_base;
> block_size = KVM_VGIC_V3_REDIST_SIZE;
> + alignment = SZ_64K;
> break;
> #endif
> default:
> @@ -1718,10 +1723,15 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write)
> goto out;
> }
>
> - if (write)
> - r = vgic_ioaddr_assign(kvm, addr_ptr, *addr, block_size);
> - else
> + if (write) {
> + if (!IS_ALIGNED(*addr, alignment))
> + r = -EINVAL;
> + else
> + r = vgic_ioaddr_assign(kvm, addr_ptr, *addr,
> + block_size);
> + } else {
> *addr = *addr_ptr;
> + }
>
> out:
> mutex_unlock(&kvm->lock);
> --
Reviewed-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
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