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Commit 4fa96afd authored by Andre Przywara's avatar Andre Przywara Committed by Christoffer Dall
Browse files

arm/arm64: KVM: force alignment of VGIC dist/CPU/redist addresses 



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: default avatarAndre Przywara <andre.przywara@arm.com>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
parent ac3d3735

Documentation/virtual/kvm/devices/arm-vgic.txt

+4 −0
Original line number Diff line number Diff line
@@ -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

virt/kvm/arm/vgic.c

+13 −3
Original line number Diff line number Diff line
@@ -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);

	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);