diff options
| -rw-r--r-- | virt/kvm/arm/vgic.c | 53 |
1 files changed, 50 insertions, 3 deletions
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c index b5aa821b89a8..a1fda798148e 100644 --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -1033,6 +1033,53 @@ static bool vgic_validate_access(const struct vgic_dist *dist, return true; } +/* + * Call the respective handler function for the given range. + * We split up any 64 bit accesses into two consecutive 32 bit + * handler calls and merge the result afterwards. + * We do this in a little endian fashion regardless of the host's + * or guest's endianness, because the GIC is always LE and the rest of + * the code (vgic_reg_access) also puts it in a LE fashion already. + * At this point we have already identified the handle function, so + * range points to that one entry and offset is relative to this. + */ +static bool call_range_handler(struct kvm_vcpu *vcpu, + struct kvm_exit_mmio *mmio, + unsigned long offset, + const struct mmio_range *range) +{ + u32 *data32 = (void *)mmio->data; + struct kvm_exit_mmio mmio32; + bool ret; + + if (likely(mmio->len <= 4)) + return range->handle_mmio(vcpu, mmio, offset); + + /* + * Any access bigger than 4 bytes (that we currently handle in KVM) + * is actually 8 bytes long, caused by a 64-bit access + */ + + mmio32.len = 4; + mmio32.is_write = mmio->is_write; + + mmio32.phys_addr = mmio->phys_addr + 4; + if (mmio->is_write) + *(u32 *)mmio32.data = data32[1]; + ret = range->handle_mmio(vcpu, &mmio32, offset + 4); + if (!mmio->is_write) + data32[1] = *(u32 *)mmio32.data; + + mmio32.phys_addr = mmio->phys_addr; + if (mmio->is_write) + *(u32 *)mmio32.data = data32[0]; + ret |= range->handle_mmio(vcpu, &mmio32, offset); + if (!mmio->is_write) + data32[0] = *(u32 *)mmio32.data; + + return ret; +} + /** * vgic_handle_mmio_range - handle an in-kernel MMIO access * @vcpu: pointer to the vcpu performing the access @@ -1064,10 +1111,10 @@ static bool vgic_handle_mmio_range(struct kvm_vcpu *vcpu, struct kvm_run *run, spin_lock(&vcpu->kvm->arch.vgic.lock); offset -= range->base; if (vgic_validate_access(dist, range, offset)) { - updated_state = range->handle_mmio(vcpu, mmio, offset); + updated_state = call_range_handler(vcpu, mmio, offset, range); } else { - vgic_reg_access(mmio, NULL, offset, - ACCESS_READ_RAZ | ACCESS_WRITE_IGNORED); + if (!mmio->is_write) + memset(mmio->data, 0, mmio->len); updated_state = false; } spin_unlock(&vcpu->kvm->arch.vgic.lock); |