On 15/06/18 16:43, Boris Ostrovsky wrote:
> On 06/15/2018 09:17 AM, Juergen Gross wrote:
>> +static int privcmd_buf_mmap(struct file *file, struct vm_area_struct *vma)
>> +{
>> +struct privcmd_buf_private *file_priv = file->private_data;
>> +struct privcmd_buf_vma_private *vma_priv;
>> +
On 15/06/18 16:35, Jan Beulich wrote:
On 15.06.18 at 15:17, wrote:
>> --- /dev/null
>> +++ b/drivers/xen/privcmd-buf.c
>> @@ -0,0 +1,216 @@
>> +// SPDX-License-Identifier: GPL-2.0 OR MIT
>> +
>> +/**
>> + *
On 06/15/2018 09:17 AM, Juergen Gross wrote:
> +static int privcmd_buf_mmap(struct file *file, struct vm_area_struct *vma)
> +{
> + struct privcmd_buf_private *file_priv = file->private_data;
> + struct privcmd_buf_vma_private *vma_priv;
> + unsigned int count = vma_pages(vma);
> +
On 15/06/18 16:15, Andrew Cooper wrote:
> On 15/06/18 14:17, Juergen Gross wrote:
>> +MODULE_LICENSE("GPL");
>> +
>> +static int limit = 64;
>> +module_param(limit, int, 0644);
>> +MODULE_PARM_DESC(limit, "Maximum number of pages that may be allocated by "
>> +"the privcmd-buf
>>> On 15.06.18 at 15:17, wrote:
> --- /dev/null
> +++ b/drivers/xen/privcmd-buf.c
> @@ -0,0 +1,216 @@
> +// SPDX-License-Identifier: GPL-2.0 OR MIT
> +
> +/**
> + * privcmd-buf.c
> + *
> + * Mmap of hypercall buffers.
>
On 15/06/18 14:17, Juergen Gross wrote:
> +MODULE_LICENSE("GPL");
> +
> +static int limit = 64;
> +module_param(limit, int, 0644);
> +MODULE_PARM_DESC(limit, "Maximum number of pages that may be allocated by "
> + "the privcmd-buf device per open file");
I have a feeling that,
For passing arbitrary data from user land to the Xen hypervisor the
Xen tools today are using mlock()ed buffers. Unfortunately the kernel
might change access rights of such buffers for brief periods of time
e.g. for page migration or compaction, leading to access faults in the
hypervisor, as the
