From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
To: Juergen Gross <jgross@suse.com>,
linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org
Subject: Re: [PATCH v2] xen: add new hypercall buffer mapping device
Date: Mon, 18 Jun 2018 11:27:05 -0400 [thread overview]
Message-ID: <5b48b1ae-bcfe-e92d-1f74-ea4e7a9a7f56@oracle.com> (raw)
In-Reply-To: <20180618073639.26066-1-jgross@suse.com>
On 06/18/2018 03:36 AM, Juergen Gross wrote:
> 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 hypervisor can't use the locks of the kernel.
>
> In order to solve this problem add a new device node to the Xen privcmd
> driver to easily allocate hypercall buffers via mmap(). The memory is
> allocated in the kernel and just mapped into user space. Marked as
> VM_IO the user mapping will not be subject to page migration et al.
>
> Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
prev parent reply other threads:[~2018-06-18 15:27 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-18 7:36 Juergen Gross
2018-06-18 8:18 ` [Xen-devel] " Andrew Cooper
2018-06-18 15:27 ` Boris Ostrovsky [this message]
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