From: "Michael S. Tsirkin" <mst@redhat.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: Qemu Developers <qemu-devel@nongnu.org>,
Eduardo Habkost <ehabkost@redhat.com>,
Igor Mammedov <imammedo@redhat.com>,
Paolo Bonzini <pbonzini@redhat.com>,
dgilbert@redhat.com,
Xiao Guangrong <xiaoguangrong.eric@gmail.com>,
Stefan Hajnoczi <stefanha@redhat.com>,
Alex Williamson <alex.williamson@redhat.com>
Subject: Re: [Qemu-devel] [PATCH v4 0/6] nvdimm: support MAP_SYNC for memory-backend-file
Date: Thu, 1 Feb 2018 19:05:03 +0200 [thread overview]
Message-ID: <20180201190326-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <CAPcyv4i0UFoq-ot0KPBeNaDhENUZJs9iFdjotKny=kSnOHXeMw@mail.gmail.com>
On Wed, Jan 31, 2018 at 07:02:27PM -0800, Dan Williams wrote:
> > Another question is how a user-space application (e.g., QEMU) knows
> > whether it's safe to mmap a file on the DAX file system?
>
> I think we fix vaddr_get_pfn() to start failing for DAX mappings
> unless/until we can add a "with lease" mechanism. Userspace will know
> when it is safe again when vfio stops failing.
I read some of the discussion around that but could not figure out what
exactly does happen if a file is truncated by a malicious userspace.
Could you let me know pls? Thanks!
--
MST
prev parent reply other threads:[~2018-02-01 17:05 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-31 6:02 [Qemu-devel] [PATCH v4 0/6] nvdimm: support MAP_SYNC for memory-backend-file Haozhong Zhang
2018-01-31 6:02 ` [Qemu-devel] [PATCH v4 1/6] util/mmap-alloc: switch qemu_ram_mmap() to 'flags' parameter Haozhong Zhang
2018-01-31 6:02 ` [Qemu-devel] [PATCH v4 2/6] exec: switch qemu_ram_alloc_from_{file, fd} to the " Haozhong Zhang
2018-01-31 6:02 ` [Qemu-devel] [PATCH v4 3/6] memory: switch memory_region_init_ram_from_file() to " Haozhong Zhang
2018-01-31 6:02 ` [Qemu-devel] [PATCH v4 4/6] util/mmap-alloc: support MAP_SYNC in qemu_ram_mmap() Haozhong Zhang
2018-01-31 6:02 ` [Qemu-devel] [PATCH v4 5/6] hostmem: add more information in error messages Haozhong Zhang
2018-01-31 6:02 ` [Qemu-devel] [PATCH v4 6/6] hostmem-file: add 'sync' option Haozhong Zhang
2018-01-31 22:25 ` [Qemu-devel] [PATCH v4 0/6] nvdimm: support MAP_SYNC for memory-backend-file Dan Williams
2018-02-01 0:02 ` Haozhong Zhang
2018-02-01 0:08 ` Dan Williams
2018-02-01 0:24 ` Haozhong Zhang
2018-02-01 0:32 ` Dan Williams
2018-02-01 2:29 ` Haozhong Zhang
2018-02-01 3:02 ` Dan Williams
2018-02-01 3:11 ` Dan Williams
2018-02-01 10:17 ` Haozhong Zhang
2018-02-01 17:43 ` Alex Williamson
2018-02-01 17:05 ` Michael S. Tsirkin [this message]
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