[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-block] [Qemu-devel] [PATCH 08/10] scsi: build qemu-pr-helper
From: |
Eric Blake |
Subject: |
Re: [Qemu-block] [Qemu-devel] [PATCH 08/10] scsi: build qemu-pr-helper |
Date: |
Thu, 24 Aug 2017 10:45:47 -0500 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 |
On 08/22/2017 08:18 AM, Paolo Bonzini wrote:
> Introduce a privileged helper to run persistent reservation commands.
> This lets virtual machines send persistent reservations without using
> CAP_SYS_RAWIO or out-of-tree patches. The helper uses Unix permissions
> and SCM_RIGHTS to restrict access to processes that can access its socket
> and prove that they have an open file descriptor for a raw SCSI device.
>
> The next patch will also correct the usage of persistent reservations
> with multipath devices.
>
> It would also be possible to support for Linux's IOC_PR_* ioctls in
> the future, to support NVMe devices. For now, however, only SCSI is
> supported.
>
> Signed-off-by: Paolo Bonzini <address@hidden>
> ---
> +++ b/docs/interop/pr-helper.rst
> @@ -0,0 +1,78 @@
> +..
> +
> +======================================
> +Persistent reservation helper protocol
> +======================================
> +
> +QEMU's SCSI passthrough devices, ``scsi-block`` and ``scsi-generic``,
> +can delegate implementation of persistent reservations to an external
> +(and typically privilege) program. Persistent Reservations allow
s/privilege/privileged/
> +
> +If a bit is 1 in ``requested_features`` and 0 in ``supported_features``,
> +the corresponding feature is not supported by the helper and the connection
> +is closed. On the other hand, it is acceptable for a bit to be 0 in
> +``requested_features`` and 1 in ``supported_features``; in this case,
> +he helper will not enable the feature.
s/^he/the/
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
signature.asc
Description: OpenPGP digital signature
- Re: [Qemu-block] [PATCH 07/10] io: add qio_channel_read/write_all, (continued)
- [Qemu-block] [PATCH 09/10] scsi: add multipath support to qemu-pr-helper, Paolo Bonzini, 2017/08/22
- [Qemu-block] [PATCH 08/10] scsi: build qemu-pr-helper, Paolo Bonzini, 2017/08/22
- [Qemu-block] [PATCH 01/10] scsi: rename scsi_convert_sense, Paolo Bonzini, 2017/08/22
- [Qemu-block] [PATCH 03/10] scsi: introduce scsi_build_sense, Paolo Bonzini, 2017/08/22
- [Qemu-block] [PATCH 04/10] scsi: introduce sg_io_sense_from_errno, Paolo Bonzini, 2017/08/22