xemu/scsi/pr-helper.h
Paolo Bonzini b855f8d175 scsi: build qemu-pr-helper
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 <pbonzini@redhat.com>
2017-09-22 21:07:24 +02:00

42 lines
1.5 KiB
C

/* Definitions for QEMU's persistent reservation helper daemon
*
* Copyright (C) 2017 Red Hat, Inc.
*
* Author:
* Paolo Bonzini <pbonzini@redhat.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#ifndef QEMU_PR_HELPER_H
#define QEMU_PR_HELPER_H 1
#include <stdint.h>
#define PR_HELPER_CDB_SIZE 16
#define PR_HELPER_SENSE_SIZE 96
#define PR_HELPER_DATA_SIZE 8192
typedef struct PRHelperResponse {
int32_t result;
int32_t sz;
uint8_t sense[PR_HELPER_SENSE_SIZE];
} PRHelperResponse;
#endif