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/dev/vfio/devices/vfioX may not exist. In that case it is still possible to open /dev/char/$major:$minor instead. Add helper function to abstract the cdev open. Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com> Reviewed-by: Cédric Le Goater <clg@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Tested-by: Eric Auger <eric.auger@redhat.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Cédric Le Goater <clg@redhat.com>
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/* | ||
* QEMU Chardev Helper | ||
* | ||
* Copyright (C) 2023 Intel Corporation. | ||
* | ||
* Authors: Yi Liu <yi.l.liu@intel.com> | ||
* | ||
* This work is licensed under the terms of the GNU GPL, version 2. See | ||
* the COPYING file in the top-level directory. | ||
*/ | ||
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#ifndef QEMU_CHARDEV_OPEN_H | ||
#define QEMU_CHARDEV_OPEN_H | ||
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int open_cdev(const char *devpath, dev_t cdev); | ||
#endif |
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/* | ||
* Copyright (c) 2019, Mellanox Technologies. All rights reserved. | ||
* Copyright (C) 2023 Intel Corporation. | ||
* | ||
* This software is available to you under a choice of one of two | ||
* licenses. You may choose to be licensed under the terms of the GNU | ||
* General Public License (GPL) Version 2, available from the file | ||
* COPYING in the main directory of this source tree, or the | ||
* OpenIB.org BSD license below: | ||
* | ||
* Redistribution and use in source and binary forms, with or | ||
* without modification, are permitted provided that the following | ||
* conditions are met: | ||
* | ||
* - Redistributions of source code must retain the above | ||
* copyright notice, this list of conditions and the following | ||
* disclaimer. | ||
* | ||
* - Redistributions in binary form must reproduce the above | ||
* copyright notice, this list of conditions and the following | ||
* disclaimer in the documentation and/or other materials | ||
* provided with the distribution. | ||
* | ||
* 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. | ||
* | ||
* Authors: Yi Liu <yi.l.liu@intel.com> | ||
* | ||
* Copied from | ||
* https://github.com/linux-rdma/rdma-core/blob/master/util/open_cdev.c | ||
* | ||
*/ | ||
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#include "qemu/osdep.h" | ||
#include "qemu/chardev_open.h" | ||
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static int open_cdev_internal(const char *path, dev_t cdev) | ||
{ | ||
struct stat st; | ||
int fd; | ||
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fd = qemu_open_old(path, O_RDWR); | ||
if (fd == -1) { | ||
return -1; | ||
} | ||
if (fstat(fd, &st) || !S_ISCHR(st.st_mode) || | ||
(cdev != 0 && st.st_rdev != cdev)) { | ||
close(fd); | ||
return -1; | ||
} | ||
return fd; | ||
} | ||
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static int open_cdev_robust(dev_t cdev) | ||
{ | ||
g_autofree char *devpath = NULL; | ||
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/* | ||
* This assumes that udev is being used and is creating the /dev/char/ | ||
* symlinks. | ||
*/ | ||
devpath = g_strdup_printf("/dev/char/%u:%u", major(cdev), minor(cdev)); | ||
return open_cdev_internal(devpath, cdev); | ||
} | ||
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int open_cdev(const char *devpath, dev_t cdev) | ||
{ | ||
int fd; | ||
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fd = open_cdev_internal(devpath, cdev); | ||
if (fd == -1 && cdev != 0) { | ||
return open_cdev_robust(cdev); | ||
} | ||
return fd; | ||
} |
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