| Message ID | 20231026103104.1686921-26-zhenzhong.duan@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vfio: Adopt iommufd | expand |
On 10/26/23 12:30, Zhenzhong Duan wrote: > From: Yi Liu <yi.l.liu@intel.com> > > /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> > Signed-off-by: Cédric Le Goater <clg@redhat.com> > --- > MAINTAINERS | 6 +++ > include/qemu/chardev_open.h | 16 ++++++++ > util/chardev_open.c | 81 +++++++++++++++++++++++++++++++++++++ > util/meson.build | 1 + > 4 files changed, 104 insertions(+) > create mode 100644 include/qemu/chardev_open.h > create mode 100644 util/chardev_open.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 7aa57ab16f..123e999bee 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -3447,6 +3447,12 @@ S: Maintained > F: include/qemu/iova-tree.h > F: util/iova-tree.c > > +cdev Open > +M: Yi Liu <yi.l.liu@intel.com> > +S: Maintained > +F: include/qemu/chardev_open.h > +F: util/chardev_open.c > + > elf2dmp > M: Viktor Prutyanov <viktor.prutyanov@phystech.edu> > S: Maintained > diff --git a/include/qemu/chardev_open.h b/include/qemu/chardev_open.h > new file mode 100644 > index 0000000000..6580d351c6 > --- /dev/null > +++ b/include/qemu/chardev_open.h > @@ -0,0 +1,16 @@ > +/* > + * 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. > + */ > + > +#ifndef QEMU_CHARDEV_HELPERS_H > +#define QEMU_CHARDEV_HELPERS_H > + > +int open_cdev(const char *devpath, dev_t cdev); > +#endif > diff --git a/util/chardev_open.c b/util/chardev_open.c > new file mode 100644 > index 0000000000..005d2b81bd > --- /dev/null > +++ b/util/chardev_open.c > @@ -0,0 +1,81 @@ > +/* > + * 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 > + * > + */ > + > +#include "qemu/osdep.h" > +#include "qemu/chardev_open.h" > + > +static int open_cdev_internal(const char *path, dev_t cdev) > +{ > + struct stat st; > + int fd; > + > + 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; > +} > + > +static int open_cdev_robust(dev_t cdev) > +{ > + g_autofree char *devpath; Please initialize g_autofree variables ( = NULL) Thanks, C. > + > + /* > + * 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); > +} > + > +int open_cdev(const char *devpath, dev_t cdev) > +{ > + int fd; > + > + fd = open_cdev_internal(devpath, cdev); > + if (fd == -1 && cdev != 0) { > + return open_cdev_robust(cdev); > + } > + return fd; > +} > diff --git a/util/meson.build b/util/meson.build > index eb677b40c2..eda0b06062 100644 > --- a/util/meson.build > +++ b/util/meson.build > @@ -107,6 +107,7 @@ if have_block > util_ss.add(files('filemonitor-stub.c')) > endif > util_ss.add(when: 'CONFIG_LINUX', if_true: files('vfio-helpers.c')) > + util_ss.add(when: 'CONFIG_LINUX', if_true: files('chardev_open.c')) > endif > > if cpu == 'aarch64'
>-----Original Message----- >From: Cédric Le Goater <clg@redhat.com> >Sent: Monday, October 30, 2023 10:54 PM >Subject: Re: [PATCH v3 25/37] util/char_dev: Add open_cdev() > >On 10/26/23 12:30, Zhenzhong Duan wrote: >> From: Yi Liu <yi.l.liu@intel.com> >> >> /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> >> Signed-off-by: Cédric Le Goater <clg@redhat.com> >> --- >> MAINTAINERS | 6 +++ >> include/qemu/chardev_open.h | 16 ++++++++ >> util/chardev_open.c | 81 +++++++++++++++++++++++++++++++++++++ >> util/meson.build | 1 + >> 4 files changed, 104 insertions(+) >> create mode 100644 include/qemu/chardev_open.h >> create mode 100644 util/chardev_open.c >> >> diff --git a/MAINTAINERS b/MAINTAINERS >> index 7aa57ab16f..123e999bee 100644 >> --- a/MAINTAINERS >> +++ b/MAINTAINERS >> @@ -3447,6 +3447,12 @@ S: Maintained >> F: include/qemu/iova-tree.h >> F: util/iova-tree.c >> >> +cdev Open >> +M: Yi Liu <yi.l.liu@intel.com> >> +S: Maintained >> +F: include/qemu/chardev_open.h >> +F: util/chardev_open.c >> + >> elf2dmp >> M: Viktor Prutyanov <viktor.prutyanov@phystech.edu> >> S: Maintained >> diff --git a/include/qemu/chardev_open.h b/include/qemu/chardev_open.h >> new file mode 100644 >> index 0000000000..6580d351c6 >> --- /dev/null >> +++ b/include/qemu/chardev_open.h >> @@ -0,0 +1,16 @@ >> +/* >> + * 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. >> + */ >> + >> +#ifndef QEMU_CHARDEV_HELPERS_H >> +#define QEMU_CHARDEV_HELPERS_H >> + >> +int open_cdev(const char *devpath, dev_t cdev); >> +#endif >> diff --git a/util/chardev_open.c b/util/chardev_open.c >> new file mode 100644 >> index 0000000000..005d2b81bd >> --- /dev/null >> +++ b/util/chardev_open.c >> @@ -0,0 +1,81 @@ >> +/* >> + * 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 >> + * >> + */ >> + >> +#include "qemu/osdep.h" >> +#include "qemu/chardev_open.h" >> + >> +static int open_cdev_internal(const char *path, dev_t cdev) >> +{ >> + struct stat st; >> + int fd; >> + >> + 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; >> +} >> + >> +static int open_cdev_robust(dev_t cdev) >> +{ >> + g_autofree char *devpath; > >Please initialize g_autofree variables ( = NULL) Thanks for point out, will fix. BRs. Zhenzhong
diff --git a/MAINTAINERS b/MAINTAINERS index 7aa57ab16f..123e999bee 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -3447,6 +3447,12 @@ S: Maintained F: include/qemu/iova-tree.h F: util/iova-tree.c +cdev Open +M: Yi Liu <yi.l.liu@intel.com> +S: Maintained +F: include/qemu/chardev_open.h +F: util/chardev_open.c + elf2dmp M: Viktor Prutyanov <viktor.prutyanov@phystech.edu> S: Maintained diff --git a/include/qemu/chardev_open.h b/include/qemu/chardev_open.h new file mode 100644 index 0000000000..6580d351c6 --- /dev/null +++ b/include/qemu/chardev_open.h @@ -0,0 +1,16 @@ +/* + * 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. + */ + +#ifndef QEMU_CHARDEV_HELPERS_H +#define QEMU_CHARDEV_HELPERS_H + +int open_cdev(const char *devpath, dev_t cdev); +#endif diff --git a/util/chardev_open.c b/util/chardev_open.c new file mode 100644 index 0000000000..005d2b81bd --- /dev/null +++ b/util/chardev_open.c @@ -0,0 +1,81 @@ +/* + * 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 + * + */ + +#include "qemu/osdep.h" +#include "qemu/chardev_open.h" + +static int open_cdev_internal(const char *path, dev_t cdev) +{ + struct stat st; + int fd; + + 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; +} + +static int open_cdev_robust(dev_t cdev) +{ + g_autofree char *devpath; + + /* + * 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); +} + +int open_cdev(const char *devpath, dev_t cdev) +{ + int fd; + + fd = open_cdev_internal(devpath, cdev); + if (fd == -1 && cdev != 0) { + return open_cdev_robust(cdev); + } + return fd; +} diff --git a/util/meson.build b/util/meson.build index eb677b40c2..eda0b06062 100644 --- a/util/meson.build +++ b/util/meson.build @@ -107,6 +107,7 @@ if have_block util_ss.add(files('filemonitor-stub.c')) endif util_ss.add(when: 'CONFIG_LINUX', if_true: files('vfio-helpers.c')) + util_ss.add(when: 'CONFIG_LINUX', if_true: files('chardev_open.c')) endif if cpu == 'aarch64'