libvirt's sVirt security driver provides SELinux MAC isolation for Qemu guest processes and their corresponding image files. In other words, sVirt uses SELinux to prevent a QEMU process from opening files that do not belong to it. sVirt provides this support by labeling guests and resources with security labels that are stored in file system extended attributes. Some file systems, such as NFS, do not support the extended attribute security namespace, and therefore cannot support sVirt isolation. A solution to this problem is to provide fd passing support, where libvirt opens files and passes file descriptors to QEMU. This, along with SELinux policy to prevent QEMU from opening files, can provide image file isolation for NFS files. This patch series adds the -filefd command-line option and the getfd_file monitor command. This will enable libvirt to open a file and push the corresponding filename and file descriptor to QEMU. When QEMU needs to "open" a file, it will first check if the file descriptor was passed by either of these methods before attempting to actually open the file. This series reuses the file_open function that Anthony Liguori <aliguori@xxxxxxxxxx> created for the most recent fd passing prototype. It also reuses the test driver that Stefan Hajnoczi <stefanha@xxxxxxxxxxxxxxxxxx> created for that prototype, with several modifications. Corey Bryant (4): qemu-options: Add -filefd command line option qmp/hmp: Add getfd_file monitor command block: Enable QEMU to retrieve passed fd before attempting open Example -filefd and getfd_file server block.c | 31 +++++++ block/raw-posix.c | 20 +++--- block/raw-win32.c | 4 +- block/vdi.c | 4 +- block/vmdk.c | 21 ++--- block/vpc.c | 2 +- block/vvfat.c | 4 +- block_int.h | 12 +++ hmp-commands.hx | 17 ++++ monitor.c | 70 +++++++++++++++++ monitor.h | 3 + qemu-config.c | 17 ++++ qemu-config.h | 1 + qemu-options.hx | 17 ++++ qemu-tool.c | 5 + qmp-commands.hx | 30 +++++++ test-fd-passing.c | 224 +++++++++++++++++++++++++++++++++++++++++++++++++++++ vl.c | 6 ++ 18 files changed, 459 insertions(+), 29 deletions(-) create mode 100644 test-fd-passing.c -- 1.7.7.6 -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list