[v5,0/8] Add hypervisor sysfs-like support

Message

Jürgen Groß Feb. 19, 2020, 8:11 a.m. UTC

On the 2019 Xen developer summit there was agreement that the Xen
hypervisor should gain support for a hierarchical name-value store
similar to the Linux kernel's sysfs.

This is a first implementation of that idea adding the basic
functionality to hypervisor and tools side. The interface to any
user program making use of that "xen-hypfs" is a new library
"libxenhypfs" with a stable interface.

As a followup switching libxl to use the hypervisor file system for
runtime parameter modifications is possible. This would enable
removal of the XEN_SYSCTL_set_parameter sysctl operation.

Changes in V5:
- switched to xsm for privilege check

Changes in V4:
- former patch 2 removed as already committed
- addressed review comments

Changes in V3:
- major rework, especially by supporting binary contents of entries
- added several new patches (1, 2, 7)
- full support of all runtime parameters
- support of writing entries (especially runtime parameters)

Changes in V2:
- all comments to V1 addressed
- added man-page for xenhypfs tool
- added runtime parameter read access for string parameters

Changes in V1:
- renamed xenfs ->xenhypfs
- added writable entries support at the interface level and in the
  xenhypfs tool
- added runtime parameter read access (integer type only for now)
- added docs/misc/hypfs-paths.pandoc for path descriptions

Juergen Gross (8):
  xen: add a generic way to include binary files as variables
  docs: add feature document for Xen hypervisor sysfs-like support
  xen: add basic hypervisor filesystem support
  libs: add libxenhypfs
  tools: add xenfs tool
  xen: provide version information in hypfs
  xen: add /buildinfo/config entry to hypervisor filesystem
  xen: add runtime parameter access support to hypfs

 .gitignore                          |   6 +
 docs/features/hypervisorfs.pandoc   |  92 +++++++
 docs/man/xenhypfs.1.pod             |  61 +++++
 docs/misc/hypfs-paths.pandoc        | 163 +++++++++++
 tools/Rules.mk                      |   6 +
 tools/flask/policy/modules/dom0.te  |   2 +-
 tools/libs/Makefile                 |   1 +
 tools/libs/hypfs/Makefile           |  16 ++
 tools/libs/hypfs/core.c             | 533 ++++++++++++++++++++++++++++++++++++
 tools/libs/hypfs/include/xenhypfs.h |  75 +++++
 tools/libs/hypfs/libxenhypfs.map    |  10 +
 tools/libs/hypfs/xenhypfs.pc.in     |  10 +
 tools/misc/Makefile                 |   6 +
 tools/misc/xenhypfs.c               | 189 +++++++++++++
 xen/arch/arm/traps.c                |   1 +
 xen/arch/arm/xen.lds.S              |   5 +
 xen/arch/x86/hvm/hypercall.c        |   1 +
 xen/arch/x86/hvm/vmx/vmcs.c         |  17 +-
 xen/arch/x86/hypercall.c            |   1 +
 xen/arch/x86/pv/domain.c            |   7 +-
 xen/arch/x86/pv/hypercall.c         |   1 +
 xen/arch/x86/xen.lds.S              |   5 +
 xen/common/Makefile                 |  13 +
 xen/common/grant_table.c            |  17 +-
 xen/common/hypfs.c                  | 395 ++++++++++++++++++++++++++
 xen/common/kernel.c                 |  78 +++++-
 xen/drivers/char/console.c          |  49 +++-
 xen/include/public/hypfs.h          | 127 +++++++++
 xen/include/public/xen.h            |   1 +
 xen/include/xen/hypercall.h         |   8 +
 xen/include/xen/hypfs.h             | 112 ++++++++
 xen/include/xen/kernel.h            |   3 +
 xen/include/xen/param.h             |  74 ++++-
 xen/include/xlat.lst                |   2 +
 xen/include/xsm/dummy.h             |   6 +
 xen/include/xsm/xsm.h               |   6 +
 xen/tools/binfile                   |  41 +++
 xen/xsm/flask/Makefile              |   5 +-
 xen/xsm/flask/flask-policy.S        |  16 --
 xen/xsm/flask/policy/access_vectors |   2 +
 40 files changed, 2123 insertions(+), 40 deletions(-)
 create mode 100644 docs/features/hypervisorfs.pandoc
 create mode 100644 docs/man/xenhypfs.1.pod
 create mode 100644 docs/misc/hypfs-paths.pandoc
 create mode 100644 tools/libs/hypfs/Makefile
 create mode 100644 tools/libs/hypfs/core.c
 create mode 100644 tools/libs/hypfs/include/xenhypfs.h
 create mode 100644 tools/libs/hypfs/libxenhypfs.map
 create mode 100644 tools/libs/hypfs/xenhypfs.pc.in
 create mode 100644 tools/misc/xenhypfs.c
 create mode 100644 xen/common/hypfs.c
 create mode 100644 xen/include/public/hypfs.h
 create mode 100644 xen/include/xen/hypfs.h
 create mode 100755 xen/tools/binfile
 delete mode 100644 xen/xsm/flask/flask-policy.S