[v9,00/12] Add hypervisor sysfs-like support

Message

Jürgen Groß May 15, 2020, 11:58 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.

The series adds read-only nodes with buildinfo data and writable
nodes with runtime parameters. xl is switched to use the new file
system for modifying the runtime parameters and the old sysctl
interface for that purpose is dropped.

Changes in V9:
- addressed review comments

Changes in V8:
- addressed review comments
- added CONFIG_HYPFS config option

Changes in V7:
- old patch 1 already applied
- add new patch 1 (carved out and modified from patch 9)
- addressed review comments
- modified public interface to have a max write size instead of a
  writable flag only

Changes in V6:
- added new patches 1, 10, 11, 12
- addressed review comments
- modified interface for creating nodes for runtime parameters

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 (12):
  xen/vmx: let opt_ept_ad always reflect the current setting
  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
  tools/libxl: use libxenhypfs for setting xen runtime parameters
  tools/libxc: remove xc_set_parameters()
  xen: remove XEN_SYSCTL_set_parameter support

 .gitignore                          |   6 +
 docs/features/hypervisorfs.pandoc   |  92 +++++
 docs/man/xenhypfs.1.pod             |  61 ++++
 docs/misc/hypfs-paths.pandoc        | 165 +++++++++
 tools/Rules.mk                      |   8 +-
 tools/flask/policy/modules/dom0.te  |   4 +-
 tools/libs/Makefile                 |   1 +
 tools/libs/hypfs/Makefile           |  16 +
 tools/libs/hypfs/core.c             | 536 ++++++++++++++++++++++++++++
 tools/libs/hypfs/include/xenhypfs.h |  90 +++++
 tools/libs/hypfs/libxenhypfs.map    |  10 +
 tools/libs/hypfs/xenhypfs.pc.in     |  10 +
 tools/libxc/include/xenctrl.h       |   1 -
 tools/libxc/xc_misc.c               |  21 --
 tools/libxl/Makefile                |   3 +-
 tools/libxl/libxl.c                 |  53 ++-
 tools/libxl/libxl_internal.h        |   1 +
 tools/libxl/xenlight.pc.in          |   2 +-
 tools/misc/Makefile                 |   6 +
 tools/misc/xenhypfs.c               | 192 ++++++++++
 tools/xl/xl_misc.c                  |   1 -
 xen/arch/arm/traps.c                |   3 +
 xen/arch/arm/xen.lds.S              |  13 +-
 xen/arch/x86/hvm/hypercall.c        |   3 +
 xen/arch/x86/hvm/vmx/vmcs.c         |  47 ++-
 xen/arch/x86/hvm/vmx/vmx.c          |   4 +-
 xen/arch/x86/hypercall.c            |   3 +
 xen/arch/x86/pv/domain.c            |  21 +-
 xen/arch/x86/pv/hypercall.c         |   3 +
 xen/arch/x86/xen.lds.S              |  12 +-
 xen/common/Kconfig                  |  23 ++
 xen/common/Makefile                 |  13 +
 xen/common/grant_table.c            |  62 +++-
 xen/common/hypfs.c                  | 448 +++++++++++++++++++++++
 xen/common/kernel.c                 |  84 ++++-
 xen/common/sysctl.c                 |  36 --
 xen/drivers/char/console.c          |  72 +++-
 xen/include/Makefile                |   1 +
 xen/include/asm-x86/hvm/vmx/vmcs.h  |   3 +-
 xen/include/public/hypfs.h          | 129 +++++++
 xen/include/public/sysctl.h         |  19 +-
 xen/include/public/xen.h            |   1 +
 xen/include/xen/hypercall.h         |  10 +
 xen/include/xen/hypfs.h             | 123 +++++++
 xen/include/xen/kernel.h            |   3 +
 xen/include/xen/lib.h               |   1 -
 xen/include/xen/param.h             | 126 +++++--
 xen/include/xlat.lst                |   2 +
 xen/include/xsm/dummy.h             |   6 +
 xen/include/xsm/xsm.h               |   6 +
 xen/tools/binfile                   |  41 +++
 xen/xsm/dummy.c                     |   1 +
 xen/xsm/flask/Makefile              |   5 +-
 xen/xsm/flask/flask-policy.S        |  16 -
 xen/xsm/flask/hooks.c               |   9 +-
 xen/xsm/flask/policy/access_vectors |   4 +-
 56 files changed, 2439 insertions(+), 193 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