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 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 | 12 +- 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 | 24 +- xen/arch/x86/pv/hypercall.c | 3 + xen/arch/x86/xen.lds.S | 12 +- xen/common/Kconfig | 22 ++ xen/common/Makefile | 13 + xen/common/grant_table.c | 62 +++- xen/common/hypfs.c | 385 ++++++++++++++++++++ xen/common/kernel.c | 82 ++++- xen/common/sysctl.c | 36 -- xen/drivers/char/console.c | 77 +++- xen/include/Makefile | 1 + xen/include/asm-x86/hvm/vmx/vmcs.h | 3 +- xen/include/public/hypfs.h | 127 +++++++ xen/include/public/sysctl.h | 19 +- xen/include/public/xen.h | 1 + xen/include/xen/hypercall.h | 10 + xen/include/xen/hypfs.h | 124 +++++++ xen/include/xen/kernel.h | 3 + xen/include/xen/lib.h | 1 - xen/include/xen/param.h | 123 +++++-- 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, 2379 insertions(+), 190 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 -- 2.26.1
