[PATCH v7 00/12] kexec kernel efi runtime support

Dave Young
2013-12-20T10:02:10Z

Here is the V7 patchset for supporting kexec kernel efi runtime.
Per pervious discussion I pass the 1st kernel efi runtime mapping
via setup_data to 2nd kernel. Besides of the runtime mapping
info I also pass the fw_vendor, runtime, config table, smbios
physical address in setup_data. EFI spec mentioned fw_vendor,
runtime, config table addresses will be converted to virt address
after entering virtual mode, but we will use it as physical address
in efi_init. For smbios EFI spec did not mention about the address
updating, but during my test on a HP workstation, the bios will
convert it to Virt addr, thus pass it in setup_data as well.

For fw_vendor, runtime, config table, I export them in /sys/firmware/
efi/, smbios is already in /sys/firmware/efi/systab.

For efi runtime mapping I add a new directory /sys/firmware/efi/
runtime-map/ like below
[dave@darkstar ~]$ tree /sys/firmware/efi/runtime-map/
/sys/firmware/efi/runtime-map/
|__ 0
| |__ attribute
| |__ num_pages
| |__ phys_addr
| |__ type
| |__ virt_addr
|__ 1
[snip]

kexec-tools will assemble them as setup_data and pass to 2nd kernel.
I will send userspace patches as well.

Limitation is I only write support for x86_64, test on below machines:
Lenovo thinkpad t420
Dell inspiron 14 - 3421
HP Z420 workstation
Qemu + OVMF

The patches are based on linus tree + tip master + matt's efi master tree

Changes from v1:
- add one flag in xloadflags, so kexec-tools can safely load old kernel
without efi support.
- coding style fixes
- function name for map phys_addr to fixed virt_addr
- Add ABI documentation for sysfs files

Changes from v2:
- 01/09: a new patch to remove unused variables in __map_region function
catched by Toshi Kani
- 09/09: a new patch to export x86 boot_params to sysfs instead of use
debugfs files
- Matt: reuse __map_region instead do same thing in another function.
add a wrapper function efi_map_region_fixed [02/09]
check return value of krealloc
sysfs dir name s/efi-runtime-map/runtime-map [06/09]
use desc_size in efi_runtime_map
for the xloadflags defination: +&& defined(CONFIG_KEXEC)
- Greg: sysfs : one file one value for fw_vendor, runtime, tables. [05/09]
Document them in ABI testing
- HPA: Document the new xloadflag
- Also there's other function cleanup and improvement for error handling.

Changes from v3:
- Greg: sysfs code move to use __ATTR_RO and attr_group
- Boris: comments and code alignment

- Added 3 new patches below
10-print-efi-runtime-memmap.patch
- 10/12: print only runtime ranges in case EFI_DEBUG printing
11-reserve-setup-data-late.patch
- fix a bug of kdump kernel, move function for reserving setup data
ranges late after parsing memmap= cmdline params because kdump kernel
will pass exact memmap late.
12-x86-kdebugfs-use-ioremap.patch
- fix a bug of x86/kernel/kdebugfs.c, use ioremap instead of __va for
low mem because __va does not work for exact memmap=

Changes from V4:
- variable efi_setup in 09/14 is changed to the physical address instead
of the virtual address because it will be not iounmapped until entering
virtual mode, it's too long and could cause leak.
- sparse warnings fixes (Matt):
Added 2 new patches to addressing sparse warnings:
01/14: x86-mm-sparse-warning-fix-for-early_memremap.patch
02/14: efi-use-early_memremap-and-early_memunmap.patch
- krealloc fixes (Boris)
- rebase on top of Linus tree + Matt's efi master tree (Boris)
- a lot of documention/spelling fixes (Boris)
- share function save_runtime_map in 1st/2nd kernel code (Matt)
- style and other fixes detail see the patch changelog themselves.

Changes from V5:
- add efi_runtime_map_setup() and remove the extern variables thus other
arches can reuse the runtime_map exporting code. (Matt)
- check efi_reuse_config return value. (Matt)
- move parse_efi_setup to efi_$(BITS).c (Boris)
- call efi_runtime_map_init in efisubsys_init (Boris)
- save_runtime_map cleanup. (Boris)

Changes from V6:
- update memmap in userspace to the saved runtime map, thus kernel code
become cleaner.
- patch 08: simplify save_runtime_map.
- patch 09: simplify efi_map_regions and efi_map_regions_fixed.
- remove the patch to handle print_efi_memmap for kexec kernel
- remove the last patch for fixing __va usage in kdebugfs since I can not
reproduce it in kdump kernel, it should be addressed seperately.
- patch 06 (efi: cleanup efi_enter_virtual_mode function):
add a share function get_systab_virt_addr()
- rebase to latest mainline tree

The patches stay in kexec-efi-testing branch of below repo for testing:
https://github.com/daveyoung/linux.git

Dave Young (12):
x86/mm: sparse warning fix for early_memremap
efi: Use early_memremap and early_memunmap to fix sparse warnings
efi: remove unused variables in __map_region
efi: add a wrapper function efi_map_region_fixed
efi: reserve boot service fix
efi: cleanup efi_enter_virtual_mode function
efi: export more efi table variable to sysfs
efi: export efi runtime memory mapping to sysfs
efi: passing kexec necessary efi data via setup_data
x86: add xloadflags bit for efi runtime support on kexec
x86: export x86 boot_params to sysfs
x86: reserve setup_data ranges late after parsing memmap cmdline

Documentation/ABI/testing/sysfs-firmware-efi | 20 ++
.../ABI/testing/sysfs-firmware-efi-runtime-map | 34 ++
Documentation/ABI/testing/sysfs-kernel-boot_params | 38 +++
Documentation/x86/boot.txt | 3 +
arch/x86/boot/header.S | 9 +-
arch/x86/include/asm/efi.h | 14 +
arch/x86/include/asm/io.h | 3 +-
arch/x86/include/uapi/asm/bootparam.h | 2 +
arch/x86/kernel/Makefile | 1 +
arch/x86/kernel/ksysfs.c | 339 ++++++++++++++++++++
arch/x86/kernel/setup.c | 7 +-
arch/x86/mm/ioremap.c | 10 +-
arch/x86/platform/efi/efi.c | 345 ++++++++++++++++-----
arch/x86/platform/efi/efi_32.c | 3 +
arch/x86/platform/efi/efi_64.c | 22 +-
drivers/firmware/efi/Kconfig | 11 +
drivers/firmware/efi/Makefile | 1 +
drivers/firmware/efi/efi.c | 49 ++-
drivers/firmware/efi/runtime-map.c | 181 +++++++++++
include/linux/efi.h | 16 +
20 files changed, 1010 insertions(+), 98 deletions(-)
create mode 100644 Documentation/ABI/testing/sysfs-firmware-efi
create mode 100644 Documentation/ABI/testing/sysfs-firmware-efi-runtime-map
create mode 100644 Documentation/ABI/testing/sysfs-kernel-boot_params
create mode 100644 arch/x86/kernel/ksysfs.c
create mode 100644 drivers/firmware/efi/runtime-map.c

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1.8.3.1