[patch 00/12 v4] kexec kernel efi runtime support

dyoung at redhat.com dyoung at redhat.com
Mon Nov 25 03:56:30 EST 2013


Sorry for the spam, the patch subject is not correct in previous
sending a while ago, send them again..

Here is the V4 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 at darkstar ~]$ tree /sys/firmware/efi/runtime-map/
├── 0
│   ├── attribute
│   ├── num_pages
│   ├── phys_addr
│   ├── type
│   └── virt_addr
├── 1
│   ├── attribute
│   ├── num_pages
│   ├── phys_addr
│   ├── type
│   └── virt_addr
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

Please help to review the patches.

The patches are based on 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
  - 10/12: print only runtime ranges in case EFI_DEBUG printing
  - 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.
  - fix a bug of x86/kernel/kdebugfs.c, use ioremap instead of __va for
    low mem because __va does not work for exact memmap=


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