linux/drivers/firmware
Ard Biesheuvel e7761d827e efi/unaccepted: Use ACPI reclaim memory for unaccepted memory table
Kyril reports that crashkernels fail to work on confidential VMs that
rely on the unaccepted memory table, and this appears to be caused by
the fact that it is not considered part of the set of firmware tables
that the crashkernel needs to map.

This is an oversight, and a result of the use of the EFI_LOADER_DATA
memory type for this table. The correct memory type to use for any
firmware table is EFI_ACPI_RECLAIM_MEMORY (including ones created by the
EFI stub), even though the name suggests that is it specific to ACPI.
ACPI reclaim means that the memory is used by the firmware to expose
information to the operating system, but that the memory region has no
special significance to the firmware itself, and the OS is free to
reclaim the memory and use it as ordinary memory if it is not interested
in the contents, or if it has already consumed them. In Linux, this
memory is never reclaimed, but it is always covered by the kernel direct
map and generally made accessible as ordinary memory.

On x86, ACPI reclaim memory is translated into E820_ACPI, which the
kexec logic already recognizes as memory that the crashkernel may need
to to access, and so it will be mapped and accessible to the booting
crash kernel.

Fixes: 745e3ed85f ("efi/libstub: Implement support for unaccepted memory")
Reported-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-09-11 06:37:51 +00:00
..
arm_ffa firmware: arm_ffa: Set handle field to zero in memory descriptor 2023-06-06 13:41:56 +01:00
arm_scmi ARM: SoC cleanups for 6.6 2023-08-30 16:49:40 -07:00
broadcom MIPS: BCM47XX: remove MODULE_LICENSE in non-modules 2023-04-13 13:13:51 -07:00
cirrus firmware: cs_dsp: Fix new control name check 2023-08-15 19:23:01 +01:00
efi efi/unaccepted: Use ACPI reclaim memory for unaccepted memory table 2023-09-11 06:37:51 +00:00
google firmware: coreboot: framebuffer: Allow building with simpledrm 2023-08-04 16:31:32 +02:00
imx ARM: SoC cleanups for 6.6 2023-08-30 16:49:40 -07:00
meson firmware: meson_sm: fix to avoid potential NULL pointer dereference 2023-08-04 15:19:01 +02:00
psci firmware/psci: demote suspend-mode warning to info level 2023-04-14 13:48:56 +02:00
smccc firmware: smccc: Fix use of uninitialised results structure 2023-07-18 10:08:05 +01:00
tegra firmware: Explicitly include correct DT includes 2023-08-12 10:31:01 +02:00
xilinx Pin control bulk changes for the v6.6 kernel cycle: 2023-08-30 19:36:19 -07:00
arm_scpi.c
arm_sdei.c arm64: sdei: abort running SDEI handlers during crash 2023-08-04 17:35:33 +01:00
dmi_scan.c firmware: dmi: Fortify entry point length checks 2022-09-23 14:53:14 +02:00
dmi-id.c driver core: make struct class.dev_uevent() take a const * 2022-11-24 17:12:15 +01:00
dmi-sysfs.c firmware: dmi-sysfs: handle HAS_IOPORT=n 2023-05-31 19:17:29 +01:00
edd.c edd: make kobj_type structure constant 2023-03-09 18:07:33 +01:00
iscsi_ibft_find.c iscsi_ibft: Fix finding the iBFT under Xen Dom 0 2023-06-26 07:47:11 +02:00
iscsi_ibft.c
Kconfig
Makefile
memmap.c
mtk-adsp-ipc.c firmware: Explicitly include correct DT includes 2023-08-12 10:31:01 +02:00
pcdp.c
pcdp.h
qcom_scm-legacy.c firmware: qcom_scm: Move qcom_scm.h to include/linux/firmware/qcom/ 2023-02-08 19:15:16 -08:00
qcom_scm-smc.c firmware: qcom_scm: Move qcom_scm.h to include/linux/firmware/qcom/ 2023-02-08 19:15:16 -08:00
qcom_scm.c firmware: qcom_scm: Convert all symbols to EXPORT_SYMBOL_GPL 2023-07-27 20:29:06 -07:00
qcom_scm.h firmware: qcom: scm: Add wait-queue handling logic 2023-01-18 21:14:40 -06:00
qemu_fw_cfg.c
raspberrypi.c firmware: Explicitly include correct DT includes 2023-08-12 10:31:01 +02:00
scpi_pm_domain.c firmware: Explicitly include correct DT includes 2023-08-12 10:31:01 +02:00
stratix10-rsu.c Char/Misc driver changes for 6.6-rc1 2023-09-01 09:53:54 -07:00
stratix10-svc.c firmware: stratix10-svc: Generic Mailbox Command 2023-08-04 16:31:37 +02:00
sysfb_simplefb.c firmware/sysfb: Fix VESA format selection 2023-04-21 14:27:31 +02:00
sysfb.c drivers/firmware: Move sysfb_init() from device_initcall to subsys_initcall_sync 2023-05-15 13:36:30 +02:00
ti_sci.c firmware: ti_sci: Fixup documentation errors 2023-07-11 13:04:14 -05:00
ti_sci.h
trusted_foundations.c
turris-mox-rwtm.c firmware: turris-mox-rwtm: make kobj_type structure constant 2023-04-07 17:17:00 +02:00