x86: Add xloadflags bit for EFI runtime support on kexec (456a29dd) · Commits · 戴 / test

Old kexec-tools can not load new kernels. The reason is kexec-tools does not fill efi_info in x86 setup header previously, thus EFI failed to initialize. In new kexec-tools it will by default to fill efi_info and pass other EFI required infomation to 2nd kernel so kexec kernel EFI initialization can succeed finally. To prevent from breaking userspace, add a new xloadflags bit so kexec-tools can check the flag and switch to old logic. Signed-off-by:

Dave Young <dyoung@redhat.com> Acked-by:

Borislav Petkov <bp@suse.de> Tested-by:

Toshi Kani <toshi.kani@hp.com> Signed-off-by:

Matt Fleming <matt.fleming@intel.com>

Documentation/x86/boot.txt

+3 −0

Original line number	Diff line number	Diff line
		@@ -608,6 +608,9 @@ Protocol: 2.12+
		- If 1, the kernel supports the 64-bit EFI handoff entry point
		given at handover_offset + 0x200.

		Bit 4 (read): XLF_EFI_KEXEC
		- If 1, the kernel supports kexec EFI boot with EFI runtime support.

		Field name: cmdline_size
		Type: read
		Offset/size: 0x238/4

arch/x86/boot/header.S

+8 −1

Original line number	Diff line number	Diff line
		@@ -391,7 +391,14 @@ xloadflags:
		#else
		# define XLF23 0
		#endif
		.word XLF0 \| XLF1 \| XLF23

		#if defined(CONFIG_X86_64) && defined(CONFIG_EFI) && defined(CONFIG_KEXEC)
		# define XLF4 XLF_EFI_KEXEC
		#else
		# define XLF4 0
		#endif

		.word XLF0 \| XLF1 \| XLF23 \| XLF4

		cmdline_size: .long COMMAND_LINE_SIZE-1 #length of the command line,
		#added with boot protocol

arch/x86/include/uapi/asm/bootparam.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -24,6 +24,7 @@
		#define XLF_CAN_BE_LOADED_ABOVE_4G (1<<1)
		#define XLF_EFI_HANDOVER_32 (1<<2)
		#define XLF_EFI_HANDOVER_64 (1<<3)
		#define XLF_EFI_KEXEC (1<<4)

		#ifndef __ASSEMBLY__

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