f1e5250094
When running as a Xen PV guest there is no need for setting up the
realmode trampoline, as realmode isn't supported in this environment.
Trying to setup the trampoline has been proven to be problematic in
some cases, especially when trying to debug early boot problems with
Xen requiring to keep the EFI boot-services memory mapped (some
firmware variants seem to claim basically all memory below 1Mb for boot
services).
Introduce new x86_platform_ops operations for that purpose, which can
be set to a NOP by the Xen PV specific kernel boot code.
[ bp: s/call_init_real_mode/do_init_real_mode/ ]
Fixes: 084ee1c641 ("x86, realmode: Relocator for realmode code")
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20221123114523.3467-1-jgross@suse.com
98 lines
2.1 KiB
C
98 lines
2.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ARCH_X86_REALMODE_H
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#define _ARCH_X86_REALMODE_H
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/*
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* Flag bit definitions for use with the flags field of the trampoline header
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* in the CONFIG_X86_64 variant.
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*/
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#define TH_FLAGS_SME_ACTIVE_BIT 0
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#define TH_FLAGS_SME_ACTIVE BIT(TH_FLAGS_SME_ACTIVE_BIT)
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#ifndef __ASSEMBLY__
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#include <linux/types.h>
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#include <asm/io.h>
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/* This must match data at realmode/rm/header.S */
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struct real_mode_header {
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u32 text_start;
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u32 ro_end;
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/* SMP trampoline */
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u32 trampoline_start;
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u32 trampoline_header;
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#ifdef CONFIG_AMD_MEM_ENCRYPT
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u32 sev_es_trampoline_start;
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#endif
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#ifdef CONFIG_X86_64
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u32 trampoline_start64;
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u32 trampoline_pgd;
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#endif
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/* ACPI S3 wakeup */
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#ifdef CONFIG_ACPI_SLEEP
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u32 wakeup_start;
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u32 wakeup_header;
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#endif
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/* APM/BIOS reboot */
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u32 machine_real_restart_asm;
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#ifdef CONFIG_X86_64
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u32 machine_real_restart_seg;
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#endif
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};
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/* This must match data at realmode/rm/trampoline_{32,64}.S */
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struct trampoline_header {
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#ifdef CONFIG_X86_32
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u32 start;
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u16 gdt_pad;
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u16 gdt_limit;
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u32 gdt_base;
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#else
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u64 start;
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u64 efer;
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u32 cr4;
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u32 flags;
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#endif
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};
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extern struct real_mode_header *real_mode_header;
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extern unsigned char real_mode_blob_end[];
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extern unsigned long initial_code;
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extern unsigned long initial_gs;
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extern unsigned long initial_stack;
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#ifdef CONFIG_AMD_MEM_ENCRYPT
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extern unsigned long initial_vc_handler;
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#endif
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extern unsigned char real_mode_blob[];
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extern unsigned char real_mode_relocs[];
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#ifdef CONFIG_X86_32
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extern unsigned char startup_32_smp[];
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extern unsigned char boot_gdt[];
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#else
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extern unsigned char secondary_startup_64[];
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extern unsigned char secondary_startup_64_no_verify[];
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#endif
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static inline size_t real_mode_size_needed(void)
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{
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if (real_mode_header)
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return 0; /* already allocated. */
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return ALIGN(real_mode_blob_end - real_mode_blob, PAGE_SIZE);
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}
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static inline void set_real_mode_mem(phys_addr_t mem)
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{
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real_mode_header = (struct real_mode_header *) __va(mem);
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}
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void reserve_real_mode(void);
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void load_trampoline_pgtable(void);
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void init_real_mode(void);
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#endif /* __ASSEMBLY__ */
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#endif /* _ARCH_X86_REALMODE_H */
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