Merge tag 'x86_boot_for_v6.6_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 boot updates from Borislav Petkov:
 "Avoid the baremetal decompressor code when booting on an EFI machine.

  This is mandated by the current tightening of EFI executables
  requirements when used in a secure boot scenario. More specifically,
  an EFI executable cannot have a single section with RWX permissions,
  which conflicts with the in-place kernel decompression that is done
  today.

  Instead, the things required by the booting kernel image are done in
  the EFI stub now.

  Work by Ard Biesheuvel"

* tag 'x86_boot_for_v6.6_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  x86/efistub: Avoid legacy decompressor when doing EFI boot
  x86/efistub: Perform SNP feature test while running in the firmware
  efi/libstub: Add limit argument to efi_random_alloc()
  x86/decompressor: Factor out kernel decompression and relocation
  x86/decompressor: Move global symbol references to C code
  decompress: Use 8 byte alignment
  x86/efistub: Prefer EFI memory attributes protocol over DXE services
  x86/efistub: Perform 4/5 level paging switch from the stub
  x86/decompressor: Merge trampoline cleanup with switching code
  x86/decompressor: Pass pgtable address to trampoline directly
  x86/decompressor: Only call the trampoline when changing paging levels
  x86/decompressor: Call trampoline directly from C code
  x86/decompressor: Avoid the need for a stack in the 32-bit trampoline
  x86/decompressor: Use standard calling convention for trampoline
  x86/decompressor: Call trampoline as a normal function
  x86/decompressor: Assign paging related global variables earlier
  x86/decompressor: Store boot_params pointer in callee save register
  x86/efistub: Clear BSS in EFI handover protocol entrypoint
  x86/decompressor: Avoid magic offsets for EFI handover entrypoint
  x86/efistub: Simplify and clean up handover entry code
  ...

3 files changed, 19 insertions, 2 deletions

diff --git a/arch/x86/include/asm/boot.h b/arch/x86/include/asm/boot.h
index 9191280d9ea3..4ae14339cb8c 100644
--- a/arch/x86/include/asm/boot.h
+++ b/arch/x86/include/asm/boot.h
@@ -62,4 +62,12 @@
 # define BOOT_STACK_SIZE	0x1000
 #endif
 
+#ifndef __ASSEMBLY__
+extern unsigned int output_len;
+extern const unsigned long kernel_total_size;
+
+unsigned long decompress_kernel(unsigned char *outbuf, unsigned long virt_addr,
+				void (*error)(char *x));
+#endif
+
 #endif /* _ASM_X86_BOOT_H */
diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 8b4be7cecdb8..b0994ae3bc23 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -90,6 +90,8 @@ static inline void efi_fpu_end(void)
 }
 
 #ifdef CONFIG_X86_32
+#define EFI_X86_KERNEL_ALLOC_LIMIT		(SZ_512M - 1)
+
 #define arch_efi_call_virt_setup()					\
 ({									\
 	efi_fpu_begin();						\
@@ -103,8 +105,7 @@ static inline void efi_fpu_end(void)
 })
 
 #else /* !CONFIG_X86_32 */
-
-#define EFI_LOADER_SIGNATURE	"EL64"
+#define EFI_X86_KERNEL_ALLOC_LIMIT		EFI_ALLOC_LIMIT
 
 extern asmlinkage u64 __efi_call(void *fp, ...);
 
@@ -218,6 +219,8 @@ efi_status_t efi_set_virtual_address_map(unsigned long memory_map_size,
 
 #ifdef CONFIG_EFI_MIXED
 
+#define EFI_ALLOC_LIMIT		(efi_is_64bit() ? ULONG_MAX : U32_MAX)
+
 #define ARCH_HAS_EFISTUB_WRAPPERS
 
 static inline bool efi_is_64bit(void)
diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index 66c806784c52..5b4a1ce3d368 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -164,6 +164,7 @@ static __always_inline void sev_es_nmi_complete(void)
 		__sev_es_nmi_complete();
 }
 extern int __init sev_es_efi_map_ghcbs(pgd_t *pgd);
+extern void sev_enable(struct boot_params *bp);
 
 static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs)
 {
@@ -210,12 +211,15 @@ bool snp_init(struct boot_params *bp);
 void __init __noreturn snp_abort(void);
 int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio);
 void snp_accept_memory(phys_addr_t start, phys_addr_t end);
+u64 snp_get_unsupported_features(u64 status);
+u64 sev_get_status(void);
 #else
 static inline void sev_es_ist_enter(struct pt_regs *regs) { }
 static inline void sev_es_ist_exit(void) { }
 static inline int sev_es_setup_ap_jump_table(struct real_mode_header *rmh) { return 0; }
 static inline void sev_es_nmi_complete(void) { }
 static inline int sev_es_efi_map_ghcbs(pgd_t *pgd) { return 0; }
+static inline void sev_enable(struct boot_params *bp) { }
 static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate) { return 0; }
 static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs) { return 0; }
 static inline void setup_ghcb(void) { }
@@ -235,6 +239,8 @@ static inline int snp_issue_guest_request(u64 exit_code, struct snp_req_data *in
 }
 
 static inline void snp_accept_memory(phys_addr_t start, phys_addr_t end) { }
+static inline u64 snp_get_unsupported_features(u64 status) { return 0; }
+static inline u64 sev_get_status(void) { return 0; }
 #endif
 
 #endif