Merge tag 'efi-next-for-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

Pull EFI updates from Ard Biesheuvel:
 "Note the removal of the EFI fake memory map support - this is believed
  to be unused and no longer worth supporting. However, we could easily
  bring it back if needed.

  With recent developments regarding confidential VMs and unaccepted
  memory, combined with kexec, creating a known inaccurate view of the
  firmware's memory map and handing it to the OS is a feature we can
  live without, hence the removal. Alternatively, I could imagine making
  this feature mutually exclusive with those confidential VM related
  features, but let's try simply removing it first.

  Summary:

   - Drop support for the 'fake' EFI memory map on x86

   - Add an SMBIOS based tweak to the EFI stub instructing the firmware
     on x86 Macbook Pros to keep both GPUs enabled

   - Replace 0-sized array with flexible array in EFI memory attributes
     table handling

   - Drop redundant BSS clearing when booting via the native PE
     entrypoint on x86

   - Avoid returning EFI_SUCCESS when aborting on an out-of-memory
     condition

   - Cosmetic tweak for arm64 KASLR loading logic"

* tag 'efi-next-for-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efi: Replace efi_memory_attributes_table_t 0-sized array with flexible array
  efi: Rename efi_early_memdesc_ptr() to efi_memdesc_ptr()
  arm64/efistub: Clean up KASLR logic
  x86/efistub: Drop redundant clearing of BSS
  x86/efistub: Avoid returning EFI_SUCCESS on error
  x86/efistub: Call Apple set_os protocol on dual GPU Intel Macs
  x86/efistub: Enable SMBIOS protocol handling for x86
  efistub/smbios: Simplify SMBIOS enumeration API
  x86/efi: Drop support for fake EFI memory maps

Author: torvalds

Documentation/admin-guide/kernel-parameters.txt

@@ -1435,27 +1435,6 @@
 			you are really sure that your UEFI does sane gc and
 			fulfills the spec otherwise your board may brick.
 
-	efi_fake_mem=	nn[KMG]@ss[KMG]:aa[,nn[KMG]@ss[KMG]:aa,..] [EFI,X86,EARLY]
-			Add arbitrary attribute to specific memory range by
-			updating original EFI memory map.
-			Region of memory which aa attribute is added to is
-			from ss to ss+nn.
-
-			If efi_fake_mem=2G@4G:0x10000,2G@0x10a0000000:0x10000
-			is specified, EFI_MEMORY_MORE_RELIABLE(0x10000)
-			attribute is added to range 0x100000000-0x180000000 and
-			0x10a0000000-0x1120000000.
-
-			If efi_fake_mem=8G@9G:0x40000 is specified, the
-			EFI_MEMORY_SP(0x40000) attribute is added to
-			range 0x240000000-0x43fffffff.
-
-			Using this parameter you can do debugging of EFI memmap
-			related features. For example, you can do debugging of
-			Address Range Mirroring feature even if your box
-			doesn't support it, or mark specific memory as
-			"soft reserved".
-
 	efivar_ssdt=	[EFI; X86] Name of an EFI variable that contains an SSDT
 			that is to be dynamically loaded by Linux. If there are
 			multiple variables with the same name but with different

arch/x86/Kconfig

@@ -2045,26 +2045,6 @@ config EFI_MIXED
 
 	  If unsure, say N.
 
-config EFI_FAKE_MEMMAP
-	bool "Enable EFI fake memory map"
-	depends on EFI
-	help
-	  Saying Y here will enable "efi_fake_mem" boot option.  By specifying
-	  this parameter, you can add arbitrary attribute to specific memory
-	  range by updating original (firmware provided) EFI memmap.  This is
-	  useful for debugging of EFI memmap related feature, e.g., Address
-	  Range Mirroring feature.
-
-config EFI_MAX_FAKE_MEM
-	int "maximum allowable number of ranges in efi_fake_mem boot option"
-	depends on EFI_FAKE_MEMMAP
-	range 1 128
-	default 8
-	help
-	  Maximum allowable number of ranges in efi_fake_mem boot option.
-	  Ranges can be set up to this value using comma-separated list.
-	  The default value is 8.
-
 config EFI_RUNTIME_MAP
 	bool "Export EFI runtime maps to sysfs" if EXPERT
 	depends on EFI

arch/x86/boot/compressed/kaslr.c

@@ -119,13 +119,8 @@ char *skip_spaces(const char *str)
 #include "../../../../lib/ctype.c"
 #include "../../../../lib/cmdline.c"
 
-enum parse_mode {
-	PARSE_MEMMAP,
-	PARSE_EFI,
-};
-
 static int
-parse_memmap(char *p, u64 *start, u64 *size, enum parse_mode mode)
+parse_memmap(char *p, u64 *start, u64 *size)
 {
 	char *oldp;
 
@@ -148,29 +143,11 @@ parse_memmap(char *p, u64 *start, u64 *size, enum parse_mode mode)
 		*start = memparse(p + 1, &p);
 		return 0;
 	case '@':
-		if (mode == PARSE_MEMMAP) {
-			/*
-			 * memmap=nn@ss specifies usable region, should
-			 * be skipped
-			 */
-			*size = 0;
-		} else {
-			u64 flags;
-
-			/*
-			 * efi_fake_mem=nn@ss:attr the attr specifies
-			 * flags that might imply a soft-reservation.
-			 */
-			*start = memparse(p + 1, &p);
-			if (p && *p == ':') {
-				p++;
-				if (kstrtoull(p, 0, &flags) < 0)
-					*size = 0;
-				else if (flags & EFI_MEMORY_SP)
-					return 0;
-			}
-			*size = 0;
-		}
+		/*
+		 * memmap=nn@ss specifies usable region, should
+		 * be skipped
+		 */
+		*size = 0;
 		fallthrough;
 	default:
 		/*
@@ -185,7 +162,7 @@ parse_memmap(char *p, u64 *start, u64 *size, enum parse_mode mode)
 	return -EINVAL;
 }
 
-static void mem_avoid_memmap(enum parse_mode mode, char *str)
+static void mem_avoid_memmap(char *str)
 {
 	static int i;
 
@@ -200,7 +177,7 @@ static void mem_avoid_memmap(enum parse_mode mode, char *str)
 		if (k)
 			*k++ = 0;
 
-		rc = parse_memmap(str, &start, &size, mode);
+		rc = parse_memmap(str, &start, &size);
 		if (rc < 0)
 			break;
 		str = k;
@@ -281,7 +258,7 @@ static void handle_mem_options(void)
 			break;
 
 		if (!strcmp(param, "memmap")) {
-			mem_avoid_memmap(PARSE_MEMMAP, val);
+			mem_avoid_memmap(val);
 		} else if (IS_ENABLED(CONFIG_X86_64) && strstr(param, "hugepages")) {
 			parse_gb_huge_pages(param, val);
 		} else if (!strcmp(param, "mem")) {
@@ -295,8 +272,6 @@ static void handle_mem_options(void)
 
 			if (mem_size < mem_limit)
 				mem_limit = mem_size;
-		} else if (!strcmp(param, "efi_fake_mem")) {
-			mem_avoid_memmap(PARSE_EFI, val);
 		}
 	}
 

arch/x86/include/asm/efi.h

@@ -229,7 +229,8 @@ static inline bool efi_is_native(void)
 
 static inline void *efi64_zero_upper(void *p)
 {
-	((u32 *)p)[1] = 0;
+	if (p)
+		((u32 *)p)[1] = 0;
 	return p;
 }
 
@@ -315,6 +316,10 @@ static inline u32 efi64_convert_status(efi_status_t status)
 #define __efi64_argmap_clear_memory_attributes(protocol, phys, size, flags) \
 	((protocol), __efi64_split(phys), __efi64_split(size), __efi64_split(flags))
 
+/* EFI SMBIOS protocol */
+#define __efi64_argmap_get_next(protocol, smbioshandle, type, record, phandle) \
+	((protocol), (smbioshandle), (type), efi64_zero_upper(record), \
+	 efi64_zero_upper(phandle))
 /*
  * The macros below handle the plumbing for the argument mapping. To add a
  * mapping for a specific EFI method, simply define a macro
@@ -384,23 +389,8 @@ static inline void efi_reserve_boot_services(void)
 }
 #endif /* CONFIG_EFI */
 
-#ifdef CONFIG_EFI_FAKE_MEMMAP
-extern void __init efi_fake_memmap_early(void);
-extern void __init efi_fake_memmap(void);
-#else
-static inline void efi_fake_memmap_early(void)
-{
-}
-
-static inline void efi_fake_memmap(void)
-{
-}
-#endif
-
 extern int __init efi_memmap_alloc(unsigned int num_entries,
 				   struct efi_memory_map_data *data);
-extern void __efi_memmap_free(u64 phys, unsigned long size,
-			      unsigned long flags);
 
 extern int __init efi_memmap_install(struct efi_memory_map_data *data);
 extern int __init efi_memmap_split_count(efi_memory_desc_t *md,

arch/x86/kernel/setup.c

@@ -997,7 +997,6 @@ void __init setup_arch(char **cmdline_p)
 	mem_encrypt_setup_arch();
 	cc_random_init();
 
-	efi_fake_memmap();
 	efi_find_mirror();
 	efi_esrt_init();
 	efi_mokvar_table_init();

arch/x86/platform/efi/Makefile

@@ -5,5 +5,4 @@ GCOV_PROFILE := n
 obj-$(CONFIG_EFI) 		+= memmap.o quirks.o efi.o efi_$(BITS).o \
 				   efi_stub_$(BITS).o
 obj-$(CONFIG_EFI_MIXED)		+= efi_thunk_$(BITS).o
-obj-$(CONFIG_EFI_FAKE_MEMMAP)	+= fake_mem.o
 obj-$(CONFIG_EFI_RUNTIME_MAP)	+= runtime-map.o

arch/x86/platform/efi/efi.c

@@ -226,8 +226,6 @@ int __init efi_memblock_x86_reserve_range(void)
 	if (add_efi_memmap || do_efi_soft_reserve())
 		do_add_efi_memmap();
 
-	efi_fake_memmap_early();
-
 	WARN(efi.memmap.desc_version != 1,
 	     "Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
 	     efi.memmap.desc_version);