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authorLinus Torvalds <torvalds@linux-foundation.org>2022-12-14 01:45:29 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-12-14 01:45:29 +0300
commit4eb77fa102ebc2a48d61941fd0293b0aeed00fee (patch)
treebbd1f30edba9ec2a3285e4415cd17b82f48cb8a2 /arch/x86/boot
parent8b9ed79c2d587bec5f603d66801478a5af9af842 (diff)
parent60253f100c5846029f1370e51be6ebaeb160dcec (diff)
downloadlinux-4eb77fa102ebc2a48d61941fd0293b0aeed00fee.tar.xz
Merge tag 'x86_boot_for_v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 boot updates from Borislav Petkov: "A of early boot cleanups and fixes. - Do some spring cleaning to the compressed boot code by moving the EFI mixed-mode code to a separate compilation unit, the AMD memory encryption early code where it belongs and fixing up build dependencies. Make the deprecated EFI handover protocol optional with the goal of removing it at some point (Ard Biesheuvel) - Skip realmode init code on Xen PV guests as it is not needed there - Remove an old 32-bit PIC code compiler workaround" * tag 'x86_boot_for_v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot: Remove x86_32 PIC using %ebx workaround x86/boot: Skip realmode init code when running as Xen PV guest x86/efi: Make the deprecated EFI handover protocol optional x86/boot/compressed: Only build mem_encrypt.S if AMD_MEM_ENCRYPT=y x86/boot/compressed: Adhere to calling convention in get_sev_encryption_bit() x86/boot/compressed: Move startup32_check_sev_cbit() out of head_64.S x86/boot/compressed: Move startup32_check_sev_cbit() into .text x86/boot/compressed: Move startup32_load_idt() out of head_64.S x86/boot/compressed: Move startup32_load_idt() into .text section x86/boot/compressed: Pull global variable reference into startup32_load_idt() x86/boot/compressed: Avoid touching ECX in startup32_set_idt_entry() x86/boot/compressed: Simplify IDT/GDT preserve/restore in the EFI thunk x86/boot/compressed, efi: Merge multiple definitions of image_offset into one x86/boot/compressed: Move efi32_pe_entry() out of head_64.S x86/boot/compressed: Move efi32_entry out of head_64.S x86/boot/compressed: Move efi32_pe_entry into .text section x86/boot/compressed: Move bootargs parsing out of 32-bit startup code x86/boot/compressed: Move 32-bit entrypoint code into .text section x86/boot/compressed: Rename efi_thunk_64.S to efi-mixed.S
Diffstat (limited to 'arch/x86/boot')
-rw-r--r--arch/x86/boot/compressed/Makefile8
-rw-r--r--arch/x86/boot/compressed/efi_mixed.S345
-rw-r--r--arch/x86/boot/compressed/efi_thunk_64.S189
-rw-r--r--arch/x86/boot/compressed/head_32.S4
-rw-r--r--arch/x86/boot/compressed/head_64.S303
-rw-r--r--arch/x86/boot/compressed/mem_encrypt.S152
-rw-r--r--arch/x86/boot/cpuflags.c15
-rw-r--r--arch/x86/boot/header.S2
-rw-r--r--arch/x86/boot/tools/build.c2
9 files changed, 512 insertions, 508 deletions
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index 3a261abb6d15..3dc5db651dd0 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -100,7 +100,7 @@ vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr.o
ifdef CONFIG_X86_64
vmlinux-objs-y += $(obj)/ident_map_64.o
vmlinux-objs-y += $(obj)/idt_64.o $(obj)/idt_handlers_64.o
- vmlinux-objs-y += $(obj)/mem_encrypt.o
+ vmlinux-objs-$(CONFIG_AMD_MEM_ENCRYPT) += $(obj)/mem_encrypt.o
vmlinux-objs-y += $(obj)/pgtable_64.o
vmlinux-objs-$(CONFIG_AMD_MEM_ENCRYPT) += $(obj)/sev.o
endif
@@ -108,11 +108,11 @@ endif
vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o
vmlinux-objs-$(CONFIG_INTEL_TDX_GUEST) += $(obj)/tdx.o $(obj)/tdcall.o
-vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o
vmlinux-objs-$(CONFIG_EFI) += $(obj)/efi.o
-efi-obj-$(CONFIG_EFI_STUB) = $(objtree)/drivers/firmware/efi/libstub/lib.a
+vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_mixed.o
+vmlinux-objs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
-$(obj)/vmlinux: $(vmlinux-objs-y) $(efi-obj-y) FORCE
+$(obj)/vmlinux: $(vmlinux-objs-y) FORCE
$(call if_changed,ld)
OBJCOPYFLAGS_vmlinux.bin := -R .comment -S
diff --git a/arch/x86/boot/compressed/efi_mixed.S b/arch/x86/boot/compressed/efi_mixed.S
new file mode 100644
index 000000000000..4ca70bf93dc0
--- /dev/null
+++ b/arch/x86/boot/compressed/efi_mixed.S
@@ -0,0 +1,345 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2014, 2015 Intel Corporation; author Matt Fleming
+ *
+ * Early support for invoking 32-bit EFI services from a 64-bit kernel.
+ *
+ * Because this thunking occurs before ExitBootServices() we have to
+ * restore the firmware's 32-bit GDT and IDT before we make EFI service
+ * calls.
+ *
+ * On the plus side, we don't have to worry about mangling 64-bit
+ * addresses into 32-bits because we're executing with an identity
+ * mapped pagetable and haven't transitioned to 64-bit virtual addresses
+ * yet.
+ */
+
+#include <linux/linkage.h>
+#include <asm/msr.h>
+#include <asm/page_types.h>
+#include <asm/processor-flags.h>
+#include <asm/segment.h>
+
+ .code64
+ .text
+/*
+ * When booting in 64-bit mode on 32-bit EFI firmware, startup_64_mixed_mode()
+ * is the first thing that runs after switching to long mode. Depending on
+ * whether the EFI handover protocol or the compat entry point was used to
+ * enter the kernel, it will either branch to the 64-bit EFI handover
+ * entrypoint at offset 0x390 in the image, or to the 64-bit EFI PE/COFF
+ * entrypoint efi_pe_entry(). In the former case, the bootloader must provide a
+ * struct bootparams pointer as the third argument, so the presence of such a
+ * pointer is used to disambiguate.
+ *
+ * +--------------+
+ * +------------------+ +------------+ +------>| efi_pe_entry |
+ * | efi32_pe_entry |---->| | | +-----------+--+
+ * +------------------+ | | +------+----------------+ |
+ * | startup_32 |---->| startup_64_mixed_mode | |
+ * +------------------+ | | +------+----------------+ V
+ * | efi32_stub_entry |---->| | | +------------------+
+ * +------------------+ +------------+ +---->| efi64_stub_entry |
+ * +-------------+----+
+ * +------------+ +----------+ |
+ * | startup_64 |<----| efi_main |<--------------+
+ * +------------+ +----------+
+ */
+SYM_FUNC_START(startup_64_mixed_mode)
+ lea efi32_boot_args(%rip), %rdx
+ mov 0(%rdx), %edi
+ mov 4(%rdx), %esi
+ mov 8(%rdx), %edx // saved bootparams pointer
+ test %edx, %edx
+ jnz efi64_stub_entry
+ /*
+ * efi_pe_entry uses MS calling convention, which requires 32 bytes of
+ * shadow space on the stack even if all arguments are passed in
+ * registers. We also need an additional 8 bytes for the space that
+ * would be occupied by the return address, and this also results in
+ * the correct stack alignment for entry.
+ */
+ sub $40, %rsp
+ mov %rdi, %rcx // MS calling convention
+ mov %rsi, %rdx
+ jmp efi_pe_entry
+SYM_FUNC_END(startup_64_mixed_mode)
+
+SYM_FUNC_START(__efi64_thunk)
+ push %rbp
+ push %rbx
+
+ movl %ds, %eax
+ push %rax
+ movl %es, %eax
+ push %rax
+ movl %ss, %eax
+ push %rax
+
+ /* Copy args passed on stack */
+ movq 0x30(%rsp), %rbp
+ movq 0x38(%rsp), %rbx
+ movq 0x40(%rsp), %rax
+
+ /*
+ * Convert x86-64 ABI params to i386 ABI
+ */
+ subq $64, %rsp
+ movl %esi, 0x0(%rsp)
+ movl %edx, 0x4(%rsp)
+ movl %ecx, 0x8(%rsp)
+ movl %r8d, 0xc(%rsp)
+ movl %r9d, 0x10(%rsp)
+ movl %ebp, 0x14(%rsp)
+ movl %ebx, 0x18(%rsp)
+ movl %eax, 0x1c(%rsp)
+
+ leaq 0x20(%rsp), %rbx
+ sgdt (%rbx)
+ sidt 16(%rbx)
+
+ leaq 1f(%rip), %rbp
+
+ /*
+ * Switch to IDT and GDT with 32-bit segments. These are the firmware
+ * GDT and IDT that were installed when the kernel started executing.
+ * The pointers were saved by the efi32_entry() routine below.
+ *
+ * Pass the saved DS selector to the 32-bit code, and use far return to
+ * restore the saved CS selector.
+ */
+ lidt efi32_boot_idt(%rip)
+ lgdt efi32_boot_gdt(%rip)
+
+ movzwl efi32_boot_ds(%rip), %edx
+ movzwq efi32_boot_cs(%rip), %rax
+ pushq %rax
+ leaq efi_enter32(%rip), %rax
+ pushq %rax
+ lretq
+
+1: addq $64, %rsp
+ movq %rdi, %rax
+
+ pop %rbx
+ movl %ebx, %ss
+ pop %rbx
+ movl %ebx, %es
+ pop %rbx
+ movl %ebx, %ds
+ /* Clear out 32-bit selector from FS and GS */
+ xorl %ebx, %ebx
+ movl %ebx, %fs
+ movl %ebx, %gs
+
+ pop %rbx
+ pop %rbp
+ RET
+SYM_FUNC_END(__efi64_thunk)
+
+ .code32
+/*
+ * EFI service pointer must be in %edi.
+ *
+ * The stack should represent the 32-bit calling convention.
+ */
+SYM_FUNC_START_LOCAL(efi_enter32)
+ /* Load firmware selector into data and stack segment registers */
+ movl %edx, %ds
+ movl %edx, %es
+ movl %edx, %fs
+ movl %edx, %gs
+ movl %edx, %ss
+
+ /* Reload pgtables */
+ movl %cr3, %eax
+ movl %eax, %cr3
+
+ /* Disable paging */
+ movl %cr0, %eax
+ btrl $X86_CR0_PG_BIT, %eax
+ movl %eax, %cr0
+
+ /* Disable long mode via EFER */
+ movl $MSR_EFER, %ecx
+ rdmsr
+ btrl $_EFER_LME, %eax
+ wrmsr
+
+ call *%edi
+
+ /* We must preserve return value */
+ movl %eax, %edi
+
+ /*
+ * Some firmware will return with interrupts enabled. Be sure to
+ * disable them before we switch GDTs and IDTs.
+ */
+ cli
+
+ lidtl 16(%ebx)
+ lgdtl (%ebx)
+
+ movl %cr4, %eax
+ btsl $(X86_CR4_PAE_BIT), %eax
+ movl %eax, %cr4
+
+ movl %cr3, %eax
+ movl %eax, %cr3
+
+ movl $MSR_EFER, %ecx
+ rdmsr
+ btsl $_EFER_LME, %eax
+ wrmsr
+
+ xorl %eax, %eax
+ lldt %ax
+
+ pushl $__KERNEL_CS
+ pushl %ebp
+
+ /* Enable paging */
+ movl %cr0, %eax
+ btsl $X86_CR0_PG_BIT, %eax
+ movl %eax, %cr0
+ lret
+SYM_FUNC_END(efi_enter32)
+
+/*
+ * This is the common EFI stub entry point for mixed mode.
+ *
+ * Arguments: %ecx image handle
+ * %edx EFI system table pointer
+ * %esi struct bootparams pointer (or NULL when not using
+ * the EFI handover protocol)
+ *
+ * Since this is the point of no return for ordinary execution, no registers
+ * are considered live except for the function parameters. [Note that the EFI
+ * stub may still exit and return to the firmware using the Exit() EFI boot
+ * service.]
+ */
+SYM_FUNC_START(efi32_entry)
+ call 1f
+1: pop %ebx
+
+ /* Save firmware GDTR and code/data selectors */
+ sgdtl (efi32_boot_gdt - 1b)(%ebx)
+ movw %cs, (efi32_boot_cs - 1b)(%ebx)
+ movw %ds, (efi32_boot_ds - 1b)(%ebx)
+
+ /* Store firmware IDT descriptor */
+ sidtl (efi32_boot_idt - 1b)(%ebx)
+
+ /* Store boot arguments */
+ leal (efi32_boot_args - 1b)(%ebx), %ebx
+ movl %ecx, 0(%ebx)
+ movl %edx, 4(%ebx)
+ movl %esi, 8(%ebx)
+ movb $0x0, 12(%ebx) // efi_is64
+
+ /* Disable paging */
+ movl %cr0, %eax
+ btrl $X86_CR0_PG_BIT, %eax
+ movl %eax, %cr0
+
+ jmp startup_32
+SYM_FUNC_END(efi32_entry)
+
+#define ST32_boottime 60 // offsetof(efi_system_table_32_t, boottime)
+#define BS32_handle_protocol 88 // offsetof(efi_boot_services_32_t, handle_protocol)
+#define LI32_image_base 32 // offsetof(efi_loaded_image_32_t, image_base)
+
+/*
+ * efi_status_t efi32_pe_entry(efi_handle_t image_handle,
+ * efi_system_table_32_t *sys_table)
+ */
+SYM_FUNC_START(efi32_pe_entry)
+ pushl %ebp
+ movl %esp, %ebp
+ pushl %eax // dummy push to allocate loaded_image
+
+ pushl %ebx // save callee-save registers
+ pushl %edi
+
+ call verify_cpu // check for long mode support
+ testl %eax, %eax
+ movl $0x80000003, %eax // EFI_UNSUPPORTED
+ jnz 2f
+
+ call 1f
+1: pop %ebx
+
+ /* Get the loaded image protocol pointer from the image handle */
+ leal -4(%ebp), %eax
+ pushl %eax // &loaded_image
+ leal (loaded_image_proto - 1b)(%ebx), %eax
+ pushl %eax // pass the GUID address
+ pushl 8(%ebp) // pass the image handle
+
+ /*
+ * Note the alignment of the stack frame.
+ * sys_table
+ * handle <-- 16-byte aligned on entry by ABI
+ * return address
+ * frame pointer
+ * loaded_image <-- local variable
+ * saved %ebx <-- 16-byte aligned here
+ * saved %edi
+ * &loaded_image
+ * &loaded_image_proto
+ * handle <-- 16-byte aligned for call to handle_protocol
+ */
+
+ movl 12(%ebp), %eax // sys_table
+ movl ST32_boottime(%eax), %eax // sys_table->boottime
+ call *BS32_handle_protocol(%eax) // sys_table->boottime->handle_protocol
+ addl $12, %esp // restore argument space
+ testl %eax, %eax
+ jnz 2f
+
+ movl 8(%ebp), %ecx // image_handle
+ movl 12(%ebp), %edx // sys_table
+ movl -4(%ebp), %esi // loaded_image
+ movl LI32_image_base(%esi), %esi // loaded_image->image_base
+ leal (startup_32 - 1b)(%ebx), %ebp // runtime address of startup_32
+ /*
+ * We need to set the image_offset variable here since startup_32() will
+ * use it before we get to the 64-bit efi_pe_entry() in C code.
+ */
+ subl %esi, %ebp // calculate image_offset
+ movl %ebp, (image_offset - 1b)(%ebx) // save image_offset
+ xorl %esi, %esi
+ jmp efi32_entry // pass %ecx, %edx, %esi
+ // no other registers remain live
+
+2: popl %edi // restore callee-save registers
+ popl %ebx
+ leave
+ RET
+SYM_FUNC_END(efi32_pe_entry)
+
+ .section ".rodata"
+ /* EFI loaded image protocol GUID */
+ .balign 4
+SYM_DATA_START_LOCAL(loaded_image_proto)
+ .long 0x5b1b31a1
+ .word 0x9562, 0x11d2
+ .byte 0x8e, 0x3f, 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b
+SYM_DATA_END(loaded_image_proto)
+
+ .data
+ .balign 8
+SYM_DATA_START_LOCAL(efi32_boot_gdt)
+ .word 0
+ .quad 0
+SYM_DATA_END(efi32_boot_gdt)
+
+SYM_DATA_START_LOCAL(efi32_boot_idt)
+ .word 0
+ .quad 0
+SYM_DATA_END(efi32_boot_idt)
+
+SYM_DATA_LOCAL(efi32_boot_cs, .word 0)
+SYM_DATA_LOCAL(efi32_boot_ds, .word 0)
+SYM_DATA_LOCAL(efi32_boot_args, .long 0, 0, 0)
+SYM_DATA(efi_is64, .byte 1)
diff --git a/arch/x86/boot/compressed/efi_thunk_64.S b/arch/x86/boot/compressed/efi_thunk_64.S
deleted file mode 100644
index 0c988f2a1243..000000000000
--- a/arch/x86/boot/compressed/efi_thunk_64.S
+++ /dev/null
@@ -1,189 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * Copyright (C) 2014, 2015 Intel Corporation; author Matt Fleming
- *
- * Early support for invoking 32-bit EFI services from a 64-bit kernel.
- *
- * Because this thunking occurs before ExitBootServices() we have to
- * restore the firmware's 32-bit GDT and IDT before we make EFI service
- * calls.
- *
- * On the plus side, we don't have to worry about mangling 64-bit
- * addresses into 32-bits because we're executing with an identity
- * mapped pagetable and haven't transitioned to 64-bit virtual addresses
- * yet.
- */
-
-#include <linux/linkage.h>
-#include <asm/msr.h>
-#include <asm/page_types.h>
-#include <asm/processor-flags.h>
-#include <asm/segment.h>
-
- .code64
- .text
-SYM_FUNC_START(__efi64_thunk)
- push %rbp
- push %rbx
-
- movl %ds, %eax
- push %rax
- movl %es, %eax
- push %rax
- movl %ss, %eax
- push %rax
-
- /* Copy args passed on stack */
- movq 0x30(%rsp), %rbp
- movq 0x38(%rsp), %rbx
- movq 0x40(%rsp), %rax
-
- /*
- * Convert x86-64 ABI params to i386 ABI
- */
- subq $64, %rsp
- movl %esi, 0x0(%rsp)
- movl %edx, 0x4(%rsp)
- movl %ecx, 0x8(%rsp)
- movl %r8d, 0xc(%rsp)
- movl %r9d, 0x10(%rsp)
- movl %ebp, 0x14(%rsp)
- movl %ebx, 0x18(%rsp)
- movl %eax, 0x1c(%rsp)
-
- leaq 0x20(%rsp), %rbx
- sgdt (%rbx)
-
- addq $16, %rbx
- sidt (%rbx)
-
- leaq 1f(%rip), %rbp
-
- /*
- * Switch to IDT and GDT with 32-bit segments. This is the firmware GDT
- * and IDT that was installed when the kernel started executing. The
- * pointers were saved at the EFI stub entry point in head_64.S.
- *
- * Pass the saved DS selector to the 32-bit code, and use far return to
- * restore the saved CS selector.
- */
- leaq efi32_boot_idt(%rip), %rax
- lidt (%rax)
- leaq efi32_boot_gdt(%rip), %rax
- lgdt (%rax)
-
- movzwl efi32_boot_ds(%rip), %edx
- movzwq efi32_boot_cs(%rip), %rax
- pushq %rax
- leaq efi_enter32(%rip), %rax
- pushq %rax
- lretq
-
-1: addq $64, %rsp
- movq %rdi, %rax
-
- pop %rbx
- movl %ebx, %ss
- pop %rbx
- movl %ebx, %es
- pop %rbx
- movl %ebx, %ds
- /* Clear out 32-bit selector from FS and GS */
- xorl %ebx, %ebx
- movl %ebx, %fs
- movl %ebx, %gs
-
- pop %rbx
- pop %rbp
- RET
-SYM_FUNC_END(__efi64_thunk)
-
- .code32
-/*
- * EFI service pointer must be in %edi.
- *
- * The stack should represent the 32-bit calling convention.
- */
-SYM_FUNC_START_LOCAL(efi_enter32)
- /* Load firmware selector into data and stack segment registers */
- movl %edx, %ds
- movl %edx, %es
- movl %edx, %fs
- movl %edx, %gs
- movl %edx, %ss
-
- /* Reload pgtables */
- movl %cr3, %eax
- movl %eax, %cr3
-
- /* Disable paging */
- movl %cr0, %eax
- btrl $X86_CR0_PG_BIT, %eax
- movl %eax, %cr0
-
- /* Disable long mode via EFER */
- movl $MSR_EFER, %ecx
- rdmsr
- btrl $_EFER_LME, %eax
- wrmsr
-
- call *%edi
-
- /* We must preserve return value */
- movl %eax, %edi
-
- /*
- * Some firmware will return with interrupts enabled. Be sure to
- * disable them before we switch GDTs and IDTs.
- */
- cli
-
- lidtl (%ebx)
- subl $16, %ebx
-
- lgdtl (%ebx)
-
- movl %cr4, %eax
- btsl $(X86_CR4_PAE_BIT), %eax
- movl %eax, %cr4
-
- movl %cr3, %eax
- movl %eax, %cr3
-
- movl $MSR_EFER, %ecx
- rdmsr
- btsl $_EFER_LME, %eax
- wrmsr
-
- xorl %eax, %eax
- lldt %ax
-
- pushl $__KERNEL_CS
- pushl %ebp
-
- /* Enable paging */
- movl %cr0, %eax
- btsl $X86_CR0_PG_BIT, %eax
- movl %eax, %cr0
- lret
-SYM_FUNC_END(efi_enter32)
-
- .data
- .balign 8
-SYM_DATA_START(efi32_boot_gdt)
- .word 0
- .quad 0
-SYM_DATA_END(efi32_boot_gdt)
-
-SYM_DATA_START(efi32_boot_idt)
- .word 0
- .quad 0
-SYM_DATA_END(efi32_boot_idt)
-
-SYM_DATA_START(efi32_boot_cs)
- .word 0
-SYM_DATA_END(efi32_boot_cs)
-
-SYM_DATA_START(efi32_boot_ds)
- .word 0
-SYM_DATA_END(efi32_boot_ds)
diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S
index 3b354eb9516d..6589ddd4cfaf 100644
--- a/arch/x86/boot/compressed/head_32.S
+++ b/arch/x86/boot/compressed/head_32.S
@@ -208,10 +208,6 @@ SYM_DATA_START_LOCAL(gdt)
.quad 0x00cf92000000ffff /* __KERNEL_DS */
SYM_DATA_END_LABEL(gdt, SYM_L_LOCAL, gdt_end)
-#ifdef CONFIG_EFI_STUB
-SYM_DATA(image_offset, .long 0)
-#endif
-
/*
* Stack and heap for uncompression
*/
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index d33f060900d2..d4c4281db635 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -118,7 +118,9 @@ SYM_FUNC_START(startup_32)
1:
/* Setup Exception handling for SEV-ES */
+#ifdef CONFIG_AMD_MEM_ENCRYPT
call startup32_load_idt
+#endif
/* Make sure cpu supports long mode. */
call verify_cpu
@@ -178,12 +180,13 @@ SYM_FUNC_START(startup_32)
*/
/*
* If SEV is active then set the encryption mask in the page tables.
- * This will insure that when the kernel is copied and decompressed
+ * This will ensure that when the kernel is copied and decompressed
* it will be done so encrypted.
*/
- call get_sev_encryption_bit
xorl %edx, %edx
#ifdef CONFIG_AMD_MEM_ENCRYPT
+ call get_sev_encryption_bit
+ xorl %edx, %edx
testl %eax, %eax
jz 1f
subl $32, %eax /* Encryption bit is always above bit 31 */
@@ -249,6 +252,11 @@ SYM_FUNC_START(startup_32)
movl $__BOOT_TSS, %eax
ltr %ax
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+ /* Check if the C-bit position is correct when SEV is active */
+ call startup32_check_sev_cbit
+#endif
+
/*
* Setup for the jump to 64bit mode
*
@@ -261,29 +269,11 @@ SYM_FUNC_START(startup_32)
*/
leal rva(startup_64)(%ebp), %eax
#ifdef CONFIG_EFI_MIXED
- movl rva(efi32_boot_args)(%ebp), %edi
- testl %edi, %edi
- jz 1f
- leal rva(efi64_stub_entry)(%ebp), %eax
- movl rva(efi32_boot_args+4)(%ebp), %esi
- movl rva(efi32_boot_args+8)(%ebp), %edx // saved bootparams pointer
- testl %edx, %edx
- jnz 1f
- /*
- * efi_pe_entry uses MS calling convention, which requires 32 bytes of
- * shadow space on the stack even if all arguments are passed in
- * registers. We also need an additional 8 bytes for the space that
- * would be occupied by the return address, and this also results in
- * the correct stack alignment for entry.
- */
- subl $40, %esp
- leal rva(efi_pe_entry)(%ebp), %eax
- movl %edi, %ecx // MS calling convention
- movl %esi, %edx
+ cmpb $1, rva(efi_is64)(%ebp)
+ je 1f
+ leal rva(startup_64_mixed_mode)(%ebp), %eax
1:
#endif
- /* Check if the C-bit position is correct when SEV is active */
- call startup32_check_sev_cbit
pushl $__KERNEL_CS
pushl %eax
@@ -296,38 +286,14 @@ SYM_FUNC_START(startup_32)
lret
SYM_FUNC_END(startup_32)
-#ifdef CONFIG_EFI_MIXED
+#if IS_ENABLED(CONFIG_EFI_MIXED) && IS_ENABLED(CONFIG_EFI_HANDOVER_PROTOCOL)
.org 0x190
SYM_FUNC_START(efi32_stub_entry)
add $0x4, %esp /* Discard return address */
popl %ecx
popl %edx
popl %esi
-
- call 1f
-1: pop %ebp
- subl $ rva(1b), %ebp
-
- movl %esi, rva(efi32_boot_args+8)(%ebp)
-SYM_INNER_LABEL(efi32_pe_stub_entry, SYM_L_LOCAL)
- movl %ecx, rva(efi32_boot_args)(%ebp)
- movl %edx, rva(efi32_boot_args+4)(%ebp)
- movb $0, rva(efi_is64)(%ebp)
-
- /* Save firmware GDTR and code/data selectors */
- sgdtl rva(efi32_boot_gdt)(%ebp)
- movw %cs, rva(efi32_boot_cs)(%ebp)
- movw %ds, rva(efi32_boot_ds)(%ebp)
-
- /* Store firmware IDT descriptor */
- sidtl rva(efi32_boot_idt)(%ebp)
-
- /* Disable paging */
- movl %cr0, %eax
- btrl $X86_CR0_PG_BIT, %eax
- movl %eax, %cr0
-
- jmp startup_32
+ jmp efi32_entry
SYM_FUNC_END(efi32_stub_entry)
#endif
@@ -550,7 +516,9 @@ trampoline_return:
SYM_CODE_END(startup_64)
#ifdef CONFIG_EFI_STUB
+#ifdef CONFIG_EFI_HANDOVER_PROTOCOL
.org 0x390
+#endif
SYM_FUNC_START(efi64_stub_entry)
and $~0xf, %rsp /* realign the stack */
movq %rdx, %rbx /* save boot_params pointer */
@@ -713,6 +681,7 @@ SYM_FUNC_START_LOCAL_NOALIGN(.Lno_longmode)
jmp 1b
SYM_FUNC_END(.Lno_longmode)
+ .globl verify_cpu
#include "../../kernel/verify_cpu.S"
.data
@@ -744,242 +713,6 @@ SYM_DATA_START(boot_idt)
.endr
SYM_DATA_END_LABEL(boot_idt, SYM_L_GLOBAL, boot_idt_end)
-#ifdef CONFIG_AMD_MEM_ENCRYPT
-SYM_DATA_START(boot32_idt_desc)
- .word boot32_idt_end - boot32_idt - 1
- .long 0
-SYM_DATA_END(boot32_idt_desc)
- .balign 8
-SYM_DATA_START(boot32_idt)
- .rept 32
- .quad 0
- .endr
-SYM_DATA_END_LABEL(boot32_idt, SYM_L_GLOBAL, boot32_idt_end)
-#endif
-
-#ifdef CONFIG_EFI_STUB
-SYM_DATA(image_offset, .long 0)
-#endif
-#ifdef CONFIG_EFI_MIXED
-SYM_DATA_LOCAL(efi32_boot_args, .long 0, 0, 0)
-SYM_DATA(efi_is64, .byte 1)
-
-#define ST32_boottime 60 // offsetof(efi_system_table_32_t, boottime)
-#define BS32_handle_protocol 88 // offsetof(efi_boot_services_32_t, handle_protocol)
-#define LI32_image_base 32 // offsetof(efi_loaded_image_32_t, image_base)
-
- __HEAD
- .code32
-SYM_FUNC_START(efi32_pe_entry)
-/*
- * efi_status_t efi32_pe_entry(efi_handle_t image_handle,
- * efi_system_table_32_t *sys_table)
- */
-
- pushl %ebp
- movl %esp, %ebp
- pushl %eax // dummy push to allocate loaded_image
-
- pushl %ebx // save callee-save registers
- pushl %edi
-
- call verify_cpu // check for long mode support
- testl %eax, %eax
- movl $0x80000003, %eax // EFI_UNSUPPORTED
- jnz 2f
-
- call 1f
-1: pop %ebx
- subl $ rva(1b), %ebx
-
- /* Get the loaded image protocol pointer from the image handle */
- leal -4(%ebp), %eax
- pushl %eax // &loaded_image
- leal rva(loaded_image_proto)(%ebx), %eax
- pushl %eax // pass the GUID address
- pushl 8(%ebp) // pass the image handle
-
- /*
- * Note the alignment of the stack frame.
- * sys_table
- * handle <-- 16-byte aligned on entry by ABI
- * return address
- * frame pointer
- * loaded_image <-- local variable
- * saved %ebx <-- 16-byte aligned here
- * saved %edi
- * &loaded_image
- * &loaded_image_proto
- * handle <-- 16-byte aligned for call to handle_protocol
- */
-
- movl 12(%ebp), %eax // sys_table
- movl ST32_boottime(%eax), %eax // sys_table->boottime
- call *BS32_handle_protocol(%eax) // sys_table->boottime->handle_protocol
- addl $12, %esp // restore argument space
- testl %eax, %eax
- jnz 2f
-
- movl 8(%ebp), %ecx // image_handle
- movl 12(%ebp), %edx // sys_table
- movl -4(%ebp), %esi // loaded_image
- movl LI32_image_base(%esi), %esi // loaded_image->image_base
- movl %ebx, %ebp // startup_32 for efi32_pe_stub_entry
- /*
- * We need to set the image_offset variable here since startup_32() will
- * use it before we get to the 64-bit efi_pe_entry() in C code.
- */
- subl %esi, %ebx
- movl %ebx, rva(image_offset)(%ebp) // save image_offset
- jmp efi32_pe_stub_entry
-
-2: popl %edi // restore callee-save registers
- popl %ebx
- leave
- RET
-SYM_FUNC_END(efi32_pe_entry)
-
- .section ".rodata"
- /* EFI loaded image protocol GUID */
- .balign 4
-SYM_DATA_START_LOCAL(loaded_image_proto)
- .long 0x5b1b31a1
- .word 0x9562, 0x11d2
- .byte 0x8e, 0x3f, 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b
-SYM_DATA_END(loaded_image_proto)
-#endif
-
-#ifdef CONFIG_AMD_MEM_ENCRYPT
- __HEAD
- .code32
-/*
- * Write an IDT entry into boot32_idt
- *
- * Parameters:
- *
- * %eax: Handler address
- * %edx: Vector number
- *
- * Physical offset is expected in %ebp
- */
-SYM_FUNC_START(startup32_set_idt_entry)
- push %ebx
- push %ecx
-
- /* IDT entry address to %ebx */
- leal rva(boot32_idt)(%ebp), %ebx
- shl $3, %edx
- addl %edx, %ebx
-
- /* Build IDT entry, lower 4 bytes */
- movl %eax, %edx
- andl $0x0000ffff, %edx # Target code segment offset [15:0]
- movl $__KERNEL32_CS, %ecx # Target code segment selector
- shl $16, %ecx
- orl %ecx, %edx
-
- /* Store lower 4 bytes to IDT */
- movl %edx, (%ebx)
-
- /* Build IDT entry, upper 4 bytes */
- movl %eax, %edx
- andl $0xffff0000, %edx # Target code segment offset [31:16]
- orl $0x00008e00, %edx # Present, Type 32-bit Interrupt Gate
-
- /* Store upper 4 bytes to IDT */
- movl %edx, 4(%ebx)
-
- pop %ecx
- pop %ebx
- RET
-SYM_FUNC_END(startup32_set_idt_entry)
-#endif
-
-SYM_FUNC_START(startup32_load_idt)
-#ifdef CONFIG_AMD_MEM_ENCRYPT
- /* #VC handler */
- leal rva(startup32_vc_handler)(%ebp), %eax
- movl $X86_TRAP_VC, %edx
- call startup32_set_idt_entry
-
- /* Load IDT */
- leal rva(boot32_idt)(%ebp), %eax
- movl %eax, rva(boot32_idt_desc+2)(%ebp)
- lidt rva(boot32_idt_desc)(%ebp)
-#endif
- RET
-SYM_FUNC_END(startup32_load_idt)
-
-/*
- * Check for the correct C-bit position when the startup_32 boot-path is used.
- *
- * The check makes use of the fact that all memory is encrypted when paging is
- * disabled. The function creates 64 bits of random data using the RDRAND
- * instruction. RDRAND is mandatory for SEV guests, so always available. If the
- * hypervisor violates that the kernel will crash right here.
- *
- * The 64 bits of random data are stored to a memory location and at the same
- * time kept in the %eax and %ebx registers. Since encryption is always active
- * when paging is off the random data will be stored encrypted in main memory.
- *
- * Then paging is enabled. When the C-bit position is correct all memory is
- * still mapped encrypted and comparing the register values with memory will
- * succeed. An incorrect C-bit position will map all memory unencrypted, so that
- * the compare will use the encrypted random data and fail.
- */
-SYM_FUNC_START(startup32_check_sev_cbit)
-#ifdef CONFIG_AMD_MEM_ENCRYPT
- pushl %eax
- pushl %ebx
- pushl %ecx
- pushl %edx
-
- /* Check for non-zero sev_status */
- movl rva(sev_status)(%ebp), %eax
- testl %eax, %eax
- jz 4f
-
- /*
- * Get two 32-bit random values - Don't bail out if RDRAND fails
- * because it is better to prevent forward progress if no random value
- * can be gathered.
- */
-1: rdrand %eax
- jnc 1b
-2: rdrand %ebx
- jnc 2b
-
- /* Store to memory and keep it in the registers */
- movl %eax, rva(sev_check_data)(%ebp)
- movl %ebx, rva(sev_check_data+4)(%ebp)
-
- /* Enable paging to see if encryption is active */
- movl %cr0, %edx /* Backup %cr0 in %edx */
- movl $(X86_CR0_PG | X86_CR0_PE), %ecx /* Enable Paging and Protected mode */
- movl %ecx, %cr0
-
- cmpl %eax, rva(sev_check_data)(%ebp)
- jne 3f
- cmpl %ebx, rva(sev_check_data+4)(%ebp)
- jne 3f
-
- movl %edx, %cr0 /* Restore previous %cr0 */
-
- jmp 4f
-
-3: /* Check failed - hlt the machine */
- hlt
- jmp 3b
-
-4:
- popl %edx
- popl %ecx
- popl %ebx
- popl %eax
-#endif
- RET
-SYM_FUNC_END(startup32_check_sev_cbit)
-
/*
* Stack and heap for uncompression
*/
diff --git a/arch/x86/boot/compressed/mem_encrypt.S b/arch/x86/boot/compressed/mem_encrypt.S
index a73e4d783cae..32f7cc8a8625 100644
--- a/arch/x86/boot/compressed/mem_encrypt.S
+++ b/arch/x86/boot/compressed/mem_encrypt.S
@@ -12,16 +12,13 @@
#include <asm/processor-flags.h>
#include <asm/msr.h>
#include <asm/asm-offsets.h>
+#include <asm/segment.h>
+#include <asm/trapnr.h>
.text
.code32
SYM_FUNC_START(get_sev_encryption_bit)
- xor %eax, %eax
-
-#ifdef CONFIG_AMD_MEM_ENCRYPT
push %ebx
- push %ecx
- push %edx
movl $0x80000000, %eax /* CPUID to check the highest leaf */
cpuid
@@ -52,12 +49,7 @@ SYM_FUNC_START(get_sev_encryption_bit)
xor %eax, %eax
.Lsev_exit:
- pop %edx
- pop %ecx
pop %ebx
-
-#endif /* CONFIG_AMD_MEM_ENCRYPT */
-
RET
SYM_FUNC_END(get_sev_encryption_bit)
@@ -98,7 +90,7 @@ SYM_CODE_START_LOCAL(sev_es_req_cpuid)
jmp 1b
SYM_CODE_END(sev_es_req_cpuid)
-SYM_CODE_START(startup32_vc_handler)
+SYM_CODE_START_LOCAL(startup32_vc_handler)
pushl %eax
pushl %ebx
pushl %ecx
@@ -184,15 +176,149 @@ SYM_CODE_START(startup32_vc_handler)
jmp .Lfail
SYM_CODE_END(startup32_vc_handler)
+/*
+ * Write an IDT entry into boot32_idt
+ *
+ * Parameters:
+ *
+ * %eax: Handler address
+ * %edx: Vector number
+ * %ecx: IDT address
+ */
+SYM_FUNC_START_LOCAL(startup32_set_idt_entry)
+ /* IDT entry address to %ecx */
+ leal (%ecx, %edx, 8), %ecx
+
+ /* Build IDT entry, lower 4 bytes */
+ movl %eax, %edx
+ andl $0x0000ffff, %edx # Target code segment offset [15:0]
+ orl $(__KERNEL32_CS << 16), %edx # Target code segment selector
+
+ /* Store lower 4 bytes to IDT */
+ movl %edx, (%ecx)
+
+ /* Build IDT entry, upper 4 bytes */
+ movl %eax, %edx
+ andl $0xffff0000, %edx # Target code segment offset [31:16]
+ orl $0x00008e00, %edx # Present, Type 32-bit Interrupt Gate
+
+ /* Store upper 4 bytes to IDT */
+ movl %edx, 4(%ecx)
+
+ RET
+SYM_FUNC_END(startup32_set_idt_entry)
+
+SYM_FUNC_START(startup32_load_idt)
+ push %ebp
+ push %ebx
+
+ call 1f
+1: pop %ebp
+
+ leal (boot32_idt - 1b)(%ebp), %ebx
+
+ /* #VC handler */
+ leal (startup32_vc_handler - 1b)(%ebp), %eax
+ movl $X86_TRAP_VC, %edx
+ movl %ebx, %ecx
+ call startup32_set_idt_entry
+
+ /* Load IDT */
+ leal (boot32_idt_desc - 1b)(%ebp), %ecx
+ movl %ebx, 2(%ecx)
+ lidt (%ecx)
+
+ pop %ebx
+ pop %ebp
+ RET
+SYM_FUNC_END(startup32_load_idt)
+
+/*
+ * Check for the correct C-bit position when the startup_32 boot-path is used.
+ *
+ * The check makes use of the fact that all memory is encrypted when paging is
+ * disabled. The function creates 64 bits of random data using the RDRAND
+ * instruction. RDRAND is mandatory for SEV guests, so always available. If the
+ * hypervisor violates that the kernel will crash right here.
+ *
+ * The 64 bits of random data are stored to a memory location and at the same
+ * time kept in the %eax and %ebx registers. Since encryption is always active
+ * when paging is off the random data will be stored encrypted in main memory.
+ *
+ * Then paging is enabled. When the C-bit position is correct all memory is
+ * still mapped encrypted and comparing the register values with memory will
+ * succeed. An incorrect C-bit position will map all memory unencrypted, so that
+ * the compare will use the encrypted random data and fail.
+ */
+SYM_FUNC_START(startup32_check_sev_cbit)
+ pushl %ebx
+ pushl %ebp
+
+ call 0f
+0: popl %ebp
+
+ /* Check for non-zero sev_status */
+ movl (sev_status - 0b)(%ebp), %eax
+ testl %eax, %eax
+ jz 4f
+
+ /*
+ * Get two 32-bit random values - Don't bail out if RDRAND fails
+ * because it is better to prevent forward progress if no random value
+ * can be gathered.
+ */
+1: rdrand %eax
+ jnc 1b
+2: rdrand %ebx
+ jnc 2b
+
+ /* Store to memory and keep it in the registers */
+ leal (sev_check_data - 0b)(%ebp), %ebp
+ movl %eax, 0(%ebp)
+ movl %ebx, 4(%ebp)
+
+ /* Enable paging to see if encryption is active */
+ movl %cr0, %edx /* Backup %cr0 in %edx */
+ movl $(X86_CR0_PG | X86_CR0_PE), %ecx /* Enable Paging and Protected mode */
+ movl %ecx, %cr0
+
+ cmpl %eax, 0(%ebp)
+ jne 3f
+ cmpl %ebx, 4(%ebp)
+ jne 3f
+
+ movl %edx, %cr0 /* Restore previous %cr0 */
+
+ jmp 4f
+
+3: /* Check failed - hlt the machine */
+ hlt
+ jmp 3b
+
+4:
+ popl %ebp
+ popl %ebx
+ RET
+SYM_FUNC_END(startup32_check_sev_cbit)
+
.code64
#include "../../kernel/sev_verify_cbit.S"
.data
-#ifdef CONFIG_AMD_MEM_ENCRYPT
.balign 8
SYM_DATA(sme_me_mask, .quad 0)
SYM_DATA(sev_status, .quad 0)
SYM_DATA(sev_check_data, .quad 0)
-#endif
+
+SYM_DATA_START_LOCAL(boot32_idt)
+ .rept 32
+ .quad 0
+ .endr
+SYM_DATA_END(boot32_idt)
+
+SYM_DATA_START_LOCAL(boot32_idt_desc)
+ .word . - boot32_idt - 1
+ .long 0
+SYM_DATA_END(boot32_idt_desc)
diff --git a/arch/x86/boot/cpuflags.c b/arch/x86/boot/cpuflags.c
index a83d67ec627d..d75237ba7ce9 100644
--- a/arch/x86/boot/cpuflags.c
+++ b/arch/x86/boot/cpuflags.c
@@ -64,20 +64,11 @@ int has_eflag(unsigned long mask)
return !!((f0^f1) & mask);
}
-/* Handle x86_32 PIC using ebx. */
-#if defined(__i386__) && defined(__PIC__)
-# define EBX_REG "=r"
-#else
-# define EBX_REG "=b"
-#endif
-
void cpuid_count(u32 id, u32 count, u32 *a, u32 *b, u32 *c, u32 *d)
{
- asm volatile(".ifnc %%ebx,%3 ; movl %%ebx,%3 ; .endif \n\t"
- "cpuid \n\t"
- ".ifnc %%ebx,%3 ; xchgl %%ebx,%3 ; .endif \n\t"
- : "=a" (*a), "=c" (*c), "=d" (*d), EBX_REG (*b)
- : "a" (id), "c" (count)
+ asm volatile("cpuid"
+ : "=a" (*a), "=b" (*b), "=c" (*c), "=d" (*d)
+ : "0" (id), "2" (count)
);
}
diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index be8f78a7ee32..9338c68e7413 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -407,7 +407,7 @@ xloadflags:
# define XLF1 0
#endif
-#ifdef CONFIG_EFI_STUB
+#ifdef CONFIG_EFI_HANDOVER_PROTOCOL
# ifdef CONFIG_EFI_MIXED
# define XLF23 (XLF_EFI_HANDOVER_32|XLF_EFI_HANDOVER_64)
# else
diff --git a/arch/x86/boot/tools/build.c b/arch/x86/boot/tools/build.c
index a3725ad46c5a..bd247692b701 100644
--- a/arch/x86/boot/tools/build.c
+++ b/arch/x86/boot/tools/build.c
@@ -290,6 +290,7 @@ static void efi_stub_entry_update(void)
{
unsigned long addr = efi32_stub_entry;
+#ifdef CONFIG_EFI_HANDOVER_PROTOCOL
#ifdef CONFIG_X86_64
/* Yes, this is really how we defined it :( */
addr = efi64_stub_entry - 0x200;
@@ -299,6 +300,7 @@ static void efi_stub_entry_update(void)
if (efi32_stub_entry != addr)
die("32-bit and 64-bit EFI entry points do not match\n");
#endif
+#endif
put_unaligned_le32(addr, &buf[0x264]);
}