diff mbox series

[RFC,6/6] x86/boot: Move early SME init code into startup/

Message ID 20250401133416.1436741-14-ardb+git@google.com
State Superseded
Headers show
Series x86: Refactor and consolidate startup code | expand

Commit Message

Ard Biesheuvel April 1, 2025, 1:34 p.m. UTC 
From: Ard Biesheuvel <ardb@kernel.org>

Move the SME initialization code, which runs from the 1:1 mapping of
memory as it operates on the kernel virtual mapping, into the new
sub-directory arch/x86/boot/startup/ where all startup code will reside
that needs to tolerate executing from the 1:1 mapping.

This allows RIP_REL_REF() macro invocations and __head annotations to be
dropped.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 arch/x86/boot/startup/Makefile                             |  1 +
 arch/x86/{mm/mem_encrypt_identity.c => boot/startup/sme.c} | 45 +++++++++-----------
 arch/x86/include/asm/mem_encrypt.h                         |  2 +-
 arch/x86/mm/Makefile                                       |  6 ---
 4 files changed, 23 insertions(+), 31 deletions(-)
diff mbox series

Patch

diff --git a/arch/x86/boot/startup/Makefile b/arch/x86/boot/startup/Makefile
index 01423063fec2..480c2d2063a0 100644
--- a/arch/x86/boot/startup/Makefile
+++ b/arch/x86/boot/startup/Makefile
@@ -16,6 +16,7 @@  UBSAN_SANITIZE	:= n
 KCOV_INSTRUMENT	:= n
 
 obj-$(CONFIG_X86_64)		+= gdt_idt.o map_kernel.o
+obj-$(CONFIG_AMD_MEM_ENCRYPT)	+= sme.o
 
 lib-$(CONFIG_X86_64)		+= la57toggle.o
 lib-$(CONFIG_EFI_MIXED)		+= efi-mixed.o
diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/boot/startup/sme.c
similarity index 92%
rename from arch/x86/mm/mem_encrypt_identity.c
rename to arch/x86/boot/startup/sme.c
index 5eecdd92da10..85bd39652535 100644
--- a/arch/x86/mm/mem_encrypt_identity.c
+++ b/arch/x86/boot/startup/sme.c
@@ -45,8 +45,6 @@ 
 #include <asm/coco.h>
 #include <asm/sev.h>
 
-#include "mm_internal.h"
-
 #define PGD_FLAGS		_KERNPG_TABLE_NOENC
 #define P4D_FLAGS		_KERNPG_TABLE_NOENC
 #define PUD_FLAGS		_KERNPG_TABLE_NOENC
@@ -93,7 +91,7 @@  struct sme_populate_pgd_data {
  */
 static char sme_workarea[2 * PMD_SIZE] __section(".init.scratch");
 
-static void __head sme_clear_pgd(struct sme_populate_pgd_data *ppd)
+static void __init sme_clear_pgd(struct sme_populate_pgd_data *ppd)
 {
 	unsigned long pgd_start, pgd_end, pgd_size;
 	pgd_t *pgd_p;
@@ -108,7 +106,7 @@  static void __head sme_clear_pgd(struct sme_populate_pgd_data *ppd)
 	memset(pgd_p, 0, pgd_size);
 }
 
-static pud_t __head *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
+static pud_t __init *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
 {
 	pgd_t *pgd;
 	p4d_t *p4d;
@@ -145,7 +143,7 @@  static pud_t __head *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
 	return pud;
 }
 
-static void __head sme_populate_pgd_large(struct sme_populate_pgd_data *ppd)
+static void __init sme_populate_pgd_large(struct sme_populate_pgd_data *ppd)
 {
 	pud_t *pud;
 	pmd_t *pmd;
@@ -161,7 +159,7 @@  static void __head sme_populate_pgd_large(struct sme_populate_pgd_data *ppd)
 	set_pmd(pmd, __pmd(ppd->paddr | ppd->pmd_flags));
 }
 
-static void __head sme_populate_pgd(struct sme_populate_pgd_data *ppd)
+static void __init sme_populate_pgd(struct sme_populate_pgd_data *ppd)
 {
 	pud_t *pud;
 	pmd_t *pmd;
@@ -187,7 +185,7 @@  static void __head sme_populate_pgd(struct sme_populate_pgd_data *ppd)
 		set_pte(pte, __pte(ppd->paddr | ppd->pte_flags));
 }
 
-static void __head __sme_map_range_pmd(struct sme_populate_pgd_data *ppd)
+static void __init __sme_map_range_pmd(struct sme_populate_pgd_data *ppd)
 {
 	while (ppd->vaddr < ppd->vaddr_end) {
 		sme_populate_pgd_large(ppd);
@@ -197,7 +195,7 @@  static void __head __sme_map_range_pmd(struct sme_populate_pgd_data *ppd)
 	}
 }
 
-static void __head __sme_map_range_pte(struct sme_populate_pgd_data *ppd)
+static void __init __sme_map_range_pte(struct sme_populate_pgd_data *ppd)
 {
 	while (ppd->vaddr < ppd->vaddr_end) {
 		sme_populate_pgd(ppd);
@@ -207,7 +205,7 @@  static void __head __sme_map_range_pte(struct sme_populate_pgd_data *ppd)
 	}
 }
 
-static void __head __sme_map_range(struct sme_populate_pgd_data *ppd,
+static void __init __sme_map_range(struct sme_populate_pgd_data *ppd,
 				   pmdval_t pmd_flags, pteval_t pte_flags)
 {
 	unsigned long vaddr_end;
@@ -231,22 +229,22 @@  static void __head __sme_map_range(struct sme_populate_pgd_data *ppd,
 	__sme_map_range_pte(ppd);
 }
 
-static void __head sme_map_range_encrypted(struct sme_populate_pgd_data *ppd)
+static void __init sme_map_range_encrypted(struct sme_populate_pgd_data *ppd)
 {
 	__sme_map_range(ppd, PMD_FLAGS_ENC, PTE_FLAGS_ENC);
 }
 
-static void __head sme_map_range_decrypted(struct sme_populate_pgd_data *ppd)
+static void __init sme_map_range_decrypted(struct sme_populate_pgd_data *ppd)
 {
 	__sme_map_range(ppd, PMD_FLAGS_DEC, PTE_FLAGS_DEC);
 }
 
-static void __head sme_map_range_decrypted_wp(struct sme_populate_pgd_data *ppd)
+static void __init sme_map_range_decrypted_wp(struct sme_populate_pgd_data *ppd)
 {
 	__sme_map_range(ppd, PMD_FLAGS_DEC_WP, PTE_FLAGS_DEC_WP);
 }
 
-static unsigned long __head sme_pgtable_calc(unsigned long len)
+static unsigned long __init sme_pgtable_calc(unsigned long len)
 {
 	unsigned long entries = 0, tables = 0;
 
@@ -283,7 +281,7 @@  static unsigned long __head sme_pgtable_calc(unsigned long len)
 	return entries + tables;
 }
 
-void __head sme_encrypt_kernel(struct boot_params *bp)
+void __init sme_encrypt_kernel(struct boot_params *bp)
 {
 	unsigned long workarea_start, workarea_end, workarea_len;
 	unsigned long execute_start, execute_end, execute_len;
@@ -299,8 +297,7 @@  void __head sme_encrypt_kernel(struct boot_params *bp)
 	 * instrumentation or checking boot_cpu_data in the cc_platform_has()
 	 * function.
 	 */
-	if (!sme_get_me_mask() ||
-	    RIP_REL_REF(sev_status) & MSR_AMD64_SEV_ENABLED)
+	if (!sme_get_me_mask() || sev_status & MSR_AMD64_SEV_ENABLED)
 		return;
 
 	/*
@@ -318,8 +315,8 @@  void __head sme_encrypt_kernel(struct boot_params *bp)
 	 *     memory from being cached.
 	 */
 
-	kernel_start = (unsigned long)RIP_REL_REF(_text);
-	kernel_end = ALIGN((unsigned long)RIP_REL_REF(_end), PMD_SIZE);
+	kernel_start = (unsigned long)_text;
+	kernel_end = ALIGN((unsigned long)_end, PMD_SIZE);
 	kernel_len = kernel_end - kernel_start;
 
 	initrd_start = 0;
@@ -345,7 +342,7 @@  void __head sme_encrypt_kernel(struct boot_params *bp)
 	 *   pagetable structures for the encryption of the kernel
 	 *   pagetable structures for workarea (in case not currently mapped)
 	 */
-	execute_start = workarea_start = (unsigned long)RIP_REL_REF(sme_workarea);
+	execute_start = workarea_start = (unsigned long)sme_workarea;
 	execute_end = execute_start + (PAGE_SIZE * 2) + PMD_SIZE;
 	execute_len = execute_end - execute_start;
 
@@ -488,7 +485,7 @@  void __head sme_encrypt_kernel(struct boot_params *bp)
 	native_write_cr3(__native_read_cr3());
 }
 
-void __head sme_enable(struct boot_params *bp)
+void __init sme_enable(struct boot_params *bp)
 {
 	unsigned int eax, ebx, ecx, edx;
 	unsigned long feature_mask;
@@ -526,7 +523,7 @@  void __head sme_enable(struct boot_params *bp)
 	me_mask = 1UL << (ebx & 0x3f);
 
 	/* Check the SEV MSR whether SEV or SME is enabled */
-	RIP_REL_REF(sev_status) = msr = __rdmsr(MSR_AMD64_SEV);
+	sev_status = msr = __rdmsr(MSR_AMD64_SEV);
 	feature_mask = (msr & MSR_AMD64_SEV_ENABLED) ? AMD_SEV_BIT : AMD_SME_BIT;
 
 	/*
@@ -562,8 +559,8 @@  void __head sme_enable(struct boot_params *bp)
 			return;
 	}
 
-	RIP_REL_REF(sme_me_mask) = me_mask;
-	RIP_REL_REF(physical_mask) &= ~me_mask;
-	RIP_REL_REF(cc_vendor) = CC_VENDOR_AMD;
+	sme_me_mask	= me_mask;
+	physical_mask	&= ~me_mask;
+	cc_vendor	= CC_VENDOR_AMD;
 	cc_set_mask(me_mask);
 }
diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h
index 1530ee301dfe..ea6494628cb0 100644
--- a/arch/x86/include/asm/mem_encrypt.h
+++ b/arch/x86/include/asm/mem_encrypt.h
@@ -61,7 +61,7 @@  void __init sev_es_init_vc_handling(void);
 
 static inline u64 sme_get_me_mask(void)
 {
-	return RIP_REL_REF(sme_me_mask);
+	return sme_me_mask;
 }
 
 #define __bss_decrypted __section(".bss..decrypted")
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index 690fbf48e853..9cbb18c99adb 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -3,12 +3,10 @@ 
 KCOV_INSTRUMENT_tlb.o			:= n
 KCOV_INSTRUMENT_mem_encrypt.o		:= n
 KCOV_INSTRUMENT_mem_encrypt_amd.o	:= n
-KCOV_INSTRUMENT_mem_encrypt_identity.o	:= n
 KCOV_INSTRUMENT_pgprot.o		:= n
 
 KASAN_SANITIZE_mem_encrypt.o		:= n
 KASAN_SANITIZE_mem_encrypt_amd.o	:= n
-KASAN_SANITIZE_mem_encrypt_identity.o	:= n
 KASAN_SANITIZE_pgprot.o		:= n
 
 # Disable KCSAN entirely, because otherwise we get warnings that some functions
@@ -16,12 +14,10 @@  KASAN_SANITIZE_pgprot.o		:= n
 KCSAN_SANITIZE := n
 # Avoid recursion by not calling KMSAN hooks for CEA code.
 KMSAN_SANITIZE_cpu_entry_area.o := n
-KMSAN_SANITIZE_mem_encrypt_identity.o := n
 
 ifdef CONFIG_FUNCTION_TRACER
 CFLAGS_REMOVE_mem_encrypt.o		= -pg
 CFLAGS_REMOVE_mem_encrypt_amd.o		= -pg
-CFLAGS_REMOVE_mem_encrypt_identity.o	= -pg
 CFLAGS_REMOVE_pgprot.o			= -pg
 endif
 
@@ -32,7 +28,6 @@  obj-y				+= pat/
 
 # Make sure __phys_addr has no stackprotector
 CFLAGS_physaddr.o		:= -fno-stack-protector
-CFLAGS_mem_encrypt_identity.o	:= -fno-stack-protector
 
 CFLAGS_fault.o := -I $(src)/../include/asm/trace
 
@@ -65,5 +60,4 @@  obj-$(CONFIG_MITIGATION_PAGE_TABLE_ISOLATION)	+= pti.o
 obj-$(CONFIG_X86_MEM_ENCRYPT)	+= mem_encrypt.o
 obj-$(CONFIG_AMD_MEM_ENCRYPT)	+= mem_encrypt_amd.o
 
-obj-$(CONFIG_AMD_MEM_ENCRYPT)	+= mem_encrypt_identity.o
 obj-$(CONFIG_AMD_MEM_ENCRYPT)	+= mem_encrypt_boot.o