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Diffstat (limited to 'arch/x86/kernel/head64.c')
-rw-r--r--arch/x86/kernel/head64.c101
1 files changed, 80 insertions, 21 deletions
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 9ba79543d9ee..bab4fa579450 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -14,6 +14,7 @@
#include <linux/start_kernel.h>
#include <linux/io.h>
#include <linux/memblock.h>
+#include <linux/mem_encrypt.h>
#include <asm/processor.h>
#include <asm/proto.h>
@@ -33,7 +34,6 @@
/*
* Manage page tables very early on.
*/
-extern pgd_t early_top_pgt[PTRS_PER_PGD];
extern pmd_t early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD];
static unsigned int __initdata next_early_pgt;
pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX);
@@ -45,9 +45,11 @@ static void __head *fixup_pointer(void *ptr, unsigned long physaddr)
return ptr - (void *)_text + (void *)physaddr;
}
-void __head __startup_64(unsigned long physaddr)
+unsigned long __head __startup_64(unsigned long physaddr,
+ struct boot_params *bp)
{
unsigned long load_delta, *p;
+ unsigned long pgtable_flags;
pgdval_t *pgd;
p4dval_t *p4d;
pudval_t *pud;
@@ -69,6 +71,12 @@ void __head __startup_64(unsigned long physaddr)
if (load_delta & ~PMD_PAGE_MASK)
for (;;);
+ /* Activate Secure Memory Encryption (SME) if supported and enabled */
+ sme_enable(bp);
+
+ /* Include the SME encryption mask in the fixup value */
+ load_delta += sme_get_me_mask();
+
/* Fixup the physical addresses in the page table */
pgd = fixup_pointer(&early_top_pgt, physaddr);
@@ -92,31 +100,35 @@ void __head __startup_64(unsigned long physaddr)
* creates a bunch of nonsense entries but that is fine --
* it avoids problems around wraparound.
*/
+
next_pgt_ptr = fixup_pointer(&next_early_pgt, physaddr);
pud = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++], physaddr);
pmd = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++], physaddr);
+ pgtable_flags = _KERNPG_TABLE_NOENC + sme_get_me_mask();
+
if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
p4d = fixup_pointer(early_dynamic_pgts[next_early_pgt++], physaddr);
i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD;
- pgd[i + 0] = (pgdval_t)p4d + _KERNPG_TABLE;
- pgd[i + 1] = (pgdval_t)p4d + _KERNPG_TABLE;
+ pgd[i + 0] = (pgdval_t)p4d + pgtable_flags;
+ pgd[i + 1] = (pgdval_t)p4d + pgtable_flags;
i = (physaddr >> P4D_SHIFT) % PTRS_PER_P4D;
- p4d[i + 0] = (pgdval_t)pud + _KERNPG_TABLE;
- p4d[i + 1] = (pgdval_t)pud + _KERNPG_TABLE;
+ p4d[i + 0] = (pgdval_t)pud + pgtable_flags;
+ p4d[i + 1] = (pgdval_t)pud + pgtable_flags;
} else {
i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD;
- pgd[i + 0] = (pgdval_t)pud + _KERNPG_TABLE;
- pgd[i + 1] = (pgdval_t)pud + _KERNPG_TABLE;
+ pgd[i + 0] = (pgdval_t)pud + pgtable_flags;
+ pgd[i + 1] = (pgdval_t)pud + pgtable_flags;
}
i = (physaddr >> PUD_SHIFT) % PTRS_PER_PUD;
- pud[i + 0] = (pudval_t)pmd + _KERNPG_TABLE;
- pud[i + 1] = (pudval_t)pmd + _KERNPG_TABLE;
+ pud[i + 0] = (pudval_t)pmd + pgtable_flags;
+ pud[i + 1] = (pudval_t)pmd + pgtable_flags;
pmd_entry = __PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL;
+ pmd_entry += sme_get_me_mask();
pmd_entry += physaddr;
for (i = 0; i < DIV_ROUND_UP(_end - _text, PMD_SIZE); i++) {
@@ -137,9 +149,30 @@ void __head __startup_64(unsigned long physaddr)
pmd[i] += load_delta;
}
- /* Fixup phys_base */
+ /*
+ * Fixup phys_base - remove the memory encryption mask to obtain
+ * the true physical address.
+ */
p = fixup_pointer(&phys_base, physaddr);
- *p += load_delta;
+ *p += load_delta - sme_get_me_mask();
+
+ /* Encrypt the kernel (if SME is active) */
+ sme_encrypt_kernel();
+
+ /*
+ * Return the SME encryption mask (if SME is active) to be used as a
+ * modifier for the initial pgdir entry programmed into CR3.
+ */
+ return sme_get_me_mask();
+}
+
+unsigned long __startup_secondary_64(void)
+{
+ /*
+ * Return the SME encryption mask (if SME is active) to be used as a
+ * modifier for the initial pgdir entry programmed into CR3.
+ */
+ return sme_get_me_mask();
}
/* Wipe all early page tables except for the kernel symbol map */
@@ -147,17 +180,17 @@ static void __init reset_early_page_tables(void)
{
memset(early_top_pgt, 0, sizeof(pgd_t)*(PTRS_PER_PGD-1));
next_early_pgt = 0;
- write_cr3(__pa_nodebug(early_top_pgt));
+ write_cr3(__sme_pa_nodebug(early_top_pgt));
}
/* Create a new PMD entry */
-int __init early_make_pgtable(unsigned long address)
+int __init __early_make_pgtable(unsigned long address, pmdval_t pmd)
{
unsigned long physaddr = address - __PAGE_OFFSET;
pgdval_t pgd, *pgd_p;
p4dval_t p4d, *p4d_p;
pudval_t pud, *pud_p;
- pmdval_t pmd, *pmd_p;
+ pmdval_t *pmd_p;
/* Invalid address or early pgt is done ? */
if (physaddr >= MAXMEM || read_cr3_pa() != __pa_nodebug(early_top_pgt))
@@ -216,12 +249,21 @@ again:
memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD);
*pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
}
- pmd = (physaddr & PMD_MASK) + early_pmd_flags;
pmd_p[pmd_index(address)] = pmd;
return 0;
}
+int __init early_make_pgtable(unsigned long address)
+{
+ unsigned long physaddr = address - __PAGE_OFFSET;
+ pmdval_t pmd;
+
+ pmd = (physaddr & PMD_MASK) + early_pmd_flags;
+
+ return __early_make_pgtable(address, pmd);
+}
+
/* Don't add a printk in there. printk relies on the PDA which is not initialized
yet. */
static void __init clear_bss(void)
@@ -244,6 +286,12 @@ static void __init copy_bootdata(char *real_mode_data)
char * command_line;
unsigned long cmd_line_ptr;
+ /*
+ * If SME is active, this will create decrypted mappings of the
+ * boot data in advance of the copy operations.
+ */
+ sme_map_bootdata(real_mode_data);
+
memcpy(&boot_params, real_mode_data, sizeof boot_params);
sanitize_boot_params(&boot_params);
cmd_line_ptr = get_cmd_line_ptr();
@@ -251,12 +299,18 @@ static void __init copy_bootdata(char *real_mode_data)
command_line = __va(cmd_line_ptr);
memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
}
+
+ /*
+ * The old boot data is no longer needed and won't be reserved,
+ * freeing up that memory for use by the system. If SME is active,
+ * we need to remove the mappings that were created so that the
+ * memory doesn't remain mapped as decrypted.
+ */
+ sme_unmap_bootdata(real_mode_data);
}
asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data)
{
- int i;
-
/*
* Build-time sanity checks on the kernel image and module
* area mappings. (these are purely build-time and produce no code)
@@ -280,11 +334,16 @@ asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data)
clear_page(init_top_pgt);
+ /*
+ * SME support may update early_pmd_flags to include the memory
+ * encryption mask, so it needs to be called before anything
+ * that may generate a page fault.
+ */
+ sme_early_init();
+
kasan_early_init();
- for (i = 0; i < NUM_EXCEPTION_VECTORS; i++)
- set_intr_gate(i, early_idt_handler_array[i]);
- load_idt((const struct desc_ptr *)&idt_descr);
+ idt_setup_early_handler();
copy_bootdata(__va(real_mode_data));