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path: root/arch/x86/mm/mem_encrypt.c
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Diffstat (limited to 'arch/x86/mm/mem_encrypt.c')
-rw-r--r--arch/x86/mm/mem_encrypt.c356
1 files changed, 260 insertions, 96 deletions
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index 391b13402e40..3ef362f598e3 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -464,37 +464,62 @@ void swiotlb_set_mem_attributes(void *vaddr, unsigned long size)
set_memory_decrypted((unsigned long)vaddr, size >> PAGE_SHIFT);
}
-static void __init sme_clear_pgd(pgd_t *pgd_base, unsigned long start,
- unsigned long end)
+struct sme_populate_pgd_data {
+ void *pgtable_area;
+ pgd_t *pgd;
+
+ pmdval_t pmd_flags;
+ pteval_t pte_flags;
+ unsigned long paddr;
+
+ unsigned long vaddr;
+ unsigned long vaddr_end;
+};
+
+static void __init sme_clear_pgd(struct sme_populate_pgd_data *ppd)
{
unsigned long pgd_start, pgd_end, pgd_size;
pgd_t *pgd_p;
- pgd_start = start & PGDIR_MASK;
- pgd_end = end & PGDIR_MASK;
+ pgd_start = ppd->vaddr & PGDIR_MASK;
+ pgd_end = ppd->vaddr_end & PGDIR_MASK;
- pgd_size = (((pgd_end - pgd_start) / PGDIR_SIZE) + 1);
- pgd_size *= sizeof(pgd_t);
+ pgd_size = (((pgd_end - pgd_start) / PGDIR_SIZE) + 1) * sizeof(pgd_t);
- pgd_p = pgd_base + pgd_index(start);
+ pgd_p = ppd->pgd + pgd_index(ppd->vaddr);
memset(pgd_p, 0, pgd_size);
}
-#define PGD_FLAGS _KERNPG_TABLE_NOENC
-#define P4D_FLAGS _KERNPG_TABLE_NOENC
-#define PUD_FLAGS _KERNPG_TABLE_NOENC
-#define PMD_FLAGS (__PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL)
+#define PGD_FLAGS _KERNPG_TABLE_NOENC
+#define P4D_FLAGS _KERNPG_TABLE_NOENC
+#define PUD_FLAGS _KERNPG_TABLE_NOENC
+#define PMD_FLAGS _KERNPG_TABLE_NOENC
+
+#define PMD_FLAGS_LARGE (__PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL)
+
+#define PMD_FLAGS_DEC PMD_FLAGS_LARGE
+#define PMD_FLAGS_DEC_WP ((PMD_FLAGS_DEC & ~_PAGE_CACHE_MASK) | \
+ (_PAGE_PAT | _PAGE_PWT))
+
+#define PMD_FLAGS_ENC (PMD_FLAGS_LARGE | _PAGE_ENC)
+
+#define PTE_FLAGS (__PAGE_KERNEL_EXEC & ~_PAGE_GLOBAL)
+
+#define PTE_FLAGS_DEC PTE_FLAGS
+#define PTE_FLAGS_DEC_WP ((PTE_FLAGS_DEC & ~_PAGE_CACHE_MASK) | \
+ (_PAGE_PAT | _PAGE_PWT))
+
+#define PTE_FLAGS_ENC (PTE_FLAGS | _PAGE_ENC)
-static void __init *sme_populate_pgd(pgd_t *pgd_base, void *pgtable_area,
- unsigned long vaddr, pmdval_t pmd_val)
+static pmd_t __init *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
{
pgd_t *pgd_p;
p4d_t *p4d_p;
pud_t *pud_p;
pmd_t *pmd_p;
- pgd_p = pgd_base + pgd_index(vaddr);
+ pgd_p = ppd->pgd + pgd_index(ppd->vaddr);
if (native_pgd_val(*pgd_p)) {
if (IS_ENABLED(CONFIG_X86_5LEVEL))
p4d_p = (p4d_t *)(native_pgd_val(*pgd_p) & ~PTE_FLAGS_MASK);
@@ -504,15 +529,15 @@ static void __init *sme_populate_pgd(pgd_t *pgd_base, void *pgtable_area,
pgd_t pgd;
if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
- p4d_p = pgtable_area;
+ p4d_p = ppd->pgtable_area;
memset(p4d_p, 0, sizeof(*p4d_p) * PTRS_PER_P4D);
- pgtable_area += sizeof(*p4d_p) * PTRS_PER_P4D;
+ ppd->pgtable_area += sizeof(*p4d_p) * PTRS_PER_P4D;
pgd = native_make_pgd((pgdval_t)p4d_p + PGD_FLAGS);
} else {
- pud_p = pgtable_area;
+ pud_p = ppd->pgtable_area;
memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
- pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
+ ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
pgd = native_make_pgd((pgdval_t)pud_p + PGD_FLAGS);
}
@@ -520,58 +545,160 @@ static void __init *sme_populate_pgd(pgd_t *pgd_base, void *pgtable_area,
}
if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
- p4d_p += p4d_index(vaddr);
+ p4d_p += p4d_index(ppd->vaddr);
if (native_p4d_val(*p4d_p)) {
pud_p = (pud_t *)(native_p4d_val(*p4d_p) & ~PTE_FLAGS_MASK);
} else {
p4d_t p4d;
- pud_p = pgtable_area;
+ pud_p = ppd->pgtable_area;
memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
- pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
+ ppd->pgtable_area += sizeof(*pud_p) * PTRS_PER_PUD;
p4d = native_make_p4d((pudval_t)pud_p + P4D_FLAGS);
native_set_p4d(p4d_p, p4d);
}
}
- pud_p += pud_index(vaddr);
+ pud_p += pud_index(ppd->vaddr);
if (native_pud_val(*pud_p)) {
if (native_pud_val(*pud_p) & _PAGE_PSE)
- goto out;
+ return NULL;
pmd_p = (pmd_t *)(native_pud_val(*pud_p) & ~PTE_FLAGS_MASK);
} else {
pud_t pud;
- pmd_p = pgtable_area;
+ pmd_p = ppd->pgtable_area;
memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD);
- pgtable_area += sizeof(*pmd_p) * PTRS_PER_PMD;
+ ppd->pgtable_area += sizeof(*pmd_p) * PTRS_PER_PMD;
pud = native_make_pud((pmdval_t)pmd_p + PUD_FLAGS);
native_set_pud(pud_p, pud);
}
- pmd_p += pmd_index(vaddr);
+ return pmd_p;
+}
+
+static void __init sme_populate_pgd_large(struct sme_populate_pgd_data *ppd)
+{
+ pmd_t *pmd_p;
+
+ pmd_p = sme_prepare_pgd(ppd);
+ if (!pmd_p)
+ return;
+
+ pmd_p += pmd_index(ppd->vaddr);
if (!native_pmd_val(*pmd_p) || !(native_pmd_val(*pmd_p) & _PAGE_PSE))
- native_set_pmd(pmd_p, native_make_pmd(pmd_val));
+ native_set_pmd(pmd_p, native_make_pmd(ppd->paddr | ppd->pmd_flags));
+}
-out:
- return pgtable_area;
+static void __init sme_populate_pgd(struct sme_populate_pgd_data *ppd)
+{
+ pmd_t *pmd_p;
+ pte_t *pte_p;
+
+ pmd_p = sme_prepare_pgd(ppd);
+ if (!pmd_p)
+ return;
+
+ pmd_p += pmd_index(ppd->vaddr);
+ if (native_pmd_val(*pmd_p)) {
+ if (native_pmd_val(*pmd_p) & _PAGE_PSE)
+ return;
+
+ pte_p = (pte_t *)(native_pmd_val(*pmd_p) & ~PTE_FLAGS_MASK);
+ } else {
+ pmd_t pmd;
+
+ pte_p = ppd->pgtable_area;
+ memset(pte_p, 0, sizeof(*pte_p) * PTRS_PER_PTE);
+ ppd->pgtable_area += sizeof(*pte_p) * PTRS_PER_PTE;
+
+ pmd = native_make_pmd((pteval_t)pte_p + PMD_FLAGS);
+ native_set_pmd(pmd_p, pmd);
+ }
+
+ pte_p += pte_index(ppd->vaddr);
+ if (!native_pte_val(*pte_p))
+ native_set_pte(pte_p, native_make_pte(ppd->paddr | ppd->pte_flags));
+}
+
+static void __init __sme_map_range_pmd(struct sme_populate_pgd_data *ppd)
+{
+ while (ppd->vaddr < ppd->vaddr_end) {
+ sme_populate_pgd_large(ppd);
+
+ ppd->vaddr += PMD_PAGE_SIZE;
+ ppd->paddr += PMD_PAGE_SIZE;
+ }
+}
+
+static void __init __sme_map_range_pte(struct sme_populate_pgd_data *ppd)
+{
+ while (ppd->vaddr < ppd->vaddr_end) {
+ sme_populate_pgd(ppd);
+
+ ppd->vaddr += PAGE_SIZE;
+ ppd->paddr += PAGE_SIZE;
+ }
+}
+
+static void __init __sme_map_range(struct sme_populate_pgd_data *ppd,
+ pmdval_t pmd_flags, pteval_t pte_flags)
+{
+ unsigned long vaddr_end;
+
+ ppd->pmd_flags = pmd_flags;
+ ppd->pte_flags = pte_flags;
+
+ /* Save original end value since we modify the struct value */
+ vaddr_end = ppd->vaddr_end;
+
+ /* If start is not 2MB aligned, create PTE entries */
+ ppd->vaddr_end = ALIGN(ppd->vaddr, PMD_PAGE_SIZE);
+ __sme_map_range_pte(ppd);
+
+ /* Create PMD entries */
+ ppd->vaddr_end = vaddr_end & PMD_PAGE_MASK;
+ __sme_map_range_pmd(ppd);
+
+ /* If end is not 2MB aligned, create PTE entries */
+ ppd->vaddr_end = vaddr_end;
+ __sme_map_range_pte(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 __init sme_map_range_decrypted(struct sme_populate_pgd_data *ppd)
+{
+ __sme_map_range(ppd, PMD_FLAGS_DEC, PTE_FLAGS_DEC);
+}
+
+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 __init sme_pgtable_calc(unsigned long len)
{
- unsigned long p4d_size, pud_size, pmd_size;
+ unsigned long p4d_size, pud_size, pmd_size, pte_size;
unsigned long total;
/*
* Perform a relatively simplistic calculation of the pagetable
- * entries that are needed. That mappings will be covered by 2MB
- * PMD entries so we can conservatively calculate the required
+ * entries that are needed. Those mappings will be covered mostly
+ * by 2MB PMD entries so we can conservatively calculate the required
* number of P4D, PUD and PMD structures needed to perform the
- * mappings. Incrementing the count for each covers the case where
- * the addresses cross entries.
+ * mappings. For mappings that are not 2MB aligned, PTE mappings
+ * would be needed for the start and end portion of the address range
+ * that fall outside of the 2MB alignment. This results in, at most,
+ * two extra pages to hold PTE entries for each range that is mapped.
+ * Incrementing the count for each covers the case where the addresses
+ * cross entries.
*/
if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
p4d_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1;
@@ -585,8 +712,9 @@ static unsigned long __init sme_pgtable_calc(unsigned long len)
}
pmd_size = (ALIGN(len, PUD_SIZE) / PUD_SIZE) + 1;
pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD;
+ pte_size = 2 * sizeof(pte_t) * PTRS_PER_PTE;
- total = p4d_size + pud_size + pmd_size;
+ total = p4d_size + pud_size + pmd_size + pte_size;
/*
* Now calculate the added pagetable structures needed to populate
@@ -610,29 +738,29 @@ static unsigned long __init sme_pgtable_calc(unsigned long len)
return total;
}
-void __init sme_encrypt_kernel(void)
+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;
unsigned long kernel_start, kernel_end, kernel_len;
+ unsigned long initrd_start, initrd_end, initrd_len;
+ struct sme_populate_pgd_data ppd;
unsigned long pgtable_area_len;
- unsigned long paddr, pmd_flags;
unsigned long decrypted_base;
- void *pgtable_area;
- pgd_t *pgd;
if (!sme_active())
return;
/*
- * Prepare for encrypting the kernel by building new pagetables with
- * the necessary attributes needed to encrypt the kernel in place.
+ * Prepare for encrypting the kernel and initrd by building new
+ * pagetables with the necessary attributes needed to encrypt the
+ * kernel in place.
*
* One range of virtual addresses will map the memory occupied
- * by the kernel as encrypted.
+ * by the kernel and initrd as encrypted.
*
* Another range of virtual addresses will map the memory occupied
- * by the kernel as decrypted and write-protected.
+ * by the kernel and initrd as decrypted and write-protected.
*
* The use of write-protect attribute will prevent any of the
* memory from being cached.
@@ -643,6 +771,20 @@ void __init sme_encrypt_kernel(void)
kernel_end = ALIGN(__pa_symbol(_end), PMD_PAGE_SIZE);
kernel_len = kernel_end - kernel_start;
+ initrd_start = 0;
+ initrd_end = 0;
+ initrd_len = 0;
+#ifdef CONFIG_BLK_DEV_INITRD
+ initrd_len = (unsigned long)bp->hdr.ramdisk_size |
+ ((unsigned long)bp->ext_ramdisk_size << 32);
+ if (initrd_len) {
+ initrd_start = (unsigned long)bp->hdr.ramdisk_image |
+ ((unsigned long)bp->ext_ramdisk_image << 32);
+ initrd_end = PAGE_ALIGN(initrd_start + initrd_len);
+ initrd_len = initrd_end - initrd_start;
+ }
+#endif
+
/* Set the encryption workarea to be immediately after the kernel */
workarea_start = kernel_end;
@@ -665,16 +807,21 @@ void __init sme_encrypt_kernel(void)
*/
pgtable_area_len = sizeof(pgd_t) * PTRS_PER_PGD;
pgtable_area_len += sme_pgtable_calc(execute_end - kernel_start) * 2;
+ if (initrd_len)
+ pgtable_area_len += sme_pgtable_calc(initrd_len) * 2;
/* PUDs and PMDs needed in the current pagetables for the workarea */
pgtable_area_len += sme_pgtable_calc(execute_len + pgtable_area_len);
/*
* The total workarea includes the executable encryption area and
- * the pagetable area.
+ * the pagetable area. The start of the workarea is already 2MB
+ * aligned, align the end of the workarea on a 2MB boundary so that
+ * we don't try to create/allocate PTE entries from the workarea
+ * before it is mapped.
*/
workarea_len = execute_len + pgtable_area_len;
- workarea_end = workarea_start + workarea_len;
+ workarea_end = ALIGN(workarea_start + workarea_len, PMD_PAGE_SIZE);
/*
* Set the address to the start of where newly created pagetable
@@ -683,45 +830,30 @@ void __init sme_encrypt_kernel(void)
* pagetables and when the new encrypted and decrypted kernel
* mappings are populated.
*/
- pgtable_area = (void *)execute_end;
+ ppd.pgtable_area = (void *)execute_end;
/*
* Make sure the current pagetable structure has entries for
* addressing the workarea.
*/
- pgd = (pgd_t *)native_read_cr3_pa();
- paddr = workarea_start;
- while (paddr < workarea_end) {
- pgtable_area = sme_populate_pgd(pgd, pgtable_area,
- paddr,
- paddr + PMD_FLAGS);
-
- paddr += PMD_PAGE_SIZE;
- }
+ ppd.pgd = (pgd_t *)native_read_cr3_pa();
+ ppd.paddr = workarea_start;
+ ppd.vaddr = workarea_start;
+ ppd.vaddr_end = workarea_end;
+ sme_map_range_decrypted(&ppd);
/* Flush the TLB - no globals so cr3 is enough */
native_write_cr3(__native_read_cr3());
/*
* A new pagetable structure is being built to allow for the kernel
- * to be encrypted. It starts with an empty PGD that will then be
- * populated with new PUDs and PMDs as the encrypted and decrypted
- * kernel mappings are created.
+ * and initrd to be encrypted. It starts with an empty PGD that will
+ * then be populated with new PUDs and PMDs as the encrypted and
+ * decrypted kernel mappings are created.
*/
- pgd = pgtable_area;
- memset(pgd, 0, sizeof(*pgd) * PTRS_PER_PGD);
- pgtable_area += sizeof(*pgd) * PTRS_PER_PGD;
-
- /* Add encrypted kernel (identity) mappings */
- pmd_flags = PMD_FLAGS | _PAGE_ENC;
- paddr = kernel_start;
- while (paddr < kernel_end) {
- pgtable_area = sme_populate_pgd(pgd, pgtable_area,
- paddr,
- paddr + pmd_flags);
-
- paddr += PMD_PAGE_SIZE;
- }
+ ppd.pgd = ppd.pgtable_area;
+ memset(ppd.pgd, 0, sizeof(pgd_t) * PTRS_PER_PGD);
+ ppd.pgtable_area += sizeof(pgd_t) * PTRS_PER_PGD;
/*
* A different PGD index/entry must be used to get different
@@ -730,47 +862,79 @@ void __init sme_encrypt_kernel(void)
* the base of the mapping.
*/
decrypted_base = (pgd_index(workarea_end) + 1) & (PTRS_PER_PGD - 1);
+ if (initrd_len) {
+ unsigned long check_base;
+
+ check_base = (pgd_index(initrd_end) + 1) & (PTRS_PER_PGD - 1);
+ decrypted_base = max(decrypted_base, check_base);
+ }
decrypted_base <<= PGDIR_SHIFT;
+ /* Add encrypted kernel (identity) mappings */
+ ppd.paddr = kernel_start;
+ ppd.vaddr = kernel_start;
+ ppd.vaddr_end = kernel_end;
+ sme_map_range_encrypted(&ppd);
+
/* Add decrypted, write-protected kernel (non-identity) mappings */
- pmd_flags = (PMD_FLAGS & ~_PAGE_CACHE_MASK) | (_PAGE_PAT | _PAGE_PWT);
- paddr = kernel_start;
- while (paddr < kernel_end) {
- pgtable_area = sme_populate_pgd(pgd, pgtable_area,
- paddr + decrypted_base,
- paddr + pmd_flags);
-
- paddr += PMD_PAGE_SIZE;
+ ppd.paddr = kernel_start;
+ ppd.vaddr = kernel_start + decrypted_base;
+ ppd.vaddr_end = kernel_end + decrypted_base;
+ sme_map_range_decrypted_wp(&ppd);
+
+ if (initrd_len) {
+ /* Add encrypted initrd (identity) mappings */
+ ppd.paddr = initrd_start;
+ ppd.vaddr = initrd_start;
+ ppd.vaddr_end = initrd_end;
+ sme_map_range_encrypted(&ppd);
+ /*
+ * Add decrypted, write-protected initrd (non-identity) mappings
+ */
+ ppd.paddr = initrd_start;
+ ppd.vaddr = initrd_start + decrypted_base;
+ ppd.vaddr_end = initrd_end + decrypted_base;
+ sme_map_range_decrypted_wp(&ppd);
}
/* Add decrypted workarea mappings to both kernel mappings */
- paddr = workarea_start;
- while (paddr < workarea_end) {
- pgtable_area = sme_populate_pgd(pgd, pgtable_area,
- paddr,
- paddr + PMD_FLAGS);
+ ppd.paddr = workarea_start;
+ ppd.vaddr = workarea_start;
+ ppd.vaddr_end = workarea_end;
+ sme_map_range_decrypted(&ppd);
- pgtable_area = sme_populate_pgd(pgd, pgtable_area,
- paddr + decrypted_base,
- paddr + PMD_FLAGS);
-
- paddr += PMD_PAGE_SIZE;
- }
+ ppd.paddr = workarea_start;
+ ppd.vaddr = workarea_start + decrypted_base;
+ ppd.vaddr_end = workarea_end + decrypted_base;
+ sme_map_range_decrypted(&ppd);
/* Perform the encryption */
sme_encrypt_execute(kernel_start, kernel_start + decrypted_base,
- kernel_len, workarea_start, (unsigned long)pgd);
+ kernel_len, workarea_start, (unsigned long)ppd.pgd);
+
+ if (initrd_len)
+ sme_encrypt_execute(initrd_start, initrd_start + decrypted_base,
+ initrd_len, workarea_start,
+ (unsigned long)ppd.pgd);
/*
* At this point we are running encrypted. Remove the mappings for
* the decrypted areas - all that is needed for this is to remove
* the PGD entry/entries.
*/
- sme_clear_pgd(pgd, kernel_start + decrypted_base,
- kernel_end + decrypted_base);
+ ppd.vaddr = kernel_start + decrypted_base;
+ ppd.vaddr_end = kernel_end + decrypted_base;
+ sme_clear_pgd(&ppd);
+
+ if (initrd_len) {
+ ppd.vaddr = initrd_start + decrypted_base;
+ ppd.vaddr_end = initrd_end + decrypted_base;
+ sme_clear_pgd(&ppd);
+ }
- sme_clear_pgd(pgd, workarea_start + decrypted_base,
- workarea_end + decrypted_base);
+ ppd.vaddr = workarea_start + decrypted_base;
+ ppd.vaddr_end = workarea_end + decrypted_base;
+ sme_clear_pgd(&ppd);
/* Flush the TLB - no globals so cr3 is enough */
native_write_cr3(__native_read_cr3());