[PATCH v16 02/15] arm64: trans_pgd: hibernate: Add trans_pgd_copy_el2_vectors
From: Pavel Tatashin
Date: Mon Aug 02 2021 - 17:54:24 EST
Users of trans_pgd may also need a copy of vector table because it is
also may be overwritten if a linear map can be overwritten.
Move setup of EL2 vectors from hibernate to trans_pgd, so it can be
later shared with kexec as well.
Signed-off-by: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
---
arch/arm64/include/asm/trans_pgd.h | 7 +++-
arch/arm64/include/asm/virt.h | 2 ++
arch/arm64/kernel/hibernate-asm.S | 52 ---------------------------
arch/arm64/kernel/hibernate.c | 26 ++++++--------
arch/arm64/mm/Makefile | 1 +
arch/arm64/mm/trans_pgd-asm.S | 58 ++++++++++++++++++++++++++++++
arch/arm64/mm/trans_pgd.c | 25 ++++++++++++-
7 files changed, 101 insertions(+), 70 deletions(-)
create mode 100644 arch/arm64/mm/trans_pgd-asm.S
diff --git a/arch/arm64/include/asm/trans_pgd.h b/arch/arm64/include/asm/trans_pgd.h
index 5d08e5adf3d5..411323bda7a4 100644
--- a/arch/arm64/include/asm/trans_pgd.h
+++ b/arch/arm64/include/asm/trans_pgd.h
@@ -1,7 +1,7 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
- * Copyright (c) 2020, Microsoft Corporation.
+ * Copyright (c) 2021, Microsoft Corporation.
* Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
*/
@@ -36,4 +36,9 @@ int trans_pgd_map_page(struct trans_pgd_info *info, pgd_t *trans_pgd,
int trans_pgd_idmap_page(struct trans_pgd_info *info, phys_addr_t *trans_ttbr0,
unsigned long *t0sz, void *page);
+int trans_pgd_copy_el2_vectors(struct trans_pgd_info *info,
+ phys_addr_t *el2_vectors);
+
+extern char trans_pgd_stub_vectors[];
+
#endif /* _ASM_TRANS_TABLE_H */
diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h
index a9457e96203c..3c8af033a997 100644
--- a/arch/arm64/include/asm/virt.h
+++ b/arch/arm64/include/asm/virt.h
@@ -67,6 +67,8 @@
*/
extern u32 __boot_cpu_mode[2];
+#define ARM64_VECTOR_TABLE_LEN SZ_2K
+
void __hyp_set_vectors(phys_addr_t phys_vector_base);
void __hyp_reset_vectors(void);
diff --git a/arch/arm64/kernel/hibernate-asm.S b/arch/arm64/kernel/hibernate-asm.S
index 81c0186a5e32..a30a2c3f905e 100644
--- a/arch/arm64/kernel/hibernate-asm.S
+++ b/arch/arm64/kernel/hibernate-asm.S
@@ -112,56 +112,4 @@ alternative_insn "dc cvau, x4", "dc civac, x4", ARM64_WORKAROUND_CLEAN_CACHE
hvc #0
3: ret
SYM_CODE_END(swsusp_arch_suspend_exit)
-
-/*
- * Restore the hyp stub.
- * This must be done before the hibernate page is unmapped by _cpu_resume(),
- * but happens before any of the hyp-stub's code is cleaned to PoC.
- *
- * x24: The physical address of __hyp_stub_vectors
- */
-SYM_CODE_START_LOCAL(el1_sync)
- msr vbar_el2, x24
- eret
-SYM_CODE_END(el1_sync)
-
-.macro invalid_vector label
-SYM_CODE_START_LOCAL(\label)
- b \label
-SYM_CODE_END(\label)
-.endm
-
- invalid_vector el2_sync_invalid
- invalid_vector el2_irq_invalid
- invalid_vector el2_fiq_invalid
- invalid_vector el2_error_invalid
- invalid_vector el1_sync_invalid
- invalid_vector el1_irq_invalid
- invalid_vector el1_fiq_invalid
- invalid_vector el1_error_invalid
-
-/* el2 vectors - switch el2 here while we restore the memory image. */
- .align 11
-SYM_CODE_START(hibernate_el2_vectors)
- ventry el2_sync_invalid // Synchronous EL2t
- ventry el2_irq_invalid // IRQ EL2t
- ventry el2_fiq_invalid // FIQ EL2t
- ventry el2_error_invalid // Error EL2t
-
- ventry el2_sync_invalid // Synchronous EL2h
- ventry el2_irq_invalid // IRQ EL2h
- ventry el2_fiq_invalid // FIQ EL2h
- ventry el2_error_invalid // Error EL2h
-
- ventry el1_sync // Synchronous 64-bit EL1
- ventry el1_irq_invalid // IRQ 64-bit EL1
- ventry el1_fiq_invalid // FIQ 64-bit EL1
- ventry el1_error_invalid // Error 64-bit EL1
-
- ventry el1_sync_invalid // Synchronous 32-bit EL1
- ventry el1_irq_invalid // IRQ 32-bit EL1
- ventry el1_fiq_invalid // FIQ 32-bit EL1
- ventry el1_error_invalid // Error 32-bit EL1
-SYM_CODE_END(hibernate_el2_vectors)
-
.popsection
diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c
index 4c9533f4c0c4..b96ef9060e4c 100644
--- a/arch/arm64/kernel/hibernate.c
+++ b/arch/arm64/kernel/hibernate.c
@@ -51,9 +51,6 @@ extern int in_suspend;
/* Do we need to reset el2? */
#define el2_reset_needed() (is_hyp_nvhe())
-/* temporary el2 vectors in the __hibernate_exit_text section. */
-extern char hibernate_el2_vectors[];
-
/* hyp-stub vectors, used to restore el2 during resume from hibernate. */
extern char __hyp_stub_vectors[];
@@ -434,6 +431,7 @@ int swsusp_arch_resume(void)
void *zero_page;
size_t exit_size;
pgd_t *tmp_pg_dir;
+ phys_addr_t el2_vectors;
void __noreturn (*hibernate_exit)(phys_addr_t, phys_addr_t, void *,
void *, phys_addr_t, phys_addr_t);
struct trans_pgd_info trans_info = {
@@ -461,6 +459,14 @@ int swsusp_arch_resume(void)
return -ENOMEM;
}
+ if (el2_reset_needed()) {
+ rc = trans_pgd_copy_el2_vectors(&trans_info, &el2_vectors);
+ if (rc) {
+ pr_err("Failed to setup el2 vectors\n");
+ return rc;
+ }
+ }
+
exit_size = __hibernate_exit_text_end - __hibernate_exit_text_start;
/*
* Copy swsusp_arch_suspend_exit() to a safe page. This will generate
@@ -473,26 +479,14 @@ int swsusp_arch_resume(void)
return rc;
}
- /*
- * The hibernate exit text contains a set of el2 vectors, that will
- * be executed at el2 with the mmu off in order to reload hyp-stub.
- */
- dcache_clean_inval_poc((unsigned long)hibernate_exit,
- (unsigned long)hibernate_exit + exit_size);
-
/*
* KASLR will cause the el2 vectors to be in a different location in
* the resumed kernel. Load hibernate's temporary copy into el2.
*
* We can skip this step if we booted at EL1, or are running with VHE.
*/
- if (el2_reset_needed()) {
- phys_addr_t el2_vectors = (phys_addr_t)hibernate_exit;
- el2_vectors += hibernate_el2_vectors -
- __hibernate_exit_text_start; /* offset */
-
+ if (el2_reset_needed())
__hyp_set_vectors(el2_vectors);
- }
hibernate_exit(virt_to_phys(tmp_pg_dir), resume_hdr.ttbr1_el1,
resume_hdr.reenter_kernel, restore_pblist,
diff --git a/arch/arm64/mm/Makefile b/arch/arm64/mm/Makefile
index f188c9092696..ff1e800ba7a1 100644
--- a/arch/arm64/mm/Makefile
+++ b/arch/arm64/mm/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_PTDUMP_CORE) += ptdump.o
obj-$(CONFIG_PTDUMP_DEBUGFS) += ptdump_debugfs.o
obj-$(CONFIG_TRANS_TABLE) += trans_pgd.o
+obj-$(CONFIG_TRANS_TABLE) += trans_pgd-asm.o
obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o
obj-$(CONFIG_ARM64_MTE) += mteswap.o
KASAN_SANITIZE_physaddr.o += n
diff --git a/arch/arm64/mm/trans_pgd-asm.S b/arch/arm64/mm/trans_pgd-asm.S
new file mode 100644
index 000000000000..831d6369494e
--- /dev/null
+++ b/arch/arm64/mm/trans_pgd-asm.S
@@ -0,0 +1,58 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+/*
+ * Copyright (c) 2021, Microsoft Corporation.
+ * Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/kvm_asm.h>
+
+.macro invalid_vector label
+SYM_CODE_START_LOCAL(\label)
+ .align 7
+ b \label
+SYM_CODE_END(\label)
+.endm
+
+.macro el1_sync_vector
+SYM_CODE_START_LOCAL(el1_sync)
+ .align 7
+ cmp x0, #HVC_SET_VECTORS /* Called from hibernate */
+ b.ne 1f
+ msr vbar_el2, x1
+ mov x0, xzr
+ eret
+1: /* Unexpected argument, set an error */
+ mov_q x0, HVC_STUB_ERR
+ eret
+SYM_CODE_END(el1_sync)
+.endm
+
+SYM_CODE_START(trans_pgd_stub_vectors)
+ invalid_vector hyp_stub_el2t_sync_invalid // Synchronous EL2t
+ invalid_vector hyp_stub_el2t_irq_invalid // IRQ EL2t
+ invalid_vector hyp_stub_el2t_fiq_invalid // FIQ EL2t
+ invalid_vector hyp_stub_el2t_error_invalid // Error EL2t
+
+ invalid_vector hyp_stub_el2h_sync_invalid // Synchronous EL2h
+ invalid_vector hyp_stub_el2h_irq_invalid // IRQ EL2h
+ invalid_vector hyp_stub_el2h_fiq_invalid // FIQ EL2h
+ invalid_vector hyp_stub_el2h_error_invalid // Error EL2h
+
+ el1_sync_vector // Synchronous 64-bit EL1
+ invalid_vector hyp_stub_el1_irq_invalid // IRQ 64-bit EL1
+ invalid_vector hyp_stub_el1_fiq_invalid // FIQ 64-bit EL1
+ invalid_vector hyp_stub_el1_error_invalid // Error 64-bit EL1
+
+ invalid_vector hyp_stub_32b_el1_sync_invalid // Synchronous 32-bit EL1
+ invalid_vector hyp_stub_32b_el1_irq_invalid // IRQ 32-bit EL1
+ invalid_vector hyp_stub_32b_el1_fiq_invalid // FIQ 32-bit EL1
+ invalid_vector hyp_stub_32b_el1_error_invalid // Error 32-bit EL1
+ .align 11
+SYM_INNER_LABEL(__trans_pgd_stub_vectors_end, SYM_L_LOCAL)
+SYM_CODE_END(trans_pgd_stub_vectors)
+
+# Check the trans_pgd_stub_vectors didn't overflow
+.org . - (__trans_pgd_stub_vectors_end - trans_pgd_stub_vectors) + SZ_2K
diff --git a/arch/arm64/mm/trans_pgd.c b/arch/arm64/mm/trans_pgd.c
index 527f0a39c3da..a08cf313c858 100644
--- a/arch/arm64/mm/trans_pgd.c
+++ b/arch/arm64/mm/trans_pgd.c
@@ -5,7 +5,7 @@
*
* This file derived from: arch/arm64/kernel/hibernate.c
*
- * Copyright (c) 2020, Microsoft Corporation.
+ * Copyright (c) 2021, Microsoft Corporation.
* Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
*
*/
@@ -322,3 +322,26 @@ int trans_pgd_idmap_page(struct trans_pgd_info *info, phys_addr_t *trans_ttbr0,
return 0;
}
+
+/*
+ * Create a copy of the vector table so we can call HVC_SET_VECTORS or
+ * HVC_SOFT_RESTART from contexts where the table may be overwritten.
+ */
+int trans_pgd_copy_el2_vectors(struct trans_pgd_info *info,
+ phys_addr_t *el2_vectors)
+{
+ void *hyp_stub = trans_alloc(info);
+
+ if (!hyp_stub)
+ return -ENOMEM;
+ *el2_vectors = virt_to_phys(hyp_stub);
+ memcpy(hyp_stub, &trans_pgd_stub_vectors, ARM64_VECTOR_TABLE_LEN);
+ caches_clean_inval_pou((unsigned long)hyp_stub,
+ (unsigned long)hyp_stub +
+ ARM64_VECTOR_TABLE_LEN);
+ dcache_clean_inval_poc((unsigned long)hyp_stub,
+ (unsigned long)hyp_stub +
+ ARM64_VECTOR_TABLE_LEN);
+
+ return 0;
+}
--
2.25.1