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Merge branch 'kvm-arm64/hyp-reloc' into kvmarm-master/next 

Signed-off-by: Marc Zyngier <maz@kernel.org>
This commit is contained in:
Marc Zyngier 2021-02-12 14:08:18 +00:00
parent c5db649f3d bc93763f17
commit e7ae2ecdc8
20 changed files with 607 additions and 138 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
arch/arm64/include/asm/hyp_image.h
View File

@ -7,6 +7,9 @@
#ifndef __ARM64_HYP_IMAGE_H__
#define __ARM64_HYP_IMAGE_H__
#define __HYP_CONCAT(a, b) a ## b
#define HYP_CONCAT(a, b) __HYP_CONCAT(a, b)
/*
* KVM nVHE code has its own symbol namespace prefixed with __kvm_nvhe_,
* to separate it from the kernel proper.
@ -21,9 +24,31 @@
*/
#define HYP_SECTION_NAME(NAME) .hyp##NAME
/* Symbol defined at the beginning of each hyp section. */
#define HYP_SECTION_SYMBOL_NAME(NAME) \
HYP_CONCAT(__hyp_section_, HYP_SECTION_NAME(NAME))
/*
* Helper to generate linker script statements starting a hyp section.
*
* A symbol with a well-known name is defined at the first byte. This
* is used as a base for hyp relocations (see gen-hyprel.c). It must
* be defined inside the section so the linker of `vmlinux` cannot
* separate it from the section data.
*/
#define BEGIN_HYP_SECTION(NAME) \
HYP_SECTION_NAME(NAME) : { \
HYP_SECTION_SYMBOL_NAME(NAME) = .;
/* Helper to generate linker script statements ending a hyp section. */
#define END_HYP_SECTION \
}
/* Defines an ELF hyp section from input section @NAME and its subsections. */
#define HYP_SECTION(NAME) \
HYP_SECTION_NAME(NAME) : { *(NAME NAME##.*) }
#define HYP_SECTION(NAME) \
BEGIN_HYP_SECTION(NAME) \
*(NAME NAME##.*) \
END_HYP_SECTION
/*
* Defines a linker script alias of a kernel-proper symbol referenced by

26
arch/arm64/include/asm/kvm_asm.h
View File

@ -199,32 +199,6 @@ extern void __vgic_v3_init_lrs(void);
extern u32 __kvm_get_mdcr_el2(void);
#if defined(GCC_VERSION) && GCC_VERSION < 50000
#define SYM_CONSTRAINT "i"
#else
#define SYM_CONSTRAINT "S"
#endif
/*
* Obtain the PC-relative address of a kernel symbol
* s: symbol
*
* The goal of this macro is to return a symbol's address based on a
* PC-relative computation, as opposed to a loading the VA from a
* constant pool or something similar. This works well for HYP, as an
* absolute VA is guaranteed to be wrong. Only use this if trying to
* obtain the address of a symbol (i.e. not something you obtained by
* following a pointer).
*/
#define hyp_symbol_addr(s) \
({ \
typeof(s) *addr; \
asm("adrp %0, %1\n" \
"add %0, %0, :lo12:%1\n" \
: "=r" (addr) : SYM_CONSTRAINT (&s)); \
addr; \
})
#define __KVM_EXTABLE(from, to) \
" .pushsection __kvm_ex_table, \"a\"\n" \
" .align 3\n" \

67
arch/arm64/include/asm/kvm_mmu.h
View File

@ -73,8 +73,18 @@ alternative_cb_end
.endm
/*
* Convert a kernel image address to a PA
* reg: kernel address to be converted in place
* Convert a hypervisor VA to a PA
* reg: hypervisor address to be converted in place
* tmp: temporary register
*/
.macro hyp_pa reg, tmp
ldr_l \tmp, hyp_physvirt_offset
add \reg, \reg, \tmp
.endm
/*
* Convert a hypervisor VA to a kernel image address
* reg: hypervisor address to be converted in place
* tmp: temporary register
*
* The actual code generation takes place in kvm_get_kimage_voffset, and
@ -82,7 +92,11 @@ alternative_cb_end
* perform the register allocation (kvm_get_kimage_voffset uses the
* specific registers encoded in the instructions).
*/
.macro kimg_pa reg, tmp
.macro hyp_kimg_va reg, tmp
/* Convert hyp VA -> PA. */
hyp_pa \reg, \tmp
/* Load kimage_voffset. */
alternative_cb kvm_get_kimage_voffset
movz \tmp, #0
movk \tmp, #0, lsl #16
@ -90,32 +104,8 @@ alternative_cb kvm_get_kimage_voffset
movk \tmp, #0, lsl #48
alternative_cb_end
/* reg = __pa(reg) */
sub \reg, \reg, \tmp
.endm
/*
* Convert a kernel image address to a hyp VA
* reg: kernel address to be converted in place
* tmp: temporary register
*
* The actual code generation takes place in kvm_get_kimage_voffset, and
* the instructions below are only there to reserve the space and
* perform the register allocation (kvm_update_kimg_phys_offset uses the
* specific registers encoded in the instructions).
*/
.macro kimg_hyp_va reg, tmp
alternative_cb kvm_update_kimg_phys_offset
movz \tmp, #0
movk \tmp, #0, lsl #16
movk \tmp, #0, lsl #32
movk \tmp, #0, lsl #48
alternative_cb_end
sub \reg, \reg, \tmp
mov_q \tmp, PAGE_OFFSET
orr \reg, \reg, \tmp
kern_hyp_va \reg
/* Convert PA -> kimg VA. */
add \reg, \reg, \tmp
.endm
#else
@ -129,6 +119,7 @@ alternative_cb_end
void kvm_update_va_mask(struct alt_instr *alt,
__le32 *origptr, __le32 *updptr, int nr_inst);
void kvm_compute_layout(void);
void kvm_apply_hyp_relocations(void);
static __always_inline unsigned long __kern_hyp_va(unsigned long v)
{
@ -144,24 +135,6 @@ static __always_inline unsigned long __kern_hyp_va(unsigned long v)
#define kern_hyp_va(v) ((typeof(v))(__kern_hyp_va((unsigned long)(v))))
static __always_inline unsigned long __kimg_hyp_va(unsigned long v)
{
unsigned long offset;
asm volatile(ALTERNATIVE_CB("movz %0, #0\n"
"movk %0, #0, lsl #16\n"
"movk %0, #0, lsl #32\n"
"movk %0, #0, lsl #48\n",
kvm_update_kimg_phys_offset)
: "=r" (offset));
return __kern_hyp_va((v - offset) | PAGE_OFFSET);
}
#define kimg_fn_hyp_va(v) ((typeof(*v))(__kimg_hyp_va((unsigned long)(v))))
#define kimg_fn_ptr(x) (typeof(x) **)(x)
/*
* We currently support using a VM-specified IPA size. For backward
* compatibility, the default IPA size is fixed to 40bits.

3
arch/arm64/include/asm/sections.h
View File

@ -11,7 +11,8 @@ extern char __alt_instructions[], __alt_instructions_end[];
extern char __hibernate_exit_text_start[], __hibernate_exit_text_end[];
extern char __hyp_idmap_text_start[], __hyp_idmap_text_end[];
extern char __hyp_text_start[], __hyp_text_end[];
extern char __hyp_data_ro_after_init_start[], __hyp_data_ro_after_init_end[];
extern char __hyp_rodata_start[], __hyp_rodata_end[];
extern char __hyp_reloc_begin[], __hyp_reloc_end[];
extern char __idmap_text_start[], __idmap_text_end[];
extern char __initdata_begin[], __initdata_end[];
extern char __inittext_begin[], __inittext_end[];

1
arch/arm64/kernel/image-vars.h
View File

@ -64,7 +64,6 @@ __efistub__ctype = _ctype;
/* Alternative callbacks for init-time patching of nVHE hyp code. */
KVM_NVHE_ALIAS(kvm_patch_vector_branch);
KVM_NVHE_ALIAS(kvm_update_va_mask);
KVM_NVHE_ALIAS(kvm_update_kimg_phys_offset);
KVM_NVHE_ALIAS(kvm_get_kimage_voffset);
/* Global kernel state accessed by nVHE hyp code. */

4
arch/arm64/kernel/smp.c
View File

@ -434,8 +434,10 @@ static void __init hyp_mode_check(void)
"CPU: CPUs started in inconsistent modes");
else
pr_info("CPU: All CPU(s) started at EL1\n");
if (IS_ENABLED(CONFIG_KVM) && !is_kernel_in_hyp_mode())
if (IS_ENABLED(CONFIG_KVM) && !is_kernel_in_hyp_mode()) {
kvm_compute_layout();
kvm_apply_hyp_relocations();
}
}
void __init smp_cpus_done(unsigned int max_cpus)

18
arch/arm64/kernel/vmlinux.lds.S
View File

@ -31,10 +31,11 @@ jiffies = jiffies_64;
__stop___kvm_ex_table = .;
#define HYPERVISOR_DATA_SECTIONS \
HYP_SECTION_NAME(.data..ro_after_init) : { \
__hyp_data_ro_after_init_start = .; \
HYP_SECTION_NAME(.rodata) : { \
__hyp_rodata_start = .; \
*(HYP_SECTION_NAME(.data..ro_after_init)) \
__hyp_data_ro_after_init_end = .; \
*(HYP_SECTION_NAME(.rodata)) \
__hyp_rodata_end = .; \
}
#define HYPERVISOR_PERCPU_SECTION \
@ -42,10 +43,19 @@ jiffies = jiffies_64;
HYP_SECTION_NAME(.data..percpu) : { \
*(HYP_SECTION_NAME(.data..percpu)) \
}
#define HYPERVISOR_RELOC_SECTION \
.hyp.reloc : ALIGN(4) { \
__hyp_reloc_begin = .; \
*(.hyp.reloc) \
__hyp_reloc_end = .; \
}
#else /* CONFIG_KVM */
#define HYPERVISOR_EXTABLE
#define HYPERVISOR_DATA_SECTIONS
#define HYPERVISOR_PERCPU_SECTION
#define HYPERVISOR_RELOC_SECTION
#endif
#define HYPERVISOR_TEXT \
@ -216,6 +226,8 @@ SECTIONS
PERCPU_SECTION(L1_CACHE_BYTES)
HYPERVISOR_PERCPU_SECTION
HYPERVISOR_RELOC_SECTION
.rela.dyn : ALIGN(8) {
*(.rela .rela*)
}

7
arch/arm64/kvm/arm.c
View File

@ -1750,11 +1750,10 @@ static int init_hyp_mode(void)
goto out_err;
}
err = create_hyp_mappings(kvm_ksym_ref(__hyp_data_ro_after_init_start),
kvm_ksym_ref(__hyp_data_ro_after_init_end),
PAGE_HYP_RO);
err = create_hyp_mappings(kvm_ksym_ref(__hyp_rodata_start),
kvm_ksym_ref(__hyp_rodata_end), PAGE_HYP_RO);
if (err) {
kvm_err("Cannot map .hyp.data..ro_after_init section\n");
kvm_err("Cannot map .hyp.rodata section\n");
goto out_err;
}

4
arch/arm64/kvm/hyp/include/hyp/switch.h
View File

@ -505,8 +505,8 @@ static inline void __kvm_unexpected_el2_exception(void)
struct exception_table_entry *entry, *end;
unsigned long elr_el2 = read_sysreg(elr_el2);
entry = hyp_symbol_addr(__start___kvm_ex_table);
end = hyp_symbol_addr(__stop___kvm_ex_table);
entry = &__start___kvm_ex_table;
end = &__stop___kvm_ex_table;
while (entry < end) {
addr = (unsigned long)&entry->insn + entry->insn;

2
arch/arm64/kvm/hyp/nvhe/.gitignore vendored
View File

@ -1,2 +1,4 @@
# SPDX-License-Identifier: GPL-2.0-only
gen-hyprel
hyp.lds
hyp-reloc.S

29
arch/arm64/kvm/hyp/nvhe/Makefile
View File

@ -6,6 +6,9 @@
asflags-y := -D__KVM_NVHE_HYPERVISOR__ -D__DISABLE_EXPORTS
ccflags-y := -D__KVM_NVHE_HYPERVISOR__ -D__DISABLE_EXPORTS
hostprogs := gen-hyprel
HOST_EXTRACFLAGS += -I$(objtree)/include
obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o host.o \
hyp-main.o hyp-smp.o psci-relay.o
obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \
@ -19,7 +22,7 @@ obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \
hyp-obj := $(patsubst %.o,%.nvhe.o,$(obj-y))
obj-y := kvm_nvhe.o
extra-y := $(hyp-obj) kvm_nvhe.tmp.o hyp.lds
extra-y := $(hyp-obj) kvm_nvhe.tmp.o kvm_nvhe.rel.o hyp.lds hyp-reloc.S hyp-reloc.o
# 1) Compile all source files to `.nvhe.o` object files. The file extension
# avoids file name clashes for files shared with VHE.
@ -42,11 +45,31 @@ LDFLAGS_kvm_nvhe.tmp.o := -r -T
$(obj)/kvm_nvhe.tmp.o: $(obj)/hyp.lds $(addprefix $(obj)/,$(hyp-obj)) FORCE
$(call if_changed,ld)
# 4) Produce the final 'kvm_nvhe.o', ready to be linked into 'vmlinux'.
# 4) Generate list of hyp code/data positions that need to be relocated at
# runtime. Because the hypervisor is part of the kernel binary, relocations
# produce a kernel VA. We enumerate relocations targeting hyp at build time
# and convert the kernel VAs at those positions to hyp VAs.
$(obj)/hyp-reloc.S: $(obj)/kvm_nvhe.tmp.o $(obj)/gen-hyprel
$(call if_changed,hyprel)
# 5) Compile hyp-reloc.S and link it into the existing partially linked object.
# The object file now contains a section with pointers to hyp positions that
# will contain kernel VAs at runtime. These pointers have relocations on them
# so that they get updated as the hyp object is linked into `vmlinux`.
LDFLAGS_kvm_nvhe.rel.o := -r
$(obj)/kvm_nvhe.rel.o: $(obj)/kvm_nvhe.tmp.o $(obj)/hyp-reloc.o FORCE
$(call if_changed,ld)
# 6) Produce the final 'kvm_nvhe.o', ready to be linked into 'vmlinux'.
# Prefixes names of ELF symbols with '__kvm_nvhe_'.
$(obj)/kvm_nvhe.o: $(obj)/kvm_nvhe.tmp.o FORCE
$(obj)/kvm_nvhe.o: $(obj)/kvm_nvhe.rel.o FORCE
$(call if_changed,hypcopy)
# The HYPREL command calls `gen-hyprel` to generate an assembly file with
# a list of relocations targeting hyp code/data.
quiet_cmd_hyprel = HYPREL $@
cmd_hyprel = $(obj)/gen-hyprel $< > $@
# The HYPCOPY command uses `objcopy` to prefix all ELF symbol names
# to avoid clashes with VHE code/data.
quiet_cmd_hypcopy = HYPCOPY $@

438
arch/arm64/kvm/hyp/nvhe/gen-hyprel.c Normal file
View File

@ -0,0 +1,438 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2020 - Google LLC
* Author: David Brazdil <dbrazdil@google.com>
*
* Generates relocation information used by the kernel to convert
* absolute addresses in hyp data from kernel VAs to hyp VAs.
*
* This is necessary because hyp code is linked into the same binary
* as the kernel but executes under different memory mappings.
* If the compiler used absolute addressing, those addresses need to
* be converted before they are used by hyp code.
*
* The input of this program is the relocatable ELF object containing
* all hyp code/data, not yet linked into vmlinux. Hyp section names
* should have been prefixed with `.hyp` at this point.
*
* The output (printed to stdout) is an assembly file containing
* an array of 32-bit integers and static relocations that instruct
* the linker of `vmlinux` to populate the array entries with offsets
* to positions in the kernel binary containing VAs used by hyp code.
*
* Note that dynamic relocations could be used for the same purpose.
* However, those are only generated if CONFIG_RELOCATABLE=y.
*/
#include <elf.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <generated/autoconf.h>
#define HYP_SECTION_PREFIX ".hyp"
#define HYP_RELOC_SECTION ".hyp.reloc"
#define HYP_SECTION_SYMBOL_PREFIX "__hyp_section_"
/*
* AArch64 relocation type constants.
* Included in case these are not defined in the host toolchain.
*/
#ifndef R_AARCH64_ABS64
#define R_AARCH64_ABS64 257
#endif
#ifndef R_AARCH64_LD_PREL_LO19
#define R_AARCH64_LD_PREL_LO19 273
#endif
#ifndef R_AARCH64_ADR_PREL_LO21
#define R_AARCH64_ADR_PREL_LO21 274
#endif
#ifndef R_AARCH64_ADR_PREL_PG_HI21
#define R_AARCH64_ADR_PREL_PG_HI21 275
#endif
#ifndef R_AARCH64_ADR_PREL_PG_HI21_NC
#define R_AARCH64_ADR_PREL_PG_HI21_NC 276
#endif
#ifndef R_AARCH64_ADD_ABS_LO12_NC
#define R_AARCH64_ADD_ABS_LO12_NC 277
#endif
#ifndef R_AARCH64_LDST8_ABS_LO12_NC
#define R_AARCH64_LDST8_ABS_LO12_NC 278
#endif
#ifndef R_AARCH64_TSTBR14
#define R_AARCH64_TSTBR14 279
#endif
#ifndef R_AARCH64_CONDBR19
#define R_AARCH64_CONDBR19 280
#endif
#ifndef R_AARCH64_JUMP26
#define R_AARCH64_JUMP26 282
#endif
#ifndef R_AARCH64_CALL26
#define R_AARCH64_CALL26 283
#endif
#ifndef R_AARCH64_LDST16_ABS_LO12_NC
#define R_AARCH64_LDST16_ABS_LO12_NC 284
#endif
#ifndef R_AARCH64_LDST32_ABS_LO12_NC
#define R_AARCH64_LDST32_ABS_LO12_NC 285
#endif
#ifndef R_AARCH64_LDST64_ABS_LO12_NC
#define R_AARCH64_LDST64_ABS_LO12_NC 286
#endif
#ifndef R_AARCH64_MOVW_PREL_G0
#define R_AARCH64_MOVW_PREL_G0 287
#endif
#ifndef R_AARCH64_MOVW_PREL_G0_NC
#define R_AARCH64_MOVW_PREL_G0_NC 288
#endif
#ifndef R_AARCH64_MOVW_PREL_G1
#define R_AARCH64_MOVW_PREL_G1 289
#endif
#ifndef R_AARCH64_MOVW_PREL_G1_NC
#define R_AARCH64_MOVW_PREL_G1_NC 290
#endif
#ifndef R_AARCH64_MOVW_PREL_G2
#define R_AARCH64_MOVW_PREL_G2 291
#endif
#ifndef R_AARCH64_MOVW_PREL_G2_NC
#define R_AARCH64_MOVW_PREL_G2_NC 292
#endif
#ifndef R_AARCH64_MOVW_PREL_G3
#define R_AARCH64_MOVW_PREL_G3 293
#endif
#ifndef R_AARCH64_LDST128_ABS_LO12_NC
#define R_AARCH64_LDST128_ABS_LO12_NC 299
#endif
/* Global state of the processed ELF. */
static struct {
const char *path;
char *begin;
size_t size;
Elf64_Ehdr *ehdr;
Elf64_Shdr *sh_table;
const char *sh_string;
} elf;
#if defined(CONFIG_CPU_LITTLE_ENDIAN)
#define elf16toh(x) le16toh(x)
#define elf32toh(x) le32toh(x)
#define elf64toh(x) le64toh(x)
#define ELFENDIAN ELFDATA2LSB
#elif defined(CONFIG_CPU_BIG_ENDIAN)
#define elf16toh(x) be16toh(x)
#define elf32toh(x) be32toh(x)
#define elf64toh(x) be64toh(x)
#define ELFENDIAN ELFDATA2MSB
#else
#error PDP-endian sadly unsupported...
#endif
#define fatal_error(fmt, ...) \
({ \
fprintf(stderr, "error: %s: " fmt "\n", \
elf.path, ## __VA_ARGS__); \
exit(EXIT_FAILURE); \
__builtin_unreachable(); \
})
#define fatal_perror(msg) \
({ \
fprintf(stderr, "error: %s: " msg ": %s\n", \
elf.path, strerror(errno)); \
exit(EXIT_FAILURE); \
__builtin_unreachable(); \
})
#define assert_op(lhs, rhs, fmt, op) \
({ \
typeof(lhs) _lhs = (lhs); \
typeof(rhs) _rhs = (rhs); \
\
if (!(_lhs op _rhs)) { \
fatal_error("assertion " #lhs " " #op " " #rhs \
" failed (lhs=" fmt ", rhs=" fmt \
", line=%d)", _lhs, _rhs, __LINE__); \
} \
})
#define assert_eq(lhs, rhs, fmt) assert_op(lhs, rhs, fmt, ==)
#define assert_ne(lhs, rhs, fmt) assert_op(lhs, rhs, fmt, !=)
#define assert_lt(lhs, rhs, fmt) assert_op(lhs, rhs, fmt, <)
#define assert_ge(lhs, rhs, fmt) assert_op(lhs, rhs, fmt, >=)
/*
* Return a pointer of a given type at a given offset from
* the beginning of the ELF file.
*/
#define elf_ptr(type, off) ((type *)(elf.begin + (off)))
/* Iterate over all sections in the ELF. */
#define for_each_section(var) \
for (var = elf.sh_table; var < elf.sh_table + elf16toh(elf.ehdr->e_shnum); ++var)
/* Iterate over all Elf64_Rela relocations in a given section. */
#define for_each_rela(shdr, var) \
for (var = elf_ptr(Elf64_Rela, elf64toh(shdr->sh_offset)); \
var < elf_ptr(Elf64_Rela, elf64toh(shdr->sh_offset) + elf64toh(shdr->sh_size)); var++)
/* True if a string starts with a given prefix. */
static inline bool starts_with(const char *str, const char *prefix)
{
return memcmp(str, prefix, strlen(prefix)) == 0;
}
/* Returns a string containing the name of a given section. */
static inline const char *section_name(Elf64_Shdr *shdr)
{
return elf.sh_string + elf32toh(shdr->sh_name);
}
/* Returns a pointer to the first byte of section data. */
static inline const char *section_begin(Elf64_Shdr *shdr)
{
return elf_ptr(char, elf64toh(shdr->sh_offset));
}
/* Find a section by its offset from the beginning of the file. */
static inline Elf64_Shdr *section_by_off(Elf64_Off off)
{
assert_ne(off, 0UL, "%lu");
return elf_ptr(Elf64_Shdr, off);
}
/* Find a section by its index. */
static inline Elf64_Shdr *section_by_idx(uint16_t idx)
{
assert_ne(idx, SHN_UNDEF, "%u");
return &elf.sh_table[idx];
}
/*
* Memory-map the given ELF file, perform sanity checks, and
* populate global state.
*/
static void init_elf(const char *path)
{
int fd, ret;
struct stat stat;
/* Store path in the global struct for error printing. */
elf.path = path;
/* Open the ELF file. */
fd = open(path, O_RDONLY);
if (fd < 0)
fatal_perror("Could not open ELF file");
/* Get status of ELF file to obtain its size. */
ret = fstat(fd, &stat);
if (ret < 0) {
close(fd);
fatal_perror("Could not get status of ELF file");
}
/* mmap() the entire ELF file read-only at an arbitrary address. */
elf.begin = mmap(0, stat.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
if (elf.begin == MAP_FAILED) {
close(fd);
fatal_perror("Could not mmap ELF file");
}
/* mmap() was successful, close the FD. */
close(fd);
/* Get pointer to the ELF header. */
assert_ge(stat.st_size, sizeof(*elf.ehdr), "%lu");
elf.ehdr = elf_ptr(Elf64_Ehdr, 0);
/* Check the ELF magic. */
assert_eq(elf.ehdr->e_ident[EI_MAG0], ELFMAG0, "0x%x");
assert_eq(elf.ehdr->e_ident[EI_MAG1], ELFMAG1, "0x%x");
assert_eq(elf.ehdr->e_ident[EI_MAG2], ELFMAG2, "0x%x");
assert_eq(elf.ehdr->e_ident[EI_MAG3], ELFMAG3, "0x%x");
/* Sanity check that this is an ELF64 relocatable object for AArch64. */
assert_eq(elf.ehdr->e_ident[EI_CLASS], ELFCLASS64, "%u");
assert_eq(elf.ehdr->e_ident[EI_DATA], ELFENDIAN, "%u");
assert_eq(elf16toh(elf.ehdr->e_type), ET_REL, "%u");
assert_eq(elf16toh(elf.ehdr->e_machine), EM_AARCH64, "%u");
/* Populate fields of the global struct. */
elf.sh_table = section_by_off(elf64toh(elf.ehdr->e_shoff));
elf.sh_string = section_begin(section_by_idx(elf16toh(elf.ehdr->e_shstrndx)));
}
/* Print the prologue of the output ASM file. */
static void emit_prologue(void)
{
printf(".data\n"
".pushsection " HYP_RELOC_SECTION ", \"a\"\n");
}
/* Print ASM statements needed as a prologue to a processed hyp section. */
static void emit_section_prologue(const char *sh_orig_name)
{
/* Declare the hyp section symbol. */
printf(".global %s%s\n", HYP_SECTION_SYMBOL_PREFIX, sh_orig_name);
}
/*
* Print ASM statements to create a hyp relocation entry for a given
* R_AARCH64_ABS64 relocation.
*
* The linker of vmlinux will populate the position given by `rela` with
* an absolute 64-bit kernel VA. If the kernel is relocatable, it will
* also generate a dynamic relocation entry so that the kernel can shift
* the address at runtime for KASLR.
*
* Emit a 32-bit offset from the current address to the position given
* by `rela`. This way the kernel can iterate over all kernel VAs used
* by hyp at runtime and convert them to hyp VAs. However, that offset
* will not be known until linking of `vmlinux`, so emit a PREL32
* relocation referencing a symbol that the hyp linker script put at
* the beginning of the relocated section + the offset from `rela`.
*/
static void emit_rela_abs64(Elf64_Rela *rela, const char *sh_orig_name)
{
/* Offset of this reloc from the beginning of HYP_RELOC_SECTION. */
static size_t reloc_offset;
/* Create storage for the 32-bit offset. */
printf(".word 0\n");
/*
* Create a PREL32 relocation which instructs the linker of `vmlinux`
* to insert offset to position <base> + <offset>, where <base> is
* a symbol at the beginning of the relocated section, and <offset>
* is `rela->r_offset`.
*/
printf(".reloc %lu, R_AARCH64_PREL32, %s%s + 0x%lx\n",
reloc_offset, HYP_SECTION_SYMBOL_PREFIX, sh_orig_name,
elf64toh(rela->r_offset));
reloc_offset += 4;
}
/* Print the epilogue of the output ASM file. */
static void emit_epilogue(void)
{
printf(".popsection\n");
}
/*
* Iterate over all RELA relocations in a given section and emit
* hyp relocation data for all absolute addresses in hyp code/data.
*
* Static relocations that generate PC-relative-addressing are ignored.
* Failure is reported for unexpected relocation types.
*/
static void emit_rela_section(Elf64_Shdr *sh_rela)
{
Elf64_Shdr *sh_orig = &elf.sh_table[elf32toh(sh_rela->sh_info)];
const char *sh_orig_name = section_name(sh_orig);
Elf64_Rela *rela;
/* Skip all non-hyp sections. */
if (!starts_with(sh_orig_name, HYP_SECTION_PREFIX))
return;
emit_section_prologue(sh_orig_name);
for_each_rela(sh_rela, rela) {
uint32_t type = (uint32_t)elf64toh(rela->r_info);
/* Check that rela points inside the relocated section. */
assert_lt(elf64toh(rela->r_offset), elf64toh(sh_orig->sh_size), "0x%lx");
switch (type) {
/*
* Data relocations to generate absolute addressing.
* Emit a hyp relocation.
*/
case R_AARCH64_ABS64:
emit_rela_abs64(rela, sh_orig_name);
break;
/* Allow relocations to generate PC-relative addressing. */
case R_AARCH64_LD_PREL_LO19:
case R_AARCH64_ADR_PREL_LO21:
case R_AARCH64_ADR_PREL_PG_HI21:
case R_AARCH64_ADR_PREL_PG_HI21_NC:
case R_AARCH64_ADD_ABS_LO12_NC:
case R_AARCH64_LDST8_ABS_LO12_NC:
case R_AARCH64_LDST16_ABS_LO12_NC:
case R_AARCH64_LDST32_ABS_LO12_NC:
case R_AARCH64_LDST64_ABS_LO12_NC:
case R_AARCH64_LDST128_ABS_LO12_NC:
break;
/* Allow relative relocations for control-flow instructions. */
case R_AARCH64_TSTBR14:
case R_AARCH64_CONDBR19:
case R_AARCH64_JUMP26:
case R_AARCH64_CALL26:
break;
/* Allow group relocations to create PC-relative offset inline. */
case R_AARCH64_MOVW_PREL_G0:
case R_AARCH64_MOVW_PREL_G0_NC:
case R_AARCH64_MOVW_PREL_G1:
case R_AARCH64_MOVW_PREL_G1_NC:
case R_AARCH64_MOVW_PREL_G2:
case R_AARCH64_MOVW_PREL_G2_NC:
case R_AARCH64_MOVW_PREL_G3:
break;
default:
fatal_error("Unexpected RELA type %u", type);
}
}
}
/* Iterate over all sections and emit hyp relocation data for RELA sections. */
static void emit_all_relocs(void)
{
Elf64_Shdr *shdr;
for_each_section(shdr) {
switch (elf32toh(shdr->sh_type)) {
case SHT_REL:
fatal_error("Unexpected SHT_REL section \"%s\"",
section_name(shdr));
case SHT_RELA:
emit_rela_section(shdr);
break;
}
}
}
int main(int argc, const char **argv)
{
if (argc != 2) {
fprintf(stderr, "Usage: %s <elf_input>\n", argv[0]);
return EXIT_FAILURE;
}
init_elf(argv[1]);
emit_prologue();
emit_all_relocs();
emit_epilogue();
return EXIT_SUCCESS;
}

29
arch/arm64/kvm/hyp/nvhe/host.S
View File

@ -74,27 +74,28 @@ SYM_FUNC_END(__host_enter)
* void __noreturn __hyp_do_panic(bool restore_host, u64 spsr, u64 elr, u64 par);
*/
SYM_FUNC_START(__hyp_do_panic)
/* Load the format arguments into x1-7 */
mov x6, x3
get_vcpu_ptr x7, x3
mrs x3, esr_el2
mrs x4, far_el2
mrs x5, hpfar_el2
/* Prepare and exit to the host's panic funciton. */
mov lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\
PSR_MODE_EL1h)
msr spsr_el2, lr
ldr lr, =panic
hyp_kimg_va lr, x6
msr elr_el2, lr
/*
* Set the panic format string and enter the host, conditionally
* restoring the host context.
*/
/* Set the panic format string. Use the, now free, LR as scratch. */
ldr lr, =__hyp_panic_string
hyp_kimg_va lr, x6
/* Load the format arguments into x1-7. */
mov x6, x3
get_vcpu_ptr x7, x3
mrs x3, esr_el2
mrs x4, far_el2
mrs x5, hpfar_el2
/* Enter the host, conditionally restoring the host context. */
cmp x0, xzr
ldr x0, =__hyp_panic_string
mov x0, lr
b.eq __host_enter_without_restoring
b __host_enter_for_panic
SYM_FUNC_END(__hyp_do_panic)
@ -124,7 +125,7 @@ SYM_FUNC_END(__hyp_do_panic)
* Preserve x0-x4, which may contain stub parameters.
*/
ldr x5, =__kvm_handle_stub_hvc
kimg_pa x5, x6
hyp_pa x5, x6
br x5
.L__vect_end\@:
.if ((.L__vect_end\@ - .L__vect_start\@) > 0x80)

4
arch/arm64/kvm/hyp/nvhe/hyp-init.S
View File

@ -18,7 +18,7 @@
#include <asm/virt.h>
.text
.pushsection .hyp.idmap.text, "ax"
.pushsection .idmap.text, "ax"
.align 11
@ -132,7 +132,6 @@ alternative_else_nop_endif
/* Set the host vector */
ldr x0, =__kvm_hyp_host_vector
kimg_hyp_va x0, x1
msr vbar_el2, x0
ret
@ -191,7 +190,6 @@ SYM_CODE_START_LOCAL(__kvm_hyp_init_cpu)
/* Leave idmap. */
mov x0, x29
ldr x1, =kvm_host_psci_cpu_entry
kimg_hyp_va x1, x2
br x1
SYM_CODE_END(__kvm_hyp_init_cpu)

11
arch/arm64/kvm/hyp/nvhe/hyp-main.c
View File

@ -108,9 +108,9 @@ static void handle___vgic_v3_restore_aprs(struct kvm_cpu_context *host_ctxt)
typedef void (*hcall_t)(struct kvm_cpu_context *);
#define HANDLE_FUNC(x) [__KVM_HOST_SMCCC_FUNC_##x] = kimg_fn_ptr(handle_##x)
#define HANDLE_FUNC(x) [__KVM_HOST_SMCCC_FUNC_##x] = (hcall_t)handle_##x
static const hcall_t *host_hcall[] = {
static const hcall_t host_hcall[] = {
HANDLE_FUNC(__kvm_vcpu_run),
HANDLE_FUNC(__kvm_flush_vm_context),
HANDLE_FUNC(__kvm_tlb_flush_vmid_ipa),
@ -130,7 +130,6 @@ static const hcall_t *host_hcall[] = {
static void handle_host_hcall(struct kvm_cpu_context *host_ctxt)
{
DECLARE_REG(unsigned long, id, host_ctxt, 0);
const hcall_t *kfn;
hcall_t hfn;
id -= KVM_HOST_SMCCC_ID(0);
@ -138,13 +137,11 @@ static void handle_host_hcall(struct kvm_cpu_context *host_ctxt)
if (unlikely(id >= ARRAY_SIZE(host_hcall)))
goto inval;
kfn = host_hcall[id];
if (unlikely(!kfn))
hfn = host_hcall[id];
if (unlikely(!hfn))
goto inval;
cpu_reg(host_ctxt, 0) = SMCCC_RET_SUCCESS;
hfn = kimg_fn_hyp_va(kfn);
hfn(host_ctxt);
return;

4
arch/arm64/kvm/hyp/nvhe/hyp-smp.c
View File

@ -33,8 +33,8 @@ unsigned long __hyp_per_cpu_offset(unsigned int cpu)
if (cpu >= ARRAY_SIZE(kvm_arm_hyp_percpu_base))
hyp_panic();
cpu_base_array = (unsigned long *)hyp_symbol_addr(kvm_arm_hyp_percpu_base);
cpu_base_array = (unsigned long *)&kvm_arm_hyp_percpu_base;
this_cpu_base = kern_hyp_va(cpu_base_array[cpu]);
elf_base = (unsigned long)hyp_symbol_addr(__per_cpu_start);
elf_base = (unsigned long)&__per_cpu_start;
return this_cpu_base - elf_base;
}

9
arch/arm64/kvm/hyp/nvhe/hyp.lds.S
View File

@ -12,14 +12,17 @@
#include <asm/memory.h>
SECTIONS {
HYP_SECTION(.idmap.text)
HYP_SECTION(.text)
HYP_SECTION(.data..ro_after_init)
HYP_SECTION(.rodata)
/*
* .hyp..data..percpu needs to be page aligned to maintain the same
* alignment for when linking into vmlinux.
*/
. = ALIGN(PAGE_SIZE);
HYP_SECTION_NAME(.data..percpu) : {
BEGIN_HYP_SECTION(.data..percpu)
PERCPU_INPUT(L1_CACHE_BYTES)
}
HYP_SECTION(.data..ro_after_init)
END_HYP_SECTION
}

24
arch/arm64/kvm/hyp/nvhe/psci-relay.c
View File

@ -128,8 +128,8 @@ static int psci_cpu_on(u64 func_id, struct kvm_cpu_context *host_ctxt)
if (cpu_id == INVALID_CPU_ID)
return PSCI_RET_INVALID_PARAMS;
boot_args = per_cpu_ptr(hyp_symbol_addr(cpu_on_args), cpu_id);
init_params = per_cpu_ptr(hyp_symbol_addr(kvm_init_params), cpu_id);
boot_args = per_cpu_ptr(&cpu_on_args, cpu_id);
init_params = per_cpu_ptr(&kvm_init_params, cpu_id);
/* Check if the target CPU is already being booted. */
if (!try_acquire_boot_args(boot_args))
@ -140,7 +140,7 @@ static int psci_cpu_on(u64 func_id, struct kvm_cpu_context *host_ctxt)
wmb();
ret = psci_call(func_id, mpidr,
__hyp_pa(hyp_symbol_addr(kvm_hyp_cpu_entry)),
__hyp_pa(&kvm_hyp_cpu_entry),
__hyp_pa(init_params));
/* If successful, the lock will be released by the target CPU. */
@ -159,8 +159,8 @@ static int psci_cpu_suspend(u64 func_id, struct kvm_cpu_context *host_ctxt)
struct psci_boot_args *boot_args;
struct kvm_nvhe_init_params *init_params;
boot_args = this_cpu_ptr(hyp_symbol_addr(suspend_args));
init_params = this_cpu_ptr(hyp_symbol_addr(kvm_init_params));
boot_args = this_cpu_ptr(&suspend_args);
init_params = this_cpu_ptr(&kvm_init_params);
/*
* No need to acquire a lock before writing to boot_args because a core
@ -174,7 +174,7 @@ static int psci_cpu_suspend(u64 func_id, struct kvm_cpu_context *host_ctxt)
* point if it is a deep sleep state.
*/
return psci_call(func_id, power_state,
__hyp_pa(hyp_symbol_addr(kvm_hyp_cpu_resume)),
__hyp_pa(&kvm_hyp_cpu_resume),
__hyp_pa(init_params));
}
@ -186,8 +186,8 @@ static int psci_system_suspend(u64 func_id, struct kvm_cpu_context *host_ctxt)
struct psci_boot_args *boot_args;
struct kvm_nvhe_init_params *init_params;
boot_args = this_cpu_ptr(hyp_symbol_addr(suspend_args));
init_params = this_cpu_ptr(hyp_symbol_addr(kvm_init_params));
boot_args = this_cpu_ptr(&suspend_args);
init_params = this_cpu_ptr(&kvm_init_params);
/*
* No need to acquire a lock before writing to boot_args because a core
@ -198,7 +198,7 @@ static int psci_system_suspend(u64 func_id, struct kvm_cpu_context *host_ctxt)
/* Will only return on error. */
return psci_call(func_id,
__hyp_pa(hyp_symbol_addr(kvm_hyp_cpu_resume)),
__hyp_pa(&kvm_hyp_cpu_resume),
__hyp_pa(init_params), 0);
}
@ -207,12 +207,12 @@ asmlinkage void __noreturn kvm_host_psci_cpu_entry(bool is_cpu_on)
struct psci_boot_args *boot_args;
struct kvm_cpu_context *host_ctxt;
host_ctxt = &this_cpu_ptr(hyp_symbol_addr(kvm_host_data))->host_ctxt;
host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
if (is_cpu_on)
boot_args = this_cpu_ptr(hyp_symbol_addr(cpu_on_args));
boot_args = this_cpu_ptr(&cpu_on_args);
else
boot_args = this_cpu_ptr(hyp_symbol_addr(suspend_args));
boot_args = this_cpu_ptr(&suspend_args);
cpu_reg(host_ctxt, 0) = boot_args->r0;
write_sysreg_el2(boot_args->pc, SYS_ELR);

2
arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c
View File

@ -64,7 +64,7 @@ int __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu)
}
rd = kvm_vcpu_dabt_get_rd(vcpu);
addr = hyp_symbol_addr(kvm_vgic_global_state)->vcpu_hyp_va;
addr = kvm_vgic_global_state.vcpu_hyp_va;
addr += fault_ipa - vgic->vgic_cpu_base;
if (kvm_vcpu_dabt_iswrite(vcpu)) {

34
arch/arm64/kvm/va_layout.c
View File

@ -81,6 +81,34 @@ __init void kvm_compute_layout(void)
init_hyp_physvirt_offset();
}
/*
* The .hyp.reloc ELF section contains a list of kimg positions that
* contains kimg VAs but will be accessed only in hyp execution context.
* Convert them to hyp VAs. See gen-hyprel.c for more details.
*/
__init void kvm_apply_hyp_relocations(void)
{
int32_t *rel;
int32_t *begin = (int32_t *)__hyp_reloc_begin;
int32_t *end = (int32_t *)__hyp_reloc_end;
for (rel = begin; rel < end; ++rel) {
uintptr_t *ptr, kimg_va;
/*
* Each entry contains a 32-bit relative offset from itself
* to a kimg VA position.
*/
ptr = (uintptr_t *)lm_alias((char *)rel + *rel);
/* Read the kimg VA value at the relocation address. */
kimg_va = *ptr;
/* Convert to hyp VA and store back to the relocation address. */
*ptr = __early_kern_hyp_va((uintptr_t)lm_alias(kimg_va));
}
}
static u32 compute_instruction(int n, u32 rd, u32 rn)
{
u32 insn = AARCH64_BREAK_FAULT;
@ -255,12 +283,6 @@ static void generate_mov_q(u64 val, __le32 *origptr, __le32 *updptr, int nr_inst
*updptr++ = cpu_to_le32(insn);
}
void kvm_update_kimg_phys_offset(struct alt_instr *alt,
__le32 *origptr, __le32 *updptr, int nr_inst)
{
generate_mov_q(kimage_voffset + PHYS_OFFSET, origptr, updptr, nr_inst);
}
void kvm_get_kimage_voffset(struct alt_instr *alt,
__le32 *origptr, __le32 *updptr, int nr_inst)
{