diff options
Diffstat (limited to 'arch/arm64/kvm/va_layout.c')
| -rw-r--r-- | arch/arm64/kvm/va_layout.c | 137 |
1 files changed, 116 insertions, 21 deletions
diff --git a/arch/arm64/kvm/va_layout.c b/arch/arm64/kvm/va_layout.c index a4f48c1ac28c..91b22a014610 100644 --- a/arch/arm64/kvm/va_layout.c +++ b/arch/arm64/kvm/va_layout.c @@ -11,6 +11,7 @@ #include <asm/debug-monitors.h> #include <asm/insn.h> #include <asm/kvm_mmu.h> +#include <asm/memory.h> /* * The LSB of the HYP VA tag @@ -23,6 +24,29 @@ static u64 tag_val; static u64 va_mask; /* + * Compute HYP VA by using the same computation as kern_hyp_va(). + */ +static u64 __early_kern_hyp_va(u64 addr) +{ + addr &= va_mask; + addr |= tag_val << tag_lsb; + return addr; +} + +/* + * Store a hyp VA <-> PA offset into a EL2-owned variable. + */ +static void init_hyp_physvirt_offset(void) +{ + u64 kern_va, hyp_va; + + /* Compute the offset from the hyp VA and PA of a random symbol. */ + kern_va = (u64)lm_alias(__hyp_text_start); + hyp_va = __early_kern_hyp_va(kern_va); + hyp_physvirt_offset = (s64)__pa(kern_va) - (s64)hyp_va; +} + +/* * We want to generate a hyp VA with the following format (with V == * vabits_actual): * @@ -48,11 +72,41 @@ __init void kvm_compute_layout(void) va_mask = GENMASK_ULL(tag_lsb - 1, 0); tag_val = hyp_va_msb; - if (tag_lsb != (vabits_actual - 1)) { + if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && tag_lsb != (vabits_actual - 1)) { /* We have some free bits to insert a random tag. */ tag_val |= get_random_long() & GENMASK_ULL(vabits_actual - 2, tag_lsb); } tag_val >>= tag_lsb; + + 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) @@ -115,7 +169,7 @@ void __init kvm_update_va_mask(struct alt_instr *alt, * dictates it and we don't have any spare bits in the * address), NOP everything after masking the kernel VA. */ - if (has_vhe() || (!tag_val && i > 0)) { + if (cpus_have_cap(ARM64_HAS_VIRT_HOST_EXTN) || (!tag_val && i > 0)) { updptr[i] = cpu_to_le32(aarch64_insn_gen_nop()); continue; } @@ -131,28 +185,22 @@ void __init kvm_update_va_mask(struct alt_instr *alt, } } -void *__kvm_bp_vect_base; -int __kvm_harden_el2_vector_slot; - void kvm_patch_vector_branch(struct alt_instr *alt, __le32 *origptr, __le32 *updptr, int nr_inst) { u64 addr; u32 insn; - BUG_ON(nr_inst != 5); + BUG_ON(nr_inst != 4); - if (has_vhe() || !cpus_have_const_cap(ARM64_HARDEN_EL2_VECTORS)) { - WARN_ON_ONCE(cpus_have_const_cap(ARM64_HARDEN_EL2_VECTORS)); + if (!cpus_have_cap(ARM64_SPECTRE_V3A) || + WARN_ON_ONCE(cpus_have_cap(ARM64_HAS_VIRT_HOST_EXTN))) return; - } /* * Compute HYP VA by using the same computation as kern_hyp_va() */ - addr = (uintptr_t)kvm_ksym_ref(__kvm_hyp_vector); - addr &= va_mask; - addr |= tag_val << tag_lsb; + addr = __early_kern_hyp_va((u64)kvm_ksym_ref(__kvm_hyp_vector)); /* Use PC[10:7] to branch to the same vector in KVM */ addr |= ((u64)origptr & GENMASK_ULL(10, 7)); @@ -163,15 +211,6 @@ void kvm_patch_vector_branch(struct alt_instr *alt, */ addr += KVM_VECTOR_PREAMBLE; - /* stp x0, x1, [sp, #-16]! */ - insn = aarch64_insn_gen_load_store_pair(AARCH64_INSN_REG_0, - AARCH64_INSN_REG_1, - AARCH64_INSN_REG_SP, - -16, - AARCH64_INSN_VARIANT_64BIT, - AARCH64_INSN_LDST_STORE_PAIR_PRE_INDEX); - *updptr++ = cpu_to_le32(insn); - /* movz x0, #(addr & 0xffff) */ insn = aarch64_insn_gen_movewide(AARCH64_INSN_REG_0, (u16)addr, @@ -201,3 +240,59 @@ void kvm_patch_vector_branch(struct alt_instr *alt, AARCH64_INSN_BRANCH_NOLINK); *updptr++ = cpu_to_le32(insn); } + +static void generate_mov_q(u64 val, __le32 *origptr, __le32 *updptr, int nr_inst) +{ + u32 insn, oinsn, rd; + + BUG_ON(nr_inst != 4); + + /* Compute target register */ + oinsn = le32_to_cpu(*origptr); + rd = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RD, oinsn); + + /* movz rd, #(val & 0xffff) */ + insn = aarch64_insn_gen_movewide(rd, + (u16)val, + 0, + AARCH64_INSN_VARIANT_64BIT, + AARCH64_INSN_MOVEWIDE_ZERO); + *updptr++ = cpu_to_le32(insn); + + /* movk rd, #((val >> 16) & 0xffff), lsl #16 */ + insn = aarch64_insn_gen_movewide(rd, + (u16)(val >> 16), + 16, + AARCH64_INSN_VARIANT_64BIT, + AARCH64_INSN_MOVEWIDE_KEEP); + *updptr++ = cpu_to_le32(insn); + + /* movk rd, #((val >> 32) & 0xffff), lsl #32 */ + insn = aarch64_insn_gen_movewide(rd, + (u16)(val >> 32), + 32, + AARCH64_INSN_VARIANT_64BIT, + AARCH64_INSN_MOVEWIDE_KEEP); + *updptr++ = cpu_to_le32(insn); + + /* movk rd, #((val >> 48) & 0xffff), lsl #48 */ + insn = aarch64_insn_gen_movewide(rd, + (u16)(val >> 48), + 48, + AARCH64_INSN_VARIANT_64BIT, + AARCH64_INSN_MOVEWIDE_KEEP); + *updptr++ = cpu_to_le32(insn); +} + +void kvm_get_kimage_voffset(struct alt_instr *alt, + __le32 *origptr, __le32 *updptr, int nr_inst) +{ + generate_mov_q(kimage_voffset, origptr, updptr, nr_inst); +} + +void kvm_compute_final_ctr_el0(struct alt_instr *alt, + __le32 *origptr, __le32 *updptr, int nr_inst) +{ + generate_mov_q(read_sanitised_ftr_reg(SYS_CTR_EL0), + origptr, updptr, nr_inst); +} |