From adc91ab7854195f107c137aa197ddfe8b82a2331 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 28 Mar 2018 11:59:13 +0100 Subject: Revert "arm64: KVM: Use SMCCC_ARCH_WORKAROUND_1 for Falkor BP hardening" Creates far too many conflicts with arm64/for-next/core, to be resent post -rc1. This reverts commit f9f5dc19509bbef6f5e675346f1a7d7b846bdb12. Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/cpucaps.h | 2 +- arch/arm64/include/asm/kvm_asm.h | 2 ++ arch/arm64/kernel/bpi.S | 8 ++++++ arch/arm64/kernel/cpu_errata.c | 55 ++++++++++++++++++++++++++-------------- arch/arm64/kvm/hyp/entry.S | 12 +++++++++ arch/arm64/kvm/hyp/switch.c | 10 ++++++++ 6 files changed, 69 insertions(+), 20 deletions(-) (limited to 'arch/arm64') diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h index c7dfe68fbcc7..d4cc54ed0656 100644 --- a/arch/arm64/include/asm/cpucaps.h +++ b/arch/arm64/include/asm/cpucaps.h @@ -43,7 +43,7 @@ #define ARM64_SVE 22 #define ARM64_UNMAP_KERNEL_AT_EL0 23 #define ARM64_HARDEN_BRANCH_PREDICTOR 24 -/* #define ARM64_UNUSED_CAP_TO_BE_REMOVED 25 */ +#define ARM64_HARDEN_BP_POST_GUEST_EXIT 25 #define ARM64_HAS_RAS_EXTN 26 #define ARM64_NCAPS 27 diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index f6648a3e4152..d53d40704416 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -71,6 +71,8 @@ extern u32 __kvm_get_mdcr_el2(void); extern u32 __init_stage2_translation(void); +extern void __qcom_hyp_sanitize_btac_predictors(void); + #else /* __ASSEMBLY__ */ .macro get_host_ctxt reg, tmp diff --git a/arch/arm64/kernel/bpi.S b/arch/arm64/kernel/bpi.S index 9404f6aecda7..bb0b67722e86 100644 --- a/arch/arm64/kernel/bpi.S +++ b/arch/arm64/kernel/bpi.S @@ -74,6 +74,14 @@ ENTRY(__bp_harden_hyp_vecs_end) .popsection +ENTRY(__qcom_hyp_sanitize_link_stack_start) + stp x29, x30, [sp, #-16]! + .rept 16 + bl . + 4 + .endr + ldp x29, x30, [sp], #16 +ENTRY(__qcom_hyp_sanitize_link_stack_end) + .macro smccc_workaround_1 inst sub sp, sp, #(8 * 4) stp x2, x3, [sp, #(8 * 0)] diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index caa73af7d26e..aacdc118c4c9 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -69,6 +69,8 @@ atomic_t arm64_el2_vector_last_slot = ATOMIC_INIT(-1); DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data); #ifdef CONFIG_KVM +extern char __qcom_hyp_sanitize_link_stack_start[]; +extern char __qcom_hyp_sanitize_link_stack_end[]; extern char __smccc_workaround_1_smc_start[]; extern char __smccc_workaround_1_smc_end[]; extern char __smccc_workaround_1_hvc_start[]; @@ -112,6 +114,8 @@ static void __install_bp_hardening_cb(bp_hardening_cb_t fn, spin_unlock(&bp_lock); } #else +#define __qcom_hyp_sanitize_link_stack_start NULL +#define __qcom_hyp_sanitize_link_stack_end NULL #define __smccc_workaround_1_smc_start NULL #define __smccc_workaround_1_smc_end NULL #define __smccc_workaround_1_hvc_start NULL @@ -156,25 +160,12 @@ static void call_hvc_arch_workaround_1(void) arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_WORKAROUND_1, NULL); } -static void qcom_link_stack_sanitization(void) -{ - u64 tmp; - - asm volatile("mov %0, x30 \n" - ".rept 16 \n" - "bl . + 4 \n" - ".endr \n" - "mov x30, %0 \n" - : "=&r" (tmp)); -} - static int enable_smccc_arch_workaround_1(void *data) { const struct arm64_cpu_capabilities *entry = data; bp_hardening_cb_t cb; void *smccc_start, *smccc_end; struct arm_smccc_res res; - u32 midr = read_cpuid_id(); if (!entry->matches(entry, SCOPE_LOCAL_CPU)) return 0; @@ -207,15 +198,33 @@ static int enable_smccc_arch_workaround_1(void *data) return 0; } - if (((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR) || - ((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR_V1)) - cb = qcom_link_stack_sanitization; - install_bp_hardening_cb(entry, cb, smccc_start, smccc_end); return 0; } +static void qcom_link_stack_sanitization(void) +{ + u64 tmp; + + asm volatile("mov %0, x30 \n" + ".rept 16 \n" + "bl . + 4 \n" + ".endr \n" + "mov x30, %0 \n" + : "=&r" (tmp)); +} + +static int qcom_enable_link_stack_sanitization(void *data) +{ + const struct arm64_cpu_capabilities *entry = data; + + install_bp_hardening_cb(entry, qcom_link_stack_sanitization, + __qcom_hyp_sanitize_link_stack_start, + __qcom_hyp_sanitize_link_stack_end); + + return 0; +} #endif /* CONFIG_HARDEN_BRANCH_PREDICTOR */ #define MIDR_RANGE(model, min, max) \ @@ -390,12 +399,20 @@ const struct arm64_cpu_capabilities arm64_errata[] = { { .capability = ARM64_HARDEN_BRANCH_PREDICTOR, MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR_V1), - .enable = enable_smccc_arch_workaround_1, + .enable = qcom_enable_link_stack_sanitization, + }, + { + .capability = ARM64_HARDEN_BP_POST_GUEST_EXIT, + MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR_V1), }, { .capability = ARM64_HARDEN_BRANCH_PREDICTOR, MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR), - .enable = enable_smccc_arch_workaround_1, + .enable = qcom_enable_link_stack_sanitization, + }, + { + .capability = ARM64_HARDEN_BP_POST_GUEST_EXIT, + MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR), }, { .capability = ARM64_HARDEN_BRANCH_PREDICTOR, diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S index e41a161d313a..1f458f7c3b44 100644 --- a/arch/arm64/kvm/hyp/entry.S +++ b/arch/arm64/kvm/hyp/entry.S @@ -209,3 +209,15 @@ alternative_endif eret ENDPROC(__fpsimd_guest_restore) + +ENTRY(__qcom_hyp_sanitize_btac_predictors) + /** + * Call SMC64 with Silicon provider serviceID 23<<8 (0xc2001700) + * 0xC2000000-0xC200FFFF: assigned to SiP Service Calls + * b15-b0: contains SiP functionID + */ + movz x0, #0x1700 + movk x0, #0xc200, lsl #16 + smc #0 + ret +ENDPROC(__qcom_hyp_sanitize_btac_predictors) diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index d9645236e474..07b572173265 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -472,6 +472,16 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu) /* And we're baaack! */ } while (fixup_guest_exit(vcpu, &exit_code)); + if (cpus_have_const_cap(ARM64_HARDEN_BP_POST_GUEST_EXIT)) { + u32 midr = read_cpuid_id(); + + /* Apply BTAC predictors mitigation to all Falkor chips */ + if (((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR) || + ((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR_V1)) { + __qcom_hyp_sanitize_btac_predictors(); + } + } + fp_enabled = __fpsimd_enabled_nvhe(); __sysreg_save_state_nvhe(guest_ctxt); -- cgit v1.2.3