From 3a0a397ff5ff8b56ca9f7908b75dee6bf0b5fabb Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 6 Feb 2018 17:56:21 +0000 Subject: [PATCH] arm64: Kill PSCI_GET_VERSION as a variant-2 workaround Now that we've standardised on SMCCC v1.1 to perform the branch prediction invalidation, let's drop the previous band-aid. If vendors haven't updated their firmware to do SMCCC 1.1, they haven't updated PSCI either, so we don't loose anything. Tested-by: Ard Biesheuvel Signed-off-by: Marc Zyngier Signed-off-by: Catalin Marinas --- arch/arm64/kernel/bpi.S | 24 ------------------ arch/arm64/kernel/cpu_errata.c | 45 ++++++++++------------------------ arch/arm64/kvm/hyp/switch.c | 14 ----------- 3 files changed, 13 insertions(+), 70 deletions(-) diff --git a/arch/arm64/kernel/bpi.S b/arch/arm64/kernel/bpi.S index fdeed629f2c6..e5de33513b5d 100644 --- a/arch/arm64/kernel/bpi.S +++ b/arch/arm64/kernel/bpi.S @@ -54,30 +54,6 @@ ENTRY(__bp_harden_hyp_vecs_start) vectors __kvm_hyp_vector .endr ENTRY(__bp_harden_hyp_vecs_end) -ENTRY(__psci_hyp_bp_inval_start) - sub sp, sp, #(8 * 18) - stp x16, x17, [sp, #(16 * 0)] - stp x14, x15, [sp, #(16 * 1)] - stp x12, x13, [sp, #(16 * 2)] - stp x10, x11, [sp, #(16 * 3)] - stp x8, x9, [sp, #(16 * 4)] - stp x6, x7, [sp, #(16 * 5)] - stp x4, x5, [sp, #(16 * 6)] - stp x2, x3, [sp, #(16 * 7)] - stp x0, x1, [sp, #(16 * 8)] - mov x0, #0x84000000 - smc #0 - ldp x16, x17, [sp, #(16 * 0)] - ldp x14, x15, [sp, #(16 * 1)] - ldp x12, x13, [sp, #(16 * 2)] - ldp x10, x11, [sp, #(16 * 3)] - ldp x8, x9, [sp, #(16 * 4)] - ldp x6, x7, [sp, #(16 * 5)] - ldp x4, x5, [sp, #(16 * 6)] - ldp x2, x3, [sp, #(16 * 7)] - ldp x0, x1, [sp, #(16 * 8)] - add sp, sp, #(8 * 18) -ENTRY(__psci_hyp_bp_inval_end) ENTRY(__qcom_hyp_sanitize_link_stack_start) stp x29, x30, [sp, #-16]! diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 9e77809a3b23..07823595b7f0 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -67,7 +67,6 @@ static int cpu_enable_trap_ctr_access(void *__unused) DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data); #ifdef CONFIG_KVM -extern char __psci_hyp_bp_inval_start[], __psci_hyp_bp_inval_end[]; extern char __qcom_hyp_sanitize_link_stack_start[]; extern char __qcom_hyp_sanitize_link_stack_end[]; extern char __smccc_workaround_1_smc_start[]; @@ -116,8 +115,6 @@ static void __install_bp_hardening_cb(bp_hardening_cb_t fn, spin_unlock(&bp_lock); } #else -#define __psci_hyp_bp_inval_start NULL -#define __psci_hyp_bp_inval_end NULL #define __qcom_hyp_sanitize_link_stack_start NULL #define __qcom_hyp_sanitize_link_stack_end NULL #define __smccc_workaround_1_smc_start NULL @@ -164,24 +161,25 @@ static void call_hvc_arch_workaround_1(void) arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_WORKAROUND_1, NULL); } -static bool check_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry) +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; if (!entry->matches(entry, SCOPE_LOCAL_CPU)) - return false; + return 0; if (psci_ops.smccc_version == SMCCC_VERSION_1_0) - return false; + return 0; switch (psci_ops.conduit) { case PSCI_CONDUIT_HVC: arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, ARM_SMCCC_ARCH_WORKAROUND_1, &res); if (res.a0) - return false; + return 0; cb = call_hvc_arch_workaround_1; smccc_start = __smccc_workaround_1_hvc_start; smccc_end = __smccc_workaround_1_hvc_end; @@ -191,35 +189,18 @@ static bool check_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *e arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, ARM_SMCCC_ARCH_WORKAROUND_1, &res); if (res.a0) - return false; + return 0; cb = call_smc_arch_workaround_1; smccc_start = __smccc_workaround_1_smc_start; smccc_end = __smccc_workaround_1_smc_end; break; default: - return false; + return 0; } install_bp_hardening_cb(entry, cb, smccc_start, smccc_end); - return true; -} - -static int enable_psci_bp_hardening(void *data) -{ - const struct arm64_cpu_capabilities *entry = data; - - if (psci_ops.get_version) { - if (check_smccc_arch_workaround_1(entry)) - return 0; - - install_bp_hardening_cb(entry, - (bp_hardening_cb_t)psci_ops.get_version, - __psci_hyp_bp_inval_start, - __psci_hyp_bp_inval_end); - } - return 0; } @@ -399,22 +380,22 @@ const struct arm64_cpu_capabilities arm64_errata[] = { { .capability = ARM64_HARDEN_BRANCH_PREDICTOR, MIDR_ALL_VERSIONS(MIDR_CORTEX_A57), - .enable = enable_psci_bp_hardening, + .enable = enable_smccc_arch_workaround_1, }, { .capability = ARM64_HARDEN_BRANCH_PREDICTOR, MIDR_ALL_VERSIONS(MIDR_CORTEX_A72), - .enable = enable_psci_bp_hardening, + .enable = enable_smccc_arch_workaround_1, }, { .capability = ARM64_HARDEN_BRANCH_PREDICTOR, MIDR_ALL_VERSIONS(MIDR_CORTEX_A73), - .enable = enable_psci_bp_hardening, + .enable = enable_smccc_arch_workaround_1, }, { .capability = ARM64_HARDEN_BRANCH_PREDICTOR, MIDR_ALL_VERSIONS(MIDR_CORTEX_A75), - .enable = enable_psci_bp_hardening, + .enable = enable_smccc_arch_workaround_1, }, { .capability = ARM64_HARDEN_BRANCH_PREDICTOR, @@ -428,12 +409,12 @@ const struct arm64_cpu_capabilities arm64_errata[] = { { .capability = ARM64_HARDEN_BRANCH_PREDICTOR, MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN), - .enable = enable_psci_bp_hardening, + .enable = enable_smccc_arch_workaround_1, }, { .capability = ARM64_HARDEN_BRANCH_PREDICTOR, MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2), - .enable = enable_psci_bp_hardening, + .enable = enable_smccc_arch_workaround_1, }, #endif { diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index 408c04d789a5..cac6a0500162 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -350,20 +350,6 @@ again: if (exit_code == ARM_EXCEPTION_TRAP && !__populate_fault_info(vcpu)) goto again; - if (exit_code == ARM_EXCEPTION_TRAP && - (kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_HVC64 || - kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_HVC32)) { - u32 val = vcpu_get_reg(vcpu, 0); - - if (val == PSCI_0_2_FN_PSCI_VERSION) { - val = kvm_psci_version(vcpu, kern_hyp_va(vcpu->kvm)); - if (unlikely(val == KVM_ARM_PSCI_0_1)) - val = PSCI_RET_NOT_SUPPORTED; - vcpu_set_reg(vcpu, 0, val); - goto again; - } - } - if (static_branch_unlikely(&vgic_v2_cpuif_trap) && exit_code == ARM_EXCEPTION_TRAP) { bool valid; -- 2.30.2