Add the detection and runtime code for ARM_SMCCC_ARCH_WORKAROUND_1. It is lovely. Really. Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> --- arch/arm64/include/asm/kvm_psci.h | 63 ++++++++++++++++++++++++++++++++++++ arch/arm64/kernel/bpi.S | 20 ++++++++++++ arch/arm64/kernel/cpu_errata.c | 68 ++++++++++++++++++++++++++++++++++++++- 3 files changed, 150 insertions(+), 1 deletion(-) create mode 100644 arch/arm64/include/asm/kvm_psci.h diff --git a/arch/arm64/include/asm/kvm_psci.h b/arch/arm64/include/asm/kvm_psci.h new file mode 100644 index 000000000000..f553e3795a4e --- /dev/null +++ b/arch/arm64/include/asm/kvm_psci.h @@ -0,0 +1,63 @@ +/* + * Copyright (C) 2012,2013 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@xxxxxxx> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#ifndef __ARM64_KVM_PSCI_H__ +#define __ARM64_KVM_PSCI_H__ + +#include <linux/kvm_host.h> + +#define PSCI_VERSION(x,y) ((((x) & 0x7fff) << 16) | ((y) & 0xffff)) +#define KVM_ARM_PSCI_0_1 PSCI_VERSION(0, 1) +#define KVM_ARM_PSCI_0_2 PSCI_VERSION(0, 2) +#define KVM_ARM_PSCI_1_0 PSCI_VERSION(1, 0) + +#define KVM_ARM_PSCI_LATEST KVM_ARM_PSCI_1_0 + +/* + * We need the KVM pointer independently from the vcpu as we can call + * this from HYP, and need to apply kern_hyp_va on it... + */ +static inline int kvm_psci_version(struct kvm_vcpu *vcpu, struct kvm *kvm) +{ + /* + * Our PSCI implementation stays the same across versions from + * v0.2 onward, only adding the few mandatory functions (such + * as FEATURES with 1.0) that are required by newer + * revisions. It is thus safe to return the latest, unless + * userspace has instructed us otherwise. + */ + if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features)) { + if (kvm->arch.psci_version) + return kvm->arch.psci_version; + + return KVM_ARM_PSCI_LATEST; + } + + return KVM_ARM_PSCI_0_1; +} + + +int kvm_hvc_call_handler(struct kvm_vcpu *vcpu); + +struct kvm_one_reg; + +int kvm_arm_get_fw_num_regs(struct kvm_vcpu *vcpu); +int kvm_arm_copy_fw_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices); +int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg); +int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg); + +#endif /* __ARM64_KVM_PSCI_H__ */ diff --git a/arch/arm64/kernel/bpi.S b/arch/arm64/kernel/bpi.S index 76225c2611ea..fdeed629f2c6 100644 --- a/arch/arm64/kernel/bpi.S +++ b/arch/arm64/kernel/bpi.S @@ -17,6 +17,7 @@ */ #include <linux/linkage.h> +#include <linux/arm-smccc.h> .macro ventry target .rept 31 @@ -85,3 +86,22 @@ ENTRY(__qcom_hyp_sanitize_link_stack_start) .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)] + stp x0, x1, [sp, #(8 * 2)] + mov w0, #ARM_SMCCC_ARCH_WORKAROUND_1 + \inst #0 + ldp x2, x3, [sp, #(8 * 0)] + ldp x0, x1, [sp, #(8 * 2)] + add sp, sp, #(8 * 4) +.endm + +ENTRY(__smccc_workaround_1_smc_start) + smccc_workaround_1 smc +ENTRY(__smccc_workaround_1_smc_end) + +ENTRY(__smccc_workaround_1_hvc_start) + smccc_workaround_1 hvc +ENTRY(__smccc_workaround_1_hvc_end) diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index ed6881882231..36cff870d5d7 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -70,6 +70,10 @@ DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data); 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[]; +extern char __smccc_workaround_1_smc_end[]; +extern char __smccc_workaround_1_hvc_start[]; +extern char __smccc_workaround_1_hvc_end[]; static void __copy_hyp_vect_bpi(int slot, const char *hyp_vecs_start, const char *hyp_vecs_end) @@ -116,6 +120,10 @@ static void __install_bp_hardening_cb(bp_hardening_cb_t fn, #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 +#define __smccc_workaround_1_smc_end NULL +#define __smccc_workaround_1_hvc_start NULL +#define __smccc_workaround_1_hvc_end NULL static void __install_bp_hardening_cb(bp_hardening_cb_t fn, const char *hyp_vecs_start, @@ -142,17 +150,75 @@ static void install_bp_hardening_cb(const struct arm64_cpu_capabilities *entry, __install_bp_hardening_cb(fn, hyp_vecs_start, hyp_vecs_end); } +#include <uapi/linux/psci.h> +#include <linux/arm-smccc.h> #include <linux/psci.h> +static void call_smc_arch_workaround_1(void) +{ + arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_1, NULL); +} + +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) +{ + bp_hardening_cb_t cb; + void *smccc_start, *smccc_end; + struct arm_smccc_res res; + + if (!entry->matches(entry, SCOPE_LOCAL_CPU)) + return false; + + if (psci_ops.variant == SMCCC_VARIANT_1_0) + return false; + + 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; + cb = call_hvc_arch_workaround_1; + smccc_start = __smccc_workaround_1_hvc_start; + smccc_end = __smccc_workaround_1_hvc_end; + break; + + case PSCI_CONDUIT_SMC: + arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, + ARM_SMCCC_ARCH_WORKAROUND_1, &res); + if (res.a0) + return false; + cb = call_smc_arch_workaround_1; + smccc_start = __smccc_workaround_1_smc_start; + smccc_end = __smccc_workaround_1_smc_end; + break; + + default: + return false; + } + + 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 (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; } -- 2.14.2 _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
