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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/arm64/kvm/reset.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm64/kvm/reset.c')
-rw-r--r-- | arch/arm64/kvm/reset.c | 427 |
1 files changed, 427 insertions, 0 deletions
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c new file mode 100644 index 000000000..f9d070473 --- /dev/null +++ b/arch/arm64/kvm/reset.c @@ -0,0 +1,427 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2012,2013 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + * + * Derived from arch/arm/kvm/reset.c + * Copyright (C) 2012 - Virtual Open Systems and Columbia University + * Author: Christoffer Dall <c.dall@virtualopensystems.com> + */ + +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/kvm_host.h> +#include <linux/kvm.h> +#include <linux/hw_breakpoint.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/types.h> + +#include <kvm/arm_arch_timer.h> + +#include <asm/cpufeature.h> +#include <asm/cputype.h> +#include <asm/fpsimd.h> +#include <asm/ptrace.h> +#include <asm/kvm_arm.h> +#include <asm/kvm_asm.h> +#include <asm/kvm_emulate.h> +#include <asm/kvm_mmu.h> +#include <asm/virt.h> + +/* Maximum phys_shift supported for any VM on this host */ +static u32 kvm_ipa_limit; + +/* + * ARMv8 Reset Values + */ +#define VCPU_RESET_PSTATE_EL1 (PSR_MODE_EL1h | PSR_A_BIT | PSR_I_BIT | \ + PSR_F_BIT | PSR_D_BIT) + +#define VCPU_RESET_PSTATE_SVC (PSR_AA32_MODE_SVC | PSR_AA32_A_BIT | \ + PSR_AA32_I_BIT | PSR_AA32_F_BIT) + +unsigned int kvm_sve_max_vl; + +int kvm_arm_init_sve(void) +{ + if (system_supports_sve()) { + kvm_sve_max_vl = sve_max_virtualisable_vl(); + + /* + * The get_sve_reg()/set_sve_reg() ioctl interface will need + * to be extended with multiple register slice support in + * order to support vector lengths greater than + * VL_ARCH_MAX: + */ + if (WARN_ON(kvm_sve_max_vl > VL_ARCH_MAX)) + kvm_sve_max_vl = VL_ARCH_MAX; + + /* + * Don't even try to make use of vector lengths that + * aren't available on all CPUs, for now: + */ + if (kvm_sve_max_vl < sve_max_vl()) + pr_warn("KVM: SVE vector length for guests limited to %u bytes\n", + kvm_sve_max_vl); + } + + return 0; +} + +static int kvm_vcpu_enable_sve(struct kvm_vcpu *vcpu) +{ + if (!system_supports_sve()) + return -EINVAL; + + vcpu->arch.sve_max_vl = kvm_sve_max_vl; + + /* + * Userspace can still customize the vector lengths by writing + * KVM_REG_ARM64_SVE_VLS. Allocation is deferred until + * kvm_arm_vcpu_finalize(), which freezes the configuration. + */ + vcpu_set_flag(vcpu, GUEST_HAS_SVE); + + return 0; +} + +/* + * Finalize vcpu's maximum SVE vector length, allocating + * vcpu->arch.sve_state as necessary. + */ +static int kvm_vcpu_finalize_sve(struct kvm_vcpu *vcpu) +{ + void *buf; + unsigned int vl; + size_t reg_sz; + int ret; + + vl = vcpu->arch.sve_max_vl; + + /* + * Responsibility for these properties is shared between + * kvm_arm_init_sve(), kvm_vcpu_enable_sve() and + * set_sve_vls(). Double-check here just to be sure: + */ + if (WARN_ON(!sve_vl_valid(vl) || vl > sve_max_virtualisable_vl() || + vl > VL_ARCH_MAX)) + return -EIO; + + reg_sz = vcpu_sve_state_size(vcpu); + buf = kzalloc(reg_sz, GFP_KERNEL_ACCOUNT); + if (!buf) + return -ENOMEM; + + ret = kvm_share_hyp(buf, buf + reg_sz); + if (ret) { + kfree(buf); + return ret; + } + + vcpu->arch.sve_state = buf; + vcpu_set_flag(vcpu, VCPU_SVE_FINALIZED); + return 0; +} + +int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu, int feature) +{ + switch (feature) { + case KVM_ARM_VCPU_SVE: + if (!vcpu_has_sve(vcpu)) + return -EINVAL; + + if (kvm_arm_vcpu_sve_finalized(vcpu)) + return -EPERM; + + return kvm_vcpu_finalize_sve(vcpu); + } + + return -EINVAL; +} + +bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu) +{ + if (vcpu_has_sve(vcpu) && !kvm_arm_vcpu_sve_finalized(vcpu)) + return false; + + return true; +} + +void kvm_arm_vcpu_destroy(struct kvm_vcpu *vcpu) +{ + void *sve_state = vcpu->arch.sve_state; + + kvm_vcpu_unshare_task_fp(vcpu); + kvm_unshare_hyp(vcpu, vcpu + 1); + if (sve_state) + kvm_unshare_hyp(sve_state, sve_state + vcpu_sve_state_size(vcpu)); + kfree(sve_state); +} + +static void kvm_vcpu_reset_sve(struct kvm_vcpu *vcpu) +{ + if (vcpu_has_sve(vcpu)) + memset(vcpu->arch.sve_state, 0, vcpu_sve_state_size(vcpu)); +} + +static int kvm_vcpu_enable_ptrauth(struct kvm_vcpu *vcpu) +{ + /* + * For now make sure that both address/generic pointer authentication + * features are requested by the userspace together and the system + * supports these capabilities. + */ + if (!test_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, vcpu->arch.features) || + !test_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, vcpu->arch.features) || + !system_has_full_ptr_auth()) + return -EINVAL; + + vcpu_set_flag(vcpu, GUEST_HAS_PTRAUTH); + return 0; +} + +/** + * kvm_set_vm_width() - set the register width for the guest + * @vcpu: Pointer to the vcpu being configured + * + * Set both KVM_ARCH_FLAG_EL1_32BIT and KVM_ARCH_FLAG_REG_WIDTH_CONFIGURED + * in the VM flags based on the vcpu's requested register width, the HW + * capabilities and other options (such as MTE). + * When REG_WIDTH_CONFIGURED is already set, the vcpu settings must be + * consistent with the value of the FLAG_EL1_32BIT bit in the flags. + * + * Return: 0 on success, negative error code on failure. + */ +static int kvm_set_vm_width(struct kvm_vcpu *vcpu) +{ + struct kvm *kvm = vcpu->kvm; + bool is32bit; + + is32bit = vcpu_has_feature(vcpu, KVM_ARM_VCPU_EL1_32BIT); + + lockdep_assert_held(&kvm->arch.config_lock); + + if (test_bit(KVM_ARCH_FLAG_REG_WIDTH_CONFIGURED, &kvm->arch.flags)) { + /* + * The guest's register width is already configured. + * Make sure that the vcpu is consistent with it. + */ + if (is32bit == test_bit(KVM_ARCH_FLAG_EL1_32BIT, &kvm->arch.flags)) + return 0; + + return -EINVAL; + } + + if (!cpus_have_const_cap(ARM64_HAS_32BIT_EL1) && is32bit) + return -EINVAL; + + /* MTE is incompatible with AArch32 */ + if (kvm_has_mte(kvm) && is32bit) + return -EINVAL; + + if (is32bit) + set_bit(KVM_ARCH_FLAG_EL1_32BIT, &kvm->arch.flags); + + set_bit(KVM_ARCH_FLAG_REG_WIDTH_CONFIGURED, &kvm->arch.flags); + + return 0; +} + +/** + * kvm_reset_vcpu - sets core registers and sys_regs to reset value + * @vcpu: The VCPU pointer + * + * This function sets the registers on the virtual CPU struct to their + * architecturally defined reset values, except for registers whose reset is + * deferred until kvm_arm_vcpu_finalize(). + * + * Note: This function can be called from two paths: The KVM_ARM_VCPU_INIT + * ioctl or as part of handling a request issued by another VCPU in the PSCI + * handling code. In the first case, the VCPU will not be loaded, and in the + * second case the VCPU will be loaded. Because this function operates purely + * on the memory-backed values of system registers, we want to do a full put if + * we were loaded (handling a request) and load the values back at the end of + * the function. Otherwise we leave the state alone. In both cases, we + * disable preemption around the vcpu reset as we would otherwise race with + * preempt notifiers which also call put/load. + */ +int kvm_reset_vcpu(struct kvm_vcpu *vcpu) +{ + struct vcpu_reset_state reset_state; + int ret; + bool loaded; + u32 pstate; + + mutex_lock(&vcpu->kvm->arch.config_lock); + ret = kvm_set_vm_width(vcpu); + mutex_unlock(&vcpu->kvm->arch.config_lock); + + if (ret) + return ret; + + spin_lock(&vcpu->arch.mp_state_lock); + reset_state = vcpu->arch.reset_state; + vcpu->arch.reset_state.reset = false; + spin_unlock(&vcpu->arch.mp_state_lock); + + /* Reset PMU outside of the non-preemptible section */ + kvm_pmu_vcpu_reset(vcpu); + + preempt_disable(); + loaded = (vcpu->cpu != -1); + if (loaded) + kvm_arch_vcpu_put(vcpu); + + if (!kvm_arm_vcpu_sve_finalized(vcpu)) { + if (test_bit(KVM_ARM_VCPU_SVE, vcpu->arch.features)) { + ret = kvm_vcpu_enable_sve(vcpu); + if (ret) + goto out; + } + } else { + kvm_vcpu_reset_sve(vcpu); + } + + if (test_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, vcpu->arch.features) || + test_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, vcpu->arch.features)) { + if (kvm_vcpu_enable_ptrauth(vcpu)) { + ret = -EINVAL; + goto out; + } + } + + switch (vcpu->arch.target) { + default: + if (vcpu_el1_is_32bit(vcpu)) { + pstate = VCPU_RESET_PSTATE_SVC; + } else { + pstate = VCPU_RESET_PSTATE_EL1; + } + + if (kvm_vcpu_has_pmu(vcpu) && !kvm_arm_support_pmu_v3()) { + ret = -EINVAL; + goto out; + } + break; + } + + /* Reset core registers */ + memset(vcpu_gp_regs(vcpu), 0, sizeof(*vcpu_gp_regs(vcpu))); + memset(&vcpu->arch.ctxt.fp_regs, 0, sizeof(vcpu->arch.ctxt.fp_regs)); + vcpu->arch.ctxt.spsr_abt = 0; + vcpu->arch.ctxt.spsr_und = 0; + vcpu->arch.ctxt.spsr_irq = 0; + vcpu->arch.ctxt.spsr_fiq = 0; + vcpu_gp_regs(vcpu)->pstate = pstate; + + /* Reset system registers */ + kvm_reset_sys_regs(vcpu); + + /* + * Additional reset state handling that PSCI may have imposed on us. + * Must be done after all the sys_reg reset. + */ + if (reset_state.reset) { + unsigned long target_pc = reset_state.pc; + + /* Gracefully handle Thumb2 entry point */ + if (vcpu_mode_is_32bit(vcpu) && (target_pc & 1)) { + target_pc &= ~1UL; + vcpu_set_thumb(vcpu); + } + + /* Propagate caller endianness */ + if (reset_state.be) + kvm_vcpu_set_be(vcpu); + + *vcpu_pc(vcpu) = target_pc; + vcpu_set_reg(vcpu, 0, reset_state.r0); + } + + /* Reset timer */ + ret = kvm_timer_vcpu_reset(vcpu); +out: + if (loaded) + kvm_arch_vcpu_load(vcpu, smp_processor_id()); + preempt_enable(); + return ret; +} + +u32 get_kvm_ipa_limit(void) +{ + return kvm_ipa_limit; +} + +int kvm_set_ipa_limit(void) +{ + unsigned int parange; + u64 mmfr0; + + mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1); + parange = cpuid_feature_extract_unsigned_field(mmfr0, + ID_AA64MMFR0_EL1_PARANGE_SHIFT); + /* + * IPA size beyond 48 bits could not be supported + * on either 4K or 16K page size. Hence let's cap + * it to 48 bits, in case it's reported as larger + * on the system. + */ + if (PAGE_SIZE != SZ_64K) + parange = min(parange, (unsigned int)ID_AA64MMFR0_EL1_PARANGE_48); + + /* + * Check with ARMv8.5-GTG that our PAGE_SIZE is supported at + * Stage-2. If not, things will stop very quickly. + */ + switch (cpuid_feature_extract_unsigned_field(mmfr0, ID_AA64MMFR0_EL1_TGRAN_2_SHIFT)) { + case ID_AA64MMFR0_EL1_TGRAN_2_SUPPORTED_NONE: + kvm_err("PAGE_SIZE not supported at Stage-2, giving up\n"); + return -EINVAL; + case ID_AA64MMFR0_EL1_TGRAN_2_SUPPORTED_DEFAULT: + kvm_debug("PAGE_SIZE supported at Stage-2 (default)\n"); + break; + case ID_AA64MMFR0_EL1_TGRAN_2_SUPPORTED_MIN ... ID_AA64MMFR0_EL1_TGRAN_2_SUPPORTED_MAX: + kvm_debug("PAGE_SIZE supported at Stage-2 (advertised)\n"); + break; + default: + kvm_err("Unsupported value for TGRAN_2, giving up\n"); + return -EINVAL; + } + + kvm_ipa_limit = id_aa64mmfr0_parange_to_phys_shift(parange); + kvm_info("IPA Size Limit: %d bits%s\n", kvm_ipa_limit, + ((kvm_ipa_limit < KVM_PHYS_SHIFT) ? + " (Reduced IPA size, limited VM/VMM compatibility)" : "")); + + return 0; +} + +int kvm_arm_setup_stage2(struct kvm *kvm, unsigned long type) +{ + u64 mmfr0, mmfr1; + u32 phys_shift; + + if (type & ~KVM_VM_TYPE_ARM_IPA_SIZE_MASK) + return -EINVAL; + + phys_shift = KVM_VM_TYPE_ARM_IPA_SIZE(type); + if (phys_shift) { + if (phys_shift > kvm_ipa_limit || + phys_shift < ARM64_MIN_PARANGE_BITS) + return -EINVAL; + } else { + phys_shift = KVM_PHYS_SHIFT; + if (phys_shift > kvm_ipa_limit) { + pr_warn_once("%s using unsupported default IPA limit, upgrade your VMM\n", + current->comm); + return -EINVAL; + } + } + + mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1); + mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1); + kvm->arch.vtcr = kvm_get_vtcr(mmfr0, mmfr1, phys_shift); + + return 0; +} |