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Diffstat (limited to 'arch/arm64/kvm/reset.c')
| -rw-r--r-- | arch/arm64/kvm/reset.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c new file mode 100644 index 000000000..0688816f1 --- /dev/null +++ b/arch/arm64/kvm/reset.c @@ -0,0 +1,181 @@ +/* + * 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> + * + * 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/>. + */ + +#include <linux/errno.h> +#include <linux/kvm_host.h> +#include <linux/kvm.h> +#include <linux/hw_breakpoint.h> + +#include <kvm/arm_arch_timer.h> + +#include <asm/cputype.h> +#include <asm/ptrace.h> +#include <asm/kvm_arm.h> +#include <asm/kvm_asm.h> +#include <asm/kvm_coproc.h> +#include <asm/kvm_emulate.h> +#include <asm/kvm_mmu.h> + +/* + * ARMv8 Reset Values + */ +static const struct kvm_regs default_regs_reset = { + .regs.pstate = (PSR_MODE_EL1h | PSR_A_BIT | PSR_I_BIT | + PSR_F_BIT | PSR_D_BIT), +}; + +static const struct kvm_regs default_regs_reset32 = { + .regs.pstate = (PSR_AA32_MODE_SVC | PSR_AA32_A_BIT | + PSR_AA32_I_BIT | PSR_AA32_F_BIT), +}; + +static bool cpu_has_32bit_el1(void) +{ + u64 pfr0; + + pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1); + return !!(pfr0 & 0x20); +} + +/** + * kvm_arch_dev_ioctl_check_extension + * + * We currently assume that the number of HW registers is uniform + * across all CPUs (see cpuinfo_sanity_check). + */ +int kvm_arch_dev_ioctl_check_extension(struct kvm *kvm, long ext) +{ + int r; + + switch (ext) { + case KVM_CAP_ARM_EL1_32BIT: + r = cpu_has_32bit_el1(); + break; + case KVM_CAP_GUEST_DEBUG_HW_BPS: + r = get_num_brps(); + break; + case KVM_CAP_GUEST_DEBUG_HW_WPS: + r = get_num_wrps(); + break; + case KVM_CAP_ARM_PMU_V3: + r = kvm_arm_support_pmu_v3(); + break; + case KVM_CAP_ARM_INJECT_SERROR_ESR: + r = cpus_have_const_cap(ARM64_HAS_RAS_EXTN); + break; + case KVM_CAP_SET_GUEST_DEBUG: + case KVM_CAP_VCPU_ATTRIBUTES: + case KVM_CAP_VCPU_EVENTS: + r = 1; + break; + default: + r = 0; + } + + return r; +} + +/** + * kvm_reset_vcpu - sets core registers and sys_regs to reset value + * @vcpu: The VCPU pointer + * + * This function finds the right table above and sets the registers on + * the virtual CPU struct to their architecturally defined reset + * values. + * + * 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 valus 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) +{ + const struct kvm_regs *cpu_reset; + int ret = -EINVAL; + bool loaded; + + /* 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); + + switch (vcpu->arch.target) { + default: + if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) { + if (!cpu_has_32bit_el1()) + goto out; + cpu_reset = &default_regs_reset32; + } else { + cpu_reset = &default_regs_reset; + } + + break; + } + + /* Reset core registers */ + memcpy(vcpu_gp_regs(vcpu), cpu_reset, sizeof(*cpu_reset)); + + /* 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 (vcpu->arch.reset_state.reset) { + unsigned long target_pc = vcpu->arch.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 (vcpu->arch.reset_state.be) + kvm_vcpu_set_be(vcpu); + + *vcpu_pc(vcpu) = target_pc; + vcpu_set_reg(vcpu, 0, vcpu->arch.reset_state.r0); + + vcpu->arch.reset_state.reset = false; + } + + /* Default workaround setup is enabled (if supported) */ + if (kvm_arm_have_ssbd() == KVM_SSBD_KERNEL) + vcpu->arch.workaround_flags |= VCPU_WORKAROUND_2_FLAG; + + /* Reset timer */ + ret = kvm_timer_vcpu_reset(vcpu); +out: + if (loaded) + kvm_arch_vcpu_load(vcpu, smp_processor_id()); + preempt_enable(); + return ret; +} |