diff options
| -rw-r--r-- | arch/loongarch/kvm/vcpu.c | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c new file mode 100644 index 000000000000..349cecca1e62 --- /dev/null +++ b/arch/loongarch/kvm/vcpu.c @@ -0,0 +1,261 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020-2023 Loongson Technology Corporation Limited + */ + +#include <linux/kvm_host.h> +#include <linux/entry-kvm.h> +#include <asm/fpu.h> +#include <asm/loongarch.h> +#include <asm/setup.h> +#include <asm/time.h> + +#define CREATE_TRACE_POINTS +#include "trace.h" + +/* + * kvm_check_requests - check and handle pending vCPU requests + * + * Return: RESUME_GUEST if we should enter the guest + * RESUME_HOST if we should exit to userspace + */ +static int kvm_check_requests(struct kvm_vcpu *vcpu) +{ + if (!kvm_request_pending(vcpu)) + return RESUME_GUEST; + + if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu)) + vcpu->arch.vpid = 0; /* Drop vpid for this vCPU */ + + if (kvm_dirty_ring_check_request(vcpu)) + return RESUME_HOST; + + return RESUME_GUEST; +} + +/* + * Check and handle pending signal and vCPU requests etc + * Run with irq enabled and preempt enabled + * + * Return: RESUME_GUEST if we should enter the guest + * RESUME_HOST if we should exit to userspace + * < 0 if we should exit to userspace, where the return value + * indicates an error + */ +static int kvm_enter_guest_check(struct kvm_vcpu *vcpu) +{ + int ret; + + /* + * Check conditions before entering the guest + */ + ret = xfer_to_guest_mode_handle_work(vcpu); + if (ret < 0) + return ret; + + ret = kvm_check_requests(vcpu); + + return ret; +} + +/* + * Called with irq enabled + * + * Return: RESUME_GUEST if we should enter the guest, and irq disabled + * Others if we should exit to userspace + */ +static int kvm_pre_enter_guest(struct kvm_vcpu *vcpu) +{ + int ret; + + do { + ret = kvm_enter_guest_check(vcpu); + if (ret != RESUME_GUEST) + break; + + /* + * Handle vcpu timer, interrupts, check requests and + * check vmid before vcpu enter guest + */ + local_irq_disable(); + kvm_acquire_timer(vcpu); + kvm_deliver_intr(vcpu); + kvm_deliver_exception(vcpu); + /* Make sure the vcpu mode has been written */ + smp_store_mb(vcpu->mode, IN_GUEST_MODE); + kvm_check_vpid(vcpu); + vcpu->arch.host_eentry = csr_read64(LOONGARCH_CSR_EENTRY); + /* Clear KVM_LARCH_SWCSR_LATEST as CSR will change when enter guest */ + vcpu->arch.aux_inuse &= ~KVM_LARCH_SWCSR_LATEST; + + if (kvm_request_pending(vcpu) || xfer_to_guest_mode_work_pending()) { + /* make sure the vcpu mode has been written */ + smp_store_mb(vcpu->mode, OUTSIDE_GUEST_MODE); + local_irq_enable(); + ret = -EAGAIN; + } + } while (ret != RESUME_GUEST); + + return ret; +} + +/* + * Return 1 for resume guest and "<= 0" for resume host. + */ +static int kvm_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu) +{ + int ret = RESUME_GUEST; + unsigned long estat = vcpu->arch.host_estat; + u32 intr = estat & 0x1fff; /* Ignore NMI */ + u32 ecode = (estat & CSR_ESTAT_EXC) >> CSR_ESTAT_EXC_SHIFT; + + vcpu->mode = OUTSIDE_GUEST_MODE; + + /* Set a default exit reason */ + run->exit_reason = KVM_EXIT_UNKNOWN; + + guest_timing_exit_irqoff(); + guest_state_exit_irqoff(); + local_irq_enable(); + + trace_kvm_exit(vcpu, ecode); + if (ecode) { + ret = kvm_handle_fault(vcpu, ecode); + } else { + WARN(!intr, "vm exiting with suspicious irq\n"); + ++vcpu->stat.int_exits; + } + + if (ret == RESUME_GUEST) + ret = kvm_pre_enter_guest(vcpu); + + if (ret != RESUME_GUEST) { + local_irq_disable(); + return ret; + } + + guest_timing_enter_irqoff(); + guest_state_enter_irqoff(); + trace_kvm_reenter(vcpu); + + return RESUME_GUEST; +} + +int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id) +{ + return 0; +} + +int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) +{ + unsigned long timer_hz; + struct loongarch_csrs *csr; + + vcpu->arch.vpid = 0; + + hrtimer_init(&vcpu->arch.swtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); + vcpu->arch.swtimer.function = kvm_swtimer_wakeup; + + vcpu->arch.handle_exit = kvm_handle_exit; + vcpu->arch.guest_eentry = (unsigned long)kvm_loongarch_ops->exc_entry; + vcpu->arch.csr = kzalloc(sizeof(struct loongarch_csrs), GFP_KERNEL); + if (!vcpu->arch.csr) + return -ENOMEM; + + /* + * All kvm exceptions share one exception entry, and host <-> guest + * switch also switch ECFG.VS field, keep host ECFG.VS info here. + */ + vcpu->arch.host_ecfg = (read_csr_ecfg() & CSR_ECFG_VS); + + /* Init */ + vcpu->arch.last_sched_cpu = -1; + + /* + * Initialize guest register state to valid architectural reset state. + */ + timer_hz = calc_const_freq(); + kvm_init_timer(vcpu, timer_hz); + + /* Set Initialize mode for guest */ + csr = vcpu->arch.csr; + kvm_write_sw_gcsr(csr, LOONGARCH_CSR_CRMD, CSR_CRMD_DA); + + /* Set cpuid */ + kvm_write_sw_gcsr(csr, LOONGARCH_CSR_TMID, vcpu->vcpu_id); + + /* Start with no pending virtual guest interrupts */ + csr->csrs[LOONGARCH_CSR_GINTC] = 0; + + return 0; +} + +void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu) +{ +} + +void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu) +{ + int cpu; + struct kvm_context *context; + + hrtimer_cancel(&vcpu->arch.swtimer); + kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_cache); + kfree(vcpu->arch.csr); + + /* + * If the vCPU is freed and reused as another vCPU, we don't want the + * matching pointer wrongly hanging around in last_vcpu. + */ + for_each_possible_cpu(cpu) { + context = per_cpu_ptr(vcpu->kvm->arch.vmcs, cpu); + if (context->last_vcpu == vcpu) + context->last_vcpu = NULL; + } +} + +int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) +{ + int r = -EINTR; + struct kvm_run *run = vcpu->run; + + if (vcpu->mmio_needed) { + if (!vcpu->mmio_is_write) + kvm_complete_mmio_read(vcpu, run); + vcpu->mmio_needed = 0; + } + + if (run->exit_reason == KVM_EXIT_LOONGARCH_IOCSR) { + if (!run->iocsr_io.is_write) + kvm_complete_iocsr_read(vcpu, run); + } + + if (run->immediate_exit) + return r; + + /* Clear exit_reason */ + run->exit_reason = KVM_EXIT_UNKNOWN; + lose_fpu(1); + vcpu_load(vcpu); + kvm_sigset_activate(vcpu); + r = kvm_pre_enter_guest(vcpu); + if (r != RESUME_GUEST) + goto out; + + guest_timing_enter_irqoff(); + guest_state_enter_irqoff(); + trace_kvm_enter(vcpu); + r = kvm_loongarch_ops->enter_guest(run, vcpu); + + trace_kvm_out(vcpu); + /* + * Guest exit is already recorded at kvm_handle_exit() + * return value must not be RESUME_GUEST + */ + local_irq_enable(); +out: + kvm_sigset_deactivate(vcpu); + vcpu_put(vcpu); + + return r; +} |