diff options
Diffstat (limited to 'arch/riscv/kvm/vcpu.c')
| -rw-r--r-- | arch/riscv/kvm/vcpu.c | 781 |
1 files changed, 781 insertions, 0 deletions
diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c new file mode 100644 index 0000000000..82229db1ce --- /dev/null +++ b/arch/riscv/kvm/vcpu.c @@ -0,0 +1,781 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 Western Digital Corporation or its affiliates. + * + * Authors: + * Anup Patel <anup.patel@wdc.com> + */ + +#include <linux/bitops.h> +#include <linux/entry-kvm.h> +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/kdebug.h> +#include <linux/module.h> +#include <linux/percpu.h> +#include <linux/vmalloc.h> +#include <linux/sched/signal.h> +#include <linux/fs.h> +#include <linux/kvm_host.h> +#include <asm/csr.h> +#include <asm/cacheflush.h> +#include <asm/kvm_vcpu_vector.h> + +const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = { + KVM_GENERIC_VCPU_STATS(), + STATS_DESC_COUNTER(VCPU, ecall_exit_stat), + STATS_DESC_COUNTER(VCPU, wfi_exit_stat), + STATS_DESC_COUNTER(VCPU, mmio_exit_user), + STATS_DESC_COUNTER(VCPU, mmio_exit_kernel), + STATS_DESC_COUNTER(VCPU, csr_exit_user), + STATS_DESC_COUNTER(VCPU, csr_exit_kernel), + STATS_DESC_COUNTER(VCPU, signal_exits), + STATS_DESC_COUNTER(VCPU, exits) +}; + +const struct kvm_stats_header kvm_vcpu_stats_header = { + .name_size = KVM_STATS_NAME_SIZE, + .num_desc = ARRAY_SIZE(kvm_vcpu_stats_desc), + .id_offset = sizeof(struct kvm_stats_header), + .desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE, + .data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE + + sizeof(kvm_vcpu_stats_desc), +}; + +static void kvm_riscv_reset_vcpu(struct kvm_vcpu *vcpu) +{ + struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr; + struct kvm_vcpu_csr *reset_csr = &vcpu->arch.guest_reset_csr; + struct kvm_cpu_context *cntx = &vcpu->arch.guest_context; + struct kvm_cpu_context *reset_cntx = &vcpu->arch.guest_reset_context; + bool loaded; + + /** + * The preemption should be disabled here because it races with + * kvm_sched_out/kvm_sched_in(called from preempt notifiers) which + * also calls vcpu_load/put. + */ + get_cpu(); + loaded = (vcpu->cpu != -1); + if (loaded) + kvm_arch_vcpu_put(vcpu); + + vcpu->arch.last_exit_cpu = -1; + + memcpy(csr, reset_csr, sizeof(*csr)); + + memcpy(cntx, reset_cntx, sizeof(*cntx)); + + kvm_riscv_vcpu_fp_reset(vcpu); + + kvm_riscv_vcpu_vector_reset(vcpu); + + kvm_riscv_vcpu_timer_reset(vcpu); + + kvm_riscv_vcpu_aia_reset(vcpu); + + bitmap_zero(vcpu->arch.irqs_pending, KVM_RISCV_VCPU_NR_IRQS); + bitmap_zero(vcpu->arch.irqs_pending_mask, KVM_RISCV_VCPU_NR_IRQS); + + kvm_riscv_vcpu_pmu_reset(vcpu); + + vcpu->arch.hfence_head = 0; + vcpu->arch.hfence_tail = 0; + memset(vcpu->arch.hfence_queue, 0, sizeof(vcpu->arch.hfence_queue)); + + /* Reset the guest CSRs for hotplug usecase */ + if (loaded) + kvm_arch_vcpu_load(vcpu, smp_processor_id()); + put_cpu(); +} + +int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id) +{ + return 0; +} + +int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) +{ + int rc; + struct kvm_cpu_context *cntx; + struct kvm_vcpu_csr *reset_csr = &vcpu->arch.guest_reset_csr; + + /* Mark this VCPU never ran */ + vcpu->arch.ran_atleast_once = false; + vcpu->arch.mmu_page_cache.gfp_zero = __GFP_ZERO; + bitmap_zero(vcpu->arch.isa, RISCV_ISA_EXT_MAX); + + /* Setup ISA features available to VCPU */ + kvm_riscv_vcpu_setup_isa(vcpu); + + /* Setup vendor, arch, and implementation details */ + vcpu->arch.mvendorid = sbi_get_mvendorid(); + vcpu->arch.marchid = sbi_get_marchid(); + vcpu->arch.mimpid = sbi_get_mimpid(); + + /* Setup VCPU hfence queue */ + spin_lock_init(&vcpu->arch.hfence_lock); + + /* Setup reset state of shadow SSTATUS and HSTATUS CSRs */ + cntx = &vcpu->arch.guest_reset_context; + cntx->sstatus = SR_SPP | SR_SPIE; + cntx->hstatus = 0; + cntx->hstatus |= HSTATUS_VTW; + cntx->hstatus |= HSTATUS_SPVP; + cntx->hstatus |= HSTATUS_SPV; + + if (kvm_riscv_vcpu_alloc_vector_context(vcpu, cntx)) + return -ENOMEM; + + /* By default, make CY, TM, and IR counters accessible in VU mode */ + reset_csr->scounteren = 0x7; + + /* Setup VCPU timer */ + kvm_riscv_vcpu_timer_init(vcpu); + + /* setup performance monitoring */ + kvm_riscv_vcpu_pmu_init(vcpu); + + /* Setup VCPU AIA */ + rc = kvm_riscv_vcpu_aia_init(vcpu); + if (rc) + return rc; + + /* Reset VCPU */ + kvm_riscv_reset_vcpu(vcpu); + + return 0; +} + +void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu) +{ + /** + * vcpu with id 0 is the designated boot cpu. + * Keep all vcpus with non-zero id in power-off state so that + * they can be brought up using SBI HSM extension. + */ + if (vcpu->vcpu_idx != 0) + kvm_riscv_vcpu_power_off(vcpu); +} + +void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu) +{ + /* Cleanup VCPU AIA context */ + kvm_riscv_vcpu_aia_deinit(vcpu); + + /* Cleanup VCPU timer */ + kvm_riscv_vcpu_timer_deinit(vcpu); + + kvm_riscv_vcpu_pmu_deinit(vcpu); + + /* Free unused pages pre-allocated for G-stage page table mappings */ + kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_cache); + + /* Free vector context space for host and guest kernel */ + kvm_riscv_vcpu_free_vector_context(vcpu); +} + +int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu) +{ + return kvm_riscv_vcpu_timer_pending(vcpu); +} + +void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) +{ + kvm_riscv_aia_wakeon_hgei(vcpu, true); +} + +void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) +{ + kvm_riscv_aia_wakeon_hgei(vcpu, false); +} + +int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu) +{ + return (kvm_riscv_vcpu_has_interrupts(vcpu, -1UL) && + !vcpu->arch.power_off && !vcpu->arch.pause); +} + +int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu) +{ + return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE; +} + +bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu) +{ + return (vcpu->arch.guest_context.sstatus & SR_SPP) ? true : false; +} + +vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf) +{ + return VM_FAULT_SIGBUS; +} + +long kvm_arch_vcpu_async_ioctl(struct file *filp, + unsigned int ioctl, unsigned long arg) +{ + struct kvm_vcpu *vcpu = filp->private_data; + void __user *argp = (void __user *)arg; + + if (ioctl == KVM_INTERRUPT) { + struct kvm_interrupt irq; + + if (copy_from_user(&irq, argp, sizeof(irq))) + return -EFAULT; + + if (irq.irq == KVM_INTERRUPT_SET) + return kvm_riscv_vcpu_set_interrupt(vcpu, IRQ_VS_EXT); + else + return kvm_riscv_vcpu_unset_interrupt(vcpu, IRQ_VS_EXT); + } + + return -ENOIOCTLCMD; +} + +long kvm_arch_vcpu_ioctl(struct file *filp, + unsigned int ioctl, unsigned long arg) +{ + struct kvm_vcpu *vcpu = filp->private_data; + void __user *argp = (void __user *)arg; + long r = -EINVAL; + + switch (ioctl) { + case KVM_SET_ONE_REG: + case KVM_GET_ONE_REG: { + struct kvm_one_reg reg; + + r = -EFAULT; + if (copy_from_user(®, argp, sizeof(reg))) + break; + + if (ioctl == KVM_SET_ONE_REG) + r = kvm_riscv_vcpu_set_reg(vcpu, ®); + else + r = kvm_riscv_vcpu_get_reg(vcpu, ®); + break; + } + case KVM_GET_REG_LIST: { + struct kvm_reg_list __user *user_list = argp; + struct kvm_reg_list reg_list; + unsigned int n; + + r = -EFAULT; + if (copy_from_user(®_list, user_list, sizeof(reg_list))) + break; + n = reg_list.n; + reg_list.n = kvm_riscv_vcpu_num_regs(vcpu); + if (copy_to_user(user_list, ®_list, sizeof(reg_list))) + break; + r = -E2BIG; + if (n < reg_list.n) + break; + r = kvm_riscv_vcpu_copy_reg_indices(vcpu, user_list->reg); + break; + } + default: + break; + } + + return r; +} + +int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu, + struct kvm_sregs *sregs) +{ + return -EINVAL; +} + +int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu, + struct kvm_sregs *sregs) +{ + return -EINVAL; +} + +int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu) +{ + return -EINVAL; +} + +int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu) +{ + return -EINVAL; +} + +int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu, + struct kvm_translation *tr) +{ + return -EINVAL; +} + +int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs) +{ + return -EINVAL; +} + +int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs) +{ + return -EINVAL; +} + +void kvm_riscv_vcpu_flush_interrupts(struct kvm_vcpu *vcpu) +{ + struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr; + unsigned long mask, val; + + if (READ_ONCE(vcpu->arch.irqs_pending_mask[0])) { + mask = xchg_acquire(&vcpu->arch.irqs_pending_mask[0], 0); + val = READ_ONCE(vcpu->arch.irqs_pending[0]) & mask; + + csr->hvip &= ~mask; + csr->hvip |= val; + } + + /* Flush AIA high interrupts */ + kvm_riscv_vcpu_aia_flush_interrupts(vcpu); +} + +void kvm_riscv_vcpu_sync_interrupts(struct kvm_vcpu *vcpu) +{ + unsigned long hvip; + struct kvm_vcpu_arch *v = &vcpu->arch; + struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr; + + /* Read current HVIP and VSIE CSRs */ + csr->vsie = csr_read(CSR_VSIE); + + /* Sync-up HVIP.VSSIP bit changes does by Guest */ + hvip = csr_read(CSR_HVIP); + if ((csr->hvip ^ hvip) & (1UL << IRQ_VS_SOFT)) { + if (hvip & (1UL << IRQ_VS_SOFT)) { + if (!test_and_set_bit(IRQ_VS_SOFT, + v->irqs_pending_mask)) + set_bit(IRQ_VS_SOFT, v->irqs_pending); + } else { + if (!test_and_set_bit(IRQ_VS_SOFT, + v->irqs_pending_mask)) + clear_bit(IRQ_VS_SOFT, v->irqs_pending); + } + } + + /* Sync-up AIA high interrupts */ + kvm_riscv_vcpu_aia_sync_interrupts(vcpu); + + /* Sync-up timer CSRs */ + kvm_riscv_vcpu_timer_sync(vcpu); +} + +int kvm_riscv_vcpu_set_interrupt(struct kvm_vcpu *vcpu, unsigned int irq) +{ + /* + * We only allow VS-mode software, timer, and external + * interrupts when irq is one of the local interrupts + * defined by RISC-V privilege specification. + */ + if (irq < IRQ_LOCAL_MAX && + irq != IRQ_VS_SOFT && + irq != IRQ_VS_TIMER && + irq != IRQ_VS_EXT) + return -EINVAL; + + set_bit(irq, vcpu->arch.irqs_pending); + smp_mb__before_atomic(); + set_bit(irq, vcpu->arch.irqs_pending_mask); + + kvm_vcpu_kick(vcpu); + + return 0; +} + +int kvm_riscv_vcpu_unset_interrupt(struct kvm_vcpu *vcpu, unsigned int irq) +{ + /* + * We only allow VS-mode software, timer, and external + * interrupts when irq is one of the local interrupts + * defined by RISC-V privilege specification. + */ + if (irq < IRQ_LOCAL_MAX && + irq != IRQ_VS_SOFT && + irq != IRQ_VS_TIMER && + irq != IRQ_VS_EXT) + return -EINVAL; + + clear_bit(irq, vcpu->arch.irqs_pending); + smp_mb__before_atomic(); + set_bit(irq, vcpu->arch.irqs_pending_mask); + + return 0; +} + +bool kvm_riscv_vcpu_has_interrupts(struct kvm_vcpu *vcpu, u64 mask) +{ + unsigned long ie; + + ie = ((vcpu->arch.guest_csr.vsie & VSIP_VALID_MASK) + << VSIP_TO_HVIP_SHIFT) & (unsigned long)mask; + ie |= vcpu->arch.guest_csr.vsie & ~IRQ_LOCAL_MASK & + (unsigned long)mask; + if (READ_ONCE(vcpu->arch.irqs_pending[0]) & ie) + return true; + + /* Check AIA high interrupts */ + return kvm_riscv_vcpu_aia_has_interrupts(vcpu, mask); +} + +void kvm_riscv_vcpu_power_off(struct kvm_vcpu *vcpu) +{ + vcpu->arch.power_off = true; + kvm_make_request(KVM_REQ_SLEEP, vcpu); + kvm_vcpu_kick(vcpu); +} + +void kvm_riscv_vcpu_power_on(struct kvm_vcpu *vcpu) +{ + vcpu->arch.power_off = false; + kvm_vcpu_wake_up(vcpu); +} + +int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu, + struct kvm_mp_state *mp_state) +{ + if (vcpu->arch.power_off) + mp_state->mp_state = KVM_MP_STATE_STOPPED; + else + mp_state->mp_state = KVM_MP_STATE_RUNNABLE; + + return 0; +} + +int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu, + struct kvm_mp_state *mp_state) +{ + int ret = 0; + + switch (mp_state->mp_state) { + case KVM_MP_STATE_RUNNABLE: + vcpu->arch.power_off = false; + break; + case KVM_MP_STATE_STOPPED: + kvm_riscv_vcpu_power_off(vcpu); + break; + default: + ret = -EINVAL; + } + + return ret; +} + +int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, + struct kvm_guest_debug *dbg) +{ + /* TODO; To be implemented later. */ + return -EINVAL; +} + +static void kvm_riscv_vcpu_update_config(const unsigned long *isa) +{ + u64 henvcfg = 0; + + if (riscv_isa_extension_available(isa, SVPBMT)) + henvcfg |= ENVCFG_PBMTE; + + if (riscv_isa_extension_available(isa, SSTC)) + henvcfg |= ENVCFG_STCE; + + if (riscv_isa_extension_available(isa, ZICBOM)) + henvcfg |= (ENVCFG_CBIE | ENVCFG_CBCFE); + + if (riscv_isa_extension_available(isa, ZICBOZ)) + henvcfg |= ENVCFG_CBZE; + + csr_write(CSR_HENVCFG, henvcfg); +#ifdef CONFIG_32BIT + csr_write(CSR_HENVCFGH, henvcfg >> 32); +#endif +} + +void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) +{ + struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr; + + csr_write(CSR_VSSTATUS, csr->vsstatus); + csr_write(CSR_VSIE, csr->vsie); + csr_write(CSR_VSTVEC, csr->vstvec); + csr_write(CSR_VSSCRATCH, csr->vsscratch); + csr_write(CSR_VSEPC, csr->vsepc); + csr_write(CSR_VSCAUSE, csr->vscause); + csr_write(CSR_VSTVAL, csr->vstval); + csr_write(CSR_HVIP, csr->hvip); + csr_write(CSR_VSATP, csr->vsatp); + + kvm_riscv_vcpu_update_config(vcpu->arch.isa); + + kvm_riscv_gstage_update_hgatp(vcpu); + + kvm_riscv_vcpu_timer_restore(vcpu); + + kvm_riscv_vcpu_host_fp_save(&vcpu->arch.host_context); + kvm_riscv_vcpu_guest_fp_restore(&vcpu->arch.guest_context, + vcpu->arch.isa); + kvm_riscv_vcpu_host_vector_save(&vcpu->arch.host_context); + kvm_riscv_vcpu_guest_vector_restore(&vcpu->arch.guest_context, + vcpu->arch.isa); + + kvm_riscv_vcpu_aia_load(vcpu, cpu); + + vcpu->cpu = cpu; +} + +void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) +{ + struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr; + + vcpu->cpu = -1; + + kvm_riscv_vcpu_aia_put(vcpu); + + kvm_riscv_vcpu_guest_fp_save(&vcpu->arch.guest_context, + vcpu->arch.isa); + kvm_riscv_vcpu_host_fp_restore(&vcpu->arch.host_context); + + kvm_riscv_vcpu_timer_save(vcpu); + kvm_riscv_vcpu_guest_vector_save(&vcpu->arch.guest_context, + vcpu->arch.isa); + kvm_riscv_vcpu_host_vector_restore(&vcpu->arch.host_context); + + csr->vsstatus = csr_read(CSR_VSSTATUS); + csr->vsie = csr_read(CSR_VSIE); + csr->vstvec = csr_read(CSR_VSTVEC); + csr->vsscratch = csr_read(CSR_VSSCRATCH); + csr->vsepc = csr_read(CSR_VSEPC); + csr->vscause = csr_read(CSR_VSCAUSE); + csr->vstval = csr_read(CSR_VSTVAL); + csr->hvip = csr_read(CSR_HVIP); + csr->vsatp = csr_read(CSR_VSATP); +} + +static void kvm_riscv_check_vcpu_requests(struct kvm_vcpu *vcpu) +{ + struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu); + + if (kvm_request_pending(vcpu)) { + if (kvm_check_request(KVM_REQ_SLEEP, vcpu)) { + kvm_vcpu_srcu_read_unlock(vcpu); + rcuwait_wait_event(wait, + (!vcpu->arch.power_off) && (!vcpu->arch.pause), + TASK_INTERRUPTIBLE); + kvm_vcpu_srcu_read_lock(vcpu); + + if (vcpu->arch.power_off || vcpu->arch.pause) { + /* + * Awaken to handle a signal, request to + * sleep again later. + */ + kvm_make_request(KVM_REQ_SLEEP, vcpu); + } + } + + if (kvm_check_request(KVM_REQ_VCPU_RESET, vcpu)) + kvm_riscv_reset_vcpu(vcpu); + + if (kvm_check_request(KVM_REQ_UPDATE_HGATP, vcpu)) + kvm_riscv_gstage_update_hgatp(vcpu); + + if (kvm_check_request(KVM_REQ_FENCE_I, vcpu)) + kvm_riscv_fence_i_process(vcpu); + + /* + * The generic KVM_REQ_TLB_FLUSH is same as + * KVM_REQ_HFENCE_GVMA_VMID_ALL + */ + if (kvm_check_request(KVM_REQ_HFENCE_GVMA_VMID_ALL, vcpu)) + kvm_riscv_hfence_gvma_vmid_all_process(vcpu); + + if (kvm_check_request(KVM_REQ_HFENCE_VVMA_ALL, vcpu)) + kvm_riscv_hfence_vvma_all_process(vcpu); + + if (kvm_check_request(KVM_REQ_HFENCE, vcpu)) + kvm_riscv_hfence_process(vcpu); + } +} + +static void kvm_riscv_update_hvip(struct kvm_vcpu *vcpu) +{ + struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr; + + csr_write(CSR_HVIP, csr->hvip); + kvm_riscv_vcpu_aia_update_hvip(vcpu); +} + +/* + * Actually run the vCPU, entering an RCU extended quiescent state (EQS) while + * the vCPU is running. + * + * This must be noinstr as instrumentation may make use of RCU, and this is not + * safe during the EQS. + */ +static void noinstr kvm_riscv_vcpu_enter_exit(struct kvm_vcpu *vcpu) +{ + guest_state_enter_irqoff(); + __kvm_riscv_switch_to(&vcpu->arch); + vcpu->arch.last_exit_cpu = vcpu->cpu; + guest_state_exit_irqoff(); +} + +int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) +{ + int ret; + struct kvm_cpu_trap trap; + struct kvm_run *run = vcpu->run; + + /* Mark this VCPU ran at least once */ + vcpu->arch.ran_atleast_once = true; + + kvm_vcpu_srcu_read_lock(vcpu); + + switch (run->exit_reason) { + case KVM_EXIT_MMIO: + /* Process MMIO value returned from user-space */ + ret = kvm_riscv_vcpu_mmio_return(vcpu, vcpu->run); + break; + case KVM_EXIT_RISCV_SBI: + /* Process SBI value returned from user-space */ + ret = kvm_riscv_vcpu_sbi_return(vcpu, vcpu->run); + break; + case KVM_EXIT_RISCV_CSR: + /* Process CSR value returned from user-space */ + ret = kvm_riscv_vcpu_csr_return(vcpu, vcpu->run); + break; + default: + ret = 0; + break; + } + if (ret) { + kvm_vcpu_srcu_read_unlock(vcpu); + return ret; + } + + if (run->immediate_exit) { + kvm_vcpu_srcu_read_unlock(vcpu); + return -EINTR; + } + + vcpu_load(vcpu); + + kvm_sigset_activate(vcpu); + + ret = 1; + run->exit_reason = KVM_EXIT_UNKNOWN; + while (ret > 0) { + /* Check conditions before entering the guest */ + ret = xfer_to_guest_mode_handle_work(vcpu); + if (ret) + continue; + ret = 1; + + kvm_riscv_gstage_vmid_update(vcpu); + + kvm_riscv_check_vcpu_requests(vcpu); + + preempt_disable(); + + /* Update AIA HW state before entering guest */ + ret = kvm_riscv_vcpu_aia_update(vcpu); + if (ret <= 0) { + preempt_enable(); + continue; + } + + local_irq_disable(); + + /* + * Ensure we set mode to IN_GUEST_MODE after we disable + * interrupts and before the final VCPU requests check. + * See the comment in kvm_vcpu_exiting_guest_mode() and + * Documentation/virt/kvm/vcpu-requests.rst + */ + vcpu->mode = IN_GUEST_MODE; + + kvm_vcpu_srcu_read_unlock(vcpu); + smp_mb__after_srcu_read_unlock(); + + /* + * We might have got VCPU interrupts updated asynchronously + * so update it in HW. + */ + kvm_riscv_vcpu_flush_interrupts(vcpu); + + /* Update HVIP CSR for current CPU */ + kvm_riscv_update_hvip(vcpu); + + if (ret <= 0 || + kvm_riscv_gstage_vmid_ver_changed(&vcpu->kvm->arch.vmid) || + kvm_request_pending(vcpu) || + xfer_to_guest_mode_work_pending()) { + vcpu->mode = OUTSIDE_GUEST_MODE; + local_irq_enable(); + preempt_enable(); + kvm_vcpu_srcu_read_lock(vcpu); + continue; + } + + /* + * Cleanup stale TLB enteries + * + * Note: This should be done after G-stage VMID has been + * updated using kvm_riscv_gstage_vmid_ver_changed() + */ + kvm_riscv_local_tlb_sanitize(vcpu); + + guest_timing_enter_irqoff(); + + kvm_riscv_vcpu_enter_exit(vcpu); + + vcpu->mode = OUTSIDE_GUEST_MODE; + vcpu->stat.exits++; + + /* + * Save SCAUSE, STVAL, HTVAL, and HTINST because we might + * get an interrupt between __kvm_riscv_switch_to() and + * local_irq_enable() which can potentially change CSRs. + */ + trap.sepc = vcpu->arch.guest_context.sepc; + trap.scause = csr_read(CSR_SCAUSE); + trap.stval = csr_read(CSR_STVAL); + trap.htval = csr_read(CSR_HTVAL); + trap.htinst = csr_read(CSR_HTINST); + + /* Syncup interrupts state with HW */ + kvm_riscv_vcpu_sync_interrupts(vcpu); + + /* + * We must ensure that any pending interrupts are taken before + * we exit guest timing so that timer ticks are accounted as + * guest time. Transiently unmask interrupts so that any + * pending interrupts are taken. + * + * There's no barrier which ensures that pending interrupts are + * recognised, so we just hope that the CPU takes any pending + * interrupts between the enable and disable. + */ + local_irq_enable(); + local_irq_disable(); + + guest_timing_exit_irqoff(); + + local_irq_enable(); + + preempt_enable(); + + kvm_vcpu_srcu_read_lock(vcpu); + + ret = kvm_riscv_vcpu_exit(vcpu, run, &trap); + } + + kvm_sigset_deactivate(vcpu); + + vcpu_put(vcpu); + + kvm_vcpu_srcu_read_unlock(vcpu); + + return ret; +} |