OSCL-LXR linux-6.0.1/​arch/​x86/​kvm/​xen.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright © 2019 Oracle and/or its affiliates. All rights reserved.
  * Copyright © 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
  *
  * KVM Xen emulation
  */
 
 #include "x86.h"
 #include "xen.h"
 #include "hyperv.h"
 #include "lapic.h"
 
 #include <linux/eventfd.h>
 #include <linux/kvm_host.h>
 #include <linux/sched/stat.h>
 
 #include <trace/events/kvm.h>
 #include <xen/interface/xen.h>
 #include <xen/interface/vcpu.h>
 #include <xen/interface/version.h>
 #include <xen/interface/event_channel.h>
 #include <xen/interface/sched.h>
 
 #include "trace.h"
 
 static int kvm_xen_set_evtchn(struct kvm_xen_evtchn *xe, struct kvm *kvm);
 static int kvm_xen_setattr_evtchn(struct kvm *kvm, struct kvm_xen_hvm_attr *data);
 static bool kvm_xen_hcall_evtchn_send(struct kvm_vcpu *vcpu, u64 param, u64 *r);
 
 DEFINE_STATIC_KEY_DEFERRED_FALSE(kvm_xen_enabled, HZ);
 
 static int kvm_xen_shared_info_init(struct kvm *kvm, gfn_t gfn)
 {
     struct gfn_to_pfn_cache *gpc = &kvm->arch.xen.shinfo_cache;
     struct pvclock_wall_clock *wc;
     gpa_t gpa = gfn_to_gpa(gfn);
     u32 *wc_sec_hi;
     u32 wc_version;
     u64 wall_nsec;
     int ret = 0;
     int idx = srcu_read_lock(&kvm->srcu);
 
     if (gfn == GPA_INVALID) {
         kvm_gfn_to_pfn_cache_destroy(kvm, gpc);
         goto out;
     }
 
     do {
         ret = kvm_gfn_to_pfn_cache_init(kvm, gpc, NULL, KVM_HOST_USES_PFN,
                         gpa, PAGE_SIZE);
         if (ret)
             goto out;
 
         /*
          * This code mirrors kvm_write_wall_clock() except that it writes
          * directly through the pfn cache and doesn't mark the page dirty.
          */
         wall_nsec = ktime_get_real_ns() - get_kvmclock_ns(kvm);
 
         /* It could be invalid again already, so we need to check */
         read_lock_irq(&gpc->lock);
 
         if (gpc->valid)
             break;
 
         read_unlock_irq(&gpc->lock);
     } while (1);
 
     /* Paranoia checks on the 32-bit struct layout */
     BUILD_BUG_ON(offsetof(struct compat_shared_info, wc) != 0x900);
     BUILD_BUG_ON(offsetof(struct compat_shared_info, arch.wc_sec_hi) != 0x924);
     BUILD_BUG_ON(offsetof(struct pvclock_vcpu_time_info, version) != 0);
 
 #ifdef CONFIG_X86_64
     /* Paranoia checks on the 64-bit struct layout */
     BUILD_BUG_ON(offsetof(struct shared_info, wc) != 0xc00);
     BUILD_BUG_ON(offsetof(struct shared_info, wc_sec_hi) != 0xc0c);
 
     if (IS_ENABLED(CONFIG_64BIT) && kvm->arch.xen.long_mode) {
         struct shared_info *shinfo = gpc->khva;
 
         wc_sec_hi = &shinfo->wc_sec_hi;
         wc = &shinfo->wc;
     } else
 #endif
     {
         struct compat_shared_info *shinfo = gpc->khva;
 
         wc_sec_hi = &shinfo->arch.wc_sec_hi;
         wc = &shinfo->wc;
     }
 
     /* Increment and ensure an odd value */
     wc_version = wc->version = (wc->version + 1) | 1;
     smp_wmb();
 
     wc->nsec = do_div(wall_nsec,  1000000000);
     wc->sec = (u32)wall_nsec;
     *wc_sec_hi = wall_nsec >> 32;
     smp_wmb();
 
     wc->version = wc_version + 1;
     read_unlock_irq(&gpc->lock);
 
     kvm_make_all_cpus_request(kvm, KVM_REQ_MASTERCLOCK_UPDATE);
 
 out:
     srcu_read_unlock(&kvm->srcu, idx);
     return ret;
 }
 
 void kvm_xen_inject_timer_irqs(struct kvm_vcpu *vcpu)
 {
     if (atomic_read(&vcpu->arch.xen.timer_pending) > 0) {
         struct kvm_xen_evtchn e;
 
         e.vcpu_id = vcpu->vcpu_id;
         e.vcpu_idx = vcpu->vcpu_idx;
         e.port = vcpu->arch.xen.timer_virq;
         e.priority = KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL;
 
         kvm_xen_set_evtchn(&e, vcpu->kvm);
 
         vcpu->arch.xen.timer_expires = 0;
         atomic_set(&vcpu->arch.xen.timer_pending, 0);
     }
 }
 
 static enum hrtimer_restart xen_timer_callback(struct hrtimer *timer)
 {
     struct kvm_vcpu *vcpu = container_of(timer, struct kvm_vcpu,
                          arch.xen.timer);
     if (atomic_read(&vcpu->arch.xen.timer_pending))
         return HRTIMER_NORESTART;
 
     atomic_inc(&vcpu->arch.xen.timer_pending);
     kvm_make_request(KVM_REQ_UNBLOCK, vcpu);
     kvm_vcpu_kick(vcpu);
 
     return HRTIMER_NORESTART;
 }
 
 static void kvm_xen_start_timer(struct kvm_vcpu *vcpu, u64 guest_abs, s64 delta_ns)
 {
     atomic_set(&vcpu->arch.xen.timer_pending, 0);
     vcpu->arch.xen.timer_expires = guest_abs;
 
     if (delta_ns <= 0) {
         xen_timer_callback(&vcpu->arch.xen.timer);
     } else {
         ktime_t ktime_now = ktime_get();
         hrtimer_start(&vcpu->arch.xen.timer,
                   ktime_add_ns(ktime_now, delta_ns),
                   HRTIMER_MODE_ABS_HARD);
     }
 }
 
 static void kvm_xen_stop_timer(struct kvm_vcpu *vcpu)
 {
     hrtimer_cancel(&vcpu->arch.xen.timer);
     vcpu->arch.xen.timer_expires = 0;
     atomic_set(&vcpu->arch.xen.timer_pending, 0);
 }
 
 static void kvm_xen_init_timer(struct kvm_vcpu *vcpu)
 {
     hrtimer_init(&vcpu->arch.xen.timer, CLOCK_MONOTONIC,
              HRTIMER_MODE_ABS_HARD);
     vcpu->arch.xen.timer.function = xen_timer_callback;
 }
 
 static void kvm_xen_update_runstate(struct kvm_vcpu *v, int state)
 {
     struct kvm_vcpu_xen *vx = &v->arch.xen;
     u64 now = get_kvmclock_ns(v->kvm);
     u64 delta_ns = now - vx->runstate_entry_time;
     u64 run_delay = current->sched_info.run_delay;
 
     if (unlikely(!vx->runstate_entry_time))
         vx->current_runstate = RUNSTATE_offline;
 
     /*
      * Time waiting for the scheduler isn't "stolen" if the
      * vCPU wasn't running anyway.
      */
     if (vx->current_runstate == RUNSTATE_running) {
         u64 steal_ns = run_delay - vx->last_steal;
 
         delta_ns -= steal_ns;
 
         vx->runstate_times[RUNSTATE_runnable] += steal_ns;
     }
     vx->last_steal = run_delay;
 
     vx->runstate_times[vx->current_runstate] += delta_ns;
     vx->current_runstate = state;
     vx->runstate_entry_time = now;
 }
 
 void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, int state)
 {
     struct kvm_vcpu_xen *vx = &v->arch.xen;
     struct gfn_to_pfn_cache *gpc = &vx->runstate_cache;
     uint64_t *user_times;
     unsigned long flags;
     size_t user_len;
     int *user_state;
 
     kvm_xen_update_runstate(v, state);
 
     if (!vx->runstate_cache.active)
         return;
 
     if (IS_ENABLED(CONFIG_64BIT) && v->kvm->arch.xen.long_mode)
         user_len = sizeof(struct vcpu_runstate_info);
     else
         user_len = sizeof(struct compat_vcpu_runstate_info);
 
     read_lock_irqsave(&gpc->lock, flags);
     while (!kvm_gfn_to_pfn_cache_check(v->kvm, gpc, gpc->gpa,
                        user_len)) {
         read_unlock_irqrestore(&gpc->lock, flags);
 
         /* When invoked from kvm_sched_out() we cannot sleep */
         if (state == RUNSTATE_runnable)
             return;
 
         if (kvm_gfn_to_pfn_cache_refresh(v->kvm, gpc, gpc->gpa, user_len))
             return;
 
         read_lock_irqsave(&gpc->lock, flags);
     }
 
     /*
      * The only difference between 32-bit and 64-bit versions of the
      * runstate struct us the alignment of uint64_t in 32-bit, which
      * means that the 64-bit version has an additional 4 bytes of
      * padding after the first field 'state'.
      *
      * So we use 'int __user *user_state' to point to the state field,
      * and 'uint64_t __user *user_times' for runstate_entry_time. So
      * the actual array of time[] in each state starts at user_times[1].
      */
     BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, state) != 0);
     BUILD_BUG_ON(offsetof(struct compat_vcpu_runstate_info, state) != 0);
     BUILD_BUG_ON(sizeof(struct compat_vcpu_runstate_info) != 0x2c);
 #ifdef CONFIG_X86_64
     BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, state_entry_time) !=
              offsetof(struct compat_vcpu_runstate_info, state_entry_time) + 4);
     BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, time) !=
              offsetof(struct compat_vcpu_runstate_info, time) + 4);
 #endif
 
     user_state = gpc->khva;
 
     if (IS_ENABLED(CONFIG_64BIT) && v->kvm->arch.xen.long_mode)
         user_times = gpc->khva + offsetof(struct vcpu_runstate_info,
                           state_entry_time);
     else
         user_times = gpc->khva + offsetof(struct compat_vcpu_runstate_info,
                           state_entry_time);
 
     /*
      * First write the updated state_entry_time at the appropriate
      * location determined by 'offset'.
      */
     BUILD_BUG_ON(sizeof_field(struct vcpu_runstate_info, state_entry_time) !=
              sizeof(user_times[0]));
     BUILD_BUG_ON(sizeof_field(struct compat_vcpu_runstate_info, state_entry_time) !=
              sizeof(user_times[0]));
 
     user_times[0] = vx->runstate_entry_time | XEN_RUNSTATE_UPDATE;
     smp_wmb();
 
     /*
      * Next, write the new runstate. This is in the *same* place
      * for 32-bit and 64-bit guests, asserted here for paranoia.
      */
     BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, state) !=
              offsetof(struct compat_vcpu_runstate_info, state));
     BUILD_BUG_ON(sizeof_field(struct vcpu_runstate_info, state) !=
              sizeof(vx->current_runstate));
     BUILD_BUG_ON(sizeof_field(struct compat_vcpu_runstate_info, state) !=
              sizeof(vx->current_runstate));
 
     *user_state = vx->current_runstate;
 
     /*
      * Write the actual runstate times immediately after the
      * runstate_entry_time.
      */
     BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, state_entry_time) !=
              offsetof(struct vcpu_runstate_info, time) - sizeof(u64));
     BUILD_BUG_ON(offsetof(struct compat_vcpu_runstate_info, state_entry_time) !=
              offsetof(struct compat_vcpu_runstate_info, time) - sizeof(u64));
     BUILD_BUG_ON(sizeof_field(struct vcpu_runstate_info, time) !=
              sizeof_field(struct compat_vcpu_runstate_info, time));
     BUILD_BUG_ON(sizeof_field(struct vcpu_runstate_info, time) !=
              sizeof(vx->runstate_times));
 
     memcpy(user_times + 1, vx->runstate_times, sizeof(vx->runstate_times));
     smp_wmb();
 
     /*
      * Finally, clear the XEN_RUNSTATE_UPDATE bit in the guest's
      * runstate_entry_time field.
      */
     user_times[0] &= ~XEN_RUNSTATE_UPDATE;
     smp_wmb();
 
     read_unlock_irqrestore(&gpc->lock, flags);
 
     mark_page_dirty_in_slot(v->kvm, gpc->memslot, gpc->gpa >> PAGE_SHIFT);
 }
 
 static void kvm_xen_inject_vcpu_vector(struct kvm_vcpu *v)
 {
     struct kvm_lapic_irq irq = { };
     int r;
 
     irq.dest_id = v->vcpu_id;
     irq.vector = v->arch.xen.upcall_vector;
     irq.dest_mode = APIC_DEST_PHYSICAL;
     irq.shorthand = APIC_DEST_NOSHORT;
     irq.delivery_mode = APIC_DM_FIXED;
     irq.level = 1;
 
     /* The fast version will always work for physical unicast */
     WARN_ON_ONCE(!kvm_irq_delivery_to_apic_fast(v->kvm, NULL, &irq, &r, NULL));
 }
 
 /*
  * On event channel delivery, the vcpu_info may not have been accessible.
  * In that case, there are bits in vcpu->arch.xen.evtchn_pending_sel which
  * need to be marked into the vcpu_info (and evtchn_upcall_pending set).
  * Do so now that we can sleep in the context of the vCPU to bring the
  * page in, and refresh the pfn cache for it.
  */
 void kvm_xen_inject_pending_events(struct kvm_vcpu *v)
 {
     unsigned long evtchn_pending_sel = READ_ONCE(v->arch.xen.evtchn_pending_sel);
     struct gfn_to_pfn_cache *gpc = &v->arch.xen.vcpu_info_cache;
     unsigned long flags;
 
     if (!evtchn_pending_sel)
         return;
 
     /*
      * Yes, this is an open-coded loop. But that's just what put_user()
      * does anyway. Page it in and retry the instruction. We're just a
      * little more honest about it.
      */
     read_lock_irqsave(&gpc->lock, flags);
     while (!kvm_gfn_to_pfn_cache_check(v->kvm, gpc, gpc->gpa,
                        sizeof(struct vcpu_info))) {
         read_unlock_irqrestore(&gpc->lock, flags);
 
         if (kvm_gfn_to_pfn_cache_refresh(v->kvm, gpc, gpc->gpa,
                          sizeof(struct vcpu_info)))
             return;
 
         read_lock_irqsave(&gpc->lock, flags);
     }
 
     /* Now gpc->khva is a valid kernel address for the vcpu_info */
     if (IS_ENABLED(CONFIG_64BIT) && v->kvm->arch.xen.long_mode) {
         struct vcpu_info *vi = gpc->khva;
 
         asm volatile(LOCK_PREFIX "orq %0, %1\n"
                  "notq %0\n"
                  LOCK_PREFIX "andq %0, %2\n"
                  : "=r" (evtchn_pending_sel),
                    "+m" (vi->evtchn_pending_sel),
                    "+m" (v->arch.xen.evtchn_pending_sel)
                  : "0" (evtchn_pending_sel));
         WRITE_ONCE(vi->evtchn_upcall_pending, 1);
     } else {
         u32 evtchn_pending_sel32 = evtchn_pending_sel;
         struct compat_vcpu_info *vi = gpc->khva;
 
         asm volatile(LOCK_PREFIX "orl %0, %1\n"
                  "notl %0\n"
                  LOCK_PREFIX "andl %0, %2\n"
                  : "=r" (evtchn_pending_sel32),
                    "+m" (vi->evtchn_pending_sel),
                    "+m" (v->arch.xen.evtchn_pending_sel)
                  : "0" (evtchn_pending_sel32));
         WRITE_ONCE(vi->evtchn_upcall_pending, 1);
     }
     read_unlock_irqrestore(&gpc->lock, flags);
 
     /* For the per-vCPU lapic vector, deliver it as MSI. */
     if (v->arch.xen.upcall_vector)
         kvm_xen_inject_vcpu_vector(v);
 
     mark_page_dirty_in_slot(v->kvm, gpc->memslot, gpc->gpa >> PAGE_SHIFT);
 }
 
 int __kvm_xen_has_interrupt(struct kvm_vcpu *v)
 {
     struct gfn_to_pfn_cache *gpc = &v->arch.xen.vcpu_info_cache;
     unsigned long flags;
     u8 rc = 0;
 
     /*
      * If the global upcall vector (HVMIRQ_callback_vector) is set and
      * the vCPU's evtchn_upcall_pending flag is set, the IRQ is pending.
      */
 
     /* No need for compat handling here */
     BUILD_BUG_ON(offsetof(struct vcpu_info, evtchn_upcall_pending) !=
              offsetof(struct compat_vcpu_info, evtchn_upcall_pending));
     BUILD_BUG_ON(sizeof(rc) !=
              sizeof_field(struct vcpu_info, evtchn_upcall_pending));
     BUILD_BUG_ON(sizeof(rc) !=
              sizeof_field(struct compat_vcpu_info, evtchn_upcall_pending));
 
     read_lock_irqsave(&gpc->lock, flags);
     while (!kvm_gfn_to_pfn_cache_check(v->kvm, gpc, gpc->gpa,
                        sizeof(struct vcpu_info))) {
         read_unlock_irqrestore(&gpc->lock, flags);
 
         /*
          * This function gets called from kvm_vcpu_block() after setting the
          * task to TASK_INTERRUPTIBLE, to see if it needs to wake immediately
          * from a HLT. So we really mustn't sleep. If the page ended up absent
          * at that point, just return 1 in order to trigger an immediate wake,
          * and we'll end up getting called again from a context where we *can*
          * fault in the page and wait for it.
          */
         if (in_atomic() || !task_is_running(current))
             return 1;
 
         if (kvm_gfn_to_pfn_cache_refresh(v->kvm, gpc, gpc->gpa,
                          sizeof(struct vcpu_info))) {
             /*
              * If this failed, userspace has screwed up the
              * vcpu_info mapping. No interrupts for you.
              */
             return 0;
         }
         read_lock_irqsave(&gpc->lock, flags);
     }
 
     rc = ((struct vcpu_info *)gpc->khva)->evtchn_upcall_pending;
     read_unlock_irqrestore(&gpc->lock, flags);
     return rc;
 }
 
 int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
 {
     int r = -ENOENT;
 
 
     switch (data->type) {
     case KVM_XEN_ATTR_TYPE_LONG_MODE:
         if (!IS_ENABLED(CONFIG_64BIT) && data->u.long_mode) {
             r = -EINVAL;
         } else {
             mutex_lock(&kvm->lock);
             kvm->arch.xen.long_mode = !!data->u.long_mode;
             mutex_unlock(&kvm->lock);
             r = 0;
         }
         break;
 
     case KVM_XEN_ATTR_TYPE_SHARED_INFO:
         mutex_lock(&kvm->lock);
         r = kvm_xen_shared_info_init(kvm, data->u.shared_info.gfn);
         mutex_unlock(&kvm->lock);
         break;
 
     case KVM_XEN_ATTR_TYPE_UPCALL_VECTOR:
         if (data->u.vector && data->u.vector < 0x10)
             r = -EINVAL;
         else {
             mutex_lock(&kvm->lock);
             kvm->arch.xen.upcall_vector = data->u.vector;
             mutex_unlock(&kvm->lock);
             r = 0;
         }
         break;
 
     case KVM_XEN_ATTR_TYPE_EVTCHN:
         r = kvm_xen_setattr_evtchn(kvm, data);
         break;
 
     case KVM_XEN_ATTR_TYPE_XEN_VERSION:
         mutex_lock(&kvm->lock);
         kvm->arch.xen.xen_version = data->u.xen_version;
         mutex_unlock(&kvm->lock);
         r = 0;
         break;
 
     default:
         break;
     }
 
     return r;
 }
 
 int kvm_xen_hvm_get_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
 {
     int r = -ENOENT;
 
     mutex_lock(&kvm->lock);
 
     switch (data->type) {
     case KVM_XEN_ATTR_TYPE_LONG_MODE:
         data->u.long_mode = kvm->arch.xen.long_mode;
         r = 0;
         break;
 
     case KVM_XEN_ATTR_TYPE_SHARED_INFO:
         if (kvm->arch.xen.shinfo_cache.active)
             data->u.shared_info.gfn = gpa_to_gfn(kvm->arch.xen.shinfo_cache.gpa);
         else
             data->u.shared_info.gfn = GPA_INVALID;
         r = 0;
         break;
 
     case KVM_XEN_ATTR_TYPE_UPCALL_VECTOR:
         data->u.vector = kvm->arch.xen.upcall_vector;
         r = 0;
         break;
 
     case KVM_XEN_ATTR_TYPE_XEN_VERSION:
         data->u.xen_version = kvm->arch.xen.xen_version;
         r = 0;
         break;
 
     default:
         break;
     }
 
     mutex_unlock(&kvm->lock);
     return r;
 }
 
 int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
 {
     int idx, r = -ENOENT;
 
     mutex_lock(&vcpu->kvm->lock);
     idx = srcu_read_lock(&vcpu->kvm->srcu);
 
     switch (data->type) {
     case KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO:
         /* No compat necessary here. */
         BUILD_BUG_ON(sizeof(struct vcpu_info) !=
                  sizeof(struct compat_vcpu_info));
         BUILD_BUG_ON(offsetof(struct vcpu_info, time) !=
                  offsetof(struct compat_vcpu_info, time));
 
         if (data->u.gpa == GPA_INVALID) {
             kvm_gfn_to_pfn_cache_destroy(vcpu->kvm, &vcpu->arch.xen.vcpu_info_cache);
             r = 0;
             break;
         }
 
         r = kvm_gfn_to_pfn_cache_init(vcpu->kvm,
                           &vcpu->arch.xen.vcpu_info_cache,
                           NULL, KVM_HOST_USES_PFN, data->u.gpa,
                           sizeof(struct vcpu_info));
         if (!r)
             kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
 
         break;
 
     case KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO:
         if (data->u.gpa == GPA_INVALID) {
             kvm_gfn_to_pfn_cache_destroy(vcpu->kvm,
                              &vcpu->arch.xen.vcpu_time_info_cache);
             r = 0;
             break;
         }
 
         r = kvm_gfn_to_pfn_cache_init(vcpu->kvm,
                           &vcpu->arch.xen.vcpu_time_info_cache,
                           NULL, KVM_HOST_USES_PFN, data->u.gpa,
                           sizeof(struct pvclock_vcpu_time_info));
         if (!r)
             kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
         break;
 
     case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR:
         if (!sched_info_on()) {
             r = -EOPNOTSUPP;
             break;
         }
         if (data->u.gpa == GPA_INVALID) {
             kvm_gfn_to_pfn_cache_destroy(vcpu->kvm,
                              &vcpu->arch.xen.runstate_cache);
             r = 0;
             break;
         }
 
         r = kvm_gfn_to_pfn_cache_init(vcpu->kvm,
                           &vcpu->arch.xen.runstate_cache,
                           NULL, KVM_HOST_USES_PFN, data->u.gpa,
                           sizeof(struct vcpu_runstate_info));
         break;
 
     case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_CURRENT:
         if (!sched_info_on()) {
             r = -EOPNOTSUPP;
             break;
         }
         if (data->u.runstate.state > RUNSTATE_offline) {
             r = -EINVAL;
             break;
         }
 
         kvm_xen_update_runstate(vcpu, data->u.runstate.state);
         r = 0;
         break;
 
     case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_DATA:
         if (!sched_info_on()) {
             r = -EOPNOTSUPP;
             break;
         }
         if (data->u.runstate.state > RUNSTATE_offline) {
             r = -EINVAL;
             break;
         }
         if (data->u.runstate.state_entry_time !=
             (data->u.runstate.time_running +
              data->u.runstate.time_runnable +
              data->u.runstate.time_blocked +
              data->u.runstate.time_offline)) {
             r = -EINVAL;
             break;
         }
         if (get_kvmclock_ns(vcpu->kvm) <
             data->u.runstate.state_entry_time) {
             r = -EINVAL;
             break;
         }
 
         vcpu->arch.xen.current_runstate = data->u.runstate.state;
         vcpu->arch.xen.runstate_entry_time =
             data->u.runstate.state_entry_time;
         vcpu->arch.xen.runstate_times[RUNSTATE_running] =
             data->u.runstate.time_running;
         vcpu->arch.xen.runstate_times[RUNSTATE_runnable] =
             data->u.runstate.time_runnable;
         vcpu->arch.xen.runstate_times[RUNSTATE_blocked] =
             data->u.runstate.time_blocked;
         vcpu->arch.xen.runstate_times[RUNSTATE_offline] =
             data->u.runstate.time_offline;
         vcpu->arch.xen.last_steal = current->sched_info.run_delay;
         r = 0;
         break;
 
     case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST:
         if (!sched_info_on()) {
             r = -EOPNOTSUPP;
             break;
         }
         if (data->u.runstate.state > RUNSTATE_offline &&
             data->u.runstate.state != (u64)-1) {
             r = -EINVAL;
             break;
         }
         /* The adjustment must add up */
         if (data->u.runstate.state_entry_time !=
             (data->u.runstate.time_running +
              data->u.runstate.time_runnable +
              data->u.runstate.time_blocked +
              data->u.runstate.time_offline)) {
             r = -EINVAL;
             break;
         }
 
         if (get_kvmclock_ns(vcpu->kvm) <
             (vcpu->arch.xen.runstate_entry_time +
              data->u.runstate.state_entry_time)) {
             r = -EINVAL;
             break;
         }
 
         vcpu->arch.xen.runstate_entry_time +=
             data->u.runstate.state_entry_time;
         vcpu->arch.xen.runstate_times[RUNSTATE_running] +=
             data->u.runstate.time_running;
         vcpu->arch.xen.runstate_times[RUNSTATE_runnable] +=
             data->u.runstate.time_runnable;
         vcpu->arch.xen.runstate_times[RUNSTATE_blocked] +=
             data->u.runstate.time_blocked;
         vcpu->arch.xen.runstate_times[RUNSTATE_offline] +=
             data->u.runstate.time_offline;
 
         if (data->u.runstate.state <= RUNSTATE_offline)
             kvm_xen_update_runstate(vcpu, data->u.runstate.state);
         r = 0;
         break;
 
     case KVM_XEN_VCPU_ATTR_TYPE_VCPU_ID:
         if (data->u.vcpu_id >= KVM_MAX_VCPUS)
             r = -EINVAL;
         else {
             vcpu->arch.xen.vcpu_id = data->u.vcpu_id;
             r = 0;
         }
         break;
 
     case KVM_XEN_VCPU_ATTR_TYPE_TIMER:
         if (data->u.timer.port &&
             data->u.timer.priority != KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL) {
             r = -EINVAL;
             break;
         }
 
         if (!vcpu->arch.xen.timer.function)
             kvm_xen_init_timer(vcpu);
 
         /* Stop the timer (if it's running) before changing the vector */
         kvm_xen_stop_timer(vcpu);
         vcpu->arch.xen.timer_virq = data->u.timer.port;
 
         /* Start the timer if the new value has a valid vector+expiry. */
         if (data->u.timer.port && data->u.timer.expires_ns)
             kvm_xen_start_timer(vcpu, data->u.timer.expires_ns,
                         data->u.timer.expires_ns -
                         get_kvmclock_ns(vcpu->kvm));
 
         r = 0;
         break;
 
     case KVM_XEN_VCPU_ATTR_TYPE_UPCALL_VECTOR:
         if (data->u.vector && data->u.vector < 0x10)
             r = -EINVAL;
         else {
             vcpu->arch.xen.upcall_vector = data->u.vector;
             r = 0;
         }
         break;
 
     default:
         break;
     }
 
     srcu_read_unlock(&vcpu->kvm->srcu, idx);
     mutex_unlock(&vcpu->kvm->lock);
     return r;
 }
 
 int kvm_xen_vcpu_get_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
 {
     int r = -ENOENT;
 
     mutex_lock(&vcpu->kvm->lock);
 
     switch (data->type) {
     case KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO:
         if (vcpu->arch.xen.vcpu_info_cache.active)
             data->u.gpa = vcpu->arch.xen.vcpu_info_cache.gpa;
         else
             data->u.gpa = GPA_INVALID;
         r = 0;
         break;
 
     case KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO:
         if (vcpu->arch.xen.vcpu_time_info_cache.active)
             data->u.gpa = vcpu->arch.xen.vcpu_time_info_cache.gpa;
         else
             data->u.gpa = GPA_INVALID;
         r = 0;
         break;
 
     case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR:
         if (!sched_info_on()) {
             r = -EOPNOTSUPP;
             break;
         }
         if (vcpu->arch.xen.runstate_cache.active) {
             data->u.gpa = vcpu->arch.xen.runstate_cache.gpa;
             r = 0;
         }
         break;
 
     case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_CURRENT:
         if (!sched_info_on()) {
             r = -EOPNOTSUPP;
             break;
         }
         data->u.runstate.state = vcpu->arch.xen.current_runstate;
         r = 0;
         break;
 
     case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_DATA:
         if (!sched_info_on()) {
             r = -EOPNOTSUPP;
             break;
         }
         data->u.runstate.state = vcpu->arch.xen.current_runstate;
         data->u.runstate.state_entry_time =
             vcpu->arch.xen.runstate_entry_time;
         data->u.runstate.time_running =
             vcpu->arch.xen.runstate_times[RUNSTATE_running];
         data->u.runstate.time_runnable =
             vcpu->arch.xen.runstate_times[RUNSTATE_runnable];
         data->u.runstate.time_blocked =
             vcpu->arch.xen.runstate_times[RUNSTATE_blocked];
         data->u.runstate.time_offline =
             vcpu->arch.xen.runstate_times[RUNSTATE_offline];
         r = 0;
         break;
 
     case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST:
         r = -EINVAL;
         break;
 
     case KVM_XEN_VCPU_ATTR_TYPE_VCPU_ID:
         data->u.vcpu_id = vcpu->arch.xen.vcpu_id;
         r = 0;
         break;
 
     case KVM_XEN_VCPU_ATTR_TYPE_TIMER:
         data->u.timer.port = vcpu->arch.xen.timer_virq;
         data->u.timer.priority = KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL;
         data->u.timer.expires_ns = vcpu->arch.xen.timer_expires;
         r = 0;
         break;
 
     case KVM_XEN_VCPU_ATTR_TYPE_UPCALL_VECTOR:
         data->u.vector = vcpu->arch.xen.upcall_vector;
         r = 0;
         break;
 
     default:
         break;
     }
 
     mutex_unlock(&vcpu->kvm->lock);
     return r;
 }
 
 int kvm_xen_write_hypercall_page(struct kvm_vcpu *vcpu, u64 data)
 {
     struct kvm *kvm = vcpu->kvm;
     u32 page_num = data & ~PAGE_MASK;
     u64 page_addr = data & PAGE_MASK;
     bool lm = is_long_mode(vcpu);
 
     /* Latch long_mode for shared_info pages etc. */
     vcpu->kvm->arch.xen.long_mode = lm;
 
     /*
      * If Xen hypercall intercept is enabled, fill the hypercall
      * page with VMCALL/VMMCALL instructions since that's what
      * we catch. Else the VMM has provided the hypercall pages
      * with instructions of its own choosing, so use those.
      */
     if (kvm_xen_hypercall_enabled(kvm)) {
         u8 instructions[32];
         int i;
 
         if (page_num)
             return 1;
 
         /* mov imm32, %eax */
         instructions[0] = 0xb8;
 
         /* vmcall / vmmcall */
         static_call(kvm_x86_patch_hypercall)(vcpu, instructions + 5);
 
         /* ret */
         instructions[8] = 0xc3;
 
         /* int3 to pad */
         memset(instructions + 9, 0xcc, sizeof(instructions) - 9);
 
         for (i = 0; i < PAGE_SIZE / sizeof(instructions); i++) {
             *(u32 *)&instructions[1] = i;
             if (kvm_vcpu_write_guest(vcpu,
                          page_addr + (i * sizeof(instructions)),
                          instructions, sizeof(instructions)))
                 return 1;
         }
     } else {
         /*
          * Note, truncation is a non-issue as 'lm' is guaranteed to be
          * false for a 32-bit kernel, i.e. when hva_t is only 4 bytes.
          */
         hva_t blob_addr = lm ? kvm->arch.xen_hvm_config.blob_addr_64
                      : kvm->arch.xen_hvm_config.blob_addr_32;
         u8 blob_size = lm ? kvm->arch.xen_hvm_config.blob_size_64
                   : kvm->arch.xen_hvm_config.blob_size_32;
         u8 *page;
 
         if (page_num >= blob_size)
             return 1;
 
         blob_addr += page_num * PAGE_SIZE;
 
         page = memdup_user((u8 __user *)blob_addr, PAGE_SIZE);
         if (IS_ERR(page))
             return PTR_ERR(page);
 
         if (kvm_vcpu_write_guest(vcpu, page_addr, page, PAGE_SIZE)) {
             kfree(page);
             return 1;
         }
     }
     return 0;
 }
 
 int kvm_xen_hvm_config(struct kvm *kvm, struct kvm_xen_hvm_config *xhc)
 {
     /* Only some feature flags need to be *enabled* by userspace */
     u32 permitted_flags = KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL |
         KVM_XEN_HVM_CONFIG_EVTCHN_SEND;
 
     if (xhc->flags & ~permitted_flags)
         return -EINVAL;
 
     /*
      * With hypercall interception the kernel generates its own
      * hypercall page so it must not be provided.
      */
     if ((xhc->flags & KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL) &&
         (xhc->blob_addr_32 || xhc->blob_addr_64 ||
          xhc->blob_size_32 || xhc->blob_size_64))
         return -EINVAL;
 
     mutex_lock(&kvm->lock);
 
     if (xhc->msr && !kvm->arch.xen_hvm_config.msr)
         static_branch_inc(&kvm_xen_enabled.key);
     else if (!xhc->msr && kvm->arch.xen_hvm_config.msr)
         static_branch_slow_dec_deferred(&kvm_xen_enabled);
 
     memcpy(&kvm->arch.xen_hvm_config, xhc, sizeof(*xhc));
 
     mutex_unlock(&kvm->lock);
     return 0;
 }
 
 static int kvm_xen_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result)
 {
     kvm_rax_write(vcpu, result);
     return kvm_skip_emulated_instruction(vcpu);
 }
 
 static int kvm_xen_hypercall_complete_userspace(struct kvm_vcpu *vcpu)
 {
     struct kvm_run *run = vcpu->run;
 
     if (unlikely(!kvm_is_linear_rip(vcpu, vcpu->arch.xen.hypercall_rip)))
         return 1;
 
     return kvm_xen_hypercall_set_result(vcpu, run->xen.u.hcall.result);
 }
 
 static bool wait_pending_event(struct kvm_vcpu *vcpu, int nr_ports,
                    evtchn_port_t *ports)
 {
     struct kvm *kvm = vcpu->kvm;
     struct gfn_to_pfn_cache *gpc = &kvm->arch.xen.shinfo_cache;
     unsigned long *pending_bits;
     unsigned long flags;
     bool ret = true;
     int idx, i;
 
     read_lock_irqsave(&gpc->lock, flags);
     idx = srcu_read_lock(&kvm->srcu);
     if (!kvm_gfn_to_pfn_cache_check(kvm, gpc, gpc->gpa, PAGE_SIZE))
         goto out_rcu;
 
     ret = false;
     if (IS_ENABLED(CONFIG_64BIT) && kvm->arch.xen.long_mode) {
         struct shared_info *shinfo = gpc->khva;
         pending_bits = (unsigned long *)&shinfo->evtchn_pending;
     } else {
         struct compat_shared_info *shinfo = gpc->khva;
         pending_bits = (unsigned long *)&shinfo->evtchn_pending;
     }
 
     for (i = 0; i < nr_ports; i++) {
         if (test_bit(ports[i], pending_bits)) {
             ret = true;
             break;
         }
     }
 
  out_rcu:
     srcu_read_unlock(&kvm->srcu, idx);
     read_unlock_irqrestore(&gpc->lock, flags);
 
     return ret;
 }
 
 static bool kvm_xen_schedop_poll(struct kvm_vcpu *vcpu, bool longmode,
                  u64 param, u64 *r)
 {
     int idx, i;
     struct sched_poll sched_poll;
     evtchn_port_t port, *ports;
     gpa_t gpa;
 
     if (!longmode || !lapic_in_kernel(vcpu) ||
         !(vcpu->kvm->arch.xen_hvm_config.flags & KVM_XEN_HVM_CONFIG_EVTCHN_SEND))
         return false;
 
     idx = srcu_read_lock(&vcpu->kvm->srcu);
     gpa = kvm_mmu_gva_to_gpa_system(vcpu, param, NULL);
     srcu_read_unlock(&vcpu->kvm->srcu, idx);
 
     if (!gpa || kvm_vcpu_read_guest(vcpu, gpa, &sched_poll,
                     sizeof(sched_poll))) {
         *r = -EFAULT;
         return true;
     }
 
     if (unlikely(sched_poll.nr_ports > 1)) {
         /* Xen (unofficially) limits number of pollers to 128 */
         if (sched_poll.nr_ports > 128) {
             *r = -EINVAL;
             return true;
         }
 
         ports = kmalloc_array(sched_poll.nr_ports,
                       sizeof(*ports), GFP_KERNEL);
         if (!ports) {
             *r = -ENOMEM;
             return true;
         }
     } else
         ports = &port;
 
     for (i = 0; i < sched_poll.nr_ports; i++) {
         idx = srcu_read_lock(&vcpu->kvm->srcu);
         gpa = kvm_mmu_gva_to_gpa_system(vcpu,
                         (gva_t)(sched_poll.ports + i),
                         NULL);
         srcu_read_unlock(&vcpu->kvm->srcu, idx);
 
         if (!gpa || kvm_vcpu_read_guest(vcpu, gpa,
                         &ports[i], sizeof(port))) {
             *r = -EFAULT;
             goto out;
         }
     }
 
     if (sched_poll.nr_ports == 1)
         vcpu->arch.xen.poll_evtchn = port;
     else
         vcpu->arch.xen.poll_evtchn = -1;
 
     set_bit(vcpu->vcpu_idx, vcpu->kvm->arch.xen.poll_mask);
 
     if (!wait_pending_event(vcpu, sched_poll.nr_ports, ports)) {
         vcpu->arch.mp_state = KVM_MP_STATE_HALTED;
 
         if (sched_poll.timeout)
             mod_timer(&vcpu->arch.xen.poll_timer,
                   jiffies + nsecs_to_jiffies(sched_poll.timeout));
 
         kvm_vcpu_halt(vcpu);
 
         if (sched_poll.timeout)
             del_timer(&vcpu->arch.xen.poll_timer);
 
         vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
         kvm_clear_request(KVM_REQ_UNHALT, vcpu);
     }
 
     vcpu->arch.xen.poll_evtchn = 0;
     *r = 0;
 out:
     /* Really, this is only needed in case of timeout */
     clear_bit(vcpu->vcpu_idx, vcpu->kvm->arch.xen.poll_mask);
 
     if (unlikely(sched_poll.nr_ports > 1))
         kfree(ports);
     return true;
 }
 
 static void cancel_evtchn_poll(struct timer_list *t)
 {
     struct kvm_vcpu *vcpu = from_timer(vcpu, t, arch.xen.poll_timer);
 
     kvm_make_request(KVM_REQ_UNBLOCK, vcpu);
     kvm_vcpu_kick(vcpu);
 }
 
 static bool kvm_xen_hcall_sched_op(struct kvm_vcpu *vcpu, bool longmode,
                    int cmd, u64 param, u64 *r)
 {
     switch (cmd) {
     case SCHEDOP_poll:
         if (kvm_xen_schedop_poll(vcpu, longmode, param, r))
             return true;
         fallthrough;
     case SCHEDOP_yield:
         kvm_vcpu_on_spin(vcpu, true);
         *r = 0;
         return true;
     default:
         break;
     }
 
     return false;
 }
 
 struct compat_vcpu_set_singleshot_timer {
     uint64_t timeout_abs_ns;
     uint32_t flags;
 } __attribute__((packed));
 
 static bool kvm_xen_hcall_vcpu_op(struct kvm_vcpu *vcpu, bool longmode, int cmd,
                   int vcpu_id, u64 param, u64 *r)
 {
     struct vcpu_set_singleshot_timer oneshot;
     s64 delta;
     gpa_t gpa;
     int idx;
 
     if (!kvm_xen_timer_enabled(vcpu))
         return false;
 
     switch (cmd) {
     case VCPUOP_set_singleshot_timer:
         if (vcpu->arch.xen.vcpu_id != vcpu_id) {
             *r = -EINVAL;
             return true;
         }
         idx = srcu_read_lock(&vcpu->kvm->srcu);
         gpa = kvm_mmu_gva_to_gpa_system(vcpu, param, NULL);
         srcu_read_unlock(&vcpu->kvm->srcu, idx);
 
         /*
          * The only difference for 32-bit compat is the 4 bytes of
          * padding after the interesting part of the structure. So
          * for a faithful emulation of Xen we have to *try* to copy
          * the padding and return -EFAULT if we can't. Otherwise we
          * might as well just have copied the 12-byte 32-bit struct.
          */
         BUILD_BUG_ON(offsetof(struct compat_vcpu_set_singleshot_timer, timeout_abs_ns) !=
                  offsetof(struct vcpu_set_singleshot_timer, timeout_abs_ns));
         BUILD_BUG_ON(sizeof_field(struct compat_vcpu_set_singleshot_timer, timeout_abs_ns) !=
                  sizeof_field(struct vcpu_set_singleshot_timer, timeout_abs_ns));
         BUILD_BUG_ON(offsetof(struct compat_vcpu_set_singleshot_timer, flags) !=
                  offsetof(struct vcpu_set_singleshot_timer, flags));
         BUILD_BUG_ON(sizeof_field(struct compat_vcpu_set_singleshot_timer, flags) !=
                  sizeof_field(struct vcpu_set_singleshot_timer, flags));
 
         if (!gpa ||
             kvm_vcpu_read_guest(vcpu, gpa, &oneshot, longmode ? sizeof(oneshot) :
                     sizeof(struct compat_vcpu_set_singleshot_timer))) {
             *r = -EFAULT;
             return true;
         }
 
         delta = oneshot.timeout_abs_ns - get_kvmclock_ns(vcpu->kvm);
         if ((oneshot.flags & VCPU_SSHOTTMR_future) && delta < 0) {
             *r = -ETIME;
             return true;
         }
 
         kvm_xen_start_timer(vcpu, oneshot.timeout_abs_ns, delta);
         *r = 0;
         return true;
 
     case VCPUOP_stop_singleshot_timer:
         if (vcpu->arch.xen.vcpu_id != vcpu_id) {
             *r = -EINVAL;
             return true;
         }
         kvm_xen_stop_timer(vcpu);
         *r = 0;
         return true;
     }
 
     return false;
 }
 
 static bool kvm_xen_hcall_set_timer_op(struct kvm_vcpu *vcpu, uint64_t timeout,
                        u64 *r)
 {
     if (!kvm_xen_timer_enabled(vcpu))
         return false;
 
     if (timeout) {
         uint64_t guest_now = get_kvmclock_ns(vcpu->kvm);
         int64_t delta = timeout - guest_now;
 
         /* Xen has a 'Linux workaround' in do_set_timer_op() which
          * checks for negative absolute timeout values (caused by
          * integer overflow), and for values about 13 days in the
          * future (2^50ns) which would be caused by jiffies
          * overflow. For those cases, it sets the timeout 100ms in
          * the future (not *too* soon, since if a guest really did
          * set a long timeout on purpose we don't want to keep
          * churning CPU time by waking it up).
          */
         if (unlikely((int64_t)timeout < 0 ||
                  (delta > 0 && (uint32_t) (delta >> 50) != 0))) {
             delta = 100 * NSEC_PER_MSEC;
             timeout = guest_now + delta;
         }
 
         kvm_xen_start_timer(vcpu, timeout, delta);
     } else {
         kvm_xen_stop_timer(vcpu);
     }
 
     *r = 0;
     return true;
 }
 
 int kvm_xen_hypercall(struct kvm_vcpu *vcpu)
 {
     bool longmode;
     u64 input, params[6], r = -ENOSYS;
     bool handled = false;
 
     input = (u64)kvm_register_read(vcpu, VCPU_REGS_RAX);
 
     /* Hyper-V hypercalls get bit 31 set in EAX */
     if ((input & 0x80000000) &&
         kvm_hv_hypercall_enabled(vcpu))
         return kvm_hv_hypercall(vcpu);
 
     longmode = is_64_bit_hypercall(vcpu);
     if (!longmode) {
         params[0] = (u32)kvm_rbx_read(vcpu);
         params[1] = (u32)kvm_rcx_read(vcpu);
         params[2] = (u32)kvm_rdx_read(vcpu);
         params[3] = (u32)kvm_rsi_read(vcpu);
         params[4] = (u32)kvm_rdi_read(vcpu);
         params[5] = (u32)kvm_rbp_read(vcpu);
     }
 #ifdef CONFIG_X86_64
     else {
         params[0] = (u64)kvm_rdi_read(vcpu);
         params[1] = (u64)kvm_rsi_read(vcpu);
         params[2] = (u64)kvm_rdx_read(vcpu);
         params[3] = (u64)kvm_r10_read(vcpu);
         params[4] = (u64)kvm_r8_read(vcpu);
         params[5] = (u64)kvm_r9_read(vcpu);
     }
 #endif
     trace_kvm_xen_hypercall(input, params[0], params[1], params[2],
                 params[3], params[4], params[5]);
 
     switch (input) {
     case __HYPERVISOR_xen_version:
         if (params[0] == XENVER_version && vcpu->kvm->arch.xen.xen_version) {
             r = vcpu->kvm->arch.xen.xen_version;
             handled = true;
         }
         break;
     case __HYPERVISOR_event_channel_op:
         if (params[0] == EVTCHNOP_send)
             handled = kvm_xen_hcall_evtchn_send(vcpu, params[1], &r);
         break;
     case __HYPERVISOR_sched_op:
         handled = kvm_xen_hcall_sched_op(vcpu, longmode, params[0],
                          params[1], &r);
         break;
     case __HYPERVISOR_vcpu_op:
         handled = kvm_xen_hcall_vcpu_op(vcpu, longmode, params[0], params[1],
                         params[2], &r);
         break;
     case __HYPERVISOR_set_timer_op: {
         u64 timeout = params[0];
         /* In 32-bit mode, the 64-bit timeout is in two 32-bit params. */
         if (!longmode)
             timeout |= params[1] << 32;
         handled = kvm_xen_hcall_set_timer_op(vcpu, timeout, &r);
         break;
     }
     default:
         break;
     }
 
     if (handled)
         return kvm_xen_hypercall_set_result(vcpu, r);
 
     vcpu->run->exit_reason = KVM_EXIT_XEN;
     vcpu->run->xen.type = KVM_EXIT_XEN_HCALL;
     vcpu->run->xen.u.hcall.longmode = longmode;
     vcpu->run->xen.u.hcall.cpl = static_call(kvm_x86_get_cpl)(vcpu);
     vcpu->run->xen.u.hcall.input = input;
     vcpu->run->xen.u.hcall.params[0] = params[0];
     vcpu->run->xen.u.hcall.params[1] = params[1];
     vcpu->run->xen.u.hcall.params[2] = params[2];
     vcpu->run->xen.u.hcall.params[3] = params[3];
     vcpu->run->xen.u.hcall.params[4] = params[4];
     vcpu->run->xen.u.hcall.params[5] = params[5];
     vcpu->arch.xen.hypercall_rip = kvm_get_linear_rip(vcpu);
     vcpu->arch.complete_userspace_io =
         kvm_xen_hypercall_complete_userspace;
 
     return 0;
 }
 
 static inline int max_evtchn_port(struct kvm *kvm)
 {
     if (IS_ENABLED(CONFIG_64BIT) && kvm->arch.xen.long_mode)
         return EVTCHN_2L_NR_CHANNELS;
     else
         return COMPAT_EVTCHN_2L_NR_CHANNELS;
 }
 
 static void kvm_xen_check_poller(struct kvm_vcpu *vcpu, int port)
 {
     int poll_evtchn = vcpu->arch.xen.poll_evtchn;
 
     if ((poll_evtchn == port || poll_evtchn == -1) &&
         test_and_clear_bit(vcpu->vcpu_idx, vcpu->kvm->arch.xen.poll_mask)) {
         kvm_make_request(KVM_REQ_UNBLOCK, vcpu);
         kvm_vcpu_kick(vcpu);
     }
 }
 
 /*
  * The return value from this function is propagated to kvm_set_irq() API,
  * so it returns:
  *  < 0   Interrupt was ignored (masked or not delivered for other reasons)
  *  = 0   Interrupt was coalesced (previous irq is still pending)
  *  > 0   Number of CPUs interrupt was delivered to
  *
  * It is also called directly from kvm_arch_set_irq_inatomic(), where the
  * only check on its return value is a comparison with -EWOULDBLOCK'.
  */
 int kvm_xen_set_evtchn_fast(struct kvm_xen_evtchn *xe, struct kvm *kvm)
 {
     struct gfn_to_pfn_cache *gpc = &kvm->arch.xen.shinfo_cache;
     struct kvm_vcpu *vcpu;
     unsigned long *pending_bits, *mask_bits;
     unsigned long flags;
     int port_word_bit;
     bool kick_vcpu = false;
     int vcpu_idx, idx, rc;
 
     vcpu_idx = READ_ONCE(xe->vcpu_idx);
     if (vcpu_idx >= 0)
         vcpu = kvm_get_vcpu(kvm, vcpu_idx);
     else {
         vcpu = kvm_get_vcpu_by_id(kvm, xe->vcpu_id);
         if (!vcpu)
             return -EINVAL;
         WRITE_ONCE(xe->vcpu_idx, vcpu->vcpu_idx);
     }
 
     if (!vcpu->arch.xen.vcpu_info_cache.active)
         return -EINVAL;
 
     if (xe->port >= max_evtchn_port(kvm))
         return -EINVAL;
 
     rc = -EWOULDBLOCK;
 
     idx = srcu_read_lock(&kvm->srcu);
 
     read_lock_irqsave(&gpc->lock, flags);
     if (!kvm_gfn_to_pfn_cache_check(kvm, gpc, gpc->gpa, PAGE_SIZE))
         goto out_rcu;
 
     if (IS_ENABLED(CONFIG_64BIT) && kvm->arch.xen.long_mode) {
         struct shared_info *shinfo = gpc->khva;
         pending_bits = (unsigned long *)&shinfo->evtchn_pending;
         mask_bits = (unsigned long *)&shinfo->evtchn_mask;
         port_word_bit = xe->port / 64;
     } else {
         struct compat_shared_info *shinfo = gpc->khva;
         pending_bits = (unsigned long *)&shinfo->evtchn_pending;
         mask_bits = (unsigned long *)&shinfo->evtchn_mask;
         port_word_bit = xe->port / 32;
     }
 
     /*
      * If this port wasn't already set, and if it isn't masked, then
      * we try to set the corresponding bit in the in-kernel shadow of
      * evtchn_pending_sel for the target vCPU. And if *that* wasn't
      * already set, then we kick the vCPU in question to write to the
      * *real* evtchn_pending_sel in its own guest vcpu_info struct.
      */
     if (test_and_set_bit(xe->port, pending_bits)) {
         rc = 0; /* It was already raised */
     } else if (test_bit(xe->port, mask_bits)) {
         rc = -ENOTCONN; /* Masked */
         kvm_xen_check_poller(vcpu, xe->port);
     } else {
         rc = 1; /* Delivered to the bitmap in shared_info. */
         /* Now switch to the vCPU's vcpu_info to set the index and pending_sel */
         read_unlock_irqrestore(&gpc->lock, flags);
         gpc = &vcpu->arch.xen.vcpu_info_cache;
 
         read_lock_irqsave(&gpc->lock, flags);
         if (!kvm_gfn_to_pfn_cache_check(kvm, gpc, gpc->gpa, sizeof(struct vcpu_info))) {
             /*
              * Could not access the vcpu_info. Set the bit in-kernel
              * and prod the vCPU to deliver it for itself.
              */
             if (!test_and_set_bit(port_word_bit, &vcpu->arch.xen.evtchn_pending_sel))
                 kick_vcpu = true;
             goto out_rcu;
         }
 
         if (IS_ENABLED(CONFIG_64BIT) && kvm->arch.xen.long_mode) {
             struct vcpu_info *vcpu_info = gpc->khva;
             if (!test_and_set_bit(port_word_bit, &vcpu_info->evtchn_pending_sel)) {
                 WRITE_ONCE(vcpu_info->evtchn_upcall_pending, 1);
                 kick_vcpu = true;
             }
         } else {
             struct compat_vcpu_info *vcpu_info = gpc->khva;
             if (!test_and_set_bit(port_word_bit,
                           (unsigned long *)&vcpu_info->evtchn_pending_sel)) {
                 WRITE_ONCE(vcpu_info->evtchn_upcall_pending, 1);
                 kick_vcpu = true;
             }
         }
 
         /* For the per-vCPU lapic vector, deliver it as MSI. */
         if (kick_vcpu && vcpu->arch.xen.upcall_vector) {
             kvm_xen_inject_vcpu_vector(vcpu);
             kick_vcpu = false;
         }
     }
 
  out_rcu:
     read_unlock_irqrestore(&gpc->lock, flags);
     srcu_read_unlock(&kvm->srcu, idx);
 
     if (kick_vcpu) {
         kvm_make_request(KVM_REQ_UNBLOCK, vcpu);
         kvm_vcpu_kick(vcpu);
     }
 
     return rc;
 }
 
 static int kvm_xen_set_evtchn(struct kvm_xen_evtchn *xe, struct kvm *kvm)
 {
     bool mm_borrowed = false;
     int rc;
 
     rc = kvm_xen_set_evtchn_fast(xe, kvm);
     if (rc != -EWOULDBLOCK)
         return rc;
 
     if (current->mm != kvm->mm) {
         /*
          * If not on a thread which already belongs to this KVM,
          * we'd better be in the irqfd workqueue.
          */
         if (WARN_ON_ONCE(current->mm))
             return -EINVAL;
 
         kthread_use_mm(kvm->mm);
         mm_borrowed = true;
     }
 
     /*
      * For the irqfd workqueue, using the main kvm->lock mutex is
      * fine since this function is invoked from kvm_set_irq() with
      * no other lock held, no srcu. In future if it will be called
      * directly from a vCPU thread (e.g. on hypercall for an IPI)
      * then it may need to switch to using a leaf-node mutex for
      * serializing the shared_info mapping.
      */
     mutex_lock(&kvm->lock);
 
     /*
      * It is theoretically possible for the page to be unmapped
      * and the MMU notifier to invalidate the shared_info before
      * we even get to use it. In that case, this looks like an
      * infinite loop. It was tempting to do it via the userspace
      * HVA instead... but that just *hides* the fact that it's
      * an infinite loop, because if a fault occurs and it waits
      * for the page to come back, it can *still* immediately
      * fault and have to wait again, repeatedly.
      *
      * Conversely, the page could also have been reinstated by
      * another thread before we even obtain the mutex above, so
      * check again *first* before remapping it.
      */
     do {
         struct gfn_to_pfn_cache *gpc = &kvm->arch.xen.shinfo_cache;
         int idx;
 
         rc = kvm_xen_set_evtchn_fast(xe, kvm);
         if (rc != -EWOULDBLOCK)
             break;
 
         idx = srcu_read_lock(&kvm->srcu);
         rc = kvm_gfn_to_pfn_cache_refresh(kvm, gpc, gpc->gpa, PAGE_SIZE);
         srcu_read_unlock(&kvm->srcu, idx);
     } while(!rc);
 
     mutex_unlock(&kvm->lock);
 
     if (mm_borrowed)
         kthread_unuse_mm(kvm->mm);
 
     return rc;
 }
 
 /* This is the version called from kvm_set_irq() as the .set function */
 static int evtchn_set_fn(struct kvm_kernel_irq_routing_entry *e, struct kvm *kvm,
              int irq_source_id, int level, bool line_status)
 {
     if (!level)
         return -EINVAL;
 
     return kvm_xen_set_evtchn(&e->xen_evtchn, kvm);
 }
 
 /*
  * Set up an event channel interrupt from the KVM IRQ routing table.
  * Used for e.g. PIRQ from passed through physical devices.
  */
 int kvm_xen_setup_evtchn(struct kvm *kvm,
              struct kvm_kernel_irq_routing_entry *e,
              const struct kvm_irq_routing_entry *ue)
 
 {
     struct kvm_vcpu *vcpu;
 
     if (ue->u.xen_evtchn.port >= max_evtchn_port(kvm))
         return -EINVAL;
 
     /* We only support 2 level event channels for now */
     if (ue->u.xen_evtchn.priority != KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL)
         return -EINVAL;
 
     /*
      * Xen gives us interesting mappings from vCPU index to APIC ID,
      * which means kvm_get_vcpu_by_id() has to iterate over all vCPUs
      * to find it. Do that once at setup time, instead of every time.
      * But beware that on live update / live migration, the routing
      * table might be reinstated before the vCPU threads have finished
      * recreating their vCPUs.
      */
     vcpu = kvm_get_vcpu_by_id(kvm, ue->u.xen_evtchn.vcpu);
     if (vcpu)
         e->xen_evtchn.vcpu_idx = vcpu->vcpu_idx;
     else
         e->xen_evtchn.vcpu_idx = -1;
 
     e->xen_evtchn.port = ue->u.xen_evtchn.port;
     e->xen_evtchn.vcpu_id = ue->u.xen_evtchn.vcpu;
     e->xen_evtchn.priority = ue->u.xen_evtchn.priority;
     e->set = evtchn_set_fn;
 
     return 0;
 }
 
 /*
  * Explicit event sending from userspace with KVM_XEN_HVM_EVTCHN_SEND ioctl.
  */
 int kvm_xen_hvm_evtchn_send(struct kvm *kvm, struct kvm_irq_routing_xen_evtchn *uxe)
 {
     struct kvm_xen_evtchn e;
     int ret;
 
     if (!uxe->port || uxe->port >= max_evtchn_port(kvm))
         return -EINVAL;
 
     /* We only support 2 level event channels for now */
     if (uxe->priority != KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL)
         return -EINVAL;
 
     e.port = uxe->port;
     e.vcpu_id = uxe->vcpu;
     e.vcpu_idx = -1;
     e.priority = uxe->priority;
 
     ret = kvm_xen_set_evtchn(&e, kvm);
 
     /*
      * None of that 'return 1 if it actually got delivered' nonsense.
      * We don't care if it was masked (-ENOTCONN) either.
      */
     if (ret > 0 || ret == -ENOTCONN)
         ret = 0;
 
     return ret;
 }
 
 /*
  * Support for *outbound* event channel events via the EVTCHNOP_send hypercall.
  */
 struct evtchnfd {
     u32 send_port;
     u32 type;
     union {
         struct kvm_xen_evtchn port;
         struct {
             u32 port; /* zero */
             struct eventfd_ctx *ctx;
         } eventfd;
     } deliver;
 };
 
 /*
  * Update target vCPU or priority for a registered sending channel.
  */
 static int kvm_xen_eventfd_update(struct kvm *kvm,
                   struct kvm_xen_hvm_attr *data)
 {
     u32 port = data->u.evtchn.send_port;
     struct evtchnfd *evtchnfd;
 
     if (!port || port >= max_evtchn_port(kvm))
         return -EINVAL;
 
     mutex_lock(&kvm->lock);
     evtchnfd = idr_find(&kvm->arch.xen.evtchn_ports, port);
     mutex_unlock(&kvm->lock);
 
     if (!evtchnfd)
         return -ENOENT;
 
     /* For an UPDATE, nothing may change except the priority/vcpu */
     if (evtchnfd->type != data->u.evtchn.type)
         return -EINVAL;
 
     /*
      * Port cannot change, and if it's zero that was an eventfd
      * which can't be changed either.
      */
     if (!evtchnfd->deliver.port.port ||
         evtchnfd->deliver.port.port != data->u.evtchn.deliver.port.port)
         return -EINVAL;
 
     /* We only support 2 level event channels for now */
     if (data->u.evtchn.deliver.port.priority != KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL)
         return -EINVAL;
 
     mutex_lock(&kvm->lock);
     evtchnfd->deliver.port.priority = data->u.evtchn.deliver.port.priority;
     if (evtchnfd->deliver.port.vcpu_id != data->u.evtchn.deliver.port.vcpu) {
         evtchnfd->deliver.port.vcpu_id = data->u.evtchn.deliver.port.vcpu;
         evtchnfd->deliver.port.vcpu_idx = -1;
     }
     mutex_unlock(&kvm->lock);
     return 0;
 }
 
 /*
  * Configure the target (eventfd or local port delivery) for sending on
  * a given event channel.
  */
 static int kvm_xen_eventfd_assign(struct kvm *kvm,
                   struct kvm_xen_hvm_attr *data)
 {
     u32 port = data->u.evtchn.send_port;
     struct eventfd_ctx *eventfd = NULL;
     struct evtchnfd *evtchnfd = NULL;
     int ret = -EINVAL;
 
     if (!port || port >= max_evtchn_port(kvm))
         return -EINVAL;
 
     evtchnfd = kzalloc(sizeof(struct evtchnfd), GFP_KERNEL);
     if (!evtchnfd)
         return -ENOMEM;
 
     switch(data->u.evtchn.type) {
     case EVTCHNSTAT_ipi:
         /* IPI  must map back to the same port# */
         if (data->u.evtchn.deliver.port.port != data->u.evtchn.send_port)
             goto out; /* -EINVAL */
         break;
 
     case EVTCHNSTAT_interdomain:
         if (data->u.evtchn.deliver.port.port) {
             if (data->u.evtchn.deliver.port.port >= max_evtchn_port(kvm))
                 goto out; /* -EINVAL */
         } else {
             eventfd = eventfd_ctx_fdget(data->u.evtchn.deliver.eventfd.fd);
             if (IS_ERR(eventfd)) {
                 ret = PTR_ERR(eventfd);
                 goto out;
             }
         }
         break;
 
     case EVTCHNSTAT_virq:
     case EVTCHNSTAT_closed:
     case EVTCHNSTAT_unbound:
     case EVTCHNSTAT_pirq:
     default: /* Unknown event channel type */
         goto out; /* -EINVAL */
     }
 
     evtchnfd->send_port = data->u.evtchn.send_port;
     evtchnfd->type = data->u.evtchn.type;
     if (eventfd) {
         evtchnfd->deliver.eventfd.ctx = eventfd;
     } else {
         /* We only support 2 level event channels for now */
         if (data->u.evtchn.deliver.port.priority != KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL)
             goto out; /* -EINVAL; */
 
         evtchnfd->deliver.port.port = data->u.evtchn.deliver.port.port;
         evtchnfd->deliver.port.vcpu_id = data->u.evtchn.deliver.port.vcpu;
         evtchnfd->deliver.port.vcpu_idx = -1;
         evtchnfd->deliver.port.priority = data->u.evtchn.deliver.port.priority;
     }
 
     mutex_lock(&kvm->lock);
     ret = idr_alloc(&kvm->arch.xen.evtchn_ports, evtchnfd, port, port + 1,
             GFP_KERNEL);
     mutex_unlock(&kvm->lock);
     if (ret >= 0)
         return 0;
 
     if (ret == -ENOSPC)
         ret = -EEXIST;
 out:
     if (eventfd)
         eventfd_ctx_put(eventfd);
     kfree(evtchnfd);
     return ret;
 }
 
 static int kvm_xen_eventfd_deassign(struct kvm *kvm, u32 port)
 {
     struct evtchnfd *evtchnfd;
 
     mutex_lock(&kvm->lock);
     evtchnfd = idr_remove(&kvm->arch.xen.evtchn_ports, port);
     mutex_unlock(&kvm->lock);
 
     if (!evtchnfd)
         return -ENOENT;
 
     if (kvm)
         synchronize_srcu(&kvm->srcu);
     if (!evtchnfd->deliver.port.port)
         eventfd_ctx_put(evtchnfd->deliver.eventfd.ctx);
     kfree(evtchnfd);
     return 0;
 }
 
 static int kvm_xen_eventfd_reset(struct kvm *kvm)
 {
     struct evtchnfd *evtchnfd;
     int i;
 
     mutex_lock(&kvm->lock);
     idr_for_each_entry(&kvm->arch.xen.evtchn_ports, evtchnfd, i) {
         idr_remove(&kvm->arch.xen.evtchn_ports, evtchnfd->send_port);
         synchronize_srcu(&kvm->srcu);
         if (!evtchnfd->deliver.port.port)
             eventfd_ctx_put(evtchnfd->deliver.eventfd.ctx);
         kfree(evtchnfd);
     }
     mutex_unlock(&kvm->lock);
 
     return 0;
 }
 
 static int kvm_xen_setattr_evtchn(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
 {
     u32 port = data->u.evtchn.send_port;
 
     if (data->u.evtchn.flags == KVM_XEN_EVTCHN_RESET)
         return kvm_xen_eventfd_reset(kvm);
 
     if (!port || port >= max_evtchn_port(kvm))
         return -EINVAL;
 
     if (data->u.evtchn.flags == KVM_XEN_EVTCHN_DEASSIGN)
         return kvm_xen_eventfd_deassign(kvm, port);
     if (data->u.evtchn.flags == KVM_XEN_EVTCHN_UPDATE)
         return kvm_xen_eventfd_update(kvm, data);
     if (data->u.evtchn.flags)
         return -EINVAL;
 
     return kvm_xen_eventfd_assign(kvm, data);
 }
 
 static bool kvm_xen_hcall_evtchn_send(struct kvm_vcpu *vcpu, u64 param, u64 *r)
 {
     struct evtchnfd *evtchnfd;
     struct evtchn_send send;
     gpa_t gpa;
     int idx;
 
     idx = srcu_read_lock(&vcpu->kvm->srcu);
     gpa = kvm_mmu_gva_to_gpa_system(vcpu, param, NULL);
     srcu_read_unlock(&vcpu->kvm->srcu, idx);
 
     if (!gpa || kvm_vcpu_read_guest(vcpu, gpa, &send, sizeof(send))) {
         *r = -EFAULT;
         return true;
     }
 
     /* The evtchn_ports idr is protected by vcpu->kvm->srcu */
     evtchnfd = idr_find(&vcpu->kvm->arch.xen.evtchn_ports, send.port);
     if (!evtchnfd)
         return false;
 
     if (evtchnfd->deliver.port.port) {
         int ret = kvm_xen_set_evtchn(&evtchnfd->deliver.port, vcpu->kvm);
         if (ret < 0 && ret != -ENOTCONN)
             return false;
     } else {
         eventfd_signal(evtchnfd->deliver.eventfd.ctx, 1);
     }
 
     *r = 0;
     return true;
 }
 
 void kvm_xen_init_vcpu(struct kvm_vcpu *vcpu)
 {
     vcpu->arch.xen.vcpu_id = vcpu->vcpu_idx;
     vcpu->arch.xen.poll_evtchn = 0;
     timer_setup(&vcpu->arch.xen.poll_timer, cancel_evtchn_poll, 0);
 }
 
 void kvm_xen_destroy_vcpu(struct kvm_vcpu *vcpu)
 {
     if (kvm_xen_timer_enabled(vcpu))
         kvm_xen_stop_timer(vcpu);
 
     kvm_gfn_to_pfn_cache_destroy(vcpu->kvm,
                      &vcpu->arch.xen.runstate_cache);
     kvm_gfn_to_pfn_cache_destroy(vcpu->kvm,
                      &vcpu->arch.xen.vcpu_info_cache);
     kvm_gfn_to_pfn_cache_destroy(vcpu->kvm,
                      &vcpu->arch.xen.vcpu_time_info_cache);
     del_timer_sync(&vcpu->arch.xen.poll_timer);
 }
 
 void kvm_xen_init_vm(struct kvm *kvm)
 {
     idr_init(&kvm->arch.xen.evtchn_ports);
 }
 
 void kvm_xen_destroy_vm(struct kvm *kvm)
 {
     struct evtchnfd *evtchnfd;
     int i;
 
     kvm_gfn_to_pfn_cache_destroy(kvm, &kvm->arch.xen.shinfo_cache);
 
     idr_for_each_entry(&kvm->arch.xen.evtchn_ports, evtchnfd, i) {
         if (!evtchnfd->deliver.port.port)
             eventfd_ctx_put(evtchnfd->deliver.eventfd.ctx);
         kfree(evtchnfd);
     }
     idr_destroy(&kvm->arch.xen.evtchn_ports);
 
     if (kvm->arch.xen_hvm_config.msr)
         static_branch_slow_dec_deferred(&kvm_xen_enabled);
 }

This page was automatically generated by the 2.1.0 LXR engine. The LXR team