| // 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_gpc_deactivate(gpc); |
| goto out; |
| } |
| |
| do { |
| ret = kvm_gpc_activate(gpc, 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_guest(struct kvm_vcpu *v, bool atomic) |
| { |
| struct kvm_vcpu_xen *vx = &v->arch.xen; |
| struct gfn_to_pfn_cache *gpc1 = &vx->runstate_cache; |
| struct gfn_to_pfn_cache *gpc2 = &vx->runstate2_cache; |
| size_t user_len, user_len1, user_len2; |
| struct vcpu_runstate_info rs; |
| unsigned long flags; |
| size_t times_ofs; |
| uint8_t *update_bit = NULL; |
| uint64_t entry_time; |
| uint64_t *rs_times; |
| int *rs_state; |
| |
| /* |
| * The only difference between 32-bit and 64-bit versions of the |
| * runstate struct is 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'. Let's be really really |
| * paranoid about that, and matching it with our internal data |
| * structures that we memcpy into it... |
| */ |
| 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 |
| /* |
| * The 64-bit structure has 4 bytes of padding before 'state_entry_time' |
| * so each subsequent field is shifted by 4, and it's 4 bytes longer. |
| */ |
| 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); |
| BUILD_BUG_ON(sizeof(struct vcpu_runstate_info) != 0x2c + 4); |
| #endif |
| /* |
| * The state field is in the same place at the start of both structs, |
| * and is the same size (int) as vx->current_runstate. |
| */ |
| 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)); |
| |
| /* |
| * The state_entry_time field is 64 bits in both versions, and the |
| * XEN_RUNSTATE_UPDATE flag is in the top bit, which given that x86 |
| * is little-endian means that it's in the last *byte* of the word. |
| * That detail is important later. |
| */ |
| BUILD_BUG_ON(sizeof_field(struct vcpu_runstate_info, state_entry_time) != |
| sizeof(uint64_t)); |
| BUILD_BUG_ON(sizeof_field(struct compat_vcpu_runstate_info, state_entry_time) != |
| sizeof(uint64_t)); |
| BUILD_BUG_ON((XEN_RUNSTATE_UPDATE >> 56) != 0x80); |
| |
| /* |
| * The time array is four 64-bit quantities in both versions, matching |
| * the vx->runstate_times and immediately following state_entry_time. |
| */ |
| BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, state_entry_time) != |
| offsetof(struct vcpu_runstate_info, time) - sizeof(uint64_t)); |
| BUILD_BUG_ON(offsetof(struct compat_vcpu_runstate_info, state_entry_time) != |
| offsetof(struct compat_vcpu_runstate_info, time) - sizeof(uint64_t)); |
| 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)); |
| |
| if (IS_ENABLED(CONFIG_64BIT) && v->kvm->arch.xen.long_mode) { |
| user_len = sizeof(struct vcpu_runstate_info); |
| times_ofs = offsetof(struct vcpu_runstate_info, |
| state_entry_time); |
| } else { |
| user_len = sizeof(struct compat_vcpu_runstate_info); |
| times_ofs = offsetof(struct compat_vcpu_runstate_info, |
| state_entry_time); |
| } |
| |
| /* |
| * There are basically no alignment constraints. The guest can set it |
| * up so it crosses from one page to the next, and at arbitrary byte |
| * alignment (and the 32-bit ABI doesn't align the 64-bit integers |
| * anyway, even if the overall struct had been 64-bit aligned). |
| */ |
| if ((gpc1->gpa & ~PAGE_MASK) + user_len >= PAGE_SIZE) { |
| user_len1 = PAGE_SIZE - (gpc1->gpa & ~PAGE_MASK); |
| user_len2 = user_len - user_len1; |
| } else { |
| user_len1 = user_len; |
| user_len2 = 0; |
| } |
| BUG_ON(user_len1 + user_len2 != user_len); |
| |
| retry: |
| /* |
| * Attempt to obtain the GPC lock on *both* (if there are two) |
| * gfn_to_pfn caches that cover the region. |
| */ |
| read_lock_irqsave(&gpc1->lock, flags); |
| while (!kvm_gpc_check(gpc1, user_len1)) { |
| read_unlock_irqrestore(&gpc1->lock, flags); |
| |
| /* When invoked from kvm_sched_out() we cannot sleep */ |
| if (atomic) |
| return; |
| |
| if (kvm_gpc_refresh(gpc1, user_len1)) |
| return; |
| |
| read_lock_irqsave(&gpc1->lock, flags); |
| } |
| |
| if (likely(!user_len2)) { |
| /* |
| * Set up three pointers directly to the runstate_info |
| * struct in the guest (via the GPC). |
| * |
| * • @rs_state → state field |
| * • @rs_times → state_entry_time field. |
| * • @update_bit → last byte of state_entry_time, which |
| * contains the XEN_RUNSTATE_UPDATE bit. |
| */ |
| rs_state = gpc1->khva; |
| rs_times = gpc1->khva + times_ofs; |
| if (v->kvm->arch.xen.runstate_update_flag) |
| update_bit = ((void *)(&rs_times[1])) - 1; |
| } else { |
| /* |
| * The guest's runstate_info is split across two pages and we |
| * need to hold and validate both GPCs simultaneously. We can |
| * declare a lock ordering GPC1 > GPC2 because nothing else |
| * takes them more than one at a time. |
| */ |
| read_lock(&gpc2->lock); |
| |
| if (!kvm_gpc_check(gpc2, user_len2)) { |
| read_unlock(&gpc2->lock); |
| read_unlock_irqrestore(&gpc1->lock, flags); |
| |
| /* When invoked from kvm_sched_out() we cannot sleep */ |
| if (atomic) |
| return; |
| |
| /* |
| * Use kvm_gpc_activate() here because if the runstate |
| * area was configured in 32-bit mode and only extends |
| * to the second page now because the guest changed to |
| * 64-bit mode, the second GPC won't have been set up. |
| */ |
| if (kvm_gpc_activate(gpc2, gpc1->gpa + user_len1, |
| user_len2)) |
| return; |
| |
| /* |
| * We dropped the lock on GPC1 so we have to go all the |
| * way back and revalidate that too. |
| */ |
| goto retry; |
| } |
| |
| /* |
| * In this case, the runstate_info struct will be assembled on |
| * the kernel stack (compat or not as appropriate) and will |
| * be copied to GPC1/GPC2 with a dual memcpy. Set up the three |
| * rs pointers accordingly. |
| */ |
| rs_times = &rs.state_entry_time; |
| |
| /* |
| * The rs_state pointer points to the start of what we'll |
| * copy to the guest, which in the case of a compat guest |
| * is the 32-bit field that the compiler thinks is padding. |
| */ |
| rs_state = ((void *)rs_times) - times_ofs; |
| |
| /* |
| * The update_bit is still directly in the guest memory, |
| * via one GPC or the other. |
| */ |
| if (v->kvm->arch.xen.runstate_update_flag) { |
| if (user_len1 >= times_ofs + sizeof(uint64_t)) |
| update_bit = gpc1->khva + times_ofs + |
| sizeof(uint64_t) - 1; |
| else |
| update_bit = gpc2->khva + times_ofs + |
| sizeof(uint64_t) - 1 - user_len1; |
| } |
| |
| #ifdef CONFIG_X86_64 |
| /* |
| * Don't leak kernel memory through the padding in the 64-bit |
| * version of the struct. |
| */ |
| memset(&rs, 0, offsetof(struct vcpu_runstate_info, state_entry_time)); |
| #endif |
| } |
| |
| /* |
| * First, set the XEN_RUNSTATE_UPDATE bit in the top bit of the |
| * state_entry_time field, directly in the guest. We need to set |
| * that (and write-barrier) before writing to the rest of the |
| * structure, and clear it last. Just as Xen does, we address the |
| * single *byte* in which it resides because it might be in a |
| * different cache line to the rest of the 64-bit word, due to |
| * the (lack of) alignment constraints. |
| */ |
| entry_time = vx->runstate_entry_time; |
| if (update_bit) { |
| entry_time |= XEN_RUNSTATE_UPDATE; |
| *update_bit = (vx->runstate_entry_time | XEN_RUNSTATE_UPDATE) >> 56; |
| smp_wmb(); |
| } |
| |
| /* |
| * Now assemble the actual structure, either on our kernel stack |
| * or directly in the guest according to how the rs_state and |
| * rs_times pointers were set up above. |
| */ |
| *rs_state = vx->current_runstate; |
| rs_times[0] = entry_time; |
| memcpy(rs_times + 1, vx->runstate_times, sizeof(vx->runstate_times)); |
| |
| /* For the split case, we have to then copy it to the guest. */ |
| if (user_len2) { |
| memcpy(gpc1->khva, rs_state, user_len1); |
| memcpy(gpc2->khva, ((void *)rs_state) + user_len1, user_len2); |
| } |
| smp_wmb(); |
| |
| /* Finally, clear the XEN_RUNSTATE_UPDATE bit. */ |
| if (update_bit) { |
| entry_time &= ~XEN_RUNSTATE_UPDATE; |
| *update_bit = entry_time >> 56; |
| smp_wmb(); |
| } |
| |
| if (user_len2) |
| read_unlock(&gpc2->lock); |
| |
| read_unlock_irqrestore(&gpc1->lock, flags); |
| |
| mark_page_dirty_in_slot(v->kvm, gpc1->memslot, gpc1->gpa >> PAGE_SHIFT); |
| if (user_len2) |
| mark_page_dirty_in_slot(v->kvm, gpc2->memslot, gpc2->gpa >> PAGE_SHIFT); |
| } |
| |
| 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; |
| |
| if (vx->runstate_cache.active) |
| kvm_xen_update_runstate_guest(v, state == RUNSTATE_runnable); |
| } |
| |
| 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_gpc_check(gpc, sizeof(struct vcpu_info))) { |
| read_unlock_irqrestore(&gpc->lock, flags); |
| |
| if (kvm_gpc_refresh(gpc, 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_gpc_check(gpc, 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_gpc_refresh(gpc, 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; |
| |
| case KVM_XEN_ATTR_TYPE_RUNSTATE_UPDATE_FLAG: |
| if (!sched_info_on()) { |
| r = -EOPNOTSUPP; |
| break; |
| } |
| mutex_lock(&kvm->lock); |
| kvm->arch.xen.runstate_update_flag = !!data->u.runstate_update_flag; |
| 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; |
| |
| case KVM_XEN_ATTR_TYPE_RUNSTATE_UPDATE_FLAG: |
| if (!sched_info_on()) { |
| r = -EOPNOTSUPP; |
| break; |
| } |
| data->u.runstate_update_flag = kvm->arch.xen.runstate_update_flag; |
| 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_gpc_deactivate(&vcpu->arch.xen.vcpu_info_cache); |
| r = 0; |
| break; |
| } |
| |
| r = kvm_gpc_activate(&vcpu->arch.xen.vcpu_info_cache, |
| 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_gpc_deactivate(&vcpu->arch.xen.vcpu_time_info_cache); |
| r = 0; |
| break; |
| } |
| |
| r = kvm_gpc_activate(&vcpu->arch.xen.vcpu_time_info_cache, |
| 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: { |
| size_t sz, sz1, sz2; |
| |
| if (!sched_info_on()) { |
| r = -EOPNOTSUPP; |
| break; |
| } |
| if (data->u.gpa == GPA_INVALID) { |
| r = 0; |
| deactivate_out: |
| kvm_gpc_deactivate(&vcpu->arch.xen.runstate_cache); |
| kvm_gpc_deactivate(&vcpu->arch.xen.runstate2_cache); |
| break; |
| } |
| |
| /* |
| * If the guest switches to 64-bit mode after setting the runstate |
| * address, that's actually OK. kvm_xen_update_runstate_guest() |
| * will cope. |
| */ |
| if (IS_ENABLED(CONFIG_64BIT) && vcpu->kvm->arch.xen.long_mode) |
| sz = sizeof(struct vcpu_runstate_info); |
| else |
| sz = sizeof(struct compat_vcpu_runstate_info); |
| |
| /* How much fits in the (first) page? */ |
| sz1 = PAGE_SIZE - (data->u.gpa & ~PAGE_MASK); |
| r = kvm_gpc_activate(&vcpu->arch.xen.runstate_cache, |
| data->u.gpa, sz1); |
| if (r) |
| goto deactivate_out; |
| |
| /* Either map the second page, or deactivate the second GPC */ |
| if (sz1 >= sz) { |
| kvm_gpc_deactivate(&vcpu->arch.xen.runstate2_cache); |
| } else { |
| sz2 = sz - sz1; |
| BUG_ON((data->u.gpa + sz1) & ~PAGE_MASK); |
| r = kvm_gpc_activate(&vcpu->arch.xen.runstate2_cache, |
| data->u.gpa + sz1, sz2); |
| if (r) |
| goto deactivate_out; |
| } |
| |
| kvm_xen_update_runstate_guest(vcpu, false); |
| 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); |
| else if (vcpu->arch.xen.runstate_cache.active) |
| kvm_xen_update_runstate_guest(vcpu, false); |
| 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 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 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; |
| |
| idx = srcu_read_lock(&kvm->srcu); |
| read_lock_irqsave(&gpc->lock, flags); |
| if (!kvm_gpc_check(gpc, 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: |
| read_unlock_irqrestore(&gpc->lock, flags); |
| srcu_read_unlock(&kvm->srcu, idx); |
| |
| 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 (!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) { |
| *r = -EFAULT; |
| return true; |
| } |
| |
| if (IS_ENABLED(CONFIG_64BIT) && !longmode) { |
| struct compat_sched_poll sp32; |
| |
| /* Sanity check that the compat struct definition is correct */ |
| BUILD_BUG_ON(sizeof(sp32) != 16); |
| |
| if (kvm_vcpu_read_guest(vcpu, gpa, &sp32, sizeof(sp32))) { |
| *r = -EFAULT; |
| return true; |
| } |
| |
| /* |
| * This is a 32-bit pointer to an array of evtchn_port_t which |
| * are uint32_t, so once it's converted no further compat |
| * handling is needed. |
| */ |
| sched_poll.ports = (void *)(unsigned long)(sp32.ports); |
| sched_poll.nr_ports = sp32.nr_ports; |
| sched_poll.timeout = sp32.timeout; |
| } else { |
| if (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 (ports[i] >= max_evtchn_port(vcpu->kvm)) { |
| *r = -EINVAL; |
| 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; |
| } |
| |
| 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; |
| u8 cpl; |
| |
| 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 |
| cpl = static_call(kvm_x86_get_cpl)(vcpu); |
| trace_kvm_xen_hypercall(cpl, input, params[0], params[1], params[2], |
| params[3], params[4], params[5]); |
| |
| /* |
| * Only allow hypercall acceleration for CPL0. The rare hypercalls that |
| * are permitted in guest userspace can be handled by the VMM. |
| */ |
| if (unlikely(cpl > 0)) |
| goto handle_in_userspace; |
| |
| 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); |
| |
| handle_in_userspace: |
| 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 = cpl; |
| 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 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_gpc_check(gpc, 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_gpc_check(gpc, 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_gpc_refresh(gpc, 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_noeventfd; /* -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_noeventfd; /* -EINVAL */ |
| } else { |
| eventfd = eventfd_ctx_fdget(data->u.evtchn.deliver.eventfd.fd); |
| if (IS_ERR(eventfd)) { |
| ret = PTR_ERR(eventfd); |
| goto out_noeventfd; |
| } |
| } |
| 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); |
| out_noeventfd: |
| 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); |
| |
| kvm_gpc_init(&vcpu->arch.xen.runstate_cache, vcpu->kvm, NULL, |
| KVM_HOST_USES_PFN); |
| kvm_gpc_init(&vcpu->arch.xen.runstate2_cache, vcpu->kvm, NULL, |
| KVM_HOST_USES_PFN); |
| kvm_gpc_init(&vcpu->arch.xen.vcpu_info_cache, vcpu->kvm, NULL, |
| KVM_HOST_USES_PFN); |
| kvm_gpc_init(&vcpu->arch.xen.vcpu_time_info_cache, vcpu->kvm, NULL, |
| KVM_HOST_USES_PFN); |
| } |
| |
| void kvm_xen_destroy_vcpu(struct kvm_vcpu *vcpu) |
| { |
| if (kvm_xen_timer_enabled(vcpu)) |
| kvm_xen_stop_timer(vcpu); |
| |
| kvm_gpc_deactivate(&vcpu->arch.xen.runstate_cache); |
| kvm_gpc_deactivate(&vcpu->arch.xen.runstate2_cache); |
| kvm_gpc_deactivate(&vcpu->arch.xen.vcpu_info_cache); |
| kvm_gpc_deactivate(&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); |
| kvm_gpc_init(&kvm->arch.xen.shinfo_cache, kvm, NULL, KVM_HOST_USES_PFN); |
| } |
| |
| void kvm_xen_destroy_vm(struct kvm *kvm) |
| { |
| struct evtchnfd *evtchnfd; |
| int i; |
| |
| kvm_gpc_deactivate(&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); |
| } |