linux_dsm_epyc7002/virt/kvm/async_pf.c
Linus Torvalds 52cd0d972f MIPS:
- Loongson port
 
 PPC:
 - Fixes
 
 ARM:
 - Fixes
 
 x86:
 - KVM_SET_USER_MEMORY_REGION optimizations
 - Fixes
 - Selftest fixes
 
 The guest side of the asynchronous page fault work has been delayed to 5.9
 in order to sync with Thomas's interrupt entry rework.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull more KVM updates from Paolo Bonzini:
 "The guest side of the asynchronous page fault work has been delayed to
  5.9 in order to sync with Thomas's interrupt entry rework, but here's
  the rest of the KVM updates for this merge window.

  MIPS:
   - Loongson port

  PPC:
   - Fixes

  ARM:
   - Fixes

  x86:
   - KVM_SET_USER_MEMORY_REGION optimizations
   - Fixes
   - Selftest fixes"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (62 commits)
  KVM: x86: do not pass poisoned hva to __kvm_set_memory_region
  KVM: selftests: fix sync_with_host() in smm_test
  KVM: async_pf: Inject 'page ready' event only if 'page not present' was previously injected
  KVM: async_pf: Cleanup kvm_setup_async_pf()
  kvm: i8254: remove redundant assignment to pointer s
  KVM: x86: respect singlestep when emulating instruction
  KVM: selftests: Don't probe KVM_CAP_HYPERV_ENLIGHTENED_VMCS when nested VMX is unsupported
  KVM: selftests: do not substitute SVM/VMX check with KVM_CAP_NESTED_STATE check
  KVM: nVMX: Consult only the "basic" exit reason when routing nested exit
  KVM: arm64: Move hyp_symbol_addr() to kvm_asm.h
  KVM: arm64: Synchronize sysreg state on injecting an AArch32 exception
  KVM: arm64: Make vcpu_cp1x() work on Big Endian hosts
  KVM: arm64: Remove host_cpu_context member from vcpu structure
  KVM: arm64: Stop sparse from moaning at __hyp_this_cpu_ptr
  KVM: arm64: Handle PtrAuth traps early
  KVM: x86: Unexport x86_fpu_cache and make it static
  KVM: selftests: Ignore KVM 5-level paging support for VM_MODE_PXXV48_4K
  KVM: arm64: Save the host's PtrAuth keys in non-preemptible context
  KVM: arm64: Stop save/restoring ACTLR_EL1
  KVM: arm64: Add emulation for 32bit guests accessing ACTLR2
  ...
2020-06-12 11:05:52 -07:00

225 lines
5.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* kvm asynchronous fault support
*
* Copyright 2010 Red Hat, Inc.
*
* Author:
* Gleb Natapov <gleb@redhat.com>
*/
#include <linux/kvm_host.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/mmu_context.h>
#include <linux/sched/mm.h>
#include "async_pf.h"
#include <trace/events/kvm.h>
static struct kmem_cache *async_pf_cache;
int kvm_async_pf_init(void)
{
async_pf_cache = KMEM_CACHE(kvm_async_pf, 0);
if (!async_pf_cache)
return -ENOMEM;
return 0;
}
void kvm_async_pf_deinit(void)
{
kmem_cache_destroy(async_pf_cache);
async_pf_cache = NULL;
}
void kvm_async_pf_vcpu_init(struct kvm_vcpu *vcpu)
{
INIT_LIST_HEAD(&vcpu->async_pf.done);
INIT_LIST_HEAD(&vcpu->async_pf.queue);
spin_lock_init(&vcpu->async_pf.lock);
}
static void async_pf_execute(struct work_struct *work)
{
struct kvm_async_pf *apf =
container_of(work, struct kvm_async_pf, work);
struct mm_struct *mm = apf->mm;
struct kvm_vcpu *vcpu = apf->vcpu;
unsigned long addr = apf->addr;
gpa_t cr2_or_gpa = apf->cr2_or_gpa;
int locked = 1;
bool first;
might_sleep();
/*
* This work is run asynchronously to the task which owns
* mm and might be done in another context, so we must
* access remotely.
*/
mmap_read_lock(mm);
get_user_pages_remote(NULL, mm, addr, 1, FOLL_WRITE, NULL, NULL,
&locked);
if (locked)
mmap_read_unlock(mm);
if (IS_ENABLED(CONFIG_KVM_ASYNC_PF_SYNC))
kvm_arch_async_page_present(vcpu, apf);
spin_lock(&vcpu->async_pf.lock);
first = list_empty(&vcpu->async_pf.done);
list_add_tail(&apf->link, &vcpu->async_pf.done);
apf->vcpu = NULL;
spin_unlock(&vcpu->async_pf.lock);
if (!IS_ENABLED(CONFIG_KVM_ASYNC_PF_SYNC) && first)
kvm_arch_async_page_present_queued(vcpu);
/*
* apf may be freed by kvm_check_async_pf_completion() after
* this point
*/
trace_kvm_async_pf_completed(addr, cr2_or_gpa);
rcuwait_wake_up(&vcpu->wait);
mmput(mm);
kvm_put_kvm(vcpu->kvm);
}
void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu)
{
spin_lock(&vcpu->async_pf.lock);
/* cancel outstanding work queue item */
while (!list_empty(&vcpu->async_pf.queue)) {
struct kvm_async_pf *work =
list_first_entry(&vcpu->async_pf.queue,
typeof(*work), queue);
list_del(&work->queue);
/*
* We know it's present in vcpu->async_pf.done, do
* nothing here.
*/
if (!work->vcpu)
continue;
spin_unlock(&vcpu->async_pf.lock);
#ifdef CONFIG_KVM_ASYNC_PF_SYNC
flush_work(&work->work);
#else
if (cancel_work_sync(&work->work)) {
mmput(work->mm);
kvm_put_kvm(vcpu->kvm); /* == work->vcpu->kvm */
kmem_cache_free(async_pf_cache, work);
}
#endif
spin_lock(&vcpu->async_pf.lock);
}
while (!list_empty(&vcpu->async_pf.done)) {
struct kvm_async_pf *work =
list_first_entry(&vcpu->async_pf.done,
typeof(*work), link);
list_del(&work->link);
kmem_cache_free(async_pf_cache, work);
}
spin_unlock(&vcpu->async_pf.lock);
vcpu->async_pf.queued = 0;
}
void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu)
{
struct kvm_async_pf *work;
while (!list_empty_careful(&vcpu->async_pf.done) &&
kvm_arch_can_dequeue_async_page_present(vcpu)) {
spin_lock(&vcpu->async_pf.lock);
work = list_first_entry(&vcpu->async_pf.done, typeof(*work),
link);
list_del(&work->link);
spin_unlock(&vcpu->async_pf.lock);
kvm_arch_async_page_ready(vcpu, work);
if (!IS_ENABLED(CONFIG_KVM_ASYNC_PF_SYNC))
kvm_arch_async_page_present(vcpu, work);
list_del(&work->queue);
vcpu->async_pf.queued--;
kmem_cache_free(async_pf_cache, work);
}
}
int kvm_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
unsigned long hva, struct kvm_arch_async_pf *arch)
{
struct kvm_async_pf *work;
if (vcpu->async_pf.queued >= ASYNC_PF_PER_VCPU)
return 0;
/* Arch specific code should not do async PF in this case */
if (unlikely(kvm_is_error_hva(hva)))
return 0;
/*
* do alloc nowait since if we are going to sleep anyway we
* may as well sleep faulting in page
*/
work = kmem_cache_zalloc(async_pf_cache, GFP_NOWAIT | __GFP_NOWARN);
if (!work)
return 0;
work->wakeup_all = false;
work->vcpu = vcpu;
work->cr2_or_gpa = cr2_or_gpa;
work->addr = hva;
work->arch = *arch;
work->mm = current->mm;
mmget(work->mm);
kvm_get_kvm(work->vcpu->kvm);
INIT_WORK(&work->work, async_pf_execute);
list_add_tail(&work->queue, &vcpu->async_pf.queue);
vcpu->async_pf.queued++;
work->notpresent_injected = kvm_arch_async_page_not_present(vcpu, work);
schedule_work(&work->work);
return 1;
}
int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu)
{
struct kvm_async_pf *work;
bool first;
if (!list_empty_careful(&vcpu->async_pf.done))
return 0;
work = kmem_cache_zalloc(async_pf_cache, GFP_ATOMIC);
if (!work)
return -ENOMEM;
work->wakeup_all = true;
INIT_LIST_HEAD(&work->queue); /* for list_del to work */
spin_lock(&vcpu->async_pf.lock);
first = list_empty(&vcpu->async_pf.done);
list_add_tail(&work->link, &vcpu->async_pf.done);
spin_unlock(&vcpu->async_pf.lock);
if (!IS_ENABLED(CONFIG_KVM_ASYNC_PF_SYNC) && first)
kvm_arch_async_page_present_queued(vcpu);
vcpu->async_pf.queued++;
return 0;
}