static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
gfn_t gfn, struct kvm_memory_slot *memslot,
unsigned long fault_status)
{
pte_t new_pte;
pfn_t pfn;
int ret;
bool write_fault, writable;
unsigned long mmu_seq;
struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache;
write_fault = kvm_is_write_fault(kvm_vcpu_get_hsr(vcpu));
if (fault_status == FSC_PERM && !write_fault) {
kvm_err("Unexpected L2 read permission error\n");
return -EFAULT;
}
/* We need minimum second+third level pages */
ret = mmu_topup_memory_cache(memcache, 2, KVM_NR_MEM_OBJS);
if (ret)
return ret;
mmu_seq = vcpu->kvm->mmu_notifier_seq;
/*
* Ensure the read of mmu_notifier_seq happens before we call
* gfn_to_pfn_prot (which calls get_user_pages), so that we don't risk
* the page we just got a reference to gets unmapped before we have a
* chance to grab the mmu_lock, which ensure that if the page gets
* unmapped afterwards, the call to kvm_unmap_hva will take it away
* from us again properly. This smp_rmb() interacts with the smp_wmb()
* in kvm_mmu_notifier_invalidate_<page|range_end>.
*/
smp_rmb();
pfn = gfn_to_pfn_prot(vcpu->kvm, gfn, write_fault, &writable);
if (is_error_pfn(pfn))
return -EFAULT;
new_pte = pfn_pte(pfn, PAGE_S2);
coherent_icache_guest_page(vcpu->kvm, gfn);
spin_lock(&vcpu->kvm->mmu_lock);
if (mmu_notifier_retry(vcpu->kvm, mmu_seq))
goto out_unlock;
if (writable) {
kvm_set_s2pte_writable(&new_pte);
kvm_set_pfn_dirty(pfn);
}
stage2_set_pte(vcpu->kvm, memcache, fault_ipa, &new_pte, false);
out_unlock:
spin_unlock(&vcpu->kvm->mmu_lock);
kvm_release_pfn_clean(pfn);
return 0;
}
static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
struct kvm_memory_slot *memslot,
unsigned long fault_status)
{
int ret;
bool write_fault, writable, hugetlb = false;
unsigned long mmu_seq;
gfn_t gfn = fault_ipa >> PAGE_SHIFT;
unsigned long hva = gfn_to_hva(vcpu->kvm, gfn);
struct kvm *kvm = vcpu->kvm;
struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache;
struct vm_area_struct *vma;
pfn_t pfn;
write_fault = kvm_is_write_fault(kvm_vcpu_get_hsr(vcpu));
if (fault_status == FSC_PERM && !write_fault) {
kvm_err("Unexpected L2 read permission error\n");
return -EFAULT;
}
/* Let's check if we will get back a huge page backed by hugetlbfs */
down_read(¤t->mm->mmap_sem);
vma = find_vma_intersection(current->mm, hva, hva + 1);
if (is_vm_hugetlb_page(vma)) {
hugetlb = true;
gfn = (fault_ipa & PMD_MASK) >> PAGE_SHIFT;
}
up_read(¤t->mm->mmap_sem);
/* We need minimum second+third level pages */
ret = mmu_topup_memory_cache(memcache, 2, KVM_NR_MEM_OBJS);
if (ret)
return ret;
mmu_seq = vcpu->kvm->mmu_notifier_seq;
/*
* Ensure the read of mmu_notifier_seq happens before we call
* gfn_to_pfn_prot (which calls get_user_pages), so that we don't risk
* the page we just got a reference to gets unmapped before we have a
* chance to grab the mmu_lock, which ensure that if the page gets
* unmapped afterwards, the call to kvm_unmap_hva will take it away
* from us again properly. This smp_rmb() interacts with the smp_wmb()
* in kvm_mmu_notifier_invalidate_<page|range_end>.
*/
smp_rmb();
pfn = gfn_to_pfn_prot(kvm, gfn, write_fault, &writable);
if (is_error_pfn(pfn))
return -EFAULT;
spin_lock(&kvm->mmu_lock);
if (mmu_notifier_retry(kvm, mmu_seq))
goto out_unlock;
if (hugetlb) {
pmd_t new_pmd = pfn_pmd(pfn, PAGE_S2);
new_pmd = pmd_mkhuge(new_pmd);
if (writable) {
kvm_set_s2pmd_writable(&new_pmd);
kvm_set_pfn_dirty(pfn);
}
coherent_icache_guest_page(kvm, hva & PMD_MASK, PMD_SIZE);
ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd);
} else {
pte_t new_pte = pfn_pte(pfn, PAGE_S2);
if (writable) {
kvm_set_s2pte_writable(&new_pte);
kvm_set_pfn_dirty(pfn);
}
coherent_icache_guest_page(kvm, hva, PAGE_SIZE);
ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, false);
}
out_unlock:
spin_unlock(&kvm->mmu_lock);
kvm_release_pfn_clean(pfn);
return ret;
}
