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kvm: avoid page allocation failure in kvm_set_memory_region()

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KVM guest can fail to startup with following trace on host:

qemu-system-x86: page allocation failure: order:4, mode:0x40d0
Call Trace:
  dump_stack+0x47/0x67
  warn_alloc_failed+0xee/0x150
  __alloc_pages_direct_compact+0x14a/0x150
  __alloc_pages_nodemask+0x776/0xb80
  alloc_kmem_pages+0x3a/0x110
  kmalloc_order+0x13/0x50
  kmemdup+0x1b/0x40
  __kvm_set_memory_region+0x24a/0x9f0 [kvm]
  kvm_set_ioapic+0x130/0x130 [kvm]
  kvm_set_memory_region+0x21/0x40 [kvm]
  kvm_vm_ioctl+0x43f/0x750 [kvm]

Failure happens when attempting to allocate pages for
'struct kvm_memslots', however it doesn't have to be
present in physically contiguous (kmalloc-ed) address
space, change allocation to kvm_kvzalloc() so that
it will be vmalloc-ed when its size is more then a page.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This commit is contained in:
Igor Mammedov 2015-03-20 12:21:37 +00:00 committed by Marcelo Tosatti
parent c806a6ad35
commit 744961341d
1 changed files with 7 additions and 7 deletions
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14
virt/kvm/kvm_main.c
View File

@ -471,7 +471,7 @@ static struct kvm *kvm_create_vm(unsigned long type)
BUILD_BUG_ON(KVM_MEM_SLOTS_NUM > SHRT_MAX);
r = -ENOMEM;
kvm->memslots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL);
kvm->memslots = kvm_kvzalloc(sizeof(struct kvm_memslots));
if (!kvm->memslots)
goto out_err_no_srcu;
@ -522,7 +522,7 @@ out_err_no_srcu:
out_err_no_disable:
for (i = 0; i < KVM_NR_BUSES; i++)
kfree(kvm->buses[i]);
kfree(kvm->memslots);
kvfree(kvm->memslots);
kvm_arch_free_vm(kvm);
return ERR_PTR(r);
}
@ -578,7 +578,7 @@ static void kvm_free_physmem(struct kvm *kvm)
kvm_for_each_memslot(memslot, slots)
kvm_free_physmem_slot(kvm, memslot, NULL);
kfree(kvm->memslots);
kvfree(kvm->memslots);
}
static void kvm_destroy_devices(struct kvm *kvm)
@ -871,10 +871,10 @@ int __kvm_set_memory_region(struct kvm *kvm,
goto out_free;
}
slots = kmemdup(kvm->memslots, sizeof(struct kvm_memslots),
GFP_KERNEL);
slots = kvm_kvzalloc(sizeof(struct kvm_memslots));
if (!slots)
goto out_free;
memcpy(slots, kvm->memslots, sizeof(struct kvm_memslots));
if ((change == KVM_MR_DELETE) || (change == KVM_MR_MOVE)) {
slot = id_to_memslot(slots, mem->slot);
@ -917,7 +917,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
kvm_arch_commit_memory_region(kvm, mem, &old, change);
kvm_free_physmem_slot(kvm, &old, &new);
kfree(old_memslots);
kvfree(old_memslots);
/*
* IOMMU mapping: New slots need to be mapped. Old slots need to be
@ -936,7 +936,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
return 0;
out_slots:
kfree(slots);
kvfree(slots);
out_free:
kvm_free_physmem_slot(kvm, &new, &old);
out: