On Fri, 20 Mar 2015 08:59:03 -0300 Marcelo Tosatti <[email protected]> wrote:
> On Fri, Mar 20, 2015 at 09:51:26AM +0000, Igor Mammedov wrote: > > 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 <[email protected]> > > Igor, two things: > > 1) kvm_create_vm should also use vmalloc > > r = -ENOMEM; > kvm->memslots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL); > if (!kvm->memslots) > goto out_err_no_srcu; > > 2) there are additional places where its necessary to use > proper freeing function, i believe: > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index ce7888a..651ff2d 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -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); > } > @@ -570,7 +570,7 @@ 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) > @@ -909,7 +922,7 @@ 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 Thanks for review, I'll respin patch after fixing it up. > > > --- > > TODO: > > - work on follow up patches to allocate space for > > actual amount of memory_slots instead of possible maximum. > > --- > > virt/kvm/kvm_main.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > > index a2214d9..7ed1f5c 100644 > > --- a/virt/kvm/kvm_main.c > > +++ b/virt/kvm/kvm_main.c > > @@ -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); > > @@ -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: > > -- > > 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
