leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

KVM: PPC: Do not warn when userspace asked for too big TCE table

Browse Source 
KVM manages emulated TCE tables for guest LIOBNs by a two level table
which maps up to 128TiB with 16MB IOMMU pages (enabled in QEMU by default)
and MAX_ORDER=11 (the kernel's default). Note that the last level of
the table is allocated when actual TCE is updated.

However these tables are created via ioctl() on kvmfd and the userspace
can trigger WARN_ON_ONCE_GFP(order >= MAX_ORDER, gfp) in mm/page_alloc.c
and flood dmesg.

This adds __GFP_NOWARN.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220628080228.1508847-1-aik@ozlabs.ru
This commit is contained in:
Alexey Kardashevskiy 2022-06-28 18:02:28 +10:00 committed by Michael Ellerman
parent f5c847ea19
commit 4dee21e0f2
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/powerpc/kvm/book3s_64_vio.c
View File

@ -307,7 +307,7 @@ long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
return ret;
ret = -ENOMEM;
stt = kzalloc(struct_size(stt, pages, npages), GFP_KERNEL);
stt = kzalloc(struct_size(stt, pages, npages), GFP_KERNEL | __GFP_NOWARN);
if (!stt)
goto fail_acct;