| Message ID | 50056E34.8080505@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jul 17, 2012 at 09:52:52PM +0800, Xiao Guangrong wrote: > It will trigger a WARN_ON if the page has been freed but it is still > used in mmu, it can help us to detect mm bug early > > Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> > --- > arch/x86/kvm/mmu.c | 8 ++++++++ > 1 files changed, 8 insertions(+), 0 deletions(-) Applied, thanks. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 28c8fbc..28b12e2 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -556,6 +556,14 @@ static int mmu_spte_clear_track_bits(u64 *sptep) return 0; pfn = spte_to_pfn(old_spte); + + /* + * KVM does not hold the refcount of the page used by + * kvm mmu, before reclaiming the page, we should + * unmap it from mmu first. + */ + WARN_ON(!kvm_is_mmio_pfn(pfn) && !page_count(pfn_to_page(pfn))); + if (!shadow_accessed_mask || old_spte & shadow_accessed_mask) kvm_set_pfn_accessed(pfn); if (!shadow_dirty_mask || (old_spte & shadow_dirty_mask))
It will trigger a WARN_ON if the page has been freed but it is still used in mmu, it can help us to detect mm bug early Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> --- arch/x86/kvm/mmu.c | 8 ++++++++ 1 files changed, 8 insertions(+), 0 deletions(-)