| Message ID | 4FF291EE.7060408@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jul 03, 2012 at 02:32:14PM +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(-) > > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index cac3408..af7e076 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -527,6 +527,14 @@ 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(!page_count(pfn_to_page(pfn))); > + Except for mmio pfns. Applied patch 1 and 2 to master, 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 cac3408..af7e076 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -527,6 +527,14 @@ 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(!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(-)