> -----Original Message----- > From: Alexander Graf [mailto:agraf@xxxxxxx] > Sent: Thursday, April 25, 2013 8:36 PM > To: Bhushan Bharat-R65777 > Cc: kvm-ppc@xxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; Wood Scott-B07421; Bhushan > Bharat-R65777 > Subject: Re: [PATCH] KVM : PPC : cache flush for kernel managed pages > > > On 23.04.2013, at 08:39, Bharat Bhushan wrote: > > > Kernel should only try flushing pages which are managed by kernel. > > pfn_to_page will returns junk struct page for pages not managed by > > kernel, so if kernel will try to flush direct mapped memory or direct > > assigned device mapping then it will work on junk struct page. > > > > Signed-off-by: Bharat Bhushan <bharat.bhushan@xxxxxxxxxxxxx> > > --- > > arch/powerpc/kvm/e500_mmu_host.c | 3 ++- > > 1 files changed, 2 insertions(+), 1 deletions(-) > > > > diff --git a/arch/powerpc/kvm/e500_mmu_host.c > > b/arch/powerpc/kvm/e500_mmu_host.c > > index 1c6a9d7..e07da21 100644 > > --- a/arch/powerpc/kvm/e500_mmu_host.c > > +++ b/arch/powerpc/kvm/e500_mmu_host.c > > @@ -455,7 +455,8 @@ static inline int kvmppc_e500_shadow_map(struct > kvmppc_vcpu_e500 *vcpu_e500, > > ref, gvaddr, stlbe); > > > > /* Clear i-cache for new pages */ > > - kvmppc_mmu_flush_icache(pfn); > > + if (pfn_valid(pfn)) > > + kvmppc_mmu_flush_icache(pfn); > > Could you please move the check into kvmppc_mmu_flush_icache()? That way we're > guaranteed we can't screw up cache flushes ever :). > > Also, please add a comment saying why we need this. Ok -Bharat > > > Alex > > > > > /* Drop refcount on page, so that mmu notifiers can clear it */ > > kvm_release_pfn_clean(pfn); > > -- > > 1.7.0.4 > > > > > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
