| Message ID | 20121120090134.GD2994@bloggs.ozlabs.ibm.com |
|---|---|
| State | New, archived |
| Headers | show |
On 20.11.2012, at 10:01, Paul Mackerras wrote: > This fixes a bug where adding a new guest HPT entry via the H_ENTER > hcall would lose the "changed" bit in the reverse map information > for the guest physical page being mapped. The result was that the > KVM_GET_DIRTY_LOG could return a zero bit for the page even though > the page had been modified by the guest. > > This fixes it by only modifying the index and present bits in the > reverse map entry, thus preserving the reference and change bits. > We were also unnecessarily setting the reference bit, and this > fixes that too. > > Signed-off-by: Paul Mackerras <paulus@samba.org> Thanks, applied to kvm-ppc-next. Alex > --- > This is against Alex Graf's kvm-ppc-next branch plus the series of three > patches I just sent, but it should be independent of that series. > > arch/powerpc/kvm/book3s_hv_rm_mmu.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c > index 2334000..fc3da32 100644 > --- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c > +++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c > @@ -59,10 +59,10 @@ void kvmppc_add_revmap_chain(struct kvm *kvm, struct revmap_entry *rev, > head->back = pte_index; > } else { > rev->forw = rev->back = pte_index; > - i = pte_index; > + *rmap = (*rmap & ~KVMPPC_RMAP_INDEX) | > + pte_index | KVMPPC_RMAP_PRESENT; > } > - smp_wmb(); > - *rmap = i | KVMPPC_RMAP_REFERENCED | KVMPPC_RMAP_PRESENT; /* unlock */ > + unlock_rmap(rmap); > } > EXPORT_SYMBOL_GPL(kvmppc_add_revmap_chain); > > -- > 1.7.10.4 > > -- > To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" 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/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c index 2334000..fc3da32 100644 --- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c +++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c @@ -59,10 +59,10 @@ void kvmppc_add_revmap_chain(struct kvm *kvm, struct revmap_entry *rev, head->back = pte_index; } else { rev->forw = rev->back = pte_index; - i = pte_index; + *rmap = (*rmap & ~KVMPPC_RMAP_INDEX) | + pte_index | KVMPPC_RMAP_PRESENT; } - smp_wmb(); - *rmap = i | KVMPPC_RMAP_REFERENCED | KVMPPC_RMAP_PRESENT; /* unlock */ + unlock_rmap(rmap); } EXPORT_SYMBOL_GPL(kvmppc_add_revmap_chain);
This fixes a bug where adding a new guest HPT entry via the H_ENTER hcall would lose the "changed" bit in the reverse map information for the guest physical page being mapped. The result was that the KVM_GET_DIRTY_LOG could return a zero bit for the page even though the page had been modified by the guest. This fixes it by only modifying the index and present bits in the reverse map entry, thus preserving the reference and change bits. We were also unnecessarily setting the reference bit, and this fixes that too. Signed-off-by: Paul Mackerras <paulus@samba.org> --- This is against Alex Graf's kvm-ppc-next branch plus the series of three patches I just sent, but it should be independent of that series. arch/powerpc/kvm/book3s_hv_rm_mmu.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)