On Fri, Dec 21, 2018 at 02:28:40PM +1100, Suraj Jitindar Singh wrote: > Nested rmap entries are used to store the translation from L1 gpa to L2 > gpa when entries are inserted into the shadow (nested) page tables. This > rmap list is located by indexing the rmap array in the memslot by L1 > gfn. When we come to search for these entries we only know the L1 page size > (which could be PAGE_SIZE, 2M or a 1G page) and so can only select a gfn > aligned to that size. This means that when we insert the entry, so we can > find it later, we need to align the gfn we use to select the rmap list > in which to insert the entry to L1 page size as well. > > By not doing this we were missing nested rmap entries when modifying L1 > ptes which were for a page also passed through to an L2 guest. > > Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@xxxxxxxxx> Reviewed-by: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx> > --- > arch/powerpc/kvm/book3s_hv_nested.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c > index 0dfbf093bde5..9dfb927ea14f 100644 > --- a/arch/powerpc/kvm/book3s_hv_nested.c > +++ b/arch/powerpc/kvm/book3s_hv_nested.c > @@ -1226,6 +1226,8 @@ static long int __kvmhv_nested_page_fault(struct kvm_vcpu *vcpu, > return ret; > shift = kvmppc_radix_level_to_shift(level); > } > + /* Align gfn to the start of the page */ > + gfn = (gpa & ~((1UL << shift) - 1)) >> PAGE_SHIFT; > > /* 3. Compute the pte we need to insert for nest_gpa -> host r_addr */ > -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
Attachment:
signature.asc
Description: PGP signature
