[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 3/3] xen-netback: handle page straddling in xenvif_set_hash_mapping()
> -----Original Message----- > From: Jan Beulich [mailto:JBeulich@xxxxxxxx] > Sent: 28 August 2018 16:00 > To: Paul Durrant <Paul.Durrant@xxxxxxxxxx>; Wei Liu <wei.liu2@xxxxxxxxxx> > Cc: davem@xxxxxxxxxxxxx; xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxxx>; > netdev@xxxxxxxxxxxxxxx > Subject: [PATCH 3/3] xen-netback: handle page straddling in > xenvif_set_hash_mapping() > > There's no guarantee that the mapping array doesn't cross a page > boundary. Use a second grant copy operation if necessary. > > Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx> Personally I think it would be cleaner to out-of-line the allocation of the mapping table and ensure it is page aligned but this works so... Reviewed-by: Paul Durrant <paul.durrant@xxxxxxxxxx> > > --- > drivers/net/xen-netback/hash.c | 25 ++++++++++++++++++------- > 1 file changed, 18 insertions(+), 7 deletions(-) > > --- 4.19-rc1-xen-netback-set-hash-mapping.orig/drivers/net/xen- > netback/hash.c > +++ 4.19-rc1-xen-netback-set-hash-mapping/drivers/net/xen- > netback/hash.c > @@ -334,28 +334,39 @@ u32 xenvif_set_hash_mapping(struct xenvi > u32 off) > { > u32 *mapping = vif->hash.mapping[!vif->hash.mapping_sel]; > - struct gnttab_copy copy_op = { > + unsigned int nr = 1; > + struct gnttab_copy copy_op[2] = {{ > .source.u.ref = gref, > .source.domid = vif->domid, > .dest.domid = DOMID_SELF, > .len = len * sizeof(*mapping), > .flags = GNTCOPY_source_gref > - }; > + }}; > > if ((off + len < off) || (off + len > vif->hash.size) || > len > XEN_PAGE_SIZE / sizeof(*mapping)) > return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER; > > - copy_op.dest.u.gmfn = virt_to_gfn(mapping + off); > - copy_op.dest.offset = xen_offset_in_page(mapping + off); > + copy_op[0].dest.u.gmfn = virt_to_gfn(mapping + off); > + copy_op[0].dest.offset = xen_offset_in_page(mapping + off); > + if (copy_op[0].dest.offset + copy_op[0].len > XEN_PAGE_SIZE) { > + copy_op[1] = copy_op[0]; > + copy_op[1].source.offset = XEN_PAGE_SIZE - > copy_op[0].dest.offset; > + copy_op[1].dest.u.gmfn = virt_to_gfn(mapping + off + len); > + copy_op[1].dest.offset = 0; > + copy_op[1].len = copy_op[0].len - copy_op[1].source.offset; > + copy_op[0].len = copy_op[1].source.offset; > + nr = 2; > + } > > memcpy(mapping, vif->hash.mapping[vif->hash.mapping_sel], > vif->hash.size * sizeof(*mapping)); > > - if (copy_op.len != 0) { > - gnttab_batch_copy(©_op, 1); > + if (copy_op[0].len != 0) { > + gnttab_batch_copy(copy_op, nr); > > - if (copy_op.status != GNTST_okay) > + if (copy_op[0].status != GNTST_okay || > + copy_op[nr - 1].status != GNTST_okay) > return > XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER; > } > > > > _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/xen-devel
|
Lists.xenproject.org is hosted with RackSpace, monitoring our |