| Message ID | 20170621125249.8805-2-paul.durrant@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, 21 Jun 2017, Paul Durrant wrote: > If grant copy is available then it will always be used in preference to > persistent maps. In this case feature-persistent should not be advertized > to the frontend, otherwise it may needlessly copy data into persistently > granted buffers. > > Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> > --- > Cc: Stefano Stabellini <sstabellini@kernel.org> > Cc: Anthony Perard <anthony.perard@citrix.com> > Cc: Kevin Wolf <kwolf@redhat.com> > Cc: Max Reitz <mreitz@redhat.com> > --- > hw/block/xen_disk.c | 15 ++++++++------- > 1 file changed, 8 insertions(+), 7 deletions(-) > > diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c > index 3a22805fbc..9b06e3aa81 100644 > --- a/hw/block/xen_disk.c > +++ b/hw/block/xen_disk.c > @@ -1023,11 +1023,18 @@ static int blk_init(struct XenDevice *xendev) > > blkdev->file_blk = BLOCK_SIZE; > > + blkdev->feature_grant_copy = > + (xengnttab_grant_copy(blkdev->xendev.gnttabdev, 0, NULL) == 0); > + > + xen_pv_printf(&blkdev->xendev, 3, "grant copy operation %s\n", > + blkdev->feature_grant_copy ? "enabled" : "disabled"); > + > /* fill info > * blk_connect supplies sector-size and sectors > */ > xenstore_write_be_int(&blkdev->xendev, "feature-flush-cache", 1); > - xenstore_write_be_int(&blkdev->xendev, "feature-persistent", 1); > + xenstore_write_be_int(&blkdev->xendev, "feature-persistent", > + !blkdev->feature_grant_copy); > xenstore_write_be_int(&blkdev->xendev, "info", info); > > blk_parse_discard(blkdev); > @@ -1202,12 +1209,6 @@ static int blk_connect(struct XenDevice *xendev) > > xen_be_bind_evtchn(&blkdev->xendev); > > - blkdev->feature_grant_copy = > - (xengnttab_grant_copy(blkdev->xendev.gnttabdev, 0, NULL) == 0); > - > - xen_pv_printf(&blkdev->xendev, 3, "grant copy operation %s\n", > - blkdev->feature_grant_copy ? "enabled" : "disabled"); > - > xen_pv_printf(&blkdev->xendev, 1, "ok: proto %s, ring-ref %d, " > "remote port %d, local port %d\n", > blkdev->xendev.protocol, blkdev->ring_ref, > -- > 2.11.0 >
diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c index 3a22805fbc..9b06e3aa81 100644 --- a/hw/block/xen_disk.c +++ b/hw/block/xen_disk.c @@ -1023,11 +1023,18 @@ static int blk_init(struct XenDevice *xendev) blkdev->file_blk = BLOCK_SIZE; + blkdev->feature_grant_copy = + (xengnttab_grant_copy(blkdev->xendev.gnttabdev, 0, NULL) == 0); + + xen_pv_printf(&blkdev->xendev, 3, "grant copy operation %s\n", + blkdev->feature_grant_copy ? "enabled" : "disabled"); + /* fill info * blk_connect supplies sector-size and sectors */ xenstore_write_be_int(&blkdev->xendev, "feature-flush-cache", 1); - xenstore_write_be_int(&blkdev->xendev, "feature-persistent", 1); + xenstore_write_be_int(&blkdev->xendev, "feature-persistent", + !blkdev->feature_grant_copy); xenstore_write_be_int(&blkdev->xendev, "info", info); blk_parse_discard(blkdev); @@ -1202,12 +1209,6 @@ static int blk_connect(struct XenDevice *xendev) xen_be_bind_evtchn(&blkdev->xendev); - blkdev->feature_grant_copy = - (xengnttab_grant_copy(blkdev->xendev.gnttabdev, 0, NULL) == 0); - - xen_pv_printf(&blkdev->xendev, 3, "grant copy operation %s\n", - blkdev->feature_grant_copy ? "enabled" : "disabled"); - xen_pv_printf(&blkdev->xendev, 1, "ok: proto %s, ring-ref %d, " "remote port %d, local port %d\n", blkdev->xendev.protocol, blkdev->ring_ref,
If grant copy is available then it will always be used in preference to persistent maps. In this case feature-persistent should not be advertized to the frontend, otherwise it may needlessly copy data into persistently granted buffers. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> --- Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Anthony Perard <anthony.perard@citrix.com> Cc: Kevin Wolf <kwolf@redhat.com> Cc: Max Reitz <mreitz@redhat.com> --- hw/block/xen_disk.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-)