hw/block/dataplane/xen-block.c | 4 +--- hw/block/trace-events | 1 + hw/block/xen-block.c | 40 ++++++++++++++++++++++++++++++---- 3 files changed, 38 insertions(+), 7 deletions(-)
Some frontend drivers will handle dynamic resizing of PV disks, so set up
the BlockDevOps resize_cb() method during xen_block_realize() to allow
this to be done.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
---
Cc: Stefan Hajnoczi <stefanha@redhat.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>
v2:
- re-write backend state after updating sectors
---
hw/block/dataplane/xen-block.c | 4 +---
hw/block/trace-events | 1 +
hw/block/xen-block.c | 40 ++++++++++++++++++++++++++++++----
3 files changed, 38 insertions(+), 7 deletions(-)
diff --git a/hw/block/dataplane/xen-block.c b/hw/block/dataplane/xen-block.c
index d0d8905a33..c6a15da024 100644
--- a/hw/block/dataplane/xen-block.c
+++ b/hw/block/dataplane/xen-block.c
@@ -50,7 +50,6 @@ struct XenBlockDataPlane {
unsigned int nr_ring_ref;
void *sring;
int64_t file_blk;
- int64_t file_size;
int protocol;
blkif_back_rings_t rings;
int more_work;
@@ -189,7 +188,7 @@ static int xen_block_parse_request(XenBlockRequest *request)
request->req.seg[i].first_sect + 1) * dataplane->file_blk;
request->size += len;
}
- if (request->start + request->size > dataplane->file_size) {
+ if (request->start + request->size > blk_getlength(dataplane->blk)) {
error_report("error: access beyond end of file");
goto err;
}
@@ -638,7 +637,6 @@ XenBlockDataPlane *xen_block_dataplane_create(XenDevice *xendev,
dataplane->xendev = xendev;
dataplane->file_blk = conf->logical_block_size;
dataplane->blk = conf->blk;
- dataplane->file_size = blk_getlength(dataplane->blk);
QLIST_INIT(&dataplane->inflight);
QLIST_INIT(&dataplane->freelist);
diff --git a/hw/block/trace-events b/hw/block/trace-events
index d0851953c5..8020f9226a 100644
--- a/hw/block/trace-events
+++ b/hw/block/trace-events
@@ -126,6 +126,7 @@ xen_block_realize(const char *type, uint32_t disk, uint32_t partition) "%s d%up%
xen_block_connect(const char *type, uint32_t disk, uint32_t partition) "%s d%up%u"
xen_block_disconnect(const char *type, uint32_t disk, uint32_t partition) "%s d%up%u"
xen_block_unrealize(const char *type, uint32_t disk, uint32_t partition) "%s d%up%u"
+xen_block_size(const char *type, uint32_t disk, uint32_t partition, int64_t sectors) "%s d%up%u %"PRIi64
xen_disk_realize(void) ""
xen_disk_unrealize(void) ""
xen_cdrom_realize(void) ""
diff --git a/hw/block/xen-block.c b/hw/block/xen-block.c
index a636487b3e..0f0799e861 100644
--- a/hw/block/xen-block.c
+++ b/hw/block/xen-block.c
@@ -144,6 +144,38 @@ static void xen_block_unrealize(XenDevice *xendev, Error **errp)
}
}
+static void xen_block_set_size(XenBlockDevice *blockdev)
+{
+ const char *type = object_get_typename(OBJECT(blockdev));
+ XenBlockVdev *vdev = &blockdev->props.vdev;
+ BlockConf *conf = &blockdev->props.conf;
+ int64_t sectors = blk_getlength(conf->blk) / conf->logical_block_size;
+ XenDevice *xendev = XEN_DEVICE(blockdev);
+
+ trace_xen_block_size(type, vdev->disk, vdev->partition, sectors);
+
+ xen_device_backend_printf(xendev, "sectors", "%"PRIi64, sectors);
+}
+
+static void xen_block_resize_cb(void *opaque)
+{
+ XenBlockDevice *blockdev = opaque;
+ XenDevice *xendev = XEN_DEVICE(blockdev);
+ enum xenbus_state backend_state = xen_device_backend_get_state(xendev);
+
+ xen_block_set_size(blockdev);
+
+ /*
+ * Mimic the behaviour of Linux xen-blkback and re-write the state
+ * to trigger the frontend watch.
+ */
+ xen_device_backend_set_state(xendev, backend_state);
+}
+
+static const BlockDevOps xen_block_dev_ops = {
+ .resize_cb = xen_block_resize_cb,
+};
+
static void xen_block_realize(XenDevice *xendev, Error **errp)
{
XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
@@ -180,7 +212,7 @@ static void xen_block_realize(XenDevice *xendev, Error **errp)
}
if (!blkconf_apply_backend_options(conf, blockdev->info & VDISK_READONLY,
- false, errp)) {
+ true, errp)) {
return;
}
@@ -197,6 +229,7 @@ static void xen_block_realize(XenDevice *xendev, Error **errp)
return;
}
+ blk_set_dev_ops(conf->blk, &xen_block_dev_ops, blockdev);
blk_set_guest_block_size(conf->blk, conf->logical_block_size);
if (conf->discard_granularity > 0) {
@@ -215,9 +248,8 @@ static void xen_block_realize(XenDevice *xendev, Error **errp)
xen_device_backend_printf(xendev, "sector-size", "%u",
conf->logical_block_size);
- xen_device_backend_printf(xendev, "sectors", "%"PRIi64,
- blk_getlength(conf->blk) /
- conf->logical_block_size);
+
+ xen_block_set_size(blockdev);
blockdev->dataplane =
xen_block_dataplane_create(xendev, conf, blockdev->props.iothread);
--
2.20.1.2.gb21ebb6
On Wed, Jan 30, 2019 at 04:19:48PM +0000, Paul Durrant wrote: > Some frontend drivers will handle dynamic resizing of PV disks, so set up > the BlockDevOps resize_cb() method during xen_block_realize() to allow > this to be done. > > Signed-off-by: Paul Durrant <paul.durrant@citrix.com> > --- > + /* > + * Mimic the behaviour of Linux xen-blkback and re-write the state > + * to trigger the frontend watch. > + */ > + xen_device_backend_set_state(xendev, backend_state); :(, that function doesn't write the state again if it hasn't changed. So in my testing, Linux never did anything. -- Anthony PERARD
> -----Original Message----- > From: Anthony PERARD [mailto:anthony.perard@citrix.com] > Sent: 31 January 2019 15:21 > To: Paul Durrant <Paul.Durrant@citrix.com> > Cc: qemu-devel@nongnu.org; qemu-block@nongnu.org; xen- > devel@lists.xenproject.org; Stefan Hajnoczi <stefanha@redhat.com>; Stefano > Stabellini <sstabellini@kernel.org>; Kevin Wolf <kwolf@redhat.com>; Max > Reitz <mreitz@redhat.com> > Subject: Re: [PATCH v2] xen-block: handle resize callback > > On Wed, Jan 30, 2019 at 04:19:48PM +0000, Paul Durrant wrote: > > Some frontend drivers will handle dynamic resizing of PV disks, so set > up > > the BlockDevOps resize_cb() method during xen_block_realize() to allow > > this to be done. > > > > Signed-off-by: Paul Durrant <paul.durrant@citrix.com> > > --- > > > > + /* > > + * Mimic the behaviour of Linux xen-blkback and re-write the state > > + * to trigger the frontend watch. > > + */ > > + xen_device_backend_set_state(xendev, backend_state); > > :(, that function doesn't write the state again if it hasn't changed. > So in my testing, Linux never did anything. Gah! I forgot about that. Alright, it's going to have to be a bit more crude. Paul > > -- > Anthony PERARD
On Thu, Jan 31, 2019 at 03:22:18PM +0000, Paul Durrant wrote: > > -----Original Message----- > > From: Anthony PERARD [mailto:anthony.perard@citrix.com] > > Sent: 31 January 2019 15:21 > > To: Paul Durrant <Paul.Durrant@citrix.com> > > Cc: qemu-devel@nongnu.org; qemu-block@nongnu.org; xen- > > devel@lists.xenproject.org; Stefan Hajnoczi <stefanha@redhat.com>; Stefano > > Stabellini <sstabellini@kernel.org>; Kevin Wolf <kwolf@redhat.com>; Max > > Reitz <mreitz@redhat.com> > > Subject: Re: [PATCH v2] xen-block: handle resize callback > > > > On Wed, Jan 30, 2019 at 04:19:48PM +0000, Paul Durrant wrote: > > > Some frontend drivers will handle dynamic resizing of PV disks, so set > > up > > > the BlockDevOps resize_cb() method during xen_block_realize() to allow > > > this to be done. > > > > > > Signed-off-by: Paul Durrant <paul.durrant@citrix.com> > > > --- > > > > > > > + /* > > > + * Mimic the behaviour of Linux xen-blkback and re-write the state > > > + * to trigger the frontend watch. > > > + */ > > > + xen_device_backend_set_state(xendev, backend_state); > > > > :(, that function doesn't write the state again if it hasn't changed. > > So in my testing, Linux never did anything. > > Gah! I forgot about that. Alright, it's going to have to be a bit more crude. more crude > Yes, I tried to ignore the check in _set_state and end-up with an infinit loop. -- Anthony PERARD
> -----Original Message----- > From: Anthony PERARD [mailto:anthony.perard@citrix.com] > Sent: 31 January 2019 15:25 > To: Paul Durrant <Paul.Durrant@citrix.com> > Cc: qemu-devel@nongnu.org; qemu-block@nongnu.org; xen- > devel@lists.xenproject.org; Stefan Hajnoczi <stefanha@redhat.com>; Stefano > Stabellini <sstabellini@kernel.org>; Kevin Wolf <kwolf@redhat.com>; Max > Reitz <mreitz@redhat.com> > Subject: Re: [PATCH v2] xen-block: handle resize callback > > On Thu, Jan 31, 2019 at 03:22:18PM +0000, Paul Durrant wrote: > > > -----Original Message----- > > > From: Anthony PERARD [mailto:anthony.perard@citrix.com] > > > Sent: 31 January 2019 15:21 > > > To: Paul Durrant <Paul.Durrant@citrix.com> > > > Cc: qemu-devel@nongnu.org; qemu-block@nongnu.org; xen- > > > devel@lists.xenproject.org; Stefan Hajnoczi <stefanha@redhat.com>; > Stefano > > > Stabellini <sstabellini@kernel.org>; Kevin Wolf <kwolf@redhat.com>; > Max > > > Reitz <mreitz@redhat.com> > > > Subject: Re: [PATCH v2] xen-block: handle resize callback > > > > > > On Wed, Jan 30, 2019 at 04:19:48PM +0000, Paul Durrant wrote: > > > > Some frontend drivers will handle dynamic resizing of PV disks, so > set > > > up > > > > the BlockDevOps resize_cb() method during xen_block_realize() to > allow > > > > this to be done. > > > > > > > > Signed-off-by: Paul Durrant <paul.durrant@citrix.com> > > > > --- > > > > > > > > > > + /* > > > > + * Mimic the behaviour of Linux xen-blkback and re-write the > state > > > > + * to trigger the frontend watch. > > > > + */ > > > > + xen_device_backend_set_state(xendev, backend_state); > > > > > > :(, that function doesn't write the state again if it hasn't changed. > > > So in my testing, Linux never did anything. > > > > Gah! I forgot about that. Alright, it's going to have to be a bit more > crude. > > more crude > Yes, I tried to ignore the check in _set_state and end-up > with an infinit loop. Yes, you would. That check is there for a reason :-) I'll replace the call in xen-block.c with a call to xen_device_backend_printf(). Paul > > -- > Anthony PERARD
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