On Tue, Mar 01, 2022 at 12:00:21PM +0000, Stefan Hajnoczi wrote: > Block devices can change size during operation. A configuration change > notification is sent by the device and the driver detects that the field > has changed. Document this behavior that has already been implemented in > Linux and QEMU since 2011. > > Signed-off-by: Stefan Hajnoczi <[email protected]>
Acked-by: Michael S. Tsirkin <[email protected]> github issue so we can track this? > --- > content.tex | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/content.tex b/content.tex > index c6f116c..96d2aa9 100644 > --- a/content.tex > +++ b/content.tex > @@ -4863,6 +4863,9 @@ \subsection{Device Operation}\label{sec:Device Types / > Block Device / Device Ope > > \drivernormative{\subsubsection}{Device Operation}{Device Types / Block > Device / Device Operation} > > +The driver SHOULD check if the content of the \field{capacity} field has > +changed upon receiving a configuration change notification. > + > A driver MUST NOT submit a request which would cause a read or write > beyond \field{capacity}. > > @@ -4909,6 +4912,10 @@ \subsection{Device Operation}\label{sec:Device Types / > Block Device / Device Ope > > \devicenormative{\subsubsection}{Device Operation}{Device Types / Block > Device / Device Operation} > > +The device MAY change the content of the \field{capacity} field during > +operation of the device. When this happens, the device SHOULD trigger a > +configuration change notification. > + > A device MUST set the \field{status} byte to VIRTIO_BLK_S_IOERR > for a write request if the VIRTIO_BLK_F_RO feature if offered, and MUST NOT > write any data. > -- > 2.35.1 --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
