| Message ID | 20220513180957.90514-3-shentey@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | PIIX3-IDE XEN cleanup | expand |
On Fri, May 13, 2022 at 08:09:56PM +0200, Bernhard Beschow wrote: > The comment is based on commit message > ae4d2eb273b167dad748ea4249720319240b1ac2 'xen-platform: add missing disk > unplug option'. Since it seems to describe design decisions and > limitations that still apply it seems worth having. > > Signed-off-by: Bernhard Beschow <shentey@gmail.com> > --- > diff --git a/hw/ide/piix.c b/hw/ide/piix.c > index 2345fe9e1d..bc1b37512a 100644 > --- a/hw/ide/piix.c > +++ b/hw/ide/piix.c > @@ -173,6 +173,17 @@ static void pci_piix_ide_realize(PCIDevice *dev, Error **errp) > } > } > > +/* > + * The Xen HVM unplug protocol [1] specifies a mechanism to allow guests to > + * request unplug of 'aux' disks (which is stated to mean all IDE disks, > + * except the primary master). > + * > + * NOTE: The semantics of what happens if unplug of all disks and 'aux' disks > + * is simultaneously requested is not clear. The implementation assumes > + * that an 'all' request overrides an 'aux' request. > + * > + * [1] https://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=docs/misc/hvm-emulated-unplug.pandoc > + */ > int pci_piix3_xen_ide_unplug(DeviceState *dev, bool aux) > { > PCIIDEState *pci_ide; That comments seems to focus on 'aux', but it also gives some pointer on what calls the function. So it looks fine. Reviewed-by: Anthony PERARD <anthony.perard@citrix.com> Thanks,
diff --git a/hw/ide/piix.c b/hw/ide/piix.c index 2345fe9e1d..bc1b37512a 100644 --- a/hw/ide/piix.c +++ b/hw/ide/piix.c @@ -173,6 +173,17 @@ static void pci_piix_ide_realize(PCIDevice *dev, Error **errp) } } +/* + * The Xen HVM unplug protocol [1] specifies a mechanism to allow guests to + * request unplug of 'aux' disks (which is stated to mean all IDE disks, + * except the primary master). + * + * NOTE: The semantics of what happens if unplug of all disks and 'aux' disks + * is simultaneously requested is not clear. The implementation assumes + * that an 'all' request overrides an 'aux' request. + * + * [1] https://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=docs/misc/hvm-emulated-unplug.pandoc + */ int pci_piix3_xen_ide_unplug(DeviceState *dev, bool aux) { PCIIDEState *pci_ide;
The comment is based on commit message ae4d2eb273b167dad748ea4249720319240b1ac2 'xen-platform: add missing disk unplug option'. Since it seems to describe design decisions and limitations that still apply it seems worth having. Signed-off-by: Bernhard Beschow <shentey@gmail.com> --- hw/ide/piix.c | 11 +++++++++++ 1 file changed, 11 insertions(+)