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charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: epam.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: VI1PR03MB3710.eurprd03.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: c908b975-f085-4d55-c2cc-08dbef296ec9 X-MS-Exchange-CrossTenant-originalarrivaltime: 27 Nov 2023 09:15:43.3919 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: b41b72d0-4e9f-4c26-8a69-f949f367c91d X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: kQHQTZK6WLjgB1ehk1w3cv1cDV3fIHrol/lqaJwfwPtoFgtO4gI7TKl6NRUc5UWLElRXuiK4jE5hC9z0mYD7kaqve31SHKL21HhhBw7gSmA= X-MS-Exchange-Transport-CrossTenantHeadersStamped: AS8PR03MB6741 X-Proofpoint-GUID: ovnmhCe0hxnTS8isImgkJDed2dlVCqQh X-Proofpoint-ORIG-GUID: ovnmhCe0hxnTS8isImgkJDed2dlVCqQh X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.987,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-11-27_07,2023-11-22_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 clxscore=1015 mlxscore=0 malwarescore=0 adultscore=0 suspectscore=0 phishscore=0 spamscore=0 mlxlogscore=999 bulkscore=0 impostorscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2311060000 definitions=main-2311270064 Hi David, "Woodhouse, David" writes: > [[S/MIME Signed Part:Undecided]] > On Fri, 2023-11-24 at 23:24 +0000, Volodymyr Babchuk wrote: >> This patch makes legacy backends optional. As was discussed at [1] >> this is a solution to a problem when we can't run QEMU as a device >> model in a non-privileged domain. This is because legacy backends >> assume that they are always running in domain with ID =3D 0. Actually, >> this may prevent running QEMU in a privileged domain with ID not equal >> to zero. >>=20 >> To be able to disable legacy backends we need to alter couple of >> source files that unintentionally depend on them. For example >> xen-all.c used xen_pv_printf to report errors, while not providing any >> additional like xendev pointer. Also, we need to move xenstore >> structure from xen-legacy-backend.c, because it is apparently used in >> xen-all.c. >>=20 >> With this patch it is possible to provide >> "--disable-xen-legacy-backends" configure option to get QEMU binary >> that can run in a driver domain. With price of not be able to use >> legacy backends of course. >>=20 >> [1] >> https://lists.gnu.org/archive/html/qemu-devel/2023-11/msg05022.html >>=20 >> Signed-off-by: Volodymyr Babchuk >>=20 >> --- >>=20 >> I am not sure if I made correct changes to the build system, thus this >> patch is tagged as RFC. > > Hm, I was imagining a new CONFIG_LEGACY_XEN_BACKENDS option which would > look a lot like CONFIG_XEN_BUS (which would now be only for the new > XenBus code). > It was my original intention too. But it appears that it is not possible to add Kconfig value and then make it configurable via ./config script. As I understood it can be set only via defconfig file. > This looks weird to me: > >> --- a/hw/display/meson.build >> +++ b/hw/display/meson.build >> @@ -14,7 +14,9 @@ system_ss.add(when: 'CONFIG_PL110', if_true: >> files('pl110.c')) >> system_ss.add(when: 'CONFIG_SII9022', if_true: files('sii9022.c')) >> system_ss.add(when: 'CONFIG_SSD0303', if_true: files('ssd0303.c')) >> system_ss.add(when: 'CONFIG_SSD0323', if_true: files('ssd0323.c')) >> -system_ss.add(when: 'CONFIG_XEN_BUS', if_true: files('xenfb.c')) >> +if have_xen_legacy_backends >> + system_ss.add(when: 'CONFIG_XEN_BUS', if_true: files('xenfb.c')) >> +endif >>=20 >> system_ss.add(when: 'CONFIG_VGA_PCI', if_true: files('vga-pci.c')) >> system_ss.add(when: 'CONFIG_VGA_ISA', if_true: files('vga-isa.c')) > > I'd prefer to see just: > > -system_ss.add(when: 'CONFIG_XEN_BUS', if_true: files('xenfb.c')) > +system_ss.add(when: 'CONFIG_XEN_LEGACY_BACKENDS', if_true: files('xenfb.= c')) I tried, but it does not work this way. I need to create Kconfig variable to do this, but then other problems appear. > > Probably also better to split out the bits in accel/xen/xen-all.c and > hw/xen/xen-legacy-backend.c to a separate preparatory commit. Okay, will do. --=20 WBR, Volodymyr=