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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?MyWUTw6v0PDMPQwR7AzzqO7eeN3gYxWYO/lCYhqumccaXetubi3tVRiMlgMB?= =?us-ascii?Q?AX6QIsygxyuAWeZf71pqgP0SBIVVWWIpAc61vKl6Y6nB/gGM1vDd+8X67ljA?= =?us-ascii?Q?/gZIB35LexYmTZ0afBcYPN0q85cwHLws5ADiqKqWXShD+CzMv/PF1/sODd3E?= =?us-ascii?Q?nfnq6Ypp9fM+1D+NO1Gj6uAoBXI3J1LhPwGsGkXLSgdgkFEnfpAtYDU9B59P?= =?us-ascii?Q?OZpOb9imrc3ONR+Nn/DAaigubRjKAQLXhuTo7mH2tDBHpqdHyBIldoD++JJK?= =?us-ascii?Q?z8956fhykpZVs+PoY8SSXuYCH46GuZb0dWddAqvHHtV0UpyYQsCnmdzdvWoT?= =?us-ascii?Q?KhFBG2QXtAHMbaOMMFPk36W3hBEBbSN3zuiZwtvVS7/KLI729KktIdBa2+BU?= =?us-ascii?Q?eLupo6VwtuSgSBuUClRh+lGBX2ULLm/qXbp2i8cGW/sLIjNyhVOkLbsjzkO1?= =?us-ascii?Q?0EvOP6Jh7fSnVBDk9vlgC2SktT6oreB4k8E2LHWZFRUVUp3RKkhsh4C/jkRx?= =?us-ascii?Q?SpbF6t7gd+WCvXfOpSGKnhLd/4AOHQC5rTf0h0chqv/Te/qQ0LaMZdanYMPT?= =?us-ascii?Q?LTrAhincibvZt2GWTFpO15Oz3NHrfluUv99mtnX1kePuvXw2xZtLeagX2TUP?= =?us-ascii?Q?D06Jv8IVqWeftRuoFMqqkSjt3nXYyGZTX8hd30EjNltupWXL7SD/Wa+F8Y42?= =?us-ascii?Q?1WRJ1OhVRc4WWlRucbqUDlfF56Oy/d0f74t1PF5E/JXOrd/O0V9EC2UpXyUF?= =?us-ascii?Q?HLN/nA7RZ+Nai6Z/OqddkP0tlowdZnXs4re4djG5QwPF22yRWwhK8oGf2H9e?= =?us-ascii?Q?JJYzbwMdaSshFveT/PJQ4KzwFw+kyLytRJenLKWrHvDpMePIvWJc1QlYYJdP?= =?us-ascii?Q?Cq6yXRgITfUWQuUgIymM1WYzQp/QMSsCzbE25KVtxCsbI6MUIkl899k06AcD?= =?us-ascii?Q?3i3rA1snd87FmsZL7Ttu3tD5YnohMxBfoNGApFhyYPbr1NjIQvztEt2rnGDh?= =?us-ascii?Q?Uvt68OqlEufpSIUn3Bd5ED4TzAMA/qbsYb6Zxkgbc49O0H6q9TtKq+sa0ZSZ?= =?us-ascii?Q?DJ4+dBLJmWjfRtsJg8CYBJx2J5qlmgNGAJlxX1Vny2hR5a9aMw76eGR7ww1Y?= =?us-ascii?Q?4Glc8RctrCWPIhnmLydO/nJdpwUOzu6nAyhwGv0/jinOJd6Woa4Ddw/beqKI?= =?us-ascii?Q?bGD8MOsmlnCfMgwrOdeUqYRavdBXzUjA+AzUcNmZCHku/6RNx4+Dfw+qO1zL?= =?us-ascii?Q?AcoaDcweR99bxp2hEY719TIVWACiplfjUQGV8ghHstWEaLdp4wznjHji6b7n?= =?us-ascii?Q?vAG3OhHEXr67gDQMK78FpV13IV8bbmfuWpb6N0tkVLh/PGyGsNtwXEih7kCR?= =?us-ascii?Q?ro2Dl36eHtISO+Y7AaA+jKU3khPdO2QL7DMzm6QbGkgt/WmLFaRkc8+PJ5m7?= =?us-ascii?Q?fwDO1VJx0Fi4W8qenb/6x2Qdg31OmaQCTJJGySbb4/Ca9vgCS5j+zUfZymoa?= =?us-ascii?Q?9Oz+sVQbsVAULTXc6lcOxllJsDoV+EeYkMY77vu68Aq1QS5q6NJ6OPeCNVj6?= =?us-ascii?Q?8j9qzM5hdfEegBvcyl1z5tPdsm/lGuHUEAEn+VjPDStjAhnmIer5bL+0rRg/?= =?us-ascii?Q?Dd//5AKAC+SpwKkVh9qgg0c=3D?= X-OriginatorOrg: suse.com X-MS-Exchange-CrossTenant-Network-Message-Id: 9729f07c-32a5-46b0-525b-08d9f6bd41ad X-MS-Exchange-CrossTenant-AuthSource: VI1PR04MB5600.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 23 Feb 2022 11:11:36.2640 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: f7a17af6-1c5c-4a36-aa8b-f5be247aa4ba X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: OTwoY5pbwLFM1q9eGidl+BcN43FUCupiSQsVXrqP5uvr3mfUSj4oBmMlr6sWH/VR32iO0AUjGYRndwqgdRxOYA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PA4PR04MB9247 On 23.02.2022 11:54, Andrew Cooper wrote: > On 23/02/2022 10:12, Jan Beulich wrote: >> This wasn't really necessary to introduce: The binutils change >> permitting use of standalone "ds" (and "cs") in 64-bit code predates >> the minimum binutils version we support. >> >> Signed-off-by: Jan Beulich >=20 > Acked-by: Andrew Cooper Thanks. > I was never a fan of NOP_DS_PREFIX.=C2=A0 Far too verbose for what it's d= oing. >=20 >> --- >> In fact we could patch _just_ the opcode prefix in flush_area_local(). >> >> --- a/xen/arch/x86/flushtlb.c >> +++ b/xen/arch/x86/flushtlb.c >> @@ -247,8 +247,7 @@ unsigned int flush_area_local(const void >> { >> alternative("", "sfence", X86_FEATURE_CLFLUSHOPT); >> for ( i =3D 0; i < sz; i +=3D c->x86_clflush_size ) >> - alternative_input(".byte " __stringify(NOP_DS_PREFIX) "= ;" >> - " clflush %0", >> + alternative_input("ds; clflush %0", >=20 > Binutils appears to be happy with "ds clflush", i.e. treating it like a > proper prefix on the instruction.=C2=A0 Drop the semicolon at the same ti= me? I'd rather not. A clever assembler may eliminate the prefix as redundant when the base register isn't stack or frame pointer. In 64-bit mode an assembler might even decide to eliminate all non-standalone segment overrides using the pre-386 segment registers. Jan