[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH v6] xen/arm, xen/common: Add Kconfig option to control Dom0 boot
- To: Oleksii Moisieiev <Oleksii_Moisieiev@xxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxxx>
- From: "Orzel, Michal" <michal.orzel@xxxxxxx>
- Date: Tue, 3 Nov 2026 14:36:51 +0100
- Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=epam.com smtp.mailfrom=amd.com; dmarc=pass (p=quarantine sp=quarantine pct=100) action=none header.from=amd.com; dkim=none (message not signed); arc=none (0)
- Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=TLXxDDzay/XWPULdaARIIP1hK/MDq+md2UPipBznMkw=; b=QvjIglebux+n6i7j/efx0vYJ3PaXFNJLYsCEp+zpyGuhjNe5M1HTUADx+N+2G3X0vfSNoYElQfJotIVx59p9yid9CjxcNeIFW7aAcivX2XEs3ree1J18zTOh4v9XDx1RK5z33iqSJHLRUrSzCCliLwrlMRROWRk0pHjPUakuOEXdm2kJMCVNTjZ6hGg+9xTGl136uFuwqsOvJ4Hze6S70+XKKUVIcIF0MVi3kfCl+905KRfV32q/P3n0Yg9DMDNdGeW0vUOyH/DHRfPYaza9IAQe+M79HmjQiI8TtXyoXOsAb1x2QEILVwOiFnMTviRS9x/iI42XNvnNIq2WHHFLPg==
- Arc-seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=FVs1mPY53ZQkrA1Kx3h8RYWIXq0dRwQh6GUwJWj+JILAQ/bTq/zHK2ZJMcZ6r22uuk+4kje3n64WsMLe6AtYQKnOzxofSd8OClAkxhDvOBTURKtPPWmdHck9vFuUKWHyvkhUyttUdikAg9sXQn70I8joeM6FSuJ4TlnfiygGa+p1z+naT7fbp0KfvwRXKdhoartdGnPbU5aFnS1dR2OmtNMHbYxatmXzAcPC2VD39lc7tyIeTkkO0lce0+IT5PIoF/rK4W5/hkjoBhkkNUCa4EgFe3dbdugiN22QyKGJ6hTMC5AHc/SKOo7q3h/wd/bQGoGL4PP8V6FK05WFK5PYFA==
- Authentication-results: eu.smtp.expurgate.cloud; dkim=pass header.s=selector1 header.d=amd.com header.i="@amd.com" header.h="From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck"
- Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>, Anthony PERARD <anthony.perard@xxxxxxxxxx>, Bertrand Marquis <bertrand.marquis@xxxxxxx>, "Jan Beulich" <jbeulich@xxxxxxxx>, Julien Grall <julien@xxxxxxx>, Roger Pau Monné <roger@xxxxxxxxxxxxxx>, Stefano Stabellini <sstabellini@xxxxxxxxxx>, Teddy Astie <teddy.astie@xxxxxxxxxx>, "Volodymyr Babchuk" <Volodymyr_Babchuk@xxxxxxxx>
- Delivery-date: Tue, 03 Nov 2026 13:39:05 +0000
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
On 02-Nov-26 15:58, Oleksii Moisieiev wrote:
> Introduce HAS_DOM0 and a default-enabled DOM0_BOOT option in common
> Kconfig. Arm and x86 select HAS_DOM0. Expert configurations can disable
> DOM0_BOOT; this patch implements the corresponding code exclusion on Arm.
> Making x86 honor the option remains a TODO, potentially as part of the
> Hyperlaunch work. In particular, x86 still builds and boots its legacy
> Dom0 even if DOM0_BOOT is disabled.
>
> On Arm, exclude legacy Dom0 creation and its private memory, vCPU, SVE
> and LLC coloring options when DOM0_BOOT is disabled. Hide DOM0_MEM in
> that configuration and disallow ACPI, since the alternative dom0less boot
> path requires device tree. Keep the x86 DOM0_MEM setting and dom0 command
> line parser available until x86 honors DOM0_BOOT.
>
> Retain the domain and hardware-domain builders, guest SVE and LLC
> coloring support, and Xenstore domain setup: these are also used by
> dom0less guests. This is a switch for legacy Dom0 boot support, not for
> all control-domain or hardware-domain functionality, and it does not
> claim to remove every unreachable path or establish MISRA compliance.
>
> Check for dom0less mode once in the Arm boot path. Otherwise, create Dom0
> when supported or panic when neither boot mode is available.
>
> RISC-V does not yet have a legacy Dom0 boot path in this staging tree,
> so it does not select HAS_DOM0.
>
> Signed-off-by: Oleksii Moisieiev <oleksii_moisieiev@xxxxxxxx>
> Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
Reviewed-by: Michal Orzel <michal.orzel@xxxxxxx>
although I think it would be nice to update the xen cmdline doc too to mention
that dom0 options depend on this config option like it's done in case of e.g.
llc coloring.
~Michal
|
