[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH v2 2/5] Mini-OS: get own domid
- To: Julien Grall <julien@xxxxxxx>
- From: Jan Beulich <jbeulich@xxxxxxxx>
- Date: Mon, 13 Nov 2023 08:37:55 +0100
- Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=suse.com; dmarc=pass action=none header.from=suse.com; dkim=pass header.d=suse.com; arc=none
- Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; 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=hDUeW0XPspN95vuVrFqgAsyIfEXIkSk9X62a717lfHE=; b=MI83sGI3vZIPr8FATsn2UXA5iNyDyIEcA0gkLr3aFv+i0fSJvYjFuZGEz7ZxcfH/LRDxrvoypvj85Nijs/825GUMhVpuQFyvYLH7UGv04opes299lanH7la19GNjGFGtwJy7PgPgw5O+TSF6DLIPA1zbgO3Ch4XJPPpXLi2aECG9z8sGSQeM3FyDXuEjZ3J90dA4YoM198/edGlA5G1qw34VWJlUkU2BDH06sDZ91IivslCfvObDfTZwJxYglLowUBFfVx7I+6fVS6CU+y5q+wA7vZUAJEwJnh04Ef7z2C3ncPYtgRdYpecF99zumuSCQUSX3uoRG/F8LH3tBqV72w==
- Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=cWkV3lsjyos/eNGhqG8WvWfZAkpH5J89lYy9+xAVy1Gl5F19O7tdOcgzPSurZQnVY90jKPCXmErZIgodOioXWhAYzKWa2x8A28bfRW+iCHT11xezYi+//fSMRrvPSqS3Cb3avnW8CE82RgRm6RtkMkbEMfSeeoNBcayeNDead8Max+w8mrRnVAV/wGF1wUOfkn/6d+zPJp159lF1h5itnWl5qJ95/c8oErDT91rGg4wZk/3+xqieMGELHBW5zqZnyMJlgjMNtUIPRD4bDpQ7OcqWozYeUGygihaOv99JhWtCY1oxjC7rLZwPzRvCQe8eFnQv5dkmPYiGhK9EtWDoJg==
- Authentication-results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=suse.com;
- Cc: minios-devel@xxxxxxxxxxxxxxxxxxxx, xen-devel@xxxxxxxxxxxxxxxxxxxx, samuel.thibault@xxxxxxxxxxxx, wl@xxxxxxx, Juergen Gross <jgross@xxxxxxxx>, Roger Pau Monné <roger.pau@xxxxxxxxxx>
- Delivery-date: Mon, 13 Nov 2023 07:38:02 +0000
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
On 10.11.2023 18:38, Julien Grall wrote:
> Hi Jan,
>
> On 10/11/2023 12:44, Jan Beulich wrote:
>> On 10.11.2023 13:23, Roger Pau Monné wrote:
>>> On Fri, Nov 10, 2023 at 12:34:32PM +0100, Juergen Gross wrote:
>>>> Get the own domid via creation of a temporary event channel. There is
>>>> no "official" way to read the own domid in PV guests, so use the event
>>>> channel interface to get it:
>>>>
>>>> - allocate an unbound event channel specifying DOMID_SELF for the
>>>> other end
>>>>
>>>> - read the event channel status which will contain the own domid in
>>>> unbound.dom
>>>>
>>>> - close the event channel
>>>
>>> Should we look into introducing a way to expose the domid, so that in
>>> the future we might not need to resort to this workarounds to get the
>>> domid?
>>>
>>> Maybe in the PV-specific cpuid leaf? It's a shame we didn't put it in
>>> a non-HVM specific leaf when it was made available to HVM for pvshim
>>> reasons.
>>
>> Couldn't we retroactively generalize the type-agnostic parts of that
>> leaf?
>
> This would only work for x86. I think we want to have a generic
> hypercalls so it can be used by all arch.
Hmm, yes, perhaps. Otoh it would seem desirable to me if arch-es also
provided some extension to an arch-natural way of feature detection
(which CPUID is on x86), without the need to invoke any hypercalls.
Jan
|
