[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH 08/10] vpci/arm: Allow updating BAR's header for non-ECAM bridges
- To: Jan Beulich <jbeulich@xxxxxxxx>, Oleksandr Andrushchenko <andr2000@xxxxxxxxx>
- From: Oleksandr Andrushchenko <Oleksandr_Andrushchenko@xxxxxxxx>
- Date: Fri, 13 Nov 2020 10:39:14 +0000
- Accept-language: en-US
- Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=epam.com; dmarc=pass action=none header.from=epam.com; dkim=pass header.d=epam.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-SenderADCheck; bh=WCClWK2e5vOQFNf52Cc4gu7Npc68nDufeBrTfr+3aYw=; b=hd4jcHk3Twjp3faG7r5HLZoBPJsYd94Aa1Gt+mUik9m8wRkP/HgSl1wIennUqa/QlMHcWO0WdxQyfQF/QsXf/1Vz6KqVpYYbmqpw4COVbC/vi5w/j7FCD7en0ghfHujWedCbrim0SXFwMnSvogSbxymfFYQoPuauioA9vvrK2fsuyA5qU6P6gmkcV2fbTuELxa0RjGs/JedR+BFA3b9f6G0VVstQIgtrTPmFJGeGwhCSdM8vLIWBb78fvU/tbC164TTPXarxqYx6d6/fCHXSvOyp8TzjIVTTjGlgy4lzdJJqzvG4FQowDwpM9n6q+To8Wt//XWNfPL5wNJFehWyMGg==
- Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=jkAUq3Od0LqaZhaB6vpXL97KzwcyLn4INdY0aoWYCzokUBSfg4GZM/XtkD2HztQ7Wf1R9yy8XCSu0ju230dFQk/FD2v67KXxkyrEXu/wQwO3CguyNExKhM9aK7sckrtwYTOcHJ8Gsk5Zvb66LIOaIzJtwb20LHlVQUEb+5Pd0/ls4lCzHUuEbfg9KAfy5TDYY9Y3BTr3MZfL4bqFdcs9H9bKyJpt0JC7rBegLWGxspkEMffH86RWbi7FWdJ4mXr/Daa8RKl8x/b/ak+LYLXbygG4sgS/90N5uq1pzdHxCF515bDaYSqhiORiZ9uPt6jSJmf2zfBty79PXGc8ykhY+w==
- Authentication-results: suse.com; dkim=none (message not signed) header.d=none;suse.com; dmarc=none action=none header.from=epam.com;
- Cc: "iwj@xxxxxxxxxxxxxx" <iwj@xxxxxxxxxxxxxx>, "wl@xxxxxxx" <wl@xxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxxx>, "julien.grall@xxxxxxx" <julien.grall@xxxxxxx>, "Bertrand.Marquis@xxxxxxx" <Bertrand.Marquis@xxxxxxx>, "sstabellini@xxxxxxxxxx" <sstabellini@xxxxxxxxxx>, "roger.pau@xxxxxxxxxx" <roger.pau@xxxxxxxxxx>, "Rahul.Singh@xxxxxxx" <Rahul.Singh@xxxxxxx>
- Delivery-date: Fri, 13 Nov 2020 10:39:28 +0000
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
- Thread-index: AQHWtpbyYHzQ7b7gKkKm7jsDdoAEE6nF4pWAgAACsYA=
- Thread-topic: [PATCH 08/10] vpci/arm: Allow updating BAR's header for non-ECAM bridges
On 11/13/20 12:29 PM, Jan Beulich wrote:
> On 09.11.2020 13:50, Oleksandr Andrushchenko wrote:
>> From: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
>>
>> Non-ECAM host bridges in hwdom go directly to PCI config space,
>> not through vpci (they use their specific method for accessing PCI
>> configuration, e.g. dedicated registers etc.).
> And access to these dedicated registers can't be intercepted?
It can. But then you have to fully emulate that bridge, e.g.
"if we write A to regB and after that write C to regZ then it
means we are accessing config space. If we write...."
I mean this would need lots of code in Xen to achieve that
> It
> would seem to me that if so, such a platform is not capable of
> being virtualized (without cooperation by all the domains in
> possession of devices).
Guest domains always use an emulated ECAM bridge and are easily
trapped and emulated
>
> Jan
|
