[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH] ns16550c: avoid crash in ns16550_endboot in PV shim mode
- To: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
- From: Roger Pau Monné <roger.pau@xxxxxxxxxx>
- Date: Fri, 20 Oct 2023 15:29:12 +0200
- Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=citrix.com; dmarc=pass action=none header.from=citrix.com; dkim=pass header.d=citrix.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=ZY9UJZzhWkYlJGnK3kQBhSXKCrMAcRkA3g4h7z8Ipec=; b=PMsq9EayDzlDIq3yIo609f6EJEkNmUuwOyl0F7VQWTePLHH0lvM6EV0GWhGAjPVW0X2BNuTNX96rQB0vX52+UhRAmp5rC+TYuciyJ0w11xBgfHMtpvywjyFnI7vF25YuRzKviM4P8md+THoB7L2QYWi+ZLKaM14L+S+lj7uFFP/cxcoXG66grYLfw3l9JDjJZqsma6LzF53ha5cK8o+sj84YZw0H9F/plFi1+XufhAmKJ167uy3Xw0mrmfgoMSeVUFy7RP7h2cgfTyitGXkRvlmK1a0zwqMsM38eNmxOSwiMk9znuxTYJ2D5kMbFqluuhwyaiNo3lsSy2+bKTJpLIg==
- Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=JONCBdlMpVVYmdLbSRjTbv9gsYk6SWnSGJ35TafVKMKCaS2UeY1fnVGJkTBvgn5mw0nsZBKOiHIFz7EcvO3v/rrWjTJJ+7E6mxzlTCAyVznh7CJhD3vC24+qwuhnkTElKlJqqdW1zPEect0Mmmss0urHJEC3JplrZ1FyODiPodbMV33YbIcUB48L9U0So2+kIrWfAIMec2kgMr8yzhq3hpX5kZ6K6mRWwJEDTSxuMCd8swuypSOdtf3jDYk2ITmdvr95uX9oby6jGwZ0V3yy8nfIFsn6IyEO88isiGTa20ACGZtFr5D4AGOxIiOcNI8mVFmQ4bVKMKw61p1w8gChRg==
- Authentication-results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=citrix.com;
- Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>, xen-devel@xxxxxxxxxxxxxxxxxxxx, George Dunlap <george.dunlap@xxxxxxxxxx>, Jan Beulich <jbeulich@xxxxxxxx>, Julien Grall <julien@xxxxxxx>, Stefano Stabellini <sstabellini@xxxxxxxxxx>, Wei Liu <wl@xxxxxxx>
- Delivery-date: Fri, 20 Oct 2023 13:29:46 +0000
- Ironport-data: A9a23:haWq6avBURcwH9KYh4v1nCNq2ufnVLNfMUV32f8akzHdYApBsoF/q tZmKWiDOq2OMDD1KotyPdu0/UJXu8eAmtVlQFNr+y1mRS0W+JbJXdiXEBz9bniYRiHhoOCLz O1FM4Wdc5pkJpP4jk3wWlQ0hSAkjclkfpKlVaicfHg3HFc4IMsYoUoLs/YjhYJ1isSODQqIu Nfjy+XSI1bg0DNvWo4uw/vrRChH4rKq41v0gnRkPaoQ5QeEzyFMZH4iDfrZw0XQE9E88tGSH 44v/JnhlkvF8hEkDM+Sk7qTWiXmlZaLYGBiIlIPM0STqkAqSh4ai87XB9JFAatjsB2bnsgZ9 Tl4ncfYpTHFnEH7sL91vxFwS0mSNEDdkVPNCSDXXce7lyUqf5ZwqhnH4Y5f0YAwo45K7W9yG fMweTAzbCidvr+M26+VS+grn8MYIuDxM9ZK0p1g5Wmx4fcOZ7nmGv+Pz/kImTA6i4ZJAOrUY NcfZXx3dhPcbhZTO1ARTpUjgOOvgXq5eDpdwL6XjfNvvy6Pk0osjf60boq9lt+iHK25mm6Co W3L5SLhCwwyP92D0zuVtHmrg4cjmAuiAt5NS+zgpqQCbFu7zGs5DUZRfH2HouCzuGmTdsIGM Bcy9X97xUQ13AnxJjXnZDW0v3ub5DYdXdRKGuE34Q3LzbDbiy6JC25BQjNfZdgOsM4tWSdsx lKPh8nuBzFkrPuSU3313rWeoC62OCMVBXQffiJCRgwAi/HhvYUygxTnXttlVqmvgbXdAirsy jqHqCw/gbQ7jsMR0ai/u1fdjFqEuZzhXgMzoALNUQqYAhhRYYekY8mi7wjd5PMZdoKBFADf7 D4DhtSU6/0IAdeVjiuRTe4RHbavofGYLDnbhl0pFJ4kn9iwx0OekUlryGkWDC9U3gwsIFcFv Ge7Vdtt2aJu
- Ironport-hdrordr: A9a23:rLSCWK+6fjuTV4Vzz1Fuk+DbI+orL9Y04lQ7vn2ZhyYlFfBw9v re+sjzsCWftN9/YgBCpTntAsm9qBDnlKKdg7NhX4tKNTOO0ACVxepZnO7fKlPbaknDHy1muZ uIsZISNDQ9NzdHZA/BjjWFLw==
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
On Fri, Oct 20, 2023 at 02:25:35PM +0100, Andrew Cooper wrote:
> On 20/10/2023 11:29 am, David Woodhouse wrote:
> > On Fri, 2023-10-20 at 11:14 +0100, Andrew Cooper wrote:
> >> On 19/10/2023 5:21 pm, David Woodhouse wrote:
> >>> From: David Woodhouse <dwmw@xxxxxxxxxxxx>
> >>>
> >>> In shim mode there is no hardware_domain. Dereferencing the pointer
> >>> doesn't end well.
> >>>
> >>> Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
> >>> ---
> >>> This is about as far as I got in my abortive attempt to use the PV shim
> >>> without an actual PV console being provided by the HVM hosting
> >>> environment. It still doesn't pass the guest's console through to
> >>> serial; that only seems to shim to an actual PV console.
> >> There's no such thing as a Xen VM without a PV console.
> > Huh? There are literally millions of them.
>
> I'm very prepared to believe there are millions which don't overtly
> malfunction when you don't fill in the HVM Params.
>
> Which is very different from saying "there's a way in the Xen guest ABI
> to express 'you don't have a PV console' ".
FWIW, Linux assumes that either the console page or the event channel
being 0 implies no console available [0], so I guess that's the ABI
now.
Roger.
[0]
https://elixir.bootlin.com/linux/latest/source/drivers/tty/hvc/hvc_xen.c#L258
|
