[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH v1 1/2] x86/viridian: Workaround Hyper-V GP fault writing to MSR
- To: Jan Beulich <jbeulich@xxxxxxxx>
- From: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
- Date: Thu, 3 Sep 2026 11:55:48 +0100
- 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=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=IgdSTHhGOXN6NHcc5q3jDwnh6tsUFiTXaHjBqXLZ37E=; b=fM37zn3dkomPNmNqYvmXSbjeFhpHXdx8ThXOgbFQNF5uH4PyO9HyuXPS5FCd4Fid07Z1f0zfpcGUvXlFLiYs3lsfxO8/jyAkDcqt50r9lUVeOeIjkmbk5Mu35b34dVwlAbB5Q6Oz8AaCWCVuPGxUwwuLBvy+fncbnlC/SKyQoDfx13rL1B4oOEllGLukBNscIoWwrmbJXpuTypO3jbJSTbcyue2ztcy9rcMBjZWF4Yb1lSDIXux8Jv+dH+MeHOIzjmp6O6EahpdZlNFN0GsFKn+BduLLSSOsIdiXrVqJMbn5dJL7rl8bEaz8pW0tZ6OGMBjnXDefjobvNYOPpCmnNA==
- Arc-seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=DxasIE8sYbZEka0dBH3enj30RHdi2Wb+A5+nQfEnjrOTkC2x0/6mc0k4COKTMctKWkhxLTB84MBxWQtrcI4fc4K+s8b1kfPfLi2p8zRniGbXh0czgz+JKolS8w5tsdYAphcqfPQimJD46fi0sR1DFlG5FV+5Fe+K9Fz0MZ0Aw1y1HpaVe3PidLdbvU2I0xEtxWs48yKRwBsIedtixcTTkTGfmvgxByRKMembbjbDdzVD74W99alULaA6MhoCUhuNrYEJumyLtIlm2bTj/o2nnpQzVkgKa9L6GLge5wMpkpEietnJ7H0u7pSXI5MKQGye4gmbKy3GUJIgmAmGdKFf/Q==
- Authentication-results: eu.smtp.expurgate.cloud; dkim=pass header.s=selector1 header.d=citrix.com header.i="@citrix.com" header.h="From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck"
- Authentication-results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=citrix.com;
- Cc: Paul Durrant <paul@xxxxxxx>, Andrew Cooper <andrew.cooper3@xxxxxxxxxx>, Roger Pau Monné <roger@xxxxxxxxxxxxxx>, Teddy Astie <teddy.astie@xxxxxxxxxx>, xen-devel@xxxxxxxxxxxxxxxxxxxx
- Delivery-date: Thu, 03 Sep 2026 10:56:12 +0000
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
On 9/3/26 11:44 AM, Jan Beulich wrote:
On 28.08.2026 15:11, Ross Lagerwall wrote:
The Viridian spec requires the vector to be >= 0x10 when writing to the
SINTx MSR, otherwise it should #GP fault.
The spec-defined initial value is 0x0000000000010000, i.e. the vector is
0. On startup, for some reason Windows 11 Hyper-V tries to set the MSR to
the spec-defined initial value and since the vector is 0, it GP faults.
To workaround this, treat the write as a no-op if the value is
unchanged.
Signed-off-by: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
I expect that despite the (valid) absence of a Fixes: tag this will want
backporting.
It should be fine to backport, though in general I think backporting nested
virt fixes at this point is not needed as there will be too many changes to go
into the stable releases for it to reach a usable state.
Ross
|
