[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH v4 1/3] amd/msr: implement VIRT_SPEC_CTRL for HVM guests on top of SPEC_CTRL
- To: Roger Pau Monne <roger.pau@xxxxxxxxxx>
- From: Jan Beulich <jbeulich@xxxxxxxx>
- Date: Thu, 28 Apr 2022 18:11:57 +0200
- 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=WaPDVnSXappEMMzZTDMOrxrg6wKA8NC0+9iz9XAOuzc=; b=cfqGBAOwmcEYyRby48+jp6RPw1f8rt9a0Bmf7Qt/h3Qyup/FRAwAbMKGoWQt212Gz8x22SjjpTmfBdkqT+w0EXr7sc9uPWAMR9334fCqS9L6bq3QNWqfn1fUQbHrwEogV6JtEoSAus2ZMAD4Hu0SoIiyULK653RQ7z0FCqhnYa6e0QVm8wtx1Jco43Lqb0BvG1SFS78T6JKn1nOPsPgquQn6p5poSFgM3GMv1+XarL8jpsoz5GdiFBLBxgcNblIsz4OUC9/Buv8Q5xgOOWeJZIFk3gFumhA9PTnwLjgM9LRoNH/AeW6z1crvtj4OkFOHHncbqsd4Pe+AKX/ZzjpeNA==
- Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=N85UBAU0JgoEh3IDXl2koyOVvqJcMVysMsiRL9iM6oGfZGZX9W+TktVViiSCs7BozrAbHNX1XyikJWVskuuo5FpPJLMRvqftZ80jEaia+Oe1zoEJcW1ruOOpjgsLNVluleNx6+xddWt9X1JMoVWChS+GysgYK+yDth46WOlbUDaSuCAzJX8eustAbh2TfO9P6jkN67BLOxWY9uGBPE4OrcddX0AWCyAT1w21btqxjQeZgMT7eYZ5xtNDwea/7HSAMTpWQg05StEUa8MJ2TgTbqtiWH9aK5H/shbW0HIn3VPM3GYg22MAFrOlRaMw0tHvHrvP7DDjhKTOC+sU/6th2A==
- Authentication-results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=suse.com;
- Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>, Wei Liu <wl@xxxxxxx>, xen-devel@xxxxxxxxxxxxxxxxxxxx
- Delivery-date: Thu, 28 Apr 2022 16:12:12 +0000
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
On 27.04.2022 12:47, Roger Pau Monne wrote:
> Use the logic to set shadow SPEC_CTRL values in order to implement
> support for VIRT_SPEC_CTRL (signaled by VIRT_SSBD CPUID flag) for HVM
> guests. This includes using the spec_ctrl vCPU MSR variable to store
> the guest set value of VIRT_SPEC_CTRL.SSBD, which will be OR'ed with
> any SPEC_CTRL values being set by the guest.
>
> On hardware having SPEC_CTRL VIRT_SPEC_CTRL will not be offered by
> default to guests. VIRT_SPEC_CTRL will only be part of the max CPUID
> policy so it can be enabled for compatibility purposes.
>
> Use '!' to annotate the feature in order to express that the presence
> of the bit is not directly tied to its value in the host policy.
>
> Suggested-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
|
