From: "Jan Beulich" <JBeulich@suse.com>
To: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Ian Jackson <Ian.Jackson@eu.citrix.com>,
Wei Liu <wei.liu2@citrix.com>,
Xen-devel <xen-devel@lists.xen.org>
Subject: Re: [PATCH v5 21/21] tools/libxc: Calculate xstate cpuid leaf from guest information
Date: Fri, 08 Apr 2016 16:38:49 -0600 [thread overview]
Message-ID: <5708410902000078000E6243@prv-mh.provo.novell.com> (raw)
In-Reply-To: <57082665.2030906@citrix.com>
>>> On 08.04.16 at 23:45, <andrew.cooper3@citrix.com> wrote:
> On 08/04/16 22:00, Jan Beulich wrote:
>>>>> On 07.04.16 at 13:57, <andrew.cooper3@citrix.com> wrote:
>>> v5:
>>> * Reintroduce PKRU, (again, lost due to rebasing).
>>> * Rewrite the commit message and comments to try and better explain why I am
>>> deliberatly removing host-specific information from the xstate calculation.
>>> * Reintroduce 0xFFFFFFFF masks for EAX, to avoid Coverity complaining about
>>> truncation on assignment.
>> Urgh - I don't think ugliness like this can be justified by Coverity
>> complaining. That would be different if the compiler complained
>> (like compilers other than gcc do).
>
> Hmm - Clang is happy with the code as was.
I should have said "like some compilers other than gcc do".
> I would prefer to avoid the Coverity issue if at all possible. Would a
> (uint32_t) cast be more acceptable?
To me, yes. However, only slightly - you know my general
opposition to casts. As to the Coverity aspect - we have tons of
such apparent truncations all over the hypervisor (and likely also
all over the tool stack), so I don't really see the point of uglifying
the code here just to avoid one single further instance.
Jan
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prev parent reply other threads:[~2016-04-08 22:38 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-07 11:57 [PATCH v5 00/21] x86: Improvements to cpuid handling for guests Andrew Cooper
2016-04-07 11:57 ` [PATCH v5 01/21] xen/x86: Annotate VM applicability in featureset Andrew Cooper
2016-04-07 23:01 ` Jan Beulich
2016-04-07 11:57 ` [PATCH v5 02/21] xen/x86: Calculate maximum host and guest featuresets Andrew Cooper
2016-04-07 23:04 ` Jan Beulich
2016-04-07 11:57 ` [PATCH v5 03/21] xen/x86: Generate deep dependencies of features Andrew Cooper
2016-04-07 23:18 ` Jan Beulich
2016-04-07 23:36 ` Andrew Cooper
2016-04-08 15:17 ` Jan Beulich
2016-04-08 15:18 ` Andrew Cooper
2016-04-07 11:57 ` [PATCH v5 04/21] xen/x86: Clear dependent features when clearing a cpu cap Andrew Cooper
2016-04-08 15:36 ` Konrad Rzeszutek Wilk
2016-04-07 11:57 ` [PATCH v5 05/21] xen/x86: Improve disabling of features which have dependencies Andrew Cooper
2016-04-08 15:04 ` Konrad Rzeszutek Wilk
2016-04-07 11:57 ` [PATCH v5 06/21] xen/x86: Improvements to in-hypervisor cpuid sanity checks Andrew Cooper
2016-04-08 16:10 ` Konrad Rzeszutek Wilk
2016-04-08 18:06 ` Jan Beulich
2016-04-07 11:57 ` [PATCH v5 07/21] x86/cpu: Move set_cpumask() calls into c_early_init() Andrew Cooper
2016-04-08 18:09 ` Jan Beulich
2016-04-07 11:57 ` [PATCH v5 08/21] x86/cpu: Sysctl and common infrastructure for levelling context switching Andrew Cooper
2016-04-07 16:54 ` Daniel De Graaf
2016-04-08 16:12 ` Konrad Rzeszutek Wilk
2016-04-07 11:57 ` [PATCH v5 09/21] x86/cpu: Rework AMD masking MSR setup Andrew Cooper
2016-04-08 16:13 ` Konrad Rzeszutek Wilk
2016-04-07 11:57 ` [PATCH v5 10/21] x86/cpu: Rework Intel masking/faulting setup Andrew Cooper
2016-04-08 16:14 ` Konrad Rzeszutek Wilk
2016-04-07 11:57 ` [PATCH v5 11/21] x86/cpu: Context switch cpuid masks and faulting state in context_switch() Andrew Cooper
2016-04-08 16:15 ` Konrad Rzeszutek Wilk
2016-04-07 11:57 ` [PATCH v5 12/21] x86/pv: Provide custom cpumasks for PV domains Andrew Cooper
2016-04-08 16:17 ` Konrad Rzeszutek Wilk
2016-04-07 11:57 ` [PATCH v5 13/21] x86/domctl: Update PV domain cpumasks when setting cpuid policy Andrew Cooper
2016-04-08 16:26 ` Konrad Rzeszutek Wilk
2016-04-07 11:57 ` [PATCH v5 14/21] xen+tools: Export maximum host and guest cpu featuresets via SYSCTL Andrew Cooper
2016-04-07 16:54 ` Daniel De Graaf
2016-04-08 16:32 ` Konrad Rzeszutek Wilk
2016-04-07 11:57 ` [PATCH v5 15/21] tools/libxc: Modify bitmap operations to take void pointers Andrew Cooper
2016-04-07 13:00 ` Wei Liu
2016-04-08 16:34 ` Konrad Rzeszutek Wilk
2016-04-07 11:57 ` [PATCH v5 16/21] tools/libxc: Use public/featureset.h for cpuid policy generation Andrew Cooper
2016-04-08 16:37 ` Konrad Rzeszutek Wilk
2016-04-07 11:57 ` [PATCH v5 17/21] tools/libxc: Expose the automatically generated cpu featuremask information Andrew Cooper
2016-04-08 16:38 ` Konrad Rzeszutek Wilk
2016-04-07 11:57 ` [PATCH v5 18/21] tools: Utility for dealing with featuresets Andrew Cooper
2016-04-07 11:57 ` [PATCH v5 19/21] tools/libxc: Wire a featureset through to cpuid policy logic Andrew Cooper
2016-04-07 11:57 ` [PATCH v5 20/21] tools/libxc: Use featuresets rather than guesswork Andrew Cooper
2016-04-07 11:57 ` [PATCH v5 21/21] tools/libxc: Calculate xstate cpuid leaf from guest information Andrew Cooper
2016-04-07 12:58 ` Wei Liu
2016-04-08 21:00 ` Jan Beulich
2016-04-08 21:45 ` Andrew Cooper
2016-04-08 22:38 ` Jan Beulich [this message]
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