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From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: Xen-devel <xen-devel@lists.xen.org>
Subject: Re: [PATCH v4 11/26] xen/x86: Improvements to in-hypervisor cpuid sanity checks
Date: Thu, 24 Mar 2016 17:01:43 +0000	[thread overview]
Message-ID: <56F41D77.50606@citrix.com> (raw)
In-Reply-To: <56F4283402000078000E04A4@prv-mh.provo.novell.com>

On 24/03/16 16:47, Jan Beulich wrote:
>>>> On 23.03.16 at 17:36, <andrew.cooper3@citrix.com> wrote:
>> +        if ( !is_pvh_domain(currd) )
>>          {
>> -            __clear_bit(X86_FEATURE_XSAVE % 32, &c);
>> -            __clear_bit(X86_FEATURE_AVX % 32, &c);
>> +            /*
>> +             * Delete the PVH condition when HVMLite formally replaces PVH,
>> +             * and HVM guests no longer enter a PV codepath.
>> +             */
>> +
>> +            /* OSXSAVE cleared by pv_featureset.  Fast-forward CR4 back in. */
>> +            if ( (is_pv_domain(currd) && guest_kernel_mode(curr, regs) &&
>> +                  (read_cr4() & X86_CR4_OSXSAVE)) ||
>> +                 (curr->arch.pv_vcpu.ctrlreg[4] & X86_CR4_OSXSAVE) )
>> +                c |= cpufeat_mask(X86_FEATURE_OSXSAVE);
>>          }
> The is_pv_domain() is now redundant with the is_pvh_domain()
> earlier on, and it would likely end up confusing the reader if on
> the right side of the || then ->arch.pv_vcpu is being referenced.

I specifically chose to order the code like this to make it easier to
remove the is_pvh_domain() conditional in the future, without having to
re-edit the PV path.

This layout matches the OSPKE version, and I would prefer to keep it
this way unless you really insist on changing it.

~Andrew

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  reply	other threads:[~2016-03-24 17:01 UTC|newest]

Thread overview: 72+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-23 16:36 [PATCH v4 00/26] x86: Improvements to cpuid handling for guests Andrew Cooper
2016-03-23 16:36 ` [PATCH v4 01/26] xen/public: Export cpu featureset information in the public API Andrew Cooper
2016-03-24 14:08   ` Jan Beulich
2016-03-24 14:12     ` Andrew Cooper
2016-03-24 14:16       ` Jan Beulich
2016-03-23 16:36 ` [PATCH v4 02/26] xen/x86: Script to automatically process featureset information Andrew Cooper
2016-03-23 16:36 ` [PATCH v4 03/26] xen/x86: Collect more cpuid feature leaves Andrew Cooper
2016-03-23 16:36 ` [PATCH v4 04/26] xen/x86: Mask out unknown features from Xen's capabilities Andrew Cooper
2016-03-23 16:36 ` [PATCH v4 05/26] xen/x86: Annotate special features Andrew Cooper
2016-03-23 16:36 ` [PATCH v4 06/26] xen/x86: Annotate VM applicability in featureset Andrew Cooper
2016-03-23 16:36 ` [PATCH v4 07/26] xen/x86: Calculate maximum host and guest featuresets Andrew Cooper
2016-03-29  8:57   ` Jan Beulich
2016-03-23 16:36 ` [PATCH v4 08/26] xen/x86: Generate deep dependencies of features Andrew Cooper
2016-03-24 16:16   ` Jan Beulich
2016-03-23 16:36 ` [PATCH v4 09/26] xen/x86: Clear dependent features when clearing a cpu cap Andrew Cooper
2016-03-23 16:36 ` [PATCH v4 10/26] xen/x86: Improve disabling of features which have dependencies Andrew Cooper
2016-03-28 15:18   ` Konrad Rzeszutek Wilk
2016-03-23 16:36 ` [PATCH v4 11/26] xen/x86: Improvements to in-hypervisor cpuid sanity checks Andrew Cooper
2016-03-24 15:38   ` Andrew Cooper
2016-03-24 16:47   ` Jan Beulich
2016-03-24 17:01     ` Andrew Cooper [this message]
2016-03-24 17:11       ` Jan Beulich
2016-03-24 17:12         ` Andrew Cooper
2016-03-28 15:29   ` Konrad Rzeszutek Wilk
2016-04-05 15:25     ` Andrew Cooper
2016-03-23 16:36 ` [PATCH v4 12/26] x86/cpu: Move set_cpumask() calls into c_early_init() Andrew Cooper
2016-03-28 15:55   ` Konrad Rzeszutek Wilk
2016-04-05 16:19     ` Andrew Cooper
2016-03-23 16:36 ` [PATCH v4 13/26] x86/cpu: Sysctl and common infrastructure for levelling context switching Andrew Cooper
2016-03-24 16:58   ` Jan Beulich
2016-03-28 16:12   ` Konrad Rzeszutek Wilk
2016-04-05 16:33     ` Andrew Cooper
2016-03-28 17:37   ` Konrad Rzeszutek Wilk
2016-03-23 16:36 ` [PATCH v4 14/26] x86/cpu: Rework AMD masking MSR setup Andrew Cooper
2016-03-28 18:55   ` Konrad Rzeszutek Wilk
2016-04-05 16:44     ` Andrew Cooper
2016-03-23 16:36 ` [PATCH v4 15/26] x86/cpu: Rework Intel masking/faulting setup Andrew Cooper
2016-03-28 19:14   ` Konrad Rzeszutek Wilk
2016-04-05 16:45     ` Andrew Cooper
2016-03-23 16:36 ` [PATCH v4 16/26] x86/cpu: Context switch cpuid masks and faulting state in context_switch() Andrew Cooper
2016-03-28 19:27   ` Konrad Rzeszutek Wilk
2016-04-05 18:34     ` Andrew Cooper
2016-03-23 16:36 ` [PATCH v4 17/26] x86/pv: Provide custom cpumasks for PV domains Andrew Cooper
2016-03-28 19:40   ` Konrad Rzeszutek Wilk
2016-04-05 16:55     ` Andrew Cooper
2016-03-23 16:36 ` [PATCH v4 18/26] x86/domctl: Update PV domain cpumasks when setting cpuid policy Andrew Cooper
2016-03-24 17:04   ` Jan Beulich
2016-03-24 17:05     ` Andrew Cooper
2016-03-28 19:51   ` Konrad Rzeszutek Wilk
2016-03-23 16:36 ` [PATCH v4 19/26] xen+tools: Export maximum host and guest cpu featuresets via SYSCTL Andrew Cooper
2016-03-28 19:59   ` Konrad Rzeszutek Wilk
2016-03-23 16:36 ` [PATCH v4 20/26] tools/libxc: Modify bitmap operations to take void pointers Andrew Cooper
2016-03-28 20:05   ` Konrad Rzeszutek Wilk
2016-03-23 16:36 ` [PATCH v4 21/26] tools/libxc: Use public/featureset.h for cpuid policy generation Andrew Cooper
2016-03-28 20:07   ` Konrad Rzeszutek Wilk
2016-03-23 16:36 ` [PATCH v4 22/26] tools/libxc: Expose the automatically generated cpu featuremask information Andrew Cooper
2016-03-28 20:08   ` Konrad Rzeszutek Wilk
2016-03-23 16:36 ` [PATCH v4 23/26] tools: Utility for dealing with featuresets Andrew Cooper
2016-03-28 20:26   ` Konrad Rzeszutek Wilk
2016-03-23 16:36 ` [PATCH v4 24/26] tools/libxc: Wire a featureset through to cpuid policy logic Andrew Cooper
2016-03-28 20:39   ` Konrad Rzeszutek Wilk
2016-03-23 16:36 ` [PATCH v4 25/26] tools/libxc: Use featuresets rather than guesswork Andrew Cooper
2016-03-23 16:36 ` [PATCH v4 26/26] tools/libxc: Calculate xstate cpuid leaf from guest information Andrew Cooper
2016-03-24 17:20   ` Wei Liu
2016-03-31  7:48   ` Jan Beulich
2016-04-05 17:48     ` Andrew Cooper
2016-04-07  0:16       ` Jan Beulich
2016-04-07  0:40         ` Andrew Cooper
2016-04-07  0:56           ` Jan Beulich
2016-04-07 11:34             ` Andrew Cooper
2016-03-24 10:27 ` [PATCH v4 00/26] x86: Improvements to cpuid handling for guests Jan Beulich
2016-03-24 10:28   ` Andrew Cooper

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