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From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Jan Beulich <JBeulich@suse.com>, FionaLi-oc <fionali-oc@zhaoxin.com>
Cc: xen-devel <xen-devel@lists.xenproject.org>,
	cobechen@zhaoxin.com, Wei Liu <wei.liu2@citrix.com>,
	Roger Pau Monne <roger.pau@citrix.com>
Subject: Re: [PATCH 2/2 v2] x86/acpi: Improve suspend and resume process for Zhaoxin CPU
Date: Thu, 25 Apr 2019 14:25:25 +0100	[thread overview]
Message-ID: <89dcdf84-214d-d100-e2a1-8bd151f215bd@citrix.com> (raw)
In-Reply-To: <5CC1B46B0200007800229134@prv1-mh.provo.novell.com>

On 25/04/2019 14:21, Jan Beulich wrote:
>>>> On 19.04.19 at 10:50, <fionali-oc@zhaoxin.com> wrote:
>> When executing SYSEXIT or SYSENTRY in Zhaoxin CPU, CPU needs to
> SYSENTER
>
>> --- a/xen/arch/x86/x86_64/traps.c
>> +++ b/xen/arch/x86/x86_64/traps.c
>> @@ -334,7 +334,8 @@ void subarch_percpu_traps_init(void)
>>                                     (unsigned long)lstar_enter);
>>      stub_va += offset;
>>  
>> -    if ( boot_cpu_data.x86_vendor & (X86_VENDOR_INTEL | X86_VENDOR_CENTAUR) )
>> +    if ( boot_cpu_data.x86_vendor &
>> +        (X86_VENDOR_INTEL | X86_VENDOR_CENTAUR | X86_VENDOR_SHANGHAI) )
>>      {
>>          /* SYSENTER entry. */
>>          wrmsrl(MSR_IA32_SYSENTER_ESP, stack_bottom);
> How is this hunk related to the title of the change? I think the
> title wants to be adjusted.
>
> Furthermore for all of the changes done, wouldn't we better
> switch to use cpu_has_sep? init_amd() as well as default_init()
> already clear this flag. Andrew, thoughts?

I wondered exactly that after queuing this patch, but didn't get around
to experimenting.

We have to be a little careful with the ordering of operations. 
cpu_has_sep is visible in CPUID but needs clobbering in AMD/Hygon before
cpu_has_sep is safe to use (although for the MSRs, it should be safe).

~Andrew

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Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel

WARNING: multiple messages have this Message-ID (diff)
From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Jan Beulich <JBeulich@suse.com>, FionaLi-oc <fionali-oc@zhaoxin.com>
Cc: xen-devel <xen-devel@lists.xenproject.org>,
	cobechen@zhaoxin.com, Wei Liu <wei.liu2@citrix.com>,
	Roger Pau Monne <roger.pau@citrix.com>
Subject: Re: [Xen-devel] [PATCH 2/2 v2] x86/acpi: Improve suspend and resume process for Zhaoxin CPU
Date: Thu, 25 Apr 2019 14:25:25 +0100	[thread overview]
Message-ID: <89dcdf84-214d-d100-e2a1-8bd151f215bd@citrix.com> (raw)
Message-ID: <20190425132525.XwmBcPfZ0huNzrIekzYit7vTm1iNWAEIIRBMMig6OSY@z> (raw)
In-Reply-To: <5CC1B46B0200007800229134@prv1-mh.provo.novell.com>

On 25/04/2019 14:21, Jan Beulich wrote:
>>>> On 19.04.19 at 10:50, <fionali-oc@zhaoxin.com> wrote:
>> When executing SYSEXIT or SYSENTRY in Zhaoxin CPU, CPU needs to
> SYSENTER
>
>> --- a/xen/arch/x86/x86_64/traps.c
>> +++ b/xen/arch/x86/x86_64/traps.c
>> @@ -334,7 +334,8 @@ void subarch_percpu_traps_init(void)
>>                                     (unsigned long)lstar_enter);
>>      stub_va += offset;
>>  
>> -    if ( boot_cpu_data.x86_vendor & (X86_VENDOR_INTEL | X86_VENDOR_CENTAUR) )
>> +    if ( boot_cpu_data.x86_vendor &
>> +        (X86_VENDOR_INTEL | X86_VENDOR_CENTAUR | X86_VENDOR_SHANGHAI) )
>>      {
>>          /* SYSENTER entry. */
>>          wrmsrl(MSR_IA32_SYSENTER_ESP, stack_bottom);
> How is this hunk related to the title of the change? I think the
> title wants to be adjusted.
>
> Furthermore for all of the changes done, wouldn't we better
> switch to use cpu_has_sep? init_amd() as well as default_init()
> already clear this flag. Andrew, thoughts?

I wondered exactly that after queuing this patch, but didn't get around
to experimenting.

We have to be a little careful with the ordering of operations. 
cpu_has_sep is visible in CPUID but needs clobbering in AMD/Hygon before
cpu_has_sep is safe to use (although for the MSRs, it should be safe).

~Andrew

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel

  reply	other threads:[~2019-04-25 13:27 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-19  8:50 [PATCH 2/2 v2] x86/acpi: Improve suspend and resume process for Zhaoxin CPU FionaLi-oc
2019-04-19  8:50 ` [Xen-devel] " FionaLi-oc
2019-04-19 10:16 ` Andrew Cooper
2019-04-19 10:16   ` [Xen-devel] " Andrew Cooper
2019-04-25 13:21 ` Jan Beulich
2019-04-25 13:21   ` [Xen-devel] " Jan Beulich
2019-04-25 13:25   ` Andrew Cooper [this message]
2019-04-25 13:25     ` Andrew Cooper
2019-04-25 13:37     ` Jan Beulich
2019-04-25 13:37       ` [Xen-devel] " Jan Beulich
2019-04-25 13:42       ` Andrew Cooper
2019-04-25 13:42         ` [Xen-devel] " Andrew Cooper
2019-04-26  9:55         ` FionaLi-oc
2019-04-26  9:55           ` [Xen-devel] " FionaLi-oc

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