All of lore.kernel.org
 help / color / mirror / Atom feed
From: Pu Wen <puwen@hygon.cn>
To: Jan Beulich <JBeulich@suse.com>,
	Andrew Cooper <andrew.cooper3@citrix.com>
Cc: xen-devel <xen-devel@lists.xenproject.org>,
	Wei Liu <wei.liu2@citrix.com>,
	Roger Pau Monne <roger.pau@citrix.com>
Subject: Re: [PATCH v3 01/14] x86/cpu: Create Hygon Dhyana architecture support file
Date: Wed, 27 Mar 2019 18:08:25 +0800	[thread overview]
Message-ID: <f811c31f-ad7f-c94b-bc59-b3bb8a329fea@hygon.cn> (raw)
In-Reply-To: <5C9B34BC0200007800222113@prv1-mh.provo.novell.com>

On 2019/3/27 16:31, Jan Beulich wrote:
> On 27.03.19 at 09:14, <puwen@hygon.cn> wrote:
>> On 2019/3/26 23:49, Jan Beulich wrote:
>>> On 25.03.19 at 14:29, <puwen@hygon.cn> wrote:
>>>> @@ -116,6 +121,9 @@ bool __init probe_cpuid_faulting(void)
>>>>    	uint64_t val;
>>>>    	int rc;
>>>>    
>>>> +	if(boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
>>>> +		return false;
>>>> +
>>>>    	if ((rc = rdmsr_safe(MSR_INTEL_PLATFORM_INFO, val)) == 0)
>>>
>>> Isn't this similarly true for AMD, in which case adding both at the
>>
>> There is no MSR_INTEL_PLATFORM_INFO for AMD family 17h and Hygon family
>> 18h. Reading this MSR will stall on Hygon system. I don't know if it
>> would successfully returned when reading it on AMD system.
> 
> What do you mean by "stall"? Reading an unimplemented MSR
> should produce #GP(0).

On certain old Hygon system there is no #GP produced. And the Xen
initialization process is stopped.

Beyond that it will indeed produce:
"traps.c:1574: GPF (0000)"
and return false from the last if() conditional.

>>> same time in a separate patch would seem better? Yet then again -
>>
>> In a separate patch is fine.
>>
>>> did you look at the description of the commit moving the function
>>> here (6e2fdc0f89 ["x86: Common cpuid faulting support"])? Hence
>>> if anything this would need qualifying by !cpu_has_hypervisor.
>>
>> Then it would be like this:
>> 	if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON &&
>> 	    !cpu_has_hypervisor)
>> 		return false;
> 
> Right, plus perhaps said AMD addition, unless Andrew objects to it
> for some reason.

Then it would be like this:
	if ((boot_cpu_data.x86_vendor == X86_VENDOR_HYGON ||
	     boot_cpu_data.x86_vendor == X86_VENDOR_AMD) &&
	    !cpu_has_hypervisor)
		return false;

Andrew, any objections?

-- 
Regards,
Pu Wen

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

  reply	other threads:[~2019-03-27 10:13 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-25 13:29 [PATCH v3 00/14] Add support for Hygon Dhyana Family 18h processor Pu Wen
2019-03-25 13:29 ` [PATCH v3 01/14] x86/cpu: Create Hygon Dhyana architecture support file Pu Wen
2019-03-26 15:48   ` Jan Beulich
2019-03-27  8:14     ` Pu Wen
2019-03-27  8:30       ` Jan Beulich
2019-03-27 10:08         ` Pu Wen [this message]
2019-03-25 13:30 ` [PATCH v3 02/14] x86/cpu/mtrr: Add Hygon Dhyana support to get TOP_MEM2 Pu Wen
2019-03-25 13:30 ` [PATCH v3 03/14] x86/cpu/vpmu: Add Hygon Dhyana and AMD Zen support for vPMU Pu Wen
2019-03-26 16:10   ` Jan Beulich
2019-03-27  8:16     ` Pu Wen
2019-03-27  8:37       ` Jan Beulich
2019-03-27 10:08         ` Pu Wen
2019-03-25 13:30 ` [PATCH v3 04/14] x86/cpu/mce: Add Hygon Dhyana support to the MCA infrastructure Pu Wen
2019-03-25 13:30 ` [PATCH v3 05/14] x86/spec_ctrl: Add Hygon Dhyana to the respective mitigation machinery Pu Wen
2019-03-25 13:30 ` [PATCH v3 06/14] x86/apic: Add Hygon Dhyana support Pu Wen
2019-03-25 13:30 ` [PATCH v3 07/14] x86/acpi: " Pu Wen
2019-03-25 13:31 ` [PATCH v3 08/14] x86/iommu: " Pu Wen
2019-03-25 13:31 ` [PATCH v3 09/14] x86/pv: Add Hygon Dhyana support to emulate MSRs access Pu Wen
2019-03-25 13:31 ` [PATCH v3 10/14] x86/domain: Add Hygon Dhyana support Pu Wen
2019-03-25 13:31 ` [PATCH v3 11/14] x86/domctl: " Pu Wen
2019-03-25 13:31 ` [PATCH v3 12/14] x86/traps: " Pu Wen
2019-03-25 13:32 ` [PATCH v3 13/14] x86/cpuid: " Pu Wen
2019-03-25 13:32 ` [PATCH v3 14/14] tools/libxc: " Pu Wen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=f811c31f-ad7f-c94b-bc59-b3bb8a329fea@hygon.cn \
    --to=puwen@hygon.cn \
    --cc=JBeulich@suse.com \
    --cc=andrew.cooper3@citrix.com \
    --cc=roger.pau@citrix.com \
    --cc=wei.liu2@citrix.com \
    --cc=xen-devel@lists.xenproject.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.