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From: Tom Lendacky <thomas.lendacky@amd.com>
To: "Woodhouse, David" <dwmw@amazon.co.uk>,
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Subject: Re: [PATCH v16 8/8] x86/smpboot: Allow parallel bringup for SEV-ES
Date: Thu, 23 Mar 2023 13:28:38 -0500	[thread overview]
Message-ID: <19ec60aa-fa11-c44e-a6d1-9583f2e7707a@amd.com> (raw)
In-Reply-To: <751f572f940220775054dc09324b20b929d7d66d.camel@amazon.co.uk>

On 3/23/23 10:34, Woodhouse, David wrote:
> On Thu, 2023-03-23 at 08:16 -0500, Tom Lendacky wrote:
>>
>> Maybe call this sev_early_get_cpuid_0b() or such to imply that the MSR
>> protocol is being used and only retrieving / returning edx.
> 
> Or indeed sev_early_get_apicid() since that's what it's actually doing,
> and the caller doesn't care *how*.

Sounds good.

> 
>> Also, since it is a function now and can be used at any point, the current
>> GHCB MSR should be saved on entry and restored on exit.
> 
> Well, I don't know that it should be callable at any point. This is
> only supposed to be called from head_64.S.

I agree. But once it's there, someone somewhere in the future may look and 
go, oh, I can call this. So I think it either needs a nice comment above 
it about how it is currently used/called and what to do if it needs to be 
called from someplace other than head_64.S or the MSR needs to be 
saved/restored.

Thanks,
Tom

> 
> 
> 
> 
> 
> Amazon Development Centre (London) Ltd. Registered in England and Wales with registration number 04543232 with its registered office at 1 Principal Place, Worship Street, London EC2A 2FA, United Kingdom.
> 
> 
> 

  parent reply	other threads:[~2023-03-23 18:28 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-21 19:40 [PATCH v16 0/8] Parallel CPU bringup for x86_64 Usama Arif
2023-03-21 19:40 ` [PATCH v16 1/8] cpu/hotplug: Move idle_thread_get() to <linux/smpboot.h> Usama Arif
2023-03-21 19:40 ` [PATCH v16 2/8] cpu/hotplug: Reset task stack state in _cpu_up() Usama Arif
2023-03-22 11:06   ` Mark Rutland
2023-03-21 19:40 ` [PATCH v16 3/8] cpu/hotplug: Add dynamic parallel bringup states before CPUHP_BRINGUP_CPU Usama Arif
2023-03-23 22:36   ` Thomas Gleixner
2023-03-23 22:49     ` David Woodhouse
2023-03-23 23:48       ` Thomas Gleixner
2023-03-24  0:06         ` David Woodhouse
2023-03-23 23:05     ` Thomas Gleixner
2023-03-23 23:12       ` David Woodhouse
2023-03-24  1:16         ` Thomas Gleixner
2023-03-24  9:31           ` David Woodhouse
2023-03-24 13:57             ` Thomas Gleixner
2023-03-24 15:33               ` David Woodhouse
2023-03-24 14:07             ` Thomas Gleixner
2023-03-24  9:46           ` Thomas Gleixner
2023-03-24 10:00             ` David Woodhouse
2023-03-27 18:48       ` David Woodhouse
2023-03-21 19:40 ` [PATCH v16 4/8] x86/smpboot: Split up native_cpu_up into separate phases and document them Usama Arif
2023-03-21 19:40 ` [PATCH v16 5/8] x86/smpboot: Support parallel startup of secondary CPUs Usama Arif
2023-03-21 19:40 ` [PATCH v16 6/8] x86/smpboot: Send INIT/SIPI/SIPI to secondary CPUs in parallel Usama Arif
2023-03-21 19:40 ` [PATCH v16 7/8] x86/smpboot: Serialize topology updates for secondary bringup Usama Arif
2023-03-21 19:40 ` [PATCH v16 8/8] x86/smpboot: Allow parallel bringup for SEV-ES Usama Arif
2023-03-22 22:47   ` Borislav Petkov
2023-03-23  8:32     ` David Woodhouse
2023-03-23  8:51       ` Borislav Petkov
2023-03-23  9:04         ` David Woodhouse
2023-03-23 14:23           ` Brian Gerst
2023-03-27 17:47             ` Borislav Petkov
2023-03-27 18:14               ` David Woodhouse
2023-03-27 19:14                 ` Tom Lendacky
2023-03-27 19:32                 ` Borislav Petkov
2023-03-23 13:16     ` Tom Lendacky
     [not found]       ` <751f572f940220775054dc09324b20b929d7d66d.camel@amazon.co.uk>
2023-03-23 18:28         ` Tom Lendacky [this message]
2023-03-23 22:13           ` Borislav Petkov
2023-03-23 22:30             ` [EXTERNAL][PATCH " David Woodhouse

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