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Date:   Tue, 10 Jan 2023 21:43:56 +0800
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Subject: Re: [RFC PATCH V2 15/18] x86/sev: Add a #HV exception handler
To:     "Gupta, Pankaj" <pankaj.gupta@amd.com>, luto@kernel.org,
        tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
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        pawan.kumar.gupta@linux.intel.com, adrian.hunter@intel.com,
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References: <20221119034633.1728632-1-ltykernel@gmail.com>
 <20221119034633.1728632-16-ltykernel@gmail.com>
 <af54107e-a509-8f95-6044-b155539a590d@amd.com>
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From:   Tianyu Lan <ltykernel@gmail.com>
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On 1/10/2023 8:47 PM, Gupta, Pankaj wrote:
>> + *
>> + * To make this work the #HV entry code tries its best to pretend it 
>> doesn't use
>> + * an IST stack by switching to the task stack if coming from 
>> user-space (which
>> + * includes early SYSCALL entry path) or back to the stack in the 
>> IRET frame if
>> + * entered from kernel-mode.
>> + *
>> + * If entered from kernel-mode the return stack is validated first, 
>> and if it is
>> + * not safe to use (e.g. because it points to the entry stack) the 
>> #HV handler
>> + * will switch to a fall-back stack (HV2) and call a special handler 
>> function.
>> + *
>> + * The macro is only used for one vector, but it is planned to be 
>> extended in
>> + * the future for the #HV exception.
> 
> Noticed same comment line in the #VC exception handling section (macro 
> idtentry_vc). Just wondering we need to remove this line as the patch 
> being proposed for the #HV exception handling? unless this is planned to 
> be extended in some other way.

Nice catch! Will remove this in the next version.

Thanks.