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Date:   Thu, 24 Feb 2022 14:14:02 -0800
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To:     "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
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References: <20220224155630.52734-1-kirill.shutemov@linux.intel.com>
 <20220224155630.52734-16-kirill.shutemov@linux.intel.com>
From:   Dave Hansen <dave.hansen@intel.com>
Subject: Re: [PATCHv4 15/30] x86/boot: Allow to hook up alternative port I/O
 helpers
In-Reply-To: <20220224155630.52734-16-kirill.shutemov@linux.intel.com>
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On 2/24/22 07:56, Kirill A. Shutemov wrote:
> Port I/O instructions trigger #VE in the TDX environment. In response to
> the exception, kernel emulates these instructions using hypercalls.
> 
> But during early boot, on the decompression stage, it is cumbersome to
> deal with #VE. It is cleaner to go to hypercalls directly, bypassing #VE
> handling.
> 
> Add a way to hook up alternative port I/O helpers in the boot stub.

I'd add one more sentence to that:

... with a new pio_ops structure.  For now, set the ops structure to
just call the normal I/O operation functions.

But, either way:

Acked-by: Dave Hansen <dave.hansen@linux.intel.com>