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Re: [PATCH 3/5] x86/PV: _PAGE_RW changes may take fast path of mod_l[234]_entry()
- To: Jan Beulich <jbeulich@xxxxxxxx>
- From: Roger Pau Monné <roger.pau@xxxxxxxxxx>
- Date: Mon, 11 Jan 2021 12:08:41 +0100
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On Tue, Nov 03, 2020 at 11:57:10AM +0100, Jan Beulich wrote:
> The only time _PAGE_RW matters when validating an L2 or higher entry is
> when a linear page table is tried to be installed. Therefore when we
> disallow such at build time, we can allow _PAGE_RW changes to take the
> fast paths there.
I think it would be helpful to note why PDEs with linear page tables
aren't allowed to have the RW bit set, likely here and in the comment
below.
Thanks, Roger.
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