linux-kernel - Re: [RFC, PATCH 19/22] x86/mm: Implement free_encrypt

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Message-ID: <20180306083851.g5yh6f66srvrtc5n@node.shutemov.name>
Date:   Tue, 6 Mar 2018 11:38:51 +0300
From:   "Kirill A. Shutemov" <kirill@...temov.name>
To:     Dave Hansen <dave.hansen@...el.com>
Cc:     "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
        Ingo Molnar <mingo@...hat.com>, x86@...nel.org,
        Thomas Gleixner <tglx@...utronix.de>,
        "H. Peter Anvin" <hpa@...or.com>,
        Tom Lendacky <thomas.lendacky@....com>,
        Kai Huang <kai.huang@...ux.intel.com>,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: Re: [RFC, PATCH 19/22] x86/mm: Implement free_encrypt_page()

On Mon, Mar 05, 2018 at 11:00:00AM -0800, Dave Hansen wrote:
> On 03/05/2018 08:26 AM, Kirill A. Shutemov wrote:
> > +void free_encrypt_page(struct page *page, int keyid, unsigned int order)
> > +{
> > +	int i;
> > +	void *v;
> > +
> > +	for (i = 0; i < (1 << order); i++) {
> > +		v = kmap_atomic_keyid(page, keyid + i);
> > +		/* See comment in prep_encrypt_page() */
> > +		clflush_cache_range(v, PAGE_SIZE);
> > +		kunmap_atomic(v);
> > +	}
> > +}
> 
> Did you miss adding the call sites for this?

No. It is in "mm, rmap: Free encrypted pages once mapcount drops to zero".
But the call is optimized out since anon_vma_encrypted() is always false
so far.

-- 
 Kirill A. Shutemov