From: Jan Beulich <jbeulich@suse.com>
To: Juergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Stefano Stabellini <sstabellini@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>,
stable@vger.kernel.org, Sander Eikelenboom <linux@eikelenboom.it>,
xen-devel@lists.xenproject.org, x86@kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] xen: fix usage of pmd/pud_poplulate in mremap for pv guests
Date: Wed, 8 Sep 2021 16:28:14 +0200 [thread overview]
Message-ID: <6862566d-4d55-dc5c-082a-da4fbcafcfce@suse.com> (raw)
In-Reply-To: <34afed98-5072-c563-5d29-97e09a0b4ebd@suse.com>
On 08.09.2021 15:32, Juergen Gross wrote:
> On 08.09.21 13:07, Jan Beulich wrote:
>> On 08.09.2021 09:36, Juergen Gross wrote:
>>> Commit 0881ace292b662 ("mm/mremap: use pmd/pud_poplulate to update page
>>> table entries") introduced a regression when running as Xen PV guest.
>>
>> The description of that change starts with "pmd/pud_populate is the
>> right interface to be used to set the respective page table entries."
>> If this is deemed true, I don't think pmd_populate() should call
>> paravirt_alloc_pte(): The latter function, as its name says, is
>> supposed to be called for newly allocated page tables only (aiui).
>
> In theory you are correct, but my experience with reality tells me that
> another set of macros for this case will not be appreciated.
Perhaps a new parameter to the macros / inlines identifying fresh
vs moved? Or perhaps the offending change wasn't really correct in
what its description said?
Jan
next prev parent reply other threads:[~2021-09-08 14:28 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-08 7:36 [PATCH] xen: fix usage of pmd/pud_poplulate in mremap for pv guests Juergen Gross
2021-09-08 11:07 ` Jan Beulich
2021-09-08 13:32 ` Juergen Gross
2021-09-08 14:28 ` Jan Beulich [this message]
2021-09-08 14:47 ` Juergen Gross
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