linux-kernel - Re: [PATCH 0/6] xen/x86: PV boot speedup

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:   Wed, 27 Oct 2021 09:17:12 -0400
From:   Boris Ostrovsky <boris.ostrovsky@...cle.com>
To:     Jan Beulich <jbeulich@...e.com>, Juergen Gross <jgross@...e.com>
Cc:     Stefano Stabellini <sstabellini@...nel.org>,
        lkml <linux-kernel@...r.kernel.org>,
        "xen-devel@...ts.xenproject.org" <xen-devel@...ts.xenproject.org>
Subject: Re: [PATCH 0/6] xen/x86: PV boot speedup


On 9/30/21 8:33 AM, Jan Beulich wrote:
> The observed (by the human eye) performance difference of early boot
> between native and PV-on-Xen was just too large to not look into. As
> it turns out, gaining performance back wasn't all that difficult.
>
> While the series (re)introduces a small number of PTWR emulations on
> the boot path (from phys_pte_init()), there has been a much larger
> number of them post-boot. Hence I think if this was of concern, the
> post-boot instances would want eliminating first.
>
> Some of the later changes aren'r directly related to the main goal of
> the series; these address aspects noticed while doing the investigation.
>
> 1: streamline set_pte_mfn()
> 2: restore (fix) xen_set_pte_init() behavior
> 3: adjust xen_set_fixmap()
> 4: adjust handling of the L3 user vsyscall special page table
> 5: there's no highmem anymore in PV mode
> 6: restrict PV Dom0 identity mapping



Applied to for-linus-5.16


-boris