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>,
Peter Zijlstra <peterz@infradead.org>,
linux-kernel@vger.kernel.org, x86@kernel.org,
xen-devel@lists.xenproject.org
Subject: Re: [PATCH 0/3] xen: remove some checks for always present Xen features
Date: Thu, 22 Apr 2021 17:16:03 +0200 [thread overview]
Message-ID: <df27aba6-c67e-d66e-f00e-75a1f76de921@suse.com> (raw)
In-Reply-To: <20210422151007.2205-1-jgross@suse.com>
On 22.04.2021 17:10, Juergen Gross wrote:
> Some features of Xen can be assumed to be always present, so add a
> central check to verify this being true and remove the other checks.
>
> Juergen Gross (3):
> xen: check required Xen features
> xen: assume XENFEAT_mmu_pt_update_preserve_ad being set for pv guests
> xen: assume XENFEAT_gnttab_map_avail_bits being set for pv guests
I wonder whether it's a good idea to infer feature presence from
version numbers. If (at some point in the past) you had inferred
gnttab v2 being available by version, this would have been broken
by its availability becoming controllable by a command line option
in Xen.
Jan
next prev parent reply other threads:[~2021-04-22 15:16 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-22 15:10 [PATCH 0/3] xen: remove some checks for always present Xen features Juergen Gross
2021-04-22 15:10 ` [PATCH 1/3] xen: check required " Juergen Gross
2021-04-22 15:26 ` Stefano Stabellini
2021-04-22 15:32 ` Juergen Gross
2021-05-10 12:11 ` Boris Ostrovsky
2021-05-10 13:21 ` Juergen Gross
2021-04-22 15:10 ` [PATCH 2/3] xen: assume XENFEAT_mmu_pt_update_preserve_ad being set for pv guests Juergen Gross
2021-04-22 15:10 ` [PATCH 3/3] xen: assume XENFEAT_gnttab_map_avail_bits " Juergen Gross
2021-04-22 15:16 ` Jan Beulich [this message]
2021-04-22 15:17 ` [PATCH 0/3] xen: remove some checks for always present Xen features Juergen Gross
2021-04-22 15:23 ` Jan Beulich
2021-04-22 15:28 ` Juergen Gross
2021-04-22 15:42 ` Jan Beulich
2021-04-22 15:49 ` Juergen Gross
2021-04-22 15:51 ` Andrew Cooper
2021-05-10 7:34 ` Juergen Gross
2021-05-10 11:31 ` Peter Zijlstra
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