From: Andy Lutomirski <luto@amacapital.net>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
kvm list <kvm@vger.kernel.org>, Andy Lutomirski <luto@kernel.org>,
Frederic Weisbecker <fweisbec@gmail.com>,
Rik van Riel <riel@redhat.com>,
Paul McKenney <paulmck@linux.vnet.ibm.com>
Subject: Re: [PATCH 3/3] x86: context_tracking: avoid irq_save/irq_restore on kernel entry and exit
Date: Tue, 27 Oct 2015 22:22:44 -0700 [thread overview]
Message-ID: <CALCETrV01xm5TPngvU1TZzhx3+Ht7eRrkOV5b3tmgU81f_o5Ug@mail.gmail.com> (raw)
In-Reply-To: <1445996397-32703-4-git-send-email-pbonzini@redhat.com>
On Tue, Oct 27, 2015 at 6:39 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> x86 always calls user_enter and user_exit with interrupt disabled.
> Therefore, it is not necessary to check for exceptions, nor to
> save/restore the IRQ state, when context tracking functions are
> called by guest_enter and guest_exit.
>
> Use the previously introduced __context_tracking_entry and
> __context_tracking_exit.
x86 isn't ready for this yet. We could do a quick-and-dirty fix with
explicit IRQs-on-and-off much protected by the static key, or we could
just wait until I finish the syscall cleanup. I favor the latter, but
you're all welcome to do the former and I'll review it.
BTW, Frederic, I have a static key patch coming that I think you'll
like. I'll send it tomorrow once I'm in front of a real computer.
--Andy
next prev parent reply other threads:[~2015-10-28 5:23 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-28 1:39 [PATCH 0/3] context_tracking: streamline code, avoid IRQ save/restore Paolo Bonzini
2015-10-28 1:39 ` [PATCH 1/3] context_tracking: remove duplicate enabled check Paolo Bonzini
2015-10-28 5:19 ` Andy Lutomirski
2015-11-07 9:38 ` Paolo Bonzini
2015-11-09 13:57 ` Rik van Riel
2015-10-28 1:39 ` [PATCH 2/3] context_tracking: avoid irq_save/irq_restore on guest entry and exit Paolo Bonzini
2015-10-28 5:20 ` Andy Lutomirski
2015-11-09 13:58 ` Rik van Riel
2015-10-28 1:39 ` [PATCH 3/3] x86: context_tracking: avoid irq_save/irq_restore on kernel " Paolo Bonzini
2015-10-28 5:22 ` Andy Lutomirski [this message]
2015-10-28 14:51 ` Paolo Bonzini
2016-03-14 19:23 ` Andy Lutomirski
2016-03-15 8:51 ` Paolo Bonzini
2015-10-28 2:05 ` [PATCH 0/3] context_tracking: streamline code, avoid IRQ save/restore Paolo Bonzini
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