From: Paolo Bonzini <pbonzini@redhat.com>
To: Ingo Molnar <mingo@kernel.org>, Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
xen-devel <Xen-devel@lists.xen.org>,
Arjan van de Ven <arjan@linux.intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
KVM list <kvm@vger.kernel.org>,
the arch/x86 maintainers <x86@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH v2 1/2] x86/msr: Carry on after a non-"safe" MSR access fails without !panic_on_oops
Date: Mon, 21 Sep 2015 14:27:31 +0200 [thread overview]
Message-ID: <55FFF7B3.5010608@redhat.com> (raw)
In-Reply-To: <20150921084642.GA30984@gmail.com>
On 21/09/2015 10:46, Ingo Molnar wrote:
> Or we could extend exception table entry encoding to include a 'warning bit', to
> not bloat the kernel. If the exception handler code encounters such an exception
> it would generate a one-time warning for that entry, but otherwise not crash the
> kernel and continue execution with an all-zeroes result for the MSR read.
The 'warning bit' already exists, it is the opcode that caused the fault. :)
The concern about bloat is a good one. However, why is it necessary to
keep native_*_msr* inline? If they are moved out-of-line, using the
exception table becomes the obvious solution and doesn't cause bloat
anymore.
Paolo
next prev parent reply other threads:[~2015-09-21 12:27 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-21 0:02 [PATCH v2 0/2] x86/msr: MSR access failure changes Andy Lutomirski
2015-09-21 0:02 ` [PATCH v2 1/2] x86/msr: Carry on after a non-"safe" MSR access fails without !panic_on_oops Andy Lutomirski
2015-09-21 0:15 ` Linus Torvalds
2015-09-21 1:13 ` Andy Lutomirski
2015-09-21 8:46 ` Ingo Molnar
2015-09-21 12:27 ` Paolo Bonzini [this message]
2015-09-21 16:36 ` Linus Torvalds
2015-09-21 16:49 ` Arjan van de Ven
2015-09-21 17:27 ` Linus Torvalds
2015-09-21 17:43 ` Andy Lutomirski
2015-09-22 8:12 ` Paolo Bonzini
2015-09-21 18:16 ` Andy Lutomirski
2015-09-21 18:36 ` Borislav Petkov
2015-09-21 18:47 ` Linus Torvalds
2015-09-22 7:14 ` Ingo Molnar
2015-09-30 13:10 ` Peter Zijlstra
2015-09-30 14:01 ` Ingo Molnar
2015-09-30 18:04 ` Andy Lutomirski
2015-10-01 7:15 ` Ingo Molnar
2016-03-11 16:48 ` Andy Lutomirski
2016-03-12 16:02 ` Ingo Molnar
2015-09-30 18:32 ` H. Peter Anvin
2015-09-21 0:02 ` [PATCH v2 2/2] x86/msr: Set the return value to zero when native_rdmsr_safe fails Andy Lutomirski
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