From: "H. Peter Anvin" <hpa@zytor.com>
To: Eduardo Habkost <ehabkost@redhat.com>,
virtualization@lists.linux-foundation.org
Cc: Jeremy Fitzhardinge <jeremy@goop.org>,
x86@kernel.org, linux-kernel@vger.kernel.org,
Chris Wright <chrisw@sous-sol.org>,
Ingo Molnar <mingo@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Alok Kataria <akataria@vmware.com>
Subject: Re: [PATCH] x86, paravirt: BUG_ON on {rd,wr}msr exceptions
Date: Mon, 28 Jul 2014 12:18:10 -0700 [thread overview]
Message-ID: <53D6A1F2.5070404@zytor.com> (raw)
In-Reply-To: <1406574278-23946-1-git-send-email-ehabkost@redhat.com>
On 07/28/2014 12:04 PM, Eduardo Habkost wrote:
> When CONFIG_PARAVIRT is enabled, the kernel is ignoring exceptions on
> the {rd,wr}msr instructions. This makes serious issues (either on the
> guest kernel, or on the host) be silently ignored, and is different from
> the native MSR code (which does not ignore the exceptions).
>
> As paravirt.h already includes linux/bug.h, I don't see what was the
> original issue preventing BUG_ON from being used.
>
> Change rdmsr(), wrmsr(), and rdmsrl() to BUG_ON() on errors.
How much does this bloat the kernel?
#include <stdparavirtrant.h>
-hpa
WARNING: multiple messages have this Message-ID (diff)
From: "H. Peter Anvin" <hpa@zytor.com>
To: Eduardo Habkost <ehabkost@redhat.com>,
virtualization@lists.linux-foundation.org
Cc: Jeremy Fitzhardinge <jeremy@goop.org>,
Chris Wright <chrisw@sous-sol.org>,
Alok Kataria <akataria@vmware.com>,
Rusty Russell <rusty@rustcorp.com.au>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86, paravirt: BUG_ON on {rd,wr}msr exceptions
Date: Mon, 28 Jul 2014 12:18:10 -0700 [thread overview]
Message-ID: <53D6A1F2.5070404@zytor.com> (raw)
In-Reply-To: <1406574278-23946-1-git-send-email-ehabkost@redhat.com>
On 07/28/2014 12:04 PM, Eduardo Habkost wrote:
> When CONFIG_PARAVIRT is enabled, the kernel is ignoring exceptions on
> the {rd,wr}msr instructions. This makes serious issues (either on the
> guest kernel, or on the host) be silently ignored, and is different from
> the native MSR code (which does not ignore the exceptions).
>
> As paravirt.h already includes linux/bug.h, I don't see what was the
> original issue preventing BUG_ON from being used.
>
> Change rdmsr(), wrmsr(), and rdmsrl() to BUG_ON() on errors.
How much does this bloat the kernel?
#include <stdparavirtrant.h>
-hpa
next prev parent reply other threads:[~2014-07-28 19:18 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-28 19:04 [PATCH] x86, paravirt: BUG_ON on {rd,wr}msr exceptions Eduardo Habkost
2014-07-28 19:04 ` Eduardo Habkost
2014-07-28 19:18 ` H. Peter Anvin [this message]
2014-07-28 19:18 ` H. Peter Anvin
2014-07-28 20:39 ` Eduardo Habkost
2014-07-28 20:39 ` Eduardo Habkost
2014-07-28 20:43 ` H. Peter Anvin
2014-07-28 20:43 ` H. Peter Anvin
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