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From: Avi Kivity <avi@redhat.com>
To: "Piotr Jaroszyński" <p.jaroszynski@gmail.com>
Cc: kvm@vger.kernel.org
Subject: Re: kvm hardlocks on hp dv9010us
Date: Mon, 11 May 2009 14:20:30 +0300	[thread overview]
Message-ID: <4A0809FE.7050801@redhat.com> (raw)
In-Reply-To: <d77765540905101220u2a10a66dsaa5d7f253d60c8fc@mail.gmail.com>

[-- Attachment #1: Type: text/plain, Size: 641 bytes --]

Piotr Jaroszyński wrote:
> I have a hp dv9010us laptop (one of those that hard locked before
> CONFIG_IO_DELAY_* options were introduced in kernel - not sure if it
> may be related at all).
>   

I skipped this bit, and it's crucial.  kvm passes port 80 to go from 
guest to host as an optimization, and of course it kills your laptop.  
I'll fix this up.

(nowadays it may be faster to emulate the port access in the kernel 
rather than pass it to the hardware, so this is likely to be a 
performance improvement as well).

In the meantime, you can use the attached patch.

-- 
error compiling committee.c: too many arguments to function


[-- Attachment #2: remove-port-80-accesses.patch --]
[-- Type: text/x-patch, Size: 460 bytes --]

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 27d5b74..f994c6d 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -384,7 +384,6 @@ static __init int svm_hardware_setup(void)
 
 	iopm_va = page_address(iopm_pages);
 	memset(iopm_va, 0xff, PAGE_SIZE * (1 << IOPM_ALLOC_ORDER));
-	clear_bit(0x80, iopm_va); /* allow direct access to PC debug port */
 	iopm_base = page_to_pfn(iopm_pages) << PAGE_SHIFT;
 
 	if (boot_cpu_has(X86_FEATURE_NX))

  parent reply	other threads:[~2009-05-11 11:20 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-05-10 19:20 kvm hardlocks on hp dv9010us Piotr Jaroszyński
2009-05-10 20:55 ` Piotr Jaroszyński
2009-05-11  9:26 ` Avi Kivity
2009-05-11 10:46   ` Piotr Jaroszyński
2009-05-11 10:57     ` Avi Kivity
2009-05-11 11:00       ` Piotr Jaroszyński
2009-05-11 11:20 ` Avi Kivity [this message]
2009-05-11 11:37   ` Piotr Jaroszyński

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