From mboxrd@z Thu Jan  1 00:00:00 1970
From: Alexander Graf <agraf@suse.de>
Subject: Re: [PATCH 2/3] kvm: svm: reset cr0 properly on vcpu reset
Date: Wed, 17 Mar 2010 19:17:32 +0100
Message-ID: <4BA11CBC.7060303@suse.de>
References: <1256359800-16893-1-git-send-email-ehabkost@redhat.com> <1256359800-16893-3-git-send-email-ehabkost@redhat.com>
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Cc: Avi Kivity <avi@redhat.com>, Marcelo Tosatti <mtosatti@redhat.com>,
	kvm@vger.kernel.org
To: Eduardo Habkost <ehabkost@redhat.com>
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Eduardo Habkost wrote:
> svm_vcpu_reset() was not properly resetting the contents of the guest-visible
> cr0 register, causing the following issue:
> https://bugzilla.redhat.com/show_bug.cgi?id=525699
>
> Without resetting cr0 properly, the vcpu was running the SIPI bootstrap routine
> with paging enabled, making the vcpu get a pagefault exception while trying to
> run it.
>
> Instead of setting vmcb->save.cr0 directly, the new code just resets
> kvm->arch.cr0 and calls kvm_set_cr0(). The bits that were set/cleared on
> vmcb->save.cr0 (PG, WP, !CD, !NW) will be set properly by svm_set_cr0().
>
> kvm_set_cr0() is used instead of calling svm_set_cr0() directly to make sure
> kvm_mmu_reset_context() is called to reset the mmu to nonpaging mode.
>
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
>   

Should this go into -stable?


Alex