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Date: Thu, 5 Mar 2009 18:39:13 -0300
From: Marcelo Tosatti <mtosatti@redhat.com>
To: Joerg Roedel <joerg.roedel@amd.com>
Cc: Avi Kivity <avi@redhat.com>, kvm@vger.kernel.org,
       linux-kernel@vger.kernel.org
Subject: Re: [PATCH 5/6] kvm/x86: call kvm_lapic_sync_from_vapic with
	preemption disabled
Message-ID: <20090305213913.GC5660@amt.cnet>
References: <1236255153-4432-1-git-send-email-joerg.roedel@amd.com> <1236255153-4432-6-git-send-email-joerg.roedel@amd.com>
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On Thu, Mar 05, 2009 at 01:12:32PM +0100, Joerg Roedel wrote:
> The function uses kmap_atomic. Calling it with preemption enabled is
> racy.

kmap_atomic disables preemption?

void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot)
{                       
        enum fixed_addresses idx;
        unsigned long vaddr;    
                        
        /* even !CONFIG_PREEMPT needs this, for in_atomic in  * do_page_fault */
        pagefault_disable();