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From: Bharath Vedartham <linux.bhar@gmail.com>
To: pbonzini@redhat.com, rkrcmar@redhat.com
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org, khalid.aziz@oracle.com
Subject: [Question-kvm] Can hva_to_pfn_fast be executed in interrupt context?
Date: Wed, 14 Aug 2019 00:44:35 +0530	[thread overview]
Message-ID: <20190813191435.GB10228@bharath12345-Inspiron-5559> (raw)

Hi all,

I was looking at the function hva_to_pfn_fast(in virt/kvm/kvm_main) which is 
executed in an atomic context(even in non-atomic context, since
hva_to_pfn_fast is much faster than hva_to_pfn_slow).

My question is can this be executed in an interrupt context? 

The motivation for this question is that in an interrupt context, we cannot
assume "current" to be the task_struct of the process of interest.
__get_user_pages_fast assume current->mm when walking the process page
tables. 

So if this function hva_to_pfn_fast can be executed in an
interrupt context, it would not be safe to retrive the pfn with
__get_user_pages_fast. 

Thoughts on this?

Thank you
Bharath


             reply	other threads:[~2019-08-13 19:14 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-13 19:14 Bharath Vedartham [this message]
2019-08-13 20:17 ` [Question-kvm] Can hva_to_pfn_fast be executed in interrupt context? Paolo Bonzini
2019-08-15 17:18   ` Bharath Vedartham
2019-08-15 18:26     ` Paolo Bonzini
2019-08-20 16:08       ` Bharath Vedartham

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