From: Marcelo Tosatti <mtosatti@redhat.com>
To: Alex Williamson <alex.williamson@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
avi@redhat.com, jan.kiszka@siemens.com
Subject: Re: [PATCH v2 1/2] kvm: unmap pages from the iommu when slots are removed
Date: Wed, 11 Apr 2012 23:03:57 -0300 [thread overview]
Message-ID: <20120412020357.GB3037@amt.cnet> (raw)
In-Reply-To: <20120411155149.13227.85904.stgit@bling.home>
On Wed, Apr 11, 2012 at 09:51:49AM -0600, Alex Williamson wrote:
> We've been adding new mappings, but not destroying old mappings.
> This can lead to a page leak as pages are pinned using
> get_user_pages, but only unpinned with put_page if they still
> exist in the memslots list on vm shutdown. A memslot that is
> destroyed while an iommu domain is enabled for the guest will
> therefore result in an elevated page reference count that is
> never cleared.
>
> Additionally, without this fix, the iommu is only programmed
> with the first translation for a gpa. This can result in
> peer-to-peer errors if a mapping is destroyed and replaced by a
> new mapping at the same gpa as the iommu will still be pointing
> to the original, pinned memory address.
>
> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Applied, thanks.
next prev parent reply other threads:[~2012-04-12 4:09 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-11 15:51 [PATCH v2 0/2] kvm: iommu unmap fixes Alex Williamson
2012-04-11 15:51 ` [PATCH v2 1/2] kvm: unmap pages from the iommu when slots are removed Alex Williamson
2012-04-12 2:03 ` Marcelo Tosatti [this message]
2012-04-11 15:51 ` [PATCH v2 2/2] kvm: unpin guest and free iommu domain after deassign last device Alex Williamson
2012-04-11 15:59 ` [PATCH v2 0/2] kvm: iommu unmap fixes Greg KH
2012-04-11 16:17 ` Alex Williamson
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