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path: root/drivers/xen/grant-table.c
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2008-04-04xen: fix grant table bugMichael Abd-El-Malek1-6/+10
fix memory corruption and crash due to mis-sized grant table. A PV OS has two grant table data structures: the grant table itself and a free list. The free list is composed of an array of pages, which grow dynamically as the guest OS requires more grants. While the grant table contains 8-byte entries, the free list contains 4-byte entries. So we have half as many pages in the free list than in the grant table. There was a bug in the free list allocation code. The free list was indexed as if it was the same size as the grant table. But it's only half as large. So memory got corrupted, and I was seeing crashes in the slab allocator later on. Taken from: http://xenbits.xensource.com/linux-2.6.18-xen.hg?rev/4018c0da3360 Signed-off-by: Michael Abd-El-Malek <mabdelmalek@cmu.edu> Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-18xen: Add grant table supportJeremy Fitzhardinge1-0/+582
Add Xen 'grant table' driver which allows granting of access to selected local memory pages by other virtual machines and, symmetrically, the mapping of remote memory pages which other virtual machines have granted access to. This driver is a prerequisite for many of the Xen virtual device drivers, which grant the 'device driver domain' restricted and temporary access to only those memory pages that are currently involved in I/O operations. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Ian Pratt <ian.pratt@xensource.com> Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk> Signed-off-by: Chris Wright <chrisw@sous-sol.org>