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path: root/drivers/xen/grant-table.c
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2008-05-27xen: implement save/restoreJeremy Fitzhardinge
This patch implements Xen save/restore and migration. Saving is triggered via xenbus, which is polled in drivers/xen/manage.c. When a suspend request comes in, the kernel prepares itself for saving by: 1 - Freeze all processes. This is primarily to prevent any partially-completed pagetable updates from confusing the suspend process. If CONFIG_PREEMPT isn't defined, then this isn't necessary. 2 - Suspend xenbus and other devices 3 - Stop_machine, to make sure all the other vcpus are quiescent. The Xen tools require the domain to run its save off vcpu0. 4 - Within the stop_machine state, it pins any unpinned pgds (under construction or destruction), performs canonicalizes various other pieces of state (mostly converting mfns to pfns), and finally 5 - Suspend the domain Restore reverses the steps used to save the domain, ending when all the frozen processes are thawed. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24xen: make grant table arch portableIsaku Yamahata
split out x86 specific part from grant-table.c and allow ia64/xen specific initialization. ia64/xen grant table is based on pseudo physical address (guest physical address) unlike x86/xen. On ia64 init_mm doesn't map identity straight mapped area. ia64/xen specific grant table initialization is necessary. Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24xen: replace callers of alloc_vm_area()/free_vm_area() with xen_ prefixed oneIsaku Yamahata
Don't use alloc_vm_area()/free_vm_area() directly, instead define xen_alloc_vm_area()/xen_free_vm_area() and use them. alloc_vm_area()/free_vm_area() are used to allocate/free area which are for grant table mapping. Xen/x86 grant table is based on virtual address so that alloc_vm_area()/free_vm_area() are suitable. On the other hand Xen/ia64 (and Xen/powerpc) grant table is based on pseudo physical address (guest physical address) so that allocation should be done differently. The original version of xenified Linux/IA64 have its own allocate_vm_area()/free_vm_area() definitions which don't allocate vm area contradictory to those names. Now vanilla Linux already has its definitions so that it's impossible to have IA64 definitions of allocate_vm_area()/free_vm_area(). Instead introduce xen_allocate_vm_area()/xen_free_vm_area() and use them. Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24xen: add missing definitions for xen grant table which ia64/xen needsIsaku Yamahata
Add xen handles realted definitions for grant table which ia64/xen needs. Pointer argumsnts for ia64/xen hypercall are passed in pseudo physical address (guest physical address) so that it is required to convert guest kernel virtual address into pseudo physical address right before issuing hypercall. The xen guest handle represents such arguments. Define necessary handles and helper functions. Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-04xen: fix grant table bugMichael Abd-El-Malek
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 Fitzhardinge
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>