aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/xen/grant-table.c
Commit message (Collapse)AuthorAgeFilesLines
* xen/p2m/m2p/gnttab: Support GNTMAP_host_map in the M2P override.Konrad Rzeszutek Wilk2011-04-181-7/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We only supported the M2P (and P2M) override only for the GNTMAP_contains_pte type mappings. Meaning that we grants operations would "contain the machine address of the PTE to update" If the flag is unset, then the grant operation is "contains a host virtual address". The latter case means that the Hypervisor takes care of updating our page table (specifically the PTE entry) with the guest's MFN. As such we should not try to do anything with the PTE. Previous to this patch we would try to clear the PTE which resulted in Xen hypervisor being upset with us: (XEN) mm.c:1066:d0 Attempt to implicitly unmap a granted PTE c0100000ccc59067 (XEN) domain_crash called from mm.c:1067 (XEN) Domain 0 (vcpu#0) crashed on cpu#3: (XEN) ----[ Xen-4.0-110228 x86_64 debug=y Not tainted ]---- and crashing us. This patch allows us to inhibit the PTE clearing in the PV guest if the GNTMAP_contains_pte is not set. On the m2p_remove_override path we provide the same parameter. Sadly in the grant-table driver we do not have a mechanism to tell m2p_remove_override whether to clear the PTE or not. Since the grant-table driver is used by user-space, we can safely assume that it operates only on PTE's. Hence the implementation for it to work on !GNTMAP_contains_pte returns -EOPNOTSUPP. In the future we can implement the support for this. It will require some extra accounting structure to keep track of the page[i], and the flag. [v1: Added documentation details, made it return -EOPNOTSUPP instead of trying to do a half-way implementation] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen/p2m/m2p/gnttab: do not add failed grant maps to m2p overrideIan Campbell2011-03-091-0/+4
| | | | | | | | | | | | | | | | | | | | The caller will not undo a mapping which failed and therefore the override will not be removed. This is especially bad in the case of GNTMAP_contains_pte mapping type mappings where m2p_add_override will destroy the kernel mapping of the page. This was observed via a failure of map_grant_pages in gntdev_mmap (due to userspace using a bad grant reference), which left the page in question unmapped (because it was a GNTMAP_contains_pte mapping) which led to a crash later on. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Cc: Daniel De Graaf <dgdegra@tycho.nsa.gov> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen-gntdev: Support mapping in HVM domainsDaniel De Graaf2011-02-141-0/+6
| | | | | | | | | | | | | | | | HVM does not allow direct PTE modification, so instead we request that Xen change its internal p2m mappings on the allocated pages and map the memory into userspace normally. Note: The HVM path for map and unmap is slightly different: HVM keeps the pages mapped until the area is deleted, while the PV case (use_ptemod being true) must unmap them when userspace unmaps the range. In the normal use case, this makes no difference to users since unmap time is deletion time. [v2: Expanded commit descr.] Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen p2m: clear the old pte when adding a page to m2p_overrideJeremy Fitzhardinge2011-01-111-3/+13
| | | | | | | | | | | | | | | | | When adding a page to m2p_override we change the p2m of the page so we need to also clear the old pte of the kernel linear mapping because it doesn't correspond anymore. When we remove the page from m2p_override we restore the original p2m of the page and we also restore the old pte of the kernel linear mapping. Before changing the p2m mappings in m2p_add_override and m2p_remove_override, check that the page passed as argument is valid and return an error if it is not. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen: introduce gnttab_map_refs and gnttab_unmap_refsStefano Stabellini2011-01-111-0/+36
| | | | | | | | | | | | gnttab_map_refs maps some grant refs and uses the new m2p override to set a proper m2p mapping for the granted pages. gnttab_unmap_refs unmaps the granted refs and removes th mappings from the m2p override. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen: Xen PCI platform device driver.Stefano Stabellini2010-07-221-10/+67
| | | | | | | | | | | | | | | | | | | | | | | | | | | Add the xen pci platform device driver that is responsible for initializing the grant table and xenbus in PV on HVM mode. Few changes to xenbus and grant table are necessary to allow the delayed initialization in HVM mode. Grant table needs few additional modifications to work in HVM mode. The Xen PCI platform device raises an irq every time an event has been delivered to us. However these interrupts are only delivered to vcpu 0. The Xen PCI platform interrupt handler calls xen_hvm_evtchn_do_upcall that is a little wrapper around __xen_evtchn_do_upcall, the traditional Xen upcall handler, the very same used with traditional PV guests. When running on HVM the event channel upcall is never called while in progress because it is a normal Linux irq handler (and we cannot switch the irq chip wholesale to the Xen PV ones as we are running QEMU and might have passed in PCI devices), therefore we cannot be sure that evtchn_upcall_pending is 0 when returning. For this reason if evtchn_upcall_pending is set by Xen we need to loop again on the event channels set pending otherwise we might loose some event channel deliveries. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
* include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-301-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* xen: move Xen-testing predicates to common headerJeremy Fitzhardinge2009-11-041-0/+1
| | | | | | | | Move xen_domain and related tests out of asm-x86 to xen/xen.h so they can be included whenever they are necessary. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* xen: clean up asm/xen/hypervisor.hJeremy Fitzhardinge2008-12-161-0/+1
| | | | | | | | | | | Impact: cleanup hypervisor.h had accumulated a lot of crud, including lots of spurious #includes. Clean it all up, and go around fixing up everything else accordingly. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen: clean up domain mode predicatesJeremy Fitzhardinge2008-08-201-1/+1
| | | | | | | | | | | | | | There are four operating modes Xen code may find itself running in: - native - hvm domain - pv dom0 - pv domU Clean up predicates for testing for these states to make them more consistent. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Xen-devel <xen-devel@lists.xensource.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen: implement save/restoreJeremy Fitzhardinge2008-05-271-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* xen: make grant table arch portableIsaku Yamahata2008-04-241-32/+3
| | | | | | | | | | | | | 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>
* xen: replace callers of alloc_vm_area()/free_vm_area() with xen_ prefixed oneIsaku Yamahata2008-04-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | 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>
* xen: add missing definitions for xen grant table which ia64/xen needsIsaku Yamahata2008-04-241-1/+1
| | | | | | | | | | | | | | | | 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>
* xen: fix grant table bugMichael Abd-El-Malek2008-04-041-6/+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>
* xen: Add grant table supportJeremy Fitzhardinge2007-07-181-0/+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>