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* lguest: allow any process to send interruptsRusty Russell2009-06-123-12/+18
| | | | | | | | | | | We currently only allow the Launcher process to send interrupts, but it as we already send interrupts from the hrtimer, it's a simple matter of extracting that code into a common set_interrupt routine. As we switch to a thread per virtqueue, this avoids a bottleneck through the main Launcher process. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: PAE fixesRusty Russell2009-06-121-17/+21
| | | | | | | | | | | | 1) j wasn't initialized in setup_pagetables, so they weren't set up for me causing immediate guest crashes. 2) gpte_addr should not re-read the pmd from the Guest. Especially not BUG_ON() based on the value. If we ever supported SMP guests, they could trigger that. And the Launcher could also trigger it (tho currently root-only). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: PAE supportMatias Zabaljauregui2009-06-124-39/+329
| | | | | | | | This version requires that host and guest have the same PAE status. NX cap is not offered to the guest, yet. Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: replace hypercall name LHCALL_SET_PMD with LHCALL_SET_PGDMatias Zabaljauregui2009-06-123-4/+4
| | | | | | | | | replace LHCALL_SET_PMD with LHCALL_SET_PGD hypercall name (That's really what it is, and the confusion gets worse with PAE support) Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Reported-by: Jeremy Fitzhardinge <jeremy@goop.org>
* lguest: use native_set_* macros, which properly handle 64-bit entries when ↵Matias Zabaljauregui2009-06-121-17/+18
| | | | | | | | | PAE is activated Some cleanups and replace direct assignment with native_set_* macros which properly handle 64-bit entries when PAE is activated Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: map switcher with executable page table entriesMatias Zabaljauregui2009-06-122-2/+2
| | | | | | | | Map switcher with executable page table entries. (This bug didn't matter before PAE and hence NX support -- RR) Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: Segment selectors are 16-bit long. Fix lg_cpu.ss1 definition.Matias Zabaljauregui2009-06-121-1/+1
| | | | | | | If GDT_ENTRIES were every > 256, this could become a problem. Signed-off-by: Matias Zabaljauregui <zabaljauregui at gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: beyond ARRAY_SIZE of cpu->arch.gdtRoel Kluin2009-06-121-1/+1
| | | | | | | Do not go beyond ARRAY_SIZE of cpu->arch.gdt Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: improve interrupt handling, speed up stream networkingRusty Russell2009-06-124-8/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | lguest never checked for pending interrupts when enabling interrupts, and things still worked. However, it makes a significant difference to TCP performance, so it's time we fixed it by introducing a pending_irq flag and checking it on irq_restore and irq_enable. These two routines are now too big to patch into the 8/10 bytes patch space, so we drop that code. Note: The high latency on interrupt delivery had a very curious effect: once everything else was optimized, networking without GSO was faster than networking with GSO, since more interrupts were sent and hence a greater chance of one getting through to the Guest! Note2: (Almost) Closing the same loophole for iret doesn't have any measurable effect, so I'm leaving that patch for the moment. Before: 1GB tcpblast Guest->Host: 30.7 seconds 1GB tcpblast Guest->Host (no GSO): 76.0 seconds After: 1GB tcpblast Guest->Host: 6.8 seconds 1GB tcpblast Guest->Host (no GSO): 27.8 seconds Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: fix race in halt codeRusty Russell2009-06-123-12/+31
| | | | | | | | | | | | | When the Guest does the LHCALL_HALT hypercall, we go to sleep, expecting that a timer or the Waker will wake_up_process() us. But we do it in a stupid way, leaving a classic missing wakeup race. So split maybe_do_interrupt() into interrupt_pending() and try_deliver_interrupt(), and check maybe_do_interrupt() and the "break_out" flag before calling schedule. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: fix lguest wake on guest clock tick, or fd activityRusty Russell2009-06-122-5/+5
| | | | | | | | | The Launcher could be inside the Guest on another CPU; wake_up_process will do nothing because it is "running". kick_process will knock it back into our kernel in this case, otherwise we'll miss it until the next guest exit. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: fix on Intel when KVM loaded (unhandled trap 13)Rusty Russell2009-05-261-9/+10
| | | | | | | | When KVM is loaded, and hence VT set up, the vmcall instruction in an lguest guest causes a #GP, not #UD. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lguest: fix guest crash on non-linear addresses in gdt pvopsRusty Russell2009-04-193-9/+11
| | | | | | | | | | | | | | Fixes guest crash 'lguest: bad read address 0x4800000 len 256' The new per-cpu allocator ends up handing a non-linear address to write_gdt_entry. We do __pa() on it, and hand it to the host, which kills us. I've long wanted to make the hypercall "LOAD_GDT_ENTRY" to match the IDT code, but had no pressing reason until now. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: lguest@ozlabs.org
* lguest: fix crash on vmlinux imagesMatias Zabaljauregui2009-04-191-0/+5
| | | | | | | | | | | | | | | | | | | | | Typical message: 'lguest: unhandled trap 6 at 0x418726 (0x0)' vmlinux guests were broken by 4cd8b5e2a159f18a1507f1187b44a1acbfa6341b 'lguest: use KVM hypercalls', which rewrites guest text from kvm hypercalls to trap 31. The Launcher mmaps the kernel image. The Guest executes and immediately faults in the first text page (read-only). Then it hits a hypercall, and we rewrite that hypercall, causing a copy-on-write. But the Guest pagetables still refer to the old page: we fault again, but as Host we see the hypercall already rewritten, and pass the fault back to the Guest. The Guest hasn't set up an IDT yet, so we kill it. This doesn't happen with bzImages: they unpack themselves and so the text pages are already read-write. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Tested-by: Patrick McHardy <kaber@trash.net>
* lguest: use bool instead of intMatias Zabaljauregui2009-03-305-26/+27
| | | | | | | | | | Impact: clean up Rusty told me, some time ago, that he had become a fan of "bool". So, here are some replacements. Signed-off-by: Matias Zabaljauregui <zabaljauregui at gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: use KVM hypercallsMatias Zabaljauregui2009-03-303-6/+67
| | | | | | | | | Impact: cleanup This patch allow us to use KVM hypercalls Signed-off-by: Matias Zabaljauregui <zabaljauregui at gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: fix spurious BUG_ON() on invalid guest stack.Rusty Russell2009-03-301-1/+3
| | | | | | | | | | Impact: fix crash on misbehaving guest gpte_addr() contains a BUG_ON(), insisting that the present flag is set. We need to return before we call it if that isn't the case. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org
* Merge branch 'core/percpu' into percpu-cpumask-x86-for-linus-2Ingo Molnar2009-03-271-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/parisc/kernel/irq.c arch/x86/include/asm/fixmap_64.h arch/x86/include/asm/setup.h kernel/irq/handle.c Semantic merge: arch/x86/include/asm/fixmap.h Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * x86: remove the Voyager 32-bit subarchIngo Molnar2009-02-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: remove unused/broken code The Voyager subarch last built successfully on the v2.6.26 kernel and has been stale since then and does not build on the v2.6.27, v2.6.28 and v2.6.29-rc5 kernels. No actual users beyond the maintainer reported this breakage. Patches were sent and most of the fixes were accepted but the discussion around how to do a few remaining issues cleanly fizzled out with no resolution and the code remained broken. In the v2.6.30 x86 tree development cycle 32-bit subarch support has been reworked and removed - and the Voyager code, beyond the build problems already known, needs serious and significant changes and probably a rewrite to support it. CONFIG_X86_VOYAGER has been marked BROKEN then. The maintainer has been notified but no patches have been sent so far to fix it. While all other subarchs have been converted to the new scheme, voyager is still broken. We'd prefer to receive patches which clean up the current situation in a constructive way, but even in case of removal there is no obstacle to add that support back after the issues have been sorted out in a mutually acceptable fashion. So remove this inactive code for now. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | lguest: fix for CONFIG_SPARSE_IRQ=yRusty Russell2009-03-091-0/+6
|/ | | | | | | | | | | | | | Impact: remove lots of lguest boot WARN_ON() when CONFIG_SPARSE_IRQ=y We now need to call irq_to_desc_alloc_cpu() before set_irq_chip_and_handler_name(), but we can't do that from init_IRQ (no kmalloc available). So do it as we use interrupts instead. Also means we only alloc for irqs we use, which was the intent of CONFIG_SPARSE_IRQ anyway. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@redhat.com>
* lguest: Fix a memory leak with the lg object during launcher closeMark Wallis2009-01-301-3/+2
| | | | | | | | | Fix a memory leak identified by Rusty Russell during LCA09 by kfree'ing the lg object instead of just clearing it when the launcher closes. Signed-off-by: Mark Wallis <mwallis@serialmonkey.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: typos fixAtsushi SAKAI2009-01-301-1/+1
| | | | | | | | | | | 3 points lguest_asm.S => i386_head.S LHCALL_BREAK => LHREQ_BREAK perferred => preferred Signed-off-by: Atsushi SAKAI <sakaia@jp.fujitsu.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: do not statically allocate root deviceMark McLoughlin2009-01-061-6/+4
| | | | | | | | | | | We shouldn't be statically allocating the root device object, so dynamically allocate it using root_device_register() instead. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Merge branch 'cpus4096-for-linus-2' of ↵Linus Torvalds2009-01-021-4/+9
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'cpus4096-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (66 commits) x86: export vector_used_by_percpu_irq x86: use logical apicid in x2apic_cluster's x2apic_cpu_mask_to_apicid_and() sched: nominate preferred wakeup cpu, fix x86: fix lguest used_vectors breakage, -v2 x86: fix warning in arch/x86/kernel/io_apic.c sched: fix warning in kernel/sched.c sched: move test_sd_parent() to an SMP section of sched.h sched: add SD_BALANCE_NEWIDLE at MC and CPU level for sched_mc>0 sched: activate active load balancing in new idle cpus sched: bias task wakeups to preferred semi-idle packages sched: nominate preferred wakeup cpu sched: favour lower logical cpu number for sched_mc balance sched: framework for sched_mc/smt_power_savings=N sched: convert BALANCE_FOR_xx_POWER to inline functions x86: use possible_cpus=NUM to extend the possible cpus allowed x86: fix cpu_mask_to_apicid_and to include cpu_online_mask x86: update io_apic.c to the new cpumask code x86: Introduce topology_core_cpumask()/topology_thread_cpumask() x86: xen: use smp_call_function_many() x86: use work_on_cpu in x86/kernel/cpu/mcheck/mce_amd_64.c ... Fixed up trivial conflict in kernel/time/tick-sched.c manually
| * x86: fix lguest used_vectors breakage, -v2Yinghai Lu2008-12-231-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: fix lguest, clean up 32-bit lguest used used_vectors to record vectors, but that model of allocating vectors changed and got broken, after we changed vector allocation to a per_cpu array. Try enable that for 64bit, and the array is used for all vectors that are not managed by vector_irq per_cpu array. Also kill system_vectors[], that is now a duplication of the used_vectors bitmap. [ merged in cpus4096 due to io_apic.c cpumask changes. ] [ -v2, fix build failure ] Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | lguest: struct device - replace bus_id with dev_name()Mark McLoughlin2008-12-301-1/+1
| | | | | | | | | | | | | | | | | | bus_id is gradually being removed, so use dev_name() instead. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* | lguest: move the initial guest page table creation code to the hostMatias Zabaljauregui2008-12-303-11/+76
| | | | | | | | | | | | | | | | This patch moves the initial guest page table creation code to the host, so the launcher keeps working with PAE enabled configs. Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* | virtio: hand virtio ring alignment as argument to vring_new_virtqueueRusty Russell2008-12-301-2/+2
| | | | | | | | | | | | | | | | This allows each virtio user to hand in the alignment appropriate to their virtio_ring structures. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
* | virtio: use LGUEST_VRING_ALIGN instead of relying on pagesizeRusty Russell2008-12-301-1/+1
|/ | | | | | | | This doesn't really matter, since lguest is i386 only at the moment, but we could actually choose a different value. (lguest doesn't have a guarenteed ABI). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: update commentryRusty Russell2008-08-261-0/+8
| | | | Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: use get_user_pages_fast() instead of get_user_pages()Rusty Russell2008-08-121-16/+9
| | | | | | | | | | | | | | | | | Using a simple page table thrashing program I measure a slight improvement. The program creates five processes. Each touches 1000 pages then schedules the next process. We repeat this 1000 times. As lguest only caches 4 cr3 values, this rebuilds a lot of shadow page tables requiring virt->phys mappings. Before: 5.93 seconds After: 5.40 seconds (Counts of slow vs fastpath in this usage are 6092 and 2852462 respectively.) And more importantly for lguest, the code is simpler. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: use cpu capability accessorsAndrew Morton2008-07-291-2/+2
| | | | | | | | | | To support my little make-x86-bitops-use-proper-typechecking projectlet. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andrea Arcangeli <andrea@qumranet.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: fix switcher_page leak on unloadJohannes Weiner2008-07-291-0/+1
| | | | | | | | map_switcher allocates the array, unmap_switcher has to free it accordingly. Signed-off-by: Johannes Weiner <hannes@saeurebad.de> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: Guest int3 fixRusty Russell2008-07-291-7/+17
| | | | | | | | | Ron Minnich noticed that guest userspace gets a GPF when it tries to int3: we need to copy the privilege level from the guest-supplied IDT to the real IDT. int3 is the only common case where guest userspace expects to invoke an interrupt, so that's the symptom of failing to do this. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: Add transport feature handling stub for virtio_ring.Rusty Russell2008-07-251-0/+3
| | | | | | | | To prepare for virtio_ring transport feature bits, hook in a call in all the users to manipulate them. This currently just clears all the bits, since it doesn't understand any features. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: Rename set_features to finalize_featuresRusty Russell2008-07-251-5/+6
| | | | | | | | | Rather than explicitly handing the features to the lower-level, we just hand the virtio_device and have it set the features. This make it clear that it has the chance to manipulate the features of the device at this point (and that all feature negotiation is already done). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* Merge branch 'generic-ipi' into generic-ipi-for-linusIngo Molnar2008-07-151-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/powerpc/Kconfig arch/s390/kernel/time.c arch/x86/kernel/apic_32.c arch/x86/kernel/cpu/perfctr-watchdog.c arch/x86/kernel/i8259_64.c arch/x86/kernel/ldt.c arch/x86/kernel/nmi_64.c arch/x86/kernel/smpboot.c arch/x86/xen/smp.c include/asm-x86/hw_irq_32.h include/asm-x86/hw_irq_64.h include/asm-x86/mach-default/irq_vectors.h include/asm-x86/mach-voyager/irq_vectors.h include/asm-x86/smp.h kernel/Makefile Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * on_each_cpu(): kill unused 'retry' parameterJens Axboe2008-06-261-2/+2
| | | | | | | | | | | | | | | | | | It's not even passed on to smp_call_function() anymore, since that was removed. So kill it. Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | x86, VisWS: turn into generic arch, eliminate Kconfig specialsIngo Molnar2008-07-101-1/+1
| | | | | | | | | | | | remove leftover traces of various VISWS related Kconfig specials. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | Merge commit 'v2.6.26-rc8' into x86/xenIngo Molnar2008-06-251-6/+9
|\| | | | | | | | | | | | | | | | | Conflicts: arch/x86/xen/enlighten.c arch/x86/xen/mmu.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * x86: fix NULL pointer deref in __switch_toSuresh Siddha2008-06-201-6/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I am able to reproduce the oops reported by Simon in __switch_to() with lguest. My debug showed that there is at least one lguest specific issue (which should be present in 2.6.25 and before aswell) and it got exposed with a kernel oops with the recent fpu dynamic allocation patches. In addition to the previous possible scenario (with fpu_counter), in the presence of lguest, it is possible that the cpu's TS bit it still set and the lguest launcher task's thread_info has TS_USEDFPU still set. This is because of the way the lguest launcher handling the guest's TS bit. (look at lguest_set_ts() in lguest_arch_run_guest()). This can result in a DNA fault while doing unlazy_fpu() in __switch_to(). This will end up causing a DNA fault in the context of new process thats getting context switched in (as opossed to handling DNA fault in the context of lguest launcher/helper process). This is wrong in both pre and post 2.6.25 kernels. In the recent 2.6.26-rc series, this is showing up as NULL pointer dereferences or sleeping function called from atomic context(__switch_to()), as we free and dynamically allocate the FPU context for the newly created threads. Older kernels might show some FPU corruption for processes running inside of lguest. With the appended patch, my test system is running for more than 50 mins now. So atleast some of your oops (hopefully all!) should get fixed. Please give it a try. I will spend more time with this fix tomorrow. Reported-by: Simon Holm Thøgersen <odie@cs.aau.dk> Reported-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | Merge branch 'linus' into x86/xenIngo Molnar2008-06-161-15/+10
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| * virtio: set device index in common code.Rusty Russell2008-05-301-14/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Anthony Liguori points out that three different transports use the virtio code, but each one keeps its own counter to set the virtio_device's index field. In theory (though not in current practice) this means that names could be duplicated, and that risk grows as more transports are created. So we move the selection of the unique virtio_device.index into the common code in virtio.c, which has the side-benefit of removing duplicate code. The only complexity is that lguest and S/390 use the index to uniquely identify the device in case of catastrophic failure before register_virtio_device() is called: now we use the offset within the descriptor page as a unique identifier for the printks. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Carsten Otte <cotte@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chris Lalancette <clalance@redhat.com> Cc: Anthony Liguori <anthony@codemonkey.ws>
| * lguest: use ioremap_cache, not ioremapRusty Russell2008-05-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Thanks to Jon Corbet & LWN. Only took me a day to join the dots. Host->Guest netcat before (with unnecessily large receive buffers): 1073741824 bytes (1.1 GB) copied, 24.7528 seconds, 43.4 MB/s After: 1073741824 bytes (1.1 GB) copied, 17.6369 seconds, 60.9 MB/s Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* | x86/paravirt: add pte_flags to just get pte flagsJeremy Fitzhardinge2008-05-271-1/+0
|/ | | | | | | | | | | | | Add pte_flags() to extract the flags from a pte. This is a special case of pte_val() which is only guaranteed to return the pte's flags correctly; the page number may be corrupted or missing. The intent is to allow paravirt implementations to return pte flags without having to do any translation of the page number (most notably, Xen). Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* lguest: make Launcher see device status updatesRusty Russell2008-05-021-7/+13
| | | | | | | This brings us closer to Real Life, where we'd examine the device features once it's set the DRIVER_OK status bit. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: remove bogus NULL cpu checkRusty Russell2008-05-021-2/+0
| | | | | | If lg isn't NULL, and cpu_id is sane, &lg->cpus[cpu_id] can't be NULL. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: avoid using NR_CPUS as a bounds check.Rusty Russell2008-05-021-1/+1
| | | | | | | | NR_CPUS (being a host number) is an arbitrary limit for the Guest. Using the array size directly (which currently happes to be NR_CPUS) is more futureproof. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: explicit advertisement of driver featuresRusty Russell2008-05-021-20/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | A recent proposed feature addition to the virtio block driver revealed some flaws in the API: in particular, we assume that feature negotiation is complete once a driver's probe function returns. There is nothing in the API to require this, however, and even I didn't notice when it was violated. So instead, we require the driver to specify what features it supports in a table, we can then move the feature negotiation into the virtio core. The intersection of device and driver features are presented in a new 'features' bitmap in the struct virtio_device. Note that this highlights the difference between Linux unsigned-long bitmaps where each unsigned long is in native endian, and a straight-forward little-endian array of bytes. Drivers can still remove feature bits in their probe routine if they really have to. API changes: - dev->config->feature() no longer gets and acks a feature. - drivers should advertise their features in the 'feature_table' field - use virtio_has_feature() for extra sanity when checking feature bits Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* drivers: Remove unnecessary inclusions of asm/semaphore.hMatthew Wilcox2008-04-181-1/+0
| | | | | | | | | None of these files use any of the functionality promised by asm/semaphore.h. It's possible that they rely on it dragging in some unrelated header file, but I can't build all these files, so we'll have fix any build failures as they come up. Signed-off-by: Matthew Wilcox <willy@linux.intel.com>