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* KVM: fix race with level interruptsMichael S. Tsirkin2012-07-201-3/+16
| | | | | | | | | | | | | | | | When more than 1 source id is in use for the same GSI, we have the following race related to handling irq_states race: CPU 0 clears bit 0. CPU 0 read irq_state as 0. CPU 1 sets level to 1. CPU 1 calls kvm_ioapic_set_irq(1). CPU 0 calls kvm_ioapic_set_irq(0). Now ioapic thinks the level is 0 but irq_state is not 0. Fix by performing all irq_states bitmap handling under pic/ioapic lock. This also removes the need for atomics with irq_states handling. Reported-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: dont clear TMR on EOIMichael S. Tsirkin2012-04-171-3/+7
| | | | | | | | | | | | | | | | | | | | | Intel spec says that TMR needs to be set/cleared when IRR is set, but kvm also clears it on EOI. I did some tests on a real (AMD based) system, and I see same TMR values both before and after EOI, so I think it's a minor bug in kvm. This patch fixes TMR to be set/cleared on IRR set only as per spec. And now that we don't clear TMR, we can save an atomic read of TMR on EOI that's not propagated to ioapic, by checking whether ioapic needs a specific vector first and calculating the mode afterwards. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: drop bsp_vcpu pointer from kvm structGleb Natapov2011-12-271-1/+1
| | | | | | | | Drop bsp_vcpu pointer from kvm struct since its only use is incorrect anyway. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: Allow aligned byte and word writes to IOAPIC registers.Julian Stecklina2011-12-271-3/+12
| | | | | | | | | This fixes byte accesses to IOAPIC_REG_SELECT as mandated by at least the ICH10 and Intel Series 5 chipset specs. It also makes ioapic_mmio_write consistent with ioapic_mmio_read, which also allows byte and word accesses. Signed-off-by: Julian Stecklina <js@alien8.de> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Intelligent device lookup on I/O busSasha Levin2011-09-251-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | Currently the method of dealing with an IO operation on a bus (PIO/MMIO) is to call the read or write callback for each device registered on the bus until we find a device which handles it. Since the number of devices on a bus can be significant due to ioeventfds and coalesced MMIO zones, this leads to a lot of overhead on each IO operation. Instead of registering devices, we now register ranges which points to a device. Lookup is done using an efficient bsearch instead of a linear search. Performance test was conducted by comparing exit count per second with 200 ioeventfds created on one byte and the guest is trying to access a different byte continuously (triggering usermode exits). Before the patch the guest has achieved 259k exits per second, after the patch the guest does 274k exits per second. Cc: Avi Kivity <avi@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: ioapic: Fix an error field referenceLiu Yuan2011-05-221-1/+1
| | | | | | | | Function ioapic_debug() in the ioapic_deliver() misnames one filed by reference. This patch correct it. Signed-off-by: Liu Yuan <tailai.ly@taobao.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Convert mask notifiers to use irqchip/pin instead of gsiGleb Natapov2010-08-021-1/+1
| | | | | | | | | Devices register mask notifier using gsi, but irqchip knows about irqchip/pin, so conversion from irqchip/pin to gsi should be done before looking for mask notifier to call. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: Update Red Hat copyrightsAvi Kivity2010-08-011-0/+1
| | | | Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: read apic->irr with ioapic lock heldMarcelo Tosatti2010-06-101-1/+2
| | | | | | | Read ioapic->irr inside ioapic->lock protected section. KVM-Stable-Tag Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: convert ioapic lock to spinlockMarcelo Tosatti2010-05-131-15/+15
| | | | | | | | | kvm_set_irq is used from non sleepable contexes, so convert ioapic from mutex to spinlock. KVM-Stable-Tag. Tested-by: Ralf Bonenkamp <ralf.bonenkamp@swyx.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.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>
* KVM: cleanup the failure path of KVM_CREATE_IRQCHIP ioctrlWei Yongjun2010-03-011-0/+11
| | | | | | | | | If we fail to init ioapic device or the fail to setup the default irq routing, the device register by kvm_create_pic() and kvm_ioapic_init() remain unregister. This patch fixed to do this. Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: kvm->arch.vioapic should be NULL if kvm_ioapic_init() failureWei Yongjun2010-03-011-1/+3
| | | | | | | | kvm->arch.vioapic should be NULL in case of kvm_ioapic_init() failure due to cannot register io dev. Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: avoid taking ioapic mutex for non-ioapic EOIsAvi Kivity2010-03-011-0/+19
| | | | | | | | | | | | | | | | | When the guest acknowledges an interrupt, it sends an EOI message to the local apic, which broadcasts it to the ioapic. To handle the EOI, we need to take the ioapic mutex. On large guests, this causes a lot of contention on this mutex. Since large guests usually don't route interrupts via the ioapic (they use msi instead), this is completely unnecessary. Avoid taking the mutex by introducing a handled_vectors bitmap. Before taking the mutex, check if the ioapic was actually responsible for the acked vector. If not, we can return early. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: convert slots_lock to a mutexMarcelo Tosatti2010-03-011-2/+2
| | | | Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: convert io_bus to SRCUMarcelo Tosatti2010-03-011-1/+3
| | | | Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: Move IO APIC to its own lockGleb Natapov2009-12-031-19/+61
| | | | | | | The allows removal of irq_lock from the injection path. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Fix coalesced interrupt reporting in IOAPICGleb Natapov2009-09-101-0/+2
| | | | | | | | | This bug was introduced by b4a2f5e723e4f7df467. Cc: stable@kernel.org Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: make io_bus interface more robustGregory Haskins2009-09-101-2/+6
| | | | | | | | | | | | | | | | Today kvm_io_bus_regsiter_dev() returns void and will internally BUG_ON if it fails. We want to create dynamic MMIO/PIO entries driven from userspace later in the series, so we need to enhance the code to be more robust with the following changes: 1) Add a return value to the registration function 2) Fix up all the callsites to check the return code, handle any failures, and percolate the error up to the caller. 3) Add an unregister function that collapses holes in the array Signed-off-by: Gregory Haskins <ghaskins@novell.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Add trace points in irqchip codeGleb Natapov2009-09-101-0/+2
| | | | | | | | | Add tracepoint in msi/ioapic/pic set_irq() functions, in IPI sending and in the point where IRQ is placed into apic's IRR. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Use temporary variable to shorten lines.Gleb Natapov2009-09-101-8/+10
| | | | | | | Cosmetic only. No logic is changed by this patch. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: fix lock imbalanceJiri Slaby2009-09-101-1/+2
| | | | | | | | There is a missing unlock on one fail path in ioapic_mmio_write, fix that. Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: remove in_range from io devicesMichael S. Tsirkin2009-09-101-10/+12
| | | | | | | | | | | | This changes bus accesses to use high-level kvm_io_bus_read/kvm_io_bus_write functions. in_range now becomes unused so it is removed from device ops in favor of read/write callbacks performing range checks internally. This allows aliasing (mostly for in-kernel virtio), as well as better error handling by making it possible to pass errors up to userspace. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: convert bus to slots_lockMichael S. Tsirkin2009-09-101-1/+1
| | | | | | | | | | Use slots_lock to protect device list on the bus. slots_lock is already taken for read everywhere, so we only need to take it for write when registering devices. This is in preparation to removing in_range and kvm->lock around it. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Introduce kvm_vcpu_is_bsp() function.Gleb Natapov2009-09-101-1/+3
| | | | | | | Use it instead of open code "vcpu_id zero is BSP" assumption. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: introduce irq_lock, use it to protect ioapicMarcelo Tosatti2009-09-101-0/+5
| | | | | | | Introduce irq_lock, and use to protect ioapic data structures. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: cleanup io_device codeGregory Haskins2009-09-101-7/+15
| | | | | | | | | | | We modernize the io_device code so that we use container_of() instead of dev->private, and move the vtable to a separate ops structure (theoretically allows better caching for multiple instances of the same ops structure) Signed-off-by: Gregory Haskins <ghaskins@novell.com> Acked-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Avoid redelivery of edge interrupt before next edgeGleb Natapov2009-08-091-5/+5
| | | | | | | | | | | | | | | | | The check for an edge is broken in current ioapic code. ioapic->irr is cleared on each edge interrupt by ioapic_service() and this makes old_irr != ioapic->irr condition in kvm_ioapic_set_irq() to be always true. The patch fixes the code to properly recognise edge. Some HW emulation calls set_irq() without level change. If each such call is propagated to an OS it may confuse a device driver. This is the case with keyboard device emulation and Windows XP x64 installer on SMP VM. Each keystroke produce two interrupts (down/up) one interrupt is submitted to CPU0 and another to CPU1. This confuses Windows somehow and it ignores keystrokes. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: APIC: get rid of deliver_bitmaskGleb Natapov2009-06-101-41/+16Star
| | | | | | | | Deliver interrupt during destination matching loop. Signed-off-by: Gleb Natapov <gleb@redhat.com> Acked-by: Xiantao Zhang <xiantao.zhang@intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: consolidate ioapic/ipi interrupt delivery logicGleb Natapov2009-06-101-1/+4
| | | | | | | | | | Use kvm_apic_match_dest() in kvm_get_intr_delivery_bitmask() instead of duplicating the same code. Use kvm_get_intr_delivery_bitmask() in apic_send_ipi() to figure out ipi destination instead of reimplementing the logic. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: ioapic/msi interrupt delivery consolidationGleb Natapov2009-06-101-29/+32
| | | | | | | | | ioapic_deliver() and kvm_set_msi() have code duplication. Move the code into ioapic_deliver_entry() function and call it from both places. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: APIC: kvm_apic_set_irq deliver all kinds of interruptsGleb Natapov2009-06-101-34/+6Star
| | | | | | | Get rid of ioapic_inj_irq() and ioapic_inj_nmi() functions. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: Merge kvm_ioapic_get_delivery_bitmask into kvm_get_intr_delivery_bitmaskSheng Yang2009-06-101-43/+3Star
| | | | | | | | | | | | | | | | | Gleb fixed bitmap ops usage in kvm_ioapic_get_delivery_bitmask. Sheng merged two functions, as well as fixed several issues in kvm_get_intr_delivery_bitmask 1. deliver_bitmask is a bitmap rather than a unsigned long intereger. 2. Lowest priority target bitmap wrong calculated by mistake. 3. Prevent potential NULL reference. 4. Declaration in include/kvm_host.h caused powerpc compilation warning. 5. Add warning for guest broadcast interrupt with lowest priority delivery mode. 6. Removed duplicate bitmap clean up in caller of kvm_get_intr_delivery_bitmask. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: bit ops for deliver_bitmapSheng Yang2009-06-101-11/+13
| | | | | | | It's also convenient when we extend KVM supported vcpu number in the future. Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Change API of kvm_ioapic_get_delivery_bitmaskSheng Yang2009-06-101-9/+8Star
| | | | | | | In order to use with bit ops. Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Unify the delivery of IOAPIC and MSI interruptsSheng Yang2009-06-101-57/+34Star
| | | | | Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Split IOAPIC structureSheng Yang2009-06-101-3/+3
| | | | | | | Prepared for reuse ioapic_redir_entry for MSI. Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Report IRQ injection status to userspace.Gleb Natapov2009-03-241-7/+16
| | | | | | | | | | | | IRQ injection status is either -1 (if there was no CPU found that should except the interrupt because IRQ was masked or ioapic was misconfigured or ...) or >= 0 in that case the number indicates to how many CPUs interrupt was injected. If the value is 0 it means that the interrupt was coalesced and probably should be reinjected. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: make irq ack notifications aware of routing tableMarcelo Tosatti2009-03-241-5/+5
| | | | | | | | | | IRQ ack notifications assume an identity mapping between pin->gsi, which might not be the case with, for example, HPET. Translate before acking. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Acked-by: Gleb Natapov <gleb@redhat.com>
* KVM: Interrupt mask notifiers for ioapicAvi Kivity2009-03-241-0/+6
| | | | | | | | | | Allow clients to request notifications when the guest masks or unmasks a particular irq line. This complements irq ack notifications, as the guest will not ack an irq line that is masked. Currently implemented for the ioapic only. Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Export ioapic_get_delivery_bitmaskSheng Yang2008-12-311-3/+4
| | | | | | | It would be used for MSI in device assignment, for MSI dispatch. Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Kick NMI receiving VCPUJan Kiszka2008-12-311-0/+1
| | | | | | | | Kick the NMI receiving VCPU in case the triggering caller runs in a different context. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: ia64: add a dummy irq ack notificationXiantao Zhang2008-10-151-1/+1
| | | | | | | | Before enabling notify_acked_irq for ia64, leave the related APIs as nop-op first. Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: irq ack notificationMarcelo Tosatti2008-10-151-7/+13
| | | | | | | | | | | | | | | | Based on a patch from: Ben-Ami Yassour <benami@il.ibm.com> which was based on a patch from: Amit Shah <amit.shah@qumranet.com> Notify IRQ acking on PIC/APIC emulation. The previous patch missed two things: - Edge triggered interrupts on IOAPIC - PIC reset with IRR/ISR set should be equivalent to ack (LAPIC probably needs something similar). Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> CC: Amit Shah <amit.shah@qumranet.com> CC: Ben-Ami Yassour <benami@il.ibm.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: kvm_io_device: extend in_range() to manage len and write attributeLaurent Vivier2008-07-201-1/+2
| | | | | | | | | | Modify member in_range() of structure kvm_io_device to pass length and the type of the I/O (write or read). This modification allows to use kvm_io_device with coalesced MMIO. Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: IOAPIC/LAPIC: Enable NMI supportSheng Yang2008-07-201-2/+18
| | | | | | | [avi: fix ia64 build breakage] Signed-off-by: Sheng Yang <sheng.yang@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: IOAPIC: Fix level-triggered irq injection hangMark McLoughlin2008-07-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The "remote_irr" variable is used to indicate an interrupt which has been received by the LAPIC, but not acked. In our EOI handler, we unset remote_irr and re-inject the interrupt if the interrupt line is still asserted. However, we do not set remote_irr here, leading to a situation where if kvm_ioapic_set_irq() is called, then we go ahead and call ioapic_service(). This means that IRR is re-asserted even though the interrupt is currently in service (i.e. LAPIC IRR is cleared and ISR/TMR set) The issue with this is that when the currently executing interrupt handler finishes and writes LAPIC EOI, then TMR is unset and EOI sent to the IOAPIC. Since IRR is now asserted, but TMR is not, then when the second interrupt is handled, no EOI is sent and if there is any pending interrupt, it is not re-injected. This fixes a hang only seen while running mke2fs -j on an 8Gb virtio disk backed by a fully sparse raw file, with aliguori "avoid fragmented virtio-blk transfers by copying" changes. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Acked-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: ioapic: fix lost interrupt when changing a device's irqAvi Kivity2008-06-241-20/+11Star
| | | | | | | | | | | | | The ioapic acknowledge path translates interrupt vectors to irqs. It currently uses a first match algorithm, stopping when it finds the first redirection table entry containing the vector. That fails however if the guest changes the irq to a different line, leaving the old redirection table entry in place (though masked). Result is interrupts not making it to the guest. Fix by always scanning the entire redirection table. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: IOAPIC: only set remote_irr if interrupt was injectedMarcelo Tosatti2008-06-061-10/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | There's a bug in the IOAPIC code for level-triggered interrupts. Its relatively easy to trigger by sharing (virtio-blk + usbtablet was the testcase, initially reported by Gerd von Egidy). The "remote_irr" variable is used to indicate accepted but not yet acked interrupts. Its cleared from the EOI handler. Problem is that the EOI handler clears remote_irr unconditionally, even if it reinjected another pending interrupt. In that case, kvm_ioapic_set_irq() proceeds to ioapic_service() which sets remote_irr even if it failed to inject (since the IRR was high due to EOI reinjection). Since the TMR bit has been cleared by the first EOI, the second one fails to clear remote_irr. End result is interrupt line dead. Fix it by setting remote_irr only if a new pending interrupt has been generated (and the TMR bit for vector in question set). Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Route irq 0 to vcpu 0 exclusivelyAvi Kivity2008-03-041-0/+8
| | | | | | | | | | Some Linux versions allow the timer interrupt to be processed by more than one cpu, leading to hangs due to tsc instability. Work around the issue by only disaptching the interrupt to vcpu 0. Problem analyzed (and patch tested) by Sheng Yang. Signed-off-by: Avi Kivity <avi@qumranet.com>
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