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2014-01-30KVM: return an error code in kvm_vm_ioctl_register_coalesced_mmio()Dan Carpenter1-6/+2
If kvm_io_bus_register_dev() fails then it returns success but it should return an error code. I also did a little cleanup like removing an impossible NULL test. Cc: stable@vger.kernel.org Fixes: 2b3c246a682c ('KVM: Make coalesced mmio use a device per zone') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-12-27KVM: make checks stricter in coalesced_mmio_in_range()Dan Carpenter1-3/+9
My testing version of Smatch complains that addr and len come from the user and they can wrap. The path is: -> kvm_vm_ioctl() -> kvm_vm_ioctl_unregister_coalesced_mmio() -> coalesced_mmio_in_range() I don't know what the implications are of wrapping here, but we may as well fix it, if only to silence the warning. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-09-25KVM: Intelligent device lookup on I/O busSasha Levin1-1/+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>
2011-09-25KVM: Make coalesced mmio use a device per zoneSasha Levin1-71/+47
This patch changes coalesced mmio to create one mmio device per zone instead of handling all zones in one device. Doing so enables us to take advantage of existing locking and prevents a race condition between coalesced mmio registration/unregistration and lookups. Suggested-by: Avi Kivity <avi@redhat.com> Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-09-25KVM: MMIO: Lock coalesced device when checking for available entrySasha Levin1-15/+27
Move the check whether there are available entries to within the spinlock. This allows working with larger amount of VCPUs and reduces premature exits when using a large number of VCPUs. Cc: Avi Kivity <avi@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-01KVM: Update Red Hat copyrightsAvi Kivity1-0/+1
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-05-17KVM: coalesced_mmio: fix kvm_coalesced_mmio_init()'s error handlingTakuya Yoshikawa1-0/+2
kvm_coalesced_mmio_init() keeps to hold the addresses of a coalesced mmio ring page and dev even after it has freed them. Also, if this function fails, though it might be rare, it seems to be suggesting the system's serious state: so we'd better stop the works following the kvm_creat_vm(). This patch clears these problems. We move the coalesced mmio's initialization out of kvm_create_vm(). This seems to be natural because it includes a registration which can be done only when vm is successfully created. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-17KVM: fix the errno of ioctl KVM_[UN]REGISTER_COALESCED_MMIO failureWei Yongjun1-2/+2
This patch change the errno of ioctl KVM_[UN]REGISTER_COALESCED_MMIO from -EINVAL to -ENXIO if no coalesced mmio dev exists. Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo1-0/+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>
2010-03-01KVM: Fix Codestyle in virt/kvm/coalesced_mmio.cJochen Maes1-2/+2
Fixed 2 codestyle issues in virt/kvm/coalesced_mmio.c Signed-off-by: Jochen Maes <jochen.maes@sejo.be> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01KVM: convert slots_lock to a mutexMarcelo Tosatti1-7/+7
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01KVM: convert io_bus to SRCUMarcelo Tosatti1-1/+3
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01KVM: Simplify coalesced mmio initializationAvi Kivity1-2/+23
- add destructor function - move related allocation into constructor - add stubs for !CONFIG_KVM_MMIO Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10KVM: make io_bus interface more robustGregory Haskins1-2/+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>
2009-09-10KVM: remove in_range from io devicesMichael S. Tsirkin1-9/+7
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>
2009-09-10KVM: convert bus to slots_lockMichael S. Tsirkin1-1/+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>
2009-09-10KVM: switch coalesced mmio changes to slots_lockMichael S. Tsirkin1-5/+5
switch coalesced mmio slots_lock. slots_lock is already taken for read everywhere, so we only need to take it for write when changing zones. This is in preparation to removing in_range and kvm->lock around it. [avi: fix build] Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10KVM: move coalesced_mmio locking to its own deviceMarcelo Tosatti1-6/+4
Move coalesced_mmio locking to its own device, instead of relying on kvm->lock. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10KVM: Calculate available entries in coalesced mmio ringAvi Kivity1-5/+5
Instead of checking whether we'll wrap around, calculate how many entries are available, and check whether we have enough (just one) for the pending mmio. By itself, this doesn't change anything, but it paves the way for making this function lockless. Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10KVM: cleanup io_device codeGregory Haskins1-10/+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>
2009-09-10KVM: Clean up coalesced_mmio destructionGregory Haskins1-1/+4
We invoke kfree() on a data member instead of the structure. This works today because the kvm_io_device is the first element of the private structure, but this could change in the future, so lets clean this up. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Acked-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Avi Kivity <avi@redhat.com>
2008-07-20KVM: Add coalesced MMIO support (common part)Laurent Vivier1-0/+156
This patch adds all needed structures to coalesce MMIOs. Until an architecture uses it, it is not compiled. Coalesced MMIO introduces two ioctl() to define where are the MMIO zones that can be coalesced: - KVM_REGISTER_COALESCED_MMIO registers a coalesced MMIO zone. It requests one parameter (struct kvm_coalesced_mmio_zone) which defines a memory area where MMIOs can be coalesced until the next switch to user space. The maximum number of MMIO zones is KVM_COALESCED_MMIO_ZONE_MAX. - KVM_UNREGISTER_COALESCED_MMIO cancels all registered zones inside the given bounds (bounds are also given by struct kvm_coalesced_mmio_zone). The userspace client can check kernel coalesced MMIO availability by asking ioctl(KVM_CHECK_EXTENSION) for the KVM_CAP_COALESCED_MMIO capability. The ioctl() call to KVM_CAP_COALESCED_MMIO will return 0 if not supported, or the page offset where will be stored the ring buffer. The page offset depends on the architecture. After an ioctl(KVM_RUN), the first page of the KVM memory mapped points to a kvm_run structure. The offset given by KVM_CAP_COALESCED_MMIO is an offset to the coalesced MMIO ring expressed in PAGE_SIZE relatively to the address of the start of th kvm_run structure. The MMIO ring buffer is defined by the structure kvm_coalesced_mmio_ring. [akio: fix oops during guest shutdown] Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Signed-off-by: Akio Takebe <takebe_akio@jp.fujitsu.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
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