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path: root/virt/kvm/coalesced_mmio.c
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2009-09-10KVM: make io_bus interface more robustGregory Haskins
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. Tsirkin
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. Tsirkin
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. Tsirkin
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 Tosatti
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 Kivity
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 Haskins
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 Haskins
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 Vivier
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>