Eric Lee / smarc-fsl-linux-kernel

26 Sep, 2011

1 commit

  • 2b3c246a6   KVM: Make coalesced mmio use a device per zone ... Browse Code »

    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
    Signed-off-by: Sasha Levin
    Signed-off-by: Marcelo Tosatti

    Sasha Levin
     

01 Mar, 2010

2 commits

10 Sep, 2009

1 commit

20 Jul, 2008

1 commit

  • 5f94c1741   KVM: Add coalesced MMIO support (common part) ... Browse Code »

    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
    Signed-off-by: Akio Takebe
    Signed-off-by: Avi Kivity

    Laurent Vivier