[KVM PATCH v8 0/3] iosignalfd

From: Gregory Haskins
Date: Thu Jun 18 2009 - 20:30:54 EST

(Applies to kvm.git/master:c27b64a0)

This is v8 of the series. For more details, please see the header to
patch 3/3.

This series has been tested against the kvm-eventfd unit test, and
appears to be functioning properly. You can download this test here:


Please consider for inclusion to kvm.git

An updated userspace for qemu-kvm.git is forthcoming.


*) Addressed Avi's review comments:
*) Simplified the unregister_dev logic in patch 1/3
*) Implemented a per-vm io-device limit (patch 2/3)
*) Removed spurious whitespace hunk
*) changed the data-match from a void* to a u64
*) check group-length violations before wildcarding

*) Implemented a resource limit (CONFIG_KVM_MAX_IOSIGNALFD_ITEMS)
to limit malicious/broken userspace from consuming arbitrary
kernel memory.
*) Rebased to kvm.git/master:c27b64a0, which already includes
Marcelo's irq-lock rework.

*) Removed "FIXME?" comment on choice over RCU vs SRCU after
discussion/numbers from Paul. I think RCU is fine to use for
now based on the conversation. We can always convert it later
if need be.
*) Fixed the "group" free path to eliminate an RCU related race
*) Fixed a memory/eventfd leak on shutdown for any iosignalfd's
which were still active at the time the guest shuts down.
*) Beefed up comments
*) Rebased to kvm.git/master:0281e88f + irq locking rework and
verified that kvm-eventfd unit test still passes.

*) Removed "cookie" field, which was a misunderstanding on my
part on what Avi wanted for a data-match feature
*) Added a new "trigger" data-match feature which I think is
much closer to what we need.
*) We retain the dev_count field in the io_bus infrastructure
and instead back-fill the array on removal.
*) Various minor cleanups
*) Rebased to kvm.git/master:25deed73

*) Fixed a bug in the original 2/4 where the PIT failure case
would potentially leave the io_bus components registered.
*) Condensed the v3 2/4 and 3/4 into one patch (2/2) since
the patches became interdependent with the fix described above
*) Rebased to kvm.git/master:74dfca0a

*) fixed patch 2/4 to handle error cases instead of BUG_ON
*) implemented same HAVE_EVENTFD protection mechanism as
irqfd to prevent compilation errors on unsupported arches
*) completed testing
*) rebased to kvm.git/master:7391a6d5

*) added optional data-matching capability (via cookie field)
*) changed name from iofd to iosignalfd
*) added io_bus unregister function
*) implemented deassign feature

*) original release (integrated into irqfd v7 series as "iofd")


Gregory Haskins (3):
KVM: add iosignalfd support
KVM: add per-vm limit on the maximum number of io-devices supported
KVM: make io_bus interface more robust

arch/x86/kvm/Kconfig | 8 +
arch/x86/kvm/i8254.c | 23 ++
arch/x86/kvm/i8259.c | 9 +
arch/x86/kvm/x86.c | 1
include/linux/kvm.h | 15 ++
include/linux/kvm_host.h | 19 ++
virt/kvm/coalesced_mmio.c | 8 +
virt/kvm/eventfd.c | 426 +++++++++++++++++++++++++++++++++++++++++++++
virt/kvm/ioapic.c | 9 +
virt/kvm/kvm_main.c | 42 ++++
10 files changed, 545 insertions(+), 15 deletions(-)

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/