On Tue, Sep 15, 2015 at 02:41:53PM +0800, Jason Wang wrote: > Hi: > > This series fixes two issues of fast mmio eventfd: > > 1) A single iodev instance were registerd on two buses: KVM_MMIO_BUS > and KVM_FAST_MMIO_BUS. This will cause double in > ioeventfd_destructor() > 2) A zero length iodev on KVM_MMIO_BUS will never be found but > kvm_io_bus_cmp(). This will lead e.g the eventfd will be trapped by > qemu instead of host. > > 1 is fixed by allocating two instances of iodev and introduce a new > capability for userspace. 2 is fixed by ignore the actual length if > the length of iodev is zero in kvm_io_bus_cmp(). > > Please review. > Changes from V5: > - move patch of explicitly checking for KVM_MMIO_BUS to patch 1 and > remove the unnecessary checks > - even more grammar and typo fixes > - rabase to kvm.git > - document KVM_CAP_FAST_MMIO
What's up with userspace using this capability? Did patches ever get posted? > > Changes from V4: > - move the location of kvm_assign_ioeventfd() in patch 1 which reduce > the change set. > - commit log typo fixes > - switch to use kvm_deassign_ioeventfd_id) when fail to register to > fast mmio bus > - change kvm_io_bus_cmp() as Paolo's suggestions > - introduce a new capability to avoid new userspace crash old kernel > - add a new patch that only try to register mmio eventfd on fast mmio > bus > > Changes from V3: > > - Don't do search on two buses when trying to do write on > KVM_MMIO_BUS. This fixes a small regression found by vmexit.flat. > - Since we don't do search on two buses, change kvm_io_bus_cmp() to > let it can find zero length iodevs. > - Fix the unnecessary lines in tracepoint patch. > > Changes from V2: > - Tweak styles and comment suggested by Cornelia. > > Changes from v1: > - change ioeventfd_bus_from_flags() to return KVM_FAST_MMIO_BUS when > needed to save lots of unnecessary changes. > > Jason Wang (6): > kvm: don't try to register to KVM_FAST_MMIO_BUS for non mmio eventfd > kvm: factor out core eventfd assign/deassign logic > kvm: fix double free for fast mmio eventfd > kvm: fix zero length mmio searching > kvm: add tracepoint for fast mmio > kvm: add fast mmio capabilitiy > > Documentation/virtual/kvm/api.txt | 7 ++- > arch/x86/kvm/trace.h | 18 ++++++ > arch/x86/kvm/vmx.c | 1 + > arch/x86/kvm/x86.c | 1 + > include/uapi/linux/kvm.h | 1 + > virt/kvm/eventfd.c | 124 > ++++++++++++++++++++++---------------- > virt/kvm/kvm_main.c | 20 +++++- > 7 files changed, 118 insertions(+), 54 deletions(-) > > -- > 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
