On Mon, Nov 09, 2015 at 12:35:45PM +0800, Jason Wang wrote: > > > On 11/09/2015 01:11 AM, Michael S. Tsirkin wrote: > > 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? > > It was renamed to KVM_CAP_IOEVENTFD_ANY_LENGTH. > > > Did patches ever get posted? > > See https://lkml.org/lkml/2015/9/28/208 Talking about userspace here. QEMU freeze is approaching, it really should use this to avoid regressions. > > > >> 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 majordomo@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
