On Sat, Feb 04, 2023 at 11:07:33PM -0500, Alexander Bulekov wrote: > These patches aim to solve two types of DMA-reentrancy issues: > > 1.) mmio -> dma -> mmio case > To solve this, we track whether the device is engaged in io by > checking/setting a reentrancy-guard within APIs used for MMIO access. > > 2.) bh -> dma write -> mmio case > This case is trickier, since we dont have a generic way to associate a > bh with the underlying Device/DeviceState. Thus, this version allows a > device to associate a reentrancy-guard with a bh, when creating it. > (Instead of calling qemu_bh_new, you call qemu_bh_new_guarded) > > I replaced most of the qemu_bh_new invocations with the guarded analog, > except for the ones where the DeviceState was not trivially accessible. > > v5 -> v6: > - Only apply checkpatch checks to code in paths containing "/hw/" > (/hw/ and include/hw/) > - Fix a bug in a _guarded call added to hw/block/virtio-blk.c > v4-> v5: > - Add corresponding checkpatch checks > - Save/restore reentrancy-flag when entering/exiting BHs > - Improve documentation > - Check object_dynamic_cast return value > > v3 -> v4: Instead of changing all of the DMA APIs, instead add an > optional reentrancy guard to the BH API. > > v2 -> v3: Bite the bullet and modify the DMA APIs, rather than > attempting to guess DeviceStates in BHs. > > Alexander Bulekov (4): > memory: prevent dma-reentracy issues > async: Add an optional reentrancy guard to the BH API > checkpatch: add qemu_bh_new/aio_bh_new checks > hw: replace most qemu_bh_new calls with qemu_bh_new_guarded > > docs/devel/multiple-iothreads.txt | 7 +++++++ > hw/9pfs/xen-9p-backend.c | 4 +++- > hw/block/dataplane/virtio-blk.c | 3 ++- > hw/block/dataplane/xen-block.c | 5 +++-- > hw/char/virtio-serial-bus.c | 3 ++- > hw/display/qxl.c | 9 ++++++--- > hw/display/virtio-gpu.c | 6 ++++-- > hw/ide/ahci.c | 3 ++- > hw/ide/core.c | 3 ++- > hw/misc/imx_rngc.c | 6 ++++-- > hw/misc/macio/mac_dbdma.c | 2 +- > hw/net/virtio-net.c | 3 ++- > hw/nvme/ctrl.c | 6 ++++-- > hw/scsi/mptsas.c | 3 ++- > hw/scsi/scsi-bus.c | 3 ++- > hw/scsi/vmw_pvscsi.c | 3 ++- > hw/usb/dev-uas.c | 3 ++- > hw/usb/hcd-dwc2.c | 3 ++- > hw/usb/hcd-ehci.c | 3 ++- > hw/usb/hcd-uhci.c | 2 +- > hw/usb/host-libusb.c | 6 ++++-- > hw/usb/redirect.c | 6 ++++-- > hw/usb/xen-usb.c | 3 ++- > hw/virtio/virtio-balloon.c | 5 +++-- > hw/virtio/virtio-crypto.c | 3 ++- > include/block/aio.h | 18 ++++++++++++++++-- > include/hw/qdev-core.h | 7 +++++++ > include/qemu/main-loop.h | 7 +++++-- > scripts/checkpatch.pl | 8 ++++++++ > softmmu/memory.c | 17 +++++++++++++++++ > softmmu/trace-events | 1 + > tests/unit/ptimer-test-stubs.c | 3 ++- > util/async.c | 18 +++++++++++++++++- > util/main-loop.c | 5 +++-- > util/trace-events | 1 + > 35 files changed, 147 insertions(+), 41 deletions(-) > > -- > 2.39.0 > Reviewed-by: Stefan Hajnoczi