On Thu, Jan 26, 2023 at 12:25:55AM -0500, Alexander Bulekov wrote: > Add a flag to the DeviceState, when a device is engaged in PIO/MMIO/DMA. > This flag is set/checked prior to calling a device's MemoryRegion > handlers, and set when device code initiates DMA. The purpose of this > flag is to prevent two types of DMA-based reentrancy issues: > > 1.) mmio -> dma -> mmio case > 2.) bh -> dma write -> mmio case > > These issues have led to problems such as stack-exhaustion and > use-after-frees. > > Summary of the problem from Peter Maydell: > https://lore.kernel.org/qemu-devel/cafeaca_23vc7he3iam-jva6w38lk4hjowae5kcknhprd5fp...@mail.gmail.com > > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/62 > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/540 > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/541 > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/556 > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/557 > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/827 > > Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com> > Signed-off-by: Alexander Bulekov <alx...@bu.edu>
Acked-by: Peter Xu <pet...@redhat.com> -- Peter Xu
