| Message ID | cover.1727425255.git.chao.liu@yeah.net |
|---|---|
| Headers | show |
| Series | Drop ignore_memory_transaction_failures for xilink_zynq | expand |
On Fri, 27 Sept 2024 at 09:52, Chao Liu <chao.liu@yeah.net> wrote: > > Hi, thank you for your prompt reply, it's a great encouragement to me! > > Based on your review suggestions, I have improved the v1 patch. > > By using create_unimplemented_device() during the initialization phase, > I added a "znyq.umip" device early on, which covers the 32-bit address space > of GPA. This can better serve as a replacement for the effect of the > ignore_memory_transaction_failures flag. > > Since create_unimplemented_device() sets the priority of the > memory region (mr) to -100, normally created devices will override the address > segments corresponding to the unimplemented devices. > > Even if our test set is not sufficiently comprehensive, we can create an > unimp_device for the maximum address space allowed by the board. This prevents > the guest system from triggering unexpected exceptions when accessing > unimplemented devices or regions. What would be the benefit of doing that? If we're going to say "we'll make accesses to regions without devices not generate faults", the simplest way to do that is to leave the ignore_memory_transaction_failures flag set the way it is. thanks -- PMM
Hi, thank you for your prompt reply, it's a great encouragement to me! Based on your review suggestions, I have improved the v1 patch. By using create_unimplemented_device() during the initialization phase, I added a "znyq.umip" device early on, which covers the 32-bit address space of GPA. This can better serve as a replacement for the effect of the ignore_memory_transaction_failures flag. Since create_unimplemented_device() sets the priority of the memory region (mr) to -100, normally created devices will override the address segments corresponding to the unimplemented devices. Even if our test set is not sufficiently comprehensive, we can create an unimp_device for the maximum address space allowed by the board. This prevents the guest system from triggering unexpected exceptions when accessing unimplemented devices or regions. Additionally, I still use create_unimplemented_device() for other unimplemented devices. This makes it easier to debug when these devices are added later. Finally, here are my testing steps: Step 1, Referring to the Xilinx Wiki, I compiled a Linux kernel binary image for convenience in testing. You can directly obtain it via: git clone https://github.com/zevorn/QEMU_CPUFreq_Zynq.git Step 2, Use the following command to run the QEMU: ./qemu/build/qemu-system-arm -M xilinx-zynq-a9 \ -serial /dev/null \ -serial mon:stdio \ -display none \ -kernel QEMU_CPUFreq_Zynq/Prebuilt_functional/kernel_standard_linux/uImage \ -dtb QEMU_CPUFreq_Zynq/Prebuilt_functional/my_devicetree.dtb \ --initrd QEMU_CPUFreq_Zynq/Prebuilt_functional/umy_ramdisk.image.gz If there are no issues during execution and it boots successfully into the terminal, for example: ... PetaLinux 2016.4 zedboard-zynq7 /dev/ttyPS0 zedboard-zynq7 login: root root@zedboard-zynq7:~# Chao Liu (2): xilink_zynq: Add various missing unimplemented devices xilink-zynq-devcfg: Fix up for memory address range size not set correctly hw/arm/xilinx_zynq.c | 46 ++++++++++++++++++++++++++++++++++++++- hw/dma/xlnx-zynq-devcfg.c | 2 +- 2 files changed, 46 insertions(+), 2 deletions(-)