<!-- This is the upstream QEMU issue tracker. If you are able to, it will greatly facilitate bug triage if you attempt to reproduce the problem with the latest qemu.git master built from source. See https://www.qemu.org/download/#source for instructions on how to do this. QEMU generally supports the last two releases advertised on https://www.qemu.org/. Problems with distro-packaged versions of QEMU older than this should be reported to the distribution instead. See https://www.qemu.org/contribute/report-a-bug/ for additional guidance. If this is a security issue, please consult https://www.qemu.org/contribute/security-process/ --> ## Host environment - Operating system: Ubuntu 22.04.2 LTS <!-- Windows 10 21H1, Fedora 37, etc. --> - OS/kernel version: 5.19.0-38-generic <!-- For POSIX hosts, use `uname -a` --> - Architecture: x86 <!-- x86, ARM, s390x, etc. --> - QEMU flavor: qemu-system-riscv64 <!-- qemu-system-x86_64, qemu-aarch64, qemu-img, etc. --> - QEMU version: 7.2.94 (v8.0.0-rc4) - QEMU command line: <!-- Give the smallest, complete command line that exhibits the problem. If you are using libvirt, virsh, or vmm, you can likely find the QEMU command line arguments in /var/log/libvirt/qemu/$GUEST.log. --> ``` qemu-system-riscv64 -append "root=/dev/root rw rootfstype=9p rootflags=version=9p2000.L,trans=virtio,cache=mmap,access=any raid=noautodetect security=none loglevel=7" -cpu rv64 -device virtio-9p-pci,fsdev=root,mount_tag=/dev/root -device virtio-net-device,netdev=net0 -device virtio-rng-device,rng=rng0 -fsdev local,id=root,path=/home/andrea/Downloads/jammy/,security_model=none -kernel /home/andrea/linux/arch/riscv/boot/Image -m 16G -machine virt -monitor telnet:127.0.0.1:55555,server,nowait -netdev user,id=net0,host=10.0.2.10,hostfwd=tcp::10022-:22 -nographic -object rng-random,filename=/dev/urandom,id=rng0 -serial mon:stdio -smp 4 ``` ## Emulated/Virtualized environment - Operating system: Ubuntu 22.04.2 LTS <!-- Windows 10 21H1, Fedora 37, etc. --> - OS/kernel version: Linux 6.3.0-rc7 (defconfig) <!-- For POSIX guests, use `uname -a`. --> - Architecture: RISC-V (riscv64-softmmu) <!-- x86, ARM, s390x, etc. --> ## Description of problem <!-- Describe the problem, including any error/crash messages seen. --> The attached user-level test is designed to do the following (in iteration): - Thread P0 on CPU0 changes some text/code, while - Thread P1 on CPU1 checks/reads the code, fence.i, then executes the same code. Results (in stdout) indicates that CPU1 has read the new code (1:x5=a009) but executed the old one (1:x7=1) (against the specification). ## Steps to reproduce 1. echo 2 > /proc/sys/vm/nr_hugepages 2. ./CoRF+fence.i ## Additional information <!-- Attach logs, stack traces, screenshots, etc. Compress the files if necessary. If using libvirt, libvirt logs and XML domain information may be relevant. --> Example output: ```[CoRF+fence.i.c](/uploads/c150ca0910783cc4bfc3886789b64c28/CoRF+fence.i.c) Test CoRF+fence.i Allowed Histogram (4 states) 25784 :>1:x5=0xa009; 1:x7=2; 24207 *>1:x5=0xa009; 1:x7=1; <-- THIS LINE 8 :>1:x5=0xa019; 1:x7=1; 1 :>1:x5=0xa019; 1:x7=2; Ok Witnesses Positive: 24207 Negative 25793 Condition exists (1:x5=0xa009 /\ 1:x7=1) is validated Observation CoRF+fence.i Sometimes 24207 25793 Time CoRF+fence.i 0.85 Hash= ``` <!-- The line below ensures that proper tags are added to the issue. Please do not remove it. -->