id = 747
title = "hvf-accelerated aarch64 hangs when switching to big endian mode"
state = "closed"
created_at = "2021-11-24T19:30:04.332Z"
closed_at = "2021-11-26T20:44:43.497Z"
labels = ["Closed::WontFix", "accel: HVF", "target: arm", "workflow::Needs Info"]
url = "https://gitlab.com/qemu-project/qemu/-/issues/747"
host-os = "macOS Monterey Version 12.0.1"
host-arch = "ARM"
qemu-version = "QEMU emulator version 6.1.0"
guest-os = "Gentoo Linux"
guest-arch = "ARM (64 bit big endian)"
description = """Trying to boot a big endian Linux kernel using the above command line on an M1 Mac Mini just hangs, there is not a single output.  However, by replacing `hvf` with `tcg`, the kernel boots up fine.  The kernel also starts if I use KVM acceleration on a Linux host system."""
reproduce = """1. Build a Linux kernel for big endian arm64
2. Try to boot it with -accel hvf on an M1 Mac
3. Observe a lot of nothing happening  :-)"""
additional = """Sample run, TCG vs HVF
```
mikan:/tmp% qemu-system-aarch64 -accel tcg -machine virt,highmem=off -cpu cortex-a72 -nographic -kernel /tmp/vmlinuz-5.10.76-gentoo-r1-arm64.be |& head -16
[    0.000000] Booting Linux on physical CPU 0x0000000000 [0x410fd083]
[    0.000000] Linux version 5.10.76-gentoo-r1-arm64 (root@localhost) (aarch64-unknown-linux-gnu-gcc (Gentoo 11.2.0 p1) 11.2.0, GNU ld (Gentoo 2.37_p1 p0) 2.37) #1 SMP Sun Nov 21 16:30:21 -00 2021
[    0.000000] Machine model: linux,dummy-virt
[    0.000000] NUMA: No NUMA configuration found
[    0.000000] NUMA: Faking a node at [mem 0x0000000040000000-0x0000000047ffffff]
[    0.000000] NUMA: NODE_DATA [mem 0x47f65300-0x47f76fff]
[    0.000000] Zone ranges:
[    0.000000]   DMA      [mem 0x0000000040000000-0x0000000047ffffff]
[    0.000000]   DMA32    empty
[    0.000000]   Normal   empty
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x0000000040000000-0x0000000047ffffff]
[    0.000000] Initmem setup node 0 [mem 0x0000000040000000-0x0000000047ffffff]
[    0.000000] psci: probing for conduit method from DT.
[    0.000000] psci: PSCIv0.2 detected in firmware.
mikan:/tmp% qemu-system-aarch64 -accel hvf -machine virt,highmem=off -cpu cortex-a72 -nographic -kernel /tmp/vmlinuz-5.10.76-gentoo-r1-arm64.be       
```
(followed by tumbleweeds)"""