Hi Peter, Thanks for the quick feedback and the background.
Peter Maydell <[email protected]> writes: > On Thu, 20 Aug 2020 at 05:55, Punit Agrawal > <[email protected]> wrote: >> >> The default_cpu_type for the Virt machine is set to "cortex-a15" for >> both the arm (qemu-system-arm) and aarch64 (qemu-system-aarch64) >> targets. >> >> As a result, starting the aarch64 target with "-machine virt" defaults >> to booting with a Arm v7 cpu which is counter to >> expectation. Debugging the issue is further hampered by lack of any >> output from a supplied arm64 firmware as it is now running on the >> wrong CPU type. >> >> Fix this by defaulting to the "max" capability CPU for the target >> architecture. After the patch both the arm and aarch64 qemu default to >> the equivalent of passing "-cpu max". > > Hi; this kind of thing has been suggested in the past several times. > Generally we've taken the view that we prefer: > * not to make changes that would break pre-existing command lines > * to maintain the general behaviour that a command line used > with qemu-system-arm will also work with qemu-system-aarch64 It did feel like too low hanging a fruit to not have been looked into before. Generally the above makes sense - though defaulting qemu-system-aarch64 to start with a 32bit cpu is stretching the above view too far I think. > It is certainly true that these days the default CPU type for > virt is not what most users want, though. I do understand it's a balancing act when it comes to changing user visible options. But it's worth revisiting the choice if most users would prefer otherwise. Thanks, Punit
