On Fri, Apr 04, 2025 at 12:27:50PM -0300, Daniel Henrique Barboza wrote: > In [1], minute 44, we have a hint from a Canonical kernel developer that > the next Ubuntu LTS will be RVA23 compliant. If this really comes to > pass, the 'virt' CPU won't run it by default - we'll need to either use > 'rva23s64' or 'max' CPUs instead because rv64 is not RVA23 compliant. > Other distros will follow suit eventually, given that RISC-V profiles > provides the most stable ABI to build a distro in the RISC-V land. > > This exposes a long standing issue with the current rv64 CPU: it doesn't > represent anything in particular. Extensions were added in it as time > went by and we ended up with a CPU that has a random set of extensions. > > Changing the default 'virt' CPU to 'max' gives users a guarantee that > the board will always run with the latest features/profile available in > QEMU, which is the intention of most regular users. Using 'max' as > default CPU is done by other QEMU archs like aarch64 so we'll be more > compatible with everyone else. > > Note that this change does not affect existing scripts that are using > the rv64 CPU, e.g. a command line like "-cpu rv64,v=true" will work the > same after this patch. > > [1] > https://fosdem.org/2025/schedule/event/fosdem-2025-6031-risc-v-hardware-where-are-we-/ > > Signed-off-by: Daniel Henrique Barboza <dbarb...@ventanamicro.com> > --- > hw/riscv/virt.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c > index c9d255d8a8..ff7a122bef 100644 > --- a/hw/riscv/virt.c > +++ b/hw/riscv/virt.c > @@ -1920,7 +1920,7 @@ static void virt_machine_class_init(ObjectClass *oc, > void *data) > mc->desc = "RISC-V VirtIO board"; > mc->init = virt_machine_init; > mc->max_cpus = VIRT_CPUS_MAX; > - mc->default_cpu_type = TYPE_RISCV_CPU_BASE; > + mc->default_cpu_type = TYPE_RISCV_CPU_MAX; > mc->block_default_type = IF_VIRTIO; > mc->no_cdrom = 1; > mc->pci_allow_0_address = true; > -- > 2.49.0 >
Reviewed-by: Andrew Jones <ajo...@ventanamicro.com>
