On Fri, Apr 28, 2023 at 04:57:28PM -0300, Daniel Henrique Barboza wrote:
At this moment it is not possible to launch a 'riscv64' domain if a CPU definition is presented in the domain. For example, adding this CPU definition:
<cpu mode='custom' match='exact' check='none'> <model fallback='forbid'>rv64</model> </cpu>
Will trigger the following error:
$ sudo ./run tools/virsh start riscv-virt1 error: Failed to start domain 'riscv-virt1' error: this function is not supported by the connection driver: cannot update guest CPU for riscv64 architecture
The error comes from virCPUUpdate(), via qemuProcessUpdateGuestCPU(), and it's caused by the absence of the 'update' API in the existing RISC-V driver.
Add an 'update' API impl to the RISC-V driver to allow for CPU definitions to be declared in RISC-V domains. This API was copied from the ARM driver (virCPUarmUpdate()) since it's a good enough implementation to get us going.
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com> --- po/POTFILES | 1 + src/cpu/cpu_riscv64.c | 28 +++++++++++++++++++++++++++- 2 files changed, 28 insertions(+), 1 deletion(-)
Using the Arm CPU driver as a base sounds reasonable, as they currently have the same level (read: pretty low) of sophistication. I've tested this against both the current version of QEMU and the upcoming one which implements query-cpu-definitions, and it works as expected. Reviewed-by: Andrea Bolognani <abologna@redhat.com> and pushed. -- Andrea Bolognani / Red Hat / Virtualization