On 20.03.2024 14:57, Roger Pau Monne wrote: > There's no reason to force HVM guests to have a valid vcpu_info area when > initializing a vCPU, as the vCPU can also be brought online using the local > APIC, and on that path there's no requirement for vcpu_info to be setup ahead > of the bring up. Note an HVM vCPU can operate normally without making use of > vcpu_info.
While I'd agree if you started with "There's no real need to force ...", I still think there is a reason: If one wants to use paravirt interfaces (i.e. hypercalls), they would better do so consistently. After all there's also no need to use VCPUOP_initialise, yet you're not disabling its use. As said in reply to Andrew's reply, besides acting as a sentinel that structure instance also acts as a sink for Xen accesses to a vCPU's vcpu_info. By removing the check, you switch that from being a safeguard to being something that actually has to be expected to be accessed. Unless you've audited all uses to prove that no such access exists. Jan
