On Mon, Apr 20, 2026 at 02:00:57PM +0100, Yeoreum Yun wrote: Hi,
> > Hi Sebastian, > > On Fri, Apr 17, 2026 at 06:57:59PM +0100, Yeoreum Yun wrote: > > > > Hello Yeoreum, > > > > > > > When pKVM is enabled, the FF-A driver must be initialized after pKVM. > > > Otherwise, pKVM cannot negotiate the FF-A version or > > > obtain RX/TX buffer information, leading to failures in FF-A calls. > > > > At the moment this already happens after you move back ffa_init() to > > device_initcall(). > > How? the kvm_arm_init() is device_initcall() if both built as built-in. > > > > > > > > > During FF-A driver initialization, check whether pKVM has been > > > initialized. > > > If not, defer probing of the FF-A driver. > > > > > > > I don't think you need to add this dependency. pKVM is > > installed through KVM's module_init() which ends up calling hyp_ffa_init() > > to > > do the proxy initialization. The ARM-FFA driver comes after it (since > > pKVM is arch specific code). We don't have to call finalize_pkvm(..) to > > be able to handle smc(FF-A) calls in the hyp-proxy. > > > > As Marc said, the before finalised_pkvm(), smc wouldn't be trapped > to pKVM. IOW, in case when both built as built-in, They are, I tested before replying to this thread. The HCR_EL2 is 0x480080000 so HCR_EL2 TSC bit is set so SMC/FF-A and trapping is enabled. In __pkvm_prot_finalize it sets the HCR_VM bit which enables stage-2 and then write the HCR_EL2 from params->hcr_el2. However I wasn't sure that this is seen as a 'hack' and not expected to work. > if ffa_init() is called before finalised_pkvm(), > it couldn't proxy the FFA_VERSION, FFA_RXTX_MAP and FFA_PARTITION_INFO_GET > called by ffa_init(). > > How can you gurantee hyp_ffa_init() which is called by kvm_arm_init() > comes first even kvm_arm_init() and ffa_init() are on device_initcall? > While they are both on device_initcall, the only difference is that kvm_arm_init is arch code which appears before the driver/ code in the linker. That's why Marc said it is not a solid construct to rely on this. Thanks, Sebastian > [...] > > Thanks > > > -- > Sincerely, > Yeoreum Yun
