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(). > > 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. > Signed-off-by: Yeoreum Yun <[email protected]> > --- > arch/arm64/kvm/arm.c | 1 + > drivers/firmware/arm_ffa/driver.c | 12 ++++++++++++ > 2 files changed, 13 insertions(+) > > diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c > index 410ffd41fd73..0f517b1c05cd 100644 > --- a/arch/arm64/kvm/arm.c > +++ b/arch/arm64/kvm/arm.c > @@ -119,6 +119,7 @@ bool is_kvm_arm_initialised(void) > { > return kvm_arm_initialised; > } > +EXPORT_SYMBOL(is_kvm_arm_initialised); > > int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu) > { > diff --git a/drivers/firmware/arm_ffa/driver.c > b/drivers/firmware/arm_ffa/driver.c > index 02c76ac1570b..2647d6554afd 100644 > --- a/drivers/firmware/arm_ffa/driver.c > +++ b/drivers/firmware/arm_ffa/driver.c > @@ -42,6 +42,8 @@ > #include <linux/uuid.h> > #include <linux/xarray.h> > > +#include <asm/virt.h> > + > #include "common.h" > > #define FFA_DRIVER_VERSION FFA_VERSION_1_2 > @@ -2035,6 +2037,16 @@ static int __init ffa_init(void) > u32 buf_sz; > size_t rxtx_bufsz = SZ_4K; > > + /* > + * When pKVM is enabled, the FF-A driver must be initialized > + * after pKVM initialization. Otherwise, pKVM cannot negotiate > + * the FF-A version or obtain RX/TX buffer information, > + * which leads to failures in FF-A calls. > + */ > + if (IS_ENABLED(CONFIG_KVM) && is_protected_kvm_enabled() && > + !is_kvm_arm_initialised()) > + return -EPROBE_DEFER; > + > ret = ffa_transport_init(&invoke_ffa_fn); > if (ret) > return ret; > -- > LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7} > Thanks, Sebastian
