On Fri, Jan 10, 2025 at 4:40 PM Sean Christopherson <seanjc@xxxxxxxxxx> wrote: > > On Fri, Jan 10, 2025, Ashish Kalra wrote: > > It looks like i have hit a serious blocker issue with this approach of moving > > SEV/SNP initialization to KVM module load time. > > > > While testing with kvm_amd and PSP driver built-in, it looks like kvm_amd > > driver is being loaded/initialized before PSP driver is loaded, and that > > causes sev_platform_init() call from sev_hardware_setup(kvm_amd) to fail: > > > > [ 10.717898] kvm_amd: TSC scaling supported > > [ 10.722470] kvm_amd: Nested Virtualization enabled > > [ 10.727816] kvm_amd: Nested Paging enabled > > [ 10.732388] kvm_amd: LBR virtualization supported > > [ 10.737639] kvm_amd: SEV enabled (ASIDs 100 - 509) > > [ 10.742985] kvm_amd: SEV-ES enabled (ASIDs 1 - 99) > > [ 10.748333] kvm_amd: SEV-SNP enabled (ASIDs 1 - 99) > > [ 10.753768] PSP driver not init <<<---- sev_platform_init() returns failure as PSP driver is still not initialized > > [ 10.757563] kvm_amd: Virtual VMLOAD VMSAVE supported > > [ 10.763124] kvm_amd: Virtual GIF supported > > ... > > ... > > [ 12.514857] ccp 0000:23:00.1: enabling device (0000 -> 0002) > > [ 12.521691] ccp 0000:23:00.1: no command queues available > > [ 12.527991] ccp 0000:23:00.1: sev enabled > > [ 12.532592] ccp 0000:23:00.1: psp enabled > > [ 12.537382] ccp 0000:a2:00.1: enabling device (0000 -> 0002) > > [ 12.544389] ccp 0000:a2:00.1: no command queues available > > [ 12.550627] ccp 0000:a2:00.1: psp enabled > > > > depmod -> modules.builtin show kernel/arch/x86/kvm/kvm_amd.ko higher on the list and before kernel/drivers/crypto/ccp/ccp.ko > > > > modules.builtin: > > kernel/arch/x86/kvm/kvm.ko > > kernel/arch/x86/kvm/kvm-amd.ko > > ... > > ... > > kernel/drivers/crypto/ccp/ccp.ko > > > > I believe that the modules which are compiled first get called first and it > > looks like that the only way to change the order for builtin modules is by > > changing which makefiles get compiled first ? > > > > Is there a way to change the load order of built-in modules and/or change > > dependency of built-in modules ? > > The least awful option I know of would be to have the PSP use a higher priority > initcall type so that it runs before the standard initcalls. When compiled as > a module, all initcall types are #defined to module_init. > > E.g. this should work, /cross fingers > > diff --git a/drivers/crypto/ccp/sp-dev.c b/drivers/crypto/ccp/sp-dev.c > index 7eb3e4668286..02c49fbf6198 100644 > --- a/drivers/crypto/ccp/sp-dev.c > +++ b/drivers/crypto/ccp/sp-dev.c > @@ -295,5 +295,6 @@ static void __exit sp_mod_exit(void) > #endif > } > > -module_init(sp_mod_init); > +/* The PSP needs to be initialized before dependent modules, e.g. before KVM. */ > +subsys_initcall(sp_mod_init); I was 2 seconds from clicking send with this exact suggestion. There are examples in 'drivers/' that use subsys_initcall / module_exit pairs. > module_exit(sp_mod_exit); -- -Dionna Glaze, PhD, CISSP, CCSP (she/her)
