[RFC PATCH 1/3] arm64: KVM: defer kvm_init() to finalise_pkvm() when pKVM is enabled

[Yeoreum Yun]

This patch is a preparatory change to address dependency issues
between the FF-A driver and pKVM.

kvm_init() should be invoked from finalise_pkvm(),
as this is the point where pKVM initialisation is finalised and
the system transitions into the protected mode.

Deferring kvm_init() ensures that KVM is initialised only after pKVM has
fully established its protected environment.

Signed-off-by: Yeoreum Yun <yeoreum....@arm.com>
---
 arch/arm64/kvm/arm.c  |  8 +++++---
 arch/arm64/kvm/pkvm.c | 15 ++++++++++++++-
 2 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 8bb2c7422cc8..663b1d447a9b 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -3025,9 +3025,11 @@ static __init int kvm_arm_init(void)
         * FIXME: Do something reasonable if kvm_init() fails after pKVM
         * hypervisor protection is finalized.
         */
-       err = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
-       if (err)
-               goto out_subs;
+       if (!is_protected_kvm_enabled()) {
+               err = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
+               if (err)
+                       goto out_subs;
+       }
 
        /*
         * This should be called after initialization is done and failure isn't
diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c
index 053e4f733e4b..48b06d384570 100644
--- a/arch/arm64/kvm/pkvm.c
+++ b/arch/arm64/kvm/pkvm.c
@@ -17,6 +17,7 @@
 #include "hyp_constants.h"
 
 DEFINE_STATIC_KEY_FALSE(kvm_protected_mode_initialized);
+EXPORT_SYMBOL_GPL(kvm_protected_mode_initialized);
 
 static struct memblock_region *hyp_memory = kvm_nvhe_sym(hyp_memory);
 static unsigned int *hyp_memblock_nr_ptr = &kvm_nvhe_sym(hyp_memblock_nr);
@@ -289,10 +290,22 @@ static int __init finalize_pkvm(void)
        kmemleak_free_part(__hyp_rodata_start, __hyp_rodata_end - 
__hyp_rodata_start);
        kmemleak_free_part_phys(hyp_mem_base, hyp_mem_size);
 
-       ret = pkvm_drop_host_privileges();
+       ret = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
        if (ret)
+               goto out_err;
+
+       ret = pkvm_drop_host_privileges();
+       if (ret) {
                pr_err("Failed to finalize Hyp protection: %d\n", ret);
+               kvm_exit();
+               goto out_err;
+       }
+
+       return 0;
 
+out_err:
+       kvm_unregister_perf_callbacks();
+       kvm_arm_vmid_alloc_free();
        return ret;
 }
 device_initcall_sync(finalize_pkvm);
-- 
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}