[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.yun at 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}