Commit 1dc0f02d authored Nov 30, 2022 by Sean Christopherson Committed by Paolo Bonzini Dec 29, 2022

KVM: arm64: Do arm/arch initialization without bouncing through kvm_init()



Do arm/arch specific initialization directly in arm's module_init(), now
called kvm_arm_init(), instead of bouncing through kvm_init() to reach
kvm_arch_init().  Invoking kvm_arch_init() is the very first action
performed by kvm_init(), so from a initialization perspective this is a
glorified nop.

Avoiding kvm_arch_init() also fixes a mostly benign bug as kvm_arch_exit()
doesn't properly unwind if a later stage of kvm_init() fails.  While the
soon-to-be-deleted comment about compiling as a module being unsupported
is correct, kvm_arch_exit() can still be called by kvm_init() if any step
after the call to kvm_arch_init() succeeds.

Add a FIXME to call out that pKVM initialization isn't unwound if
kvm_init() fails, which is a pre-existing problem inherited from
kvm_arch_exit().

Making kvm_arch_init() a nop will also allow dropping kvm_arch_init() and
kvm_arch_exit() entirely once all other architectures follow suit.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221130230934.1014142-20-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

parent 78b3bf48

arch/arm64/kvm/arm.c

+16 −9

Original line number	Diff line number	Diff line
		@@ -2207,7 +2207,7 @@ void kvm_arch_irq_bypass_start(struct irq_bypass_consumer *cons)
		/**
		* Initialize Hyp-mode and memory mappings on all CPUs.
		*/
		int kvm_arch_init(void *opaque)
		int kvm_arm_init(void)
		{
		int err;
		bool in_hyp_mode;
		@@ -2281,6 +2281,14 @@ int kvm_arch_init(void *opaque)
		kvm_info("Hyp mode initialized successfully\n");
		}

		/*
		* FIXME: Do something reasonable if kvm_init() fails after pKVM
		* hypervisor protection is finalized.
		*/
		err = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
		if (err)
		goto out_subs;

		return 0;

		out_subs:
		@@ -2293,10 +2301,15 @@ int kvm_arch_init(void *opaque)
		return err;
		}

		int kvm_arch_init(void *opaque)
		{
		return 0;
		}

		/* NOP: Compiling as a module not supported */
		void kvm_arch_exit(void)
		{
		kvm_unregister_perf_callbacks();

		}

		static int __init early_kvm_mode_cfg(char *arg)
		@@ -2337,10 +2350,4 @@ enum kvm_mode kvm_get_mode(void)
		return kvm_mode;
		}

		static int arm_init(void)
		{
		int rc = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
		return rc;
		}

		module_init(arm_init);
		module_init(kvm_arm_init);