Commit 2f2e1a50 authored by Will Deacon's avatar Will Deacon Committed by Marc Zyngier
Browse files

KVM: arm64: Propagate errors from __pkvm_prot_finalize hypercall 



If the __pkvm_prot_finalize hypercall returns an error, we WARN but fail
to propagate the failure code back to kvm_arch_init().

Pass a pointer to a zero-initialised return variable so that failure
to finalise the pKVM protections on a host CPU can be reported back to
KVM.

Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Signed-off-by: default avatarWill Deacon <will@kernel.org>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211008135839.1193-5-will@kernel.org
parent 8579a185

arch/arm64/kvm/arm.c

+19 −11
Original line number Diff line number Diff line
@@ -1986,9 +1986,25 @@ static int init_hyp_mode(void) 
	return err;

}



static void _kvm_host_prot_finalize(void *discard)

static void _kvm_host_prot_finalize(void *arg)

{

	WARN_ON(kvm_call_hyp_nvhe(__pkvm_prot_finalize));

	int *err = arg;



	if (WARN_ON(kvm_call_hyp_nvhe(__pkvm_prot_finalize)))

		WRITE_ONCE(*err, -EINVAL);

}



static int pkvm_drop_host_privileges(void)

{

	int ret = 0;



	/*

	 * Flip the static key upfront as that may no longer be possible

	 * once the host stage 2 is installed.

	 */

	static_branch_enable(&kvm_protected_mode_initialized);

	on_each_cpu(_kvm_host_prot_finalize, &ret, 1);

	return ret;

}



static int finalize_hyp_mode(void)
@@ -2002,15 +2018,7 @@ static int finalize_hyp_mode(void) 
	 * None of other sections should ever be introspected.

	 */

	kmemleak_free_part(__hyp_bss_start, __hyp_bss_end - __hyp_bss_start);



	/*

	 * Flip the static key upfront as that may no longer be possible

	 * once the host stage 2 is installed.

	 */

	static_branch_enable(&kvm_protected_mode_initialized);

	on_each_cpu(_kvm_host_prot_finalize, NULL, 1);



	return 0;

	return pkvm_drop_host_privileges();

}



struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr)