Commit 7e42ad66 authored by Claudio Imbrenda's avatar Claudio Imbrenda
Browse files

KVM: s390: Remove unneeded srcu lock 



All paths leading to handle_essa() already hold the kvm->srcu.
Remove unneeded srcu locking from handle_essa().
Add lockdep assertion to make sure we will always be holding kvm->srcu
when entering handle_essa().

Reviewed-by: default avatarNina Schoetterl-Glausch <nsg@linux.ibm.com>
Reviewed-by: default avatarChristian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: default avatarChristoph Schlameuss <schlameuss@linux.ibm.com>
Reviewed-by: default avatarSteffen Eiden <seiden@linux.ibm.com>
Link: https://lore.kernel.org/r/20250528095502.226213-3-imbrenda@linux.ibm.com


Signed-off-by: default avatarClaudio Imbrenda <imbrenda@linux.ibm.com>
Message-ID: <20250528095502.226213-3-imbrenda@linux.ibm.com>
parent af941f3d

arch/s390/kvm/priv.c

+2 −4
Original line number Diff line number Diff line
@@ -1248,6 +1248,8 @@ static inline int __do_essa(struct kvm_vcpu *vcpu, const int orc) 


static int handle_essa(struct kvm_vcpu *vcpu)

{

	lockdep_assert_held(&vcpu->kvm->srcu);



	/* entries expected to be 1FF */

	int entries = (vcpu->arch.sie_block->cbrlo & ~PAGE_MASK) >> 3;

	unsigned long *cbrlo;
@@ -1297,12 +1299,8 @@ static int handle_essa(struct kvm_vcpu *vcpu) 
		/* Retry the ESSA instruction */

		kvm_s390_retry_instr(vcpu);

	} else {

		int srcu_idx;



		mmap_read_lock(vcpu->kvm->mm);

		srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);

		i = __do_essa(vcpu, orc);

		srcu_read_unlock(&vcpu->kvm->srcu, srcu_idx);

		mmap_read_unlock(vcpu->kvm->mm);

		if (i < 0)

			return i;