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Commit f6c137ff authored by Christian Borntraeger's avatar Christian Borntraeger
Browse files

KVM: s390: randomize sca address 



We allocate a page for the 2k sca, so lets use the space to improve
hit rate of some internal cpu caches. No need to change the freeing
of the page, as this will shift away the page offset bits anyway.

Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: default avatarDavid Hildenbrand <dahi@linux.vnet.ibm.com>
parent 94b3ffcd

arch/s390/kvm/kvm-s390.c

+5 −0
Original line number Diff line number Diff line
@@ -215,6 +215,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) 
{

	int rc;

	char debug_name[16];

	static unsigned long sca_offset;



	rc = -EINVAL;

#ifdef CONFIG_KVM_S390_UCONTROL
@@ -236,6 +237,10 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) 
	kvm->arch.sca = (struct sca_block *) get_zeroed_page(GFP_KERNEL);

	if (!kvm->arch.sca)

		goto out_err;

	spin_lock(&kvm_lock);

	sca_offset = (sca_offset + 16) & 0x7f0;

	kvm->arch.sca = (struct sca_block *) ((char *) kvm->arch.sca + sca_offset);

	spin_unlock(&kvm_lock);



	sprintf(debug_name, "kvm-%u", current->pid);