From 87e28a15c42cc592009c32a8c20e5789059027c2 Mon Sep 17 00:00:00 2001 From: Pierre Morel Date: Mon, 7 Sep 2020 15:26:07 +0200 Subject: KVM: s390: diag9c (directed yield) forwarding When we intercept a DIAG_9C from the guest we verify that the target real CPU associated with the virtual CPU designated by the guest is running and if not we forward the DIAG_9C to the target real CPU. To avoid a diag9c storm we allow a maximal rate of diag9c forwarding. The rate is calculated as a count per second defined as a new parameter of the s390 kvm module: diag9c_forwarding_hz . The default value of 0 is to not forward diag9c. Signed-off-by: Pierre Morel Link: https://lore.kernel.org/r/1613997661-22525-2-git-send-email-pmorel@linux.ibm.com Reviewed-by: Cornelia Huck Signed-off-by: Christian Borntraeger --- arch/s390/kvm/kvm-s390.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'arch/s390/kvm/kvm-s390.h') diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h index 79dcd647b378..9fad25109b0d 100644 --- a/arch/s390/kvm/kvm-s390.h +++ b/arch/s390/kvm/kvm-s390.h @@ -471,4 +471,12 @@ void kvm_s390_reinject_machine_check(struct kvm_vcpu *vcpu, * @kvm: the KVM guest */ void kvm_s390_vcpu_crypto_reset_all(struct kvm *kvm); + +/** + * diag9c_forwarding_hz + * + * Set the maximum number of diag9c forwarding per second + */ +extern unsigned int diag9c_forwarding_hz; + #endif -- cgit v1.2.3