From a3e03bc1368c1bc16e19b001fc96dc7430573cc8 Mon Sep 17 00:00:00 2001 From: Halil Pasic Date: Fri, 27 Aug 2021 14:54:29 +0200 Subject: KVM: s390: index kvm->arch.idle_mask by vcpu_idx MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit While in practice vcpu->vcpu_idx == vcpu->vcp_id is often true, it may not always be, and we must not rely on this. Reason is that KVM decides the vcpu_idx, userspace decides the vcpu_id, thus the two might not match. Currently kvm->arch.idle_mask is indexed by vcpu_id, which implies that code like for_each_set_bit(vcpu_id, kvm->arch.idle_mask, online_vcpus) { vcpu = kvm_get_vcpu(kvm, vcpu_id); do_stuff(vcpu); } is not legit. Reason is that kvm_get_vcpu expects an vcpu_idx, not an vcpu_id. The trouble is, we do actually use kvm->arch.idle_mask like this. To fix this problem we have two options. Either use kvm_get_vcpu_by_id(vcpu_id), which would loop to find the right vcpu_id, or switch to indexing via vcpu_idx. The latter is preferable for obvious reasons. Let us make switch from indexing kvm->arch.idle_mask by vcpu_id to indexing it by vcpu_idx. To keep gisa_int.kicked_mask indexed by the same index as idle_mask lets make the same change for it as well. Fixes: 1ee0bc559dc3 ("KVM: s390: get rid of local_int array") Signed-off-by: Halil Pasic Reviewed-by: Christian Bornträger Reviewed-by: Claudio Imbrenda Cc: # 3.15+ Link: https://lore.kernel.org/r/20210827125429.1912577-1-pasic@linux.ibm.com Signed-off-by: Christian Borntraeger --- arch/s390/kvm/interrupt.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'arch/s390/kvm/interrupt.c') diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index d548d60caed2..16256e17a544 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -419,13 +419,13 @@ static unsigned long deliverable_irqs(struct kvm_vcpu *vcpu) static void __set_cpu_idle(struct kvm_vcpu *vcpu) { kvm_s390_set_cpuflags(vcpu, CPUSTAT_WAIT); - set_bit(vcpu->vcpu_id, vcpu->kvm->arch.idle_mask); + set_bit(kvm_vcpu_get_idx(vcpu), vcpu->kvm->arch.idle_mask); } static void __unset_cpu_idle(struct kvm_vcpu *vcpu) { kvm_s390_clear_cpuflags(vcpu, CPUSTAT_WAIT); - clear_bit(vcpu->vcpu_id, vcpu->kvm->arch.idle_mask); + clear_bit(kvm_vcpu_get_idx(vcpu), vcpu->kvm->arch.idle_mask); } static void __reset_intercept_indicators(struct kvm_vcpu *vcpu) @@ -3050,18 +3050,18 @@ int kvm_s390_get_irq_state(struct kvm_vcpu *vcpu, __u8 __user *buf, int len) static void __airqs_kick_single_vcpu(struct kvm *kvm, u8 deliverable_mask) { - int vcpu_id, online_vcpus = atomic_read(&kvm->online_vcpus); + int vcpu_idx, online_vcpus = atomic_read(&kvm->online_vcpus); struct kvm_s390_gisa_interrupt *gi = &kvm->arch.gisa_int; struct kvm_vcpu *vcpu; - for_each_set_bit(vcpu_id, kvm->arch.idle_mask, online_vcpus) { - vcpu = kvm_get_vcpu(kvm, vcpu_id); + for_each_set_bit(vcpu_idx, kvm->arch.idle_mask, online_vcpus) { + vcpu = kvm_get_vcpu(kvm, vcpu_idx); if (psw_ioint_disabled(vcpu)) continue; deliverable_mask &= (u8)(vcpu->arch.sie_block->gcr[6] >> 24); if (deliverable_mask) { /* lately kicked but not yet running */ - if (test_and_set_bit(vcpu_id, gi->kicked_mask)) + if (test_and_set_bit(vcpu_idx, gi->kicked_mask)) return; kvm_s390_vcpu_wakeup(vcpu); return; -- cgit v1.2.3