From 79fd50c67f91136add9726fb7719b57a66c6f763 Mon Sep 17 00:00:00 2001 From: Cornelia Huck Date: Thu, 7 Feb 2013 13:20:52 +0100 Subject: [PATCH] KVM: s390: Fix handling of iscs. There are two ways to express an interruption subclass: - As a bitmask, as used in cr6. - As a number, as used in the I/O interruption word. Unfortunately, we have treated the I/O interruption word as if it contained the bitmask as well, which went unnoticed so far as - (not-yet-released) qemu made the same mistake, and - Linux guest kernels don't check the isc value in the I/O interruption word for subchannel interrupts. Make sure that we treat the I/O interruption word correctly. Reviewed-by: Christian Borntraeger Signed-off-by: Cornelia Huck Signed-off-by: Gleb Natapov --- arch/s390/kvm/interrupt.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index 9a12835..2f6ccb0 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -55,6 +55,13 @@ static int psw_interrupts_disabled(struct kvm_vcpu *vcpu) return 1; } +static u64 int_word_to_isc_bits(u32 int_word) +{ + u8 isc = (int_word & 0x38000000) >> 27; + + return (0x80 >> isc) << 24; +} + static int __interrupt_is_deliverable(struct kvm_vcpu *vcpu, struct kvm_s390_interrupt_info *inti) { @@ -96,7 +103,8 @@ static int __interrupt_is_deliverable(struct kvm_vcpu *vcpu, case KVM_S390_INT_IO_MIN...KVM_S390_INT_IO_MAX: if (psw_ioint_disabled(vcpu)) return 0; - if (vcpu->arch.sie_block->gcr[6] & inti->io.io_int_word) + if (vcpu->arch.sie_block->gcr[6] & + int_word_to_isc_bits(inti->io.io_int_word)) return 1; return 0; default: @@ -724,7 +732,8 @@ struct kvm_s390_interrupt_info *kvm_s390_get_io_int(struct kvm *kvm, list_for_each_entry(iter, &fi->list, list) { if (!is_ioint(iter->type)) continue; - if (cr6 && ((cr6 & iter->io.io_int_word) == 0)) + if (cr6 && + ((cr6 & int_word_to_isc_bits(iter->io.io_int_word)) == 0)) continue; if (schid) { if (((schid & 0x00000000ffff0000) >> 16) != @@ -811,11 +820,14 @@ int kvm_s390_inject_vm(struct kvm *kvm, if (!is_ioint(inti->type)) list_add_tail(&inti->list, &fi->list); else { + u64 isc_bits = int_word_to_isc_bits(inti->io.io_int_word); + /* Keep I/O interrupts sorted in isc order. */ list_for_each_entry(iter, &fi->list, list) { if (!is_ioint(iter->type)) continue; - if (iter->io.io_int_word <= inti->io.io_int_word) + if (int_word_to_isc_bits(iter->io.io_int_word) + <= isc_bits) continue; break; } -- 2.7.4