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 <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
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 @@
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 @@
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 @@
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 @@
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;
}