Re: [PATCH v5 05/15] KVM: s390: unify pending_irqs() and pending_irqs_no_gisa()

From: Michael Mueller
Date: Thu Dec 20 2018 - 06:50:08 EST

On 20.12.18 12:06, Cornelia Huck wrote:
On Wed, 19 Dec 2018 20:17:46 +0100
Michael Mueller <mimu@xxxxxxxxxxxxx> wrote:

Use a single function with parameter irq_flags to differentiate
between cases.

New irq flag:
IRQ_FLAG_LOCAL: include vcpu local interruptions pending
IRQ_FLAG_FLOATING: include vcpu floating interruptions pending
IRQ_FLAG_GISA: include GISA interruptions pending in IPM

I presume that means that irqs may be in more than one set? Or are gisa
irqs not considered floating irqs, because they use a different

Currently, the interruptions managed in GISA are floating only. But
that might change in future. The idea is not to subsume IRQ_FLAG_GISA
in IRQ_FLAG_FLOATING but to be able to address the right set of procedures to determine the irq pending set for a given subset of irq
types that have different implementations.

There might be a better name for IRQ_FLAG_FLOATING then?

New irq masks:
IRQ_MASK_ALL: include all types
IRQ_MASK_NO_GISA: include all types but GISA

pending_irqs(vcpu, IRQ_MASK_ALL)
pending_irqs(vcpu, IRQ_MASK_NO_GISA)

There will be more irq flags with upcoming patches.

Signed-off-by: Michael Mueller <mimu@xxxxxxxxxxxxx>
arch/s390/kvm/interrupt.c | 33 +++++++++++++++++++++------------
1 file changed, 21 insertions(+), 12 deletions(-)

diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 093b568b6356..4ab20d2eb180 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -31,6 +31,13 @@
#define PFAULT_DONE 0x0680
#define VIRTIO_PARAM 0x0d00
+#define IRQ_FLAG_LOCAL 0x8000 /* include local interruption pending mask */
+#define IRQ_FLAG_FLOATING 0x4000 /* include float interruption pending mask */
+#define IRQ_FLAG_GISA 0x2000 /* include GISA interruption pending mask */
/* handle external calls via sigp interpretation facility */
static int sca_ext_call_pending(struct kvm_vcpu *vcpu, int *src_id)
@@ -237,16 +244,18 @@ static inline int kvm_s390_gisa_tac_ipm_gisc(struct kvm_s390_gisa *gisa, u32 gis
return test_and_clear_bit_inv(IPM_BIT_OFFSET + gisc, (unsigned long *) gisa);
-static inline unsigned long pending_irqs_no_gisa(struct kvm_vcpu *vcpu)
+static inline unsigned long pending_irqs(struct kvm_vcpu *vcpu, u16 irq_flags)

Any deeper reason why this is a u16? 16 bits should be enough for
everyone? :)

I want to use the 8 bits for the IRQ type and the other 8 for additional controls, see: "KVM: s390: restore IAM in get_ipm() when IPM is clean"

- return vcpu->kvm->arch.float_int.pending_irqs |
- vcpu->arch.local_int.pending_irqs;
+ unsigned long pending_irqs = 0;
-static inline unsigned long pending_irqs(struct kvm_vcpu *vcpu)
- return pending_irqs_no_gisa(vcpu) |
- kvm_s390_gisa_get_ipm(vcpu->kvm->arch.gisa) << IRQ_PEND_IO_ISC_7;
+ if (irq_flags & IRQ_FLAG_LOCAL)
+ pending_irqs |= vcpu->arch.local_int.pending_irqs;
+ if (irq_flags & IRQ_FLAG_FLOATING)
+ pending_irqs |= vcpu->kvm->arch.float_int.pending_irqs;
+ if (irq_flags & IRQ_FLAG_GISA)
+ pending_irqs |= kvm_s390_gisa_get_ipm(vcpu->kvm->arch.gisa) <<
+ return pending_irqs;
static inline int isc_to_irq_type(unsigned long isc)
@@ -275,7 +284,7 @@ static unsigned long deliverable_irqs(struct kvm_vcpu *vcpu)
unsigned long active_mask;
- active_mask = pending_irqs(vcpu);
+ active_mask = pending_irqs(vcpu, IRQ_MASK_ALL);
if (!active_mask)
return 0;
@@ -343,7 +352,7 @@ static void __reset_intercept_indicators(struct kvm_vcpu *vcpu)
static void set_intercept_indicators_io(struct kvm_vcpu *vcpu)
- if (!(pending_irqs_no_gisa(vcpu) & IRQ_PEND_IO_MASK))
+ if (!(pending_irqs(vcpu, IRQ_MASK_NO_GISA) & IRQ_PEND_IO_MASK))

I/O interrupts are always floating, so you probably could check for
only floating (excluding gisa) irqs here.

That's right.

else if (psw_ioint_disabled(vcpu))
kvm_s390_set_cpuflags(vcpu, CPUSTAT_IO_INT);Store Data
@@ -353,7 +362,7 @@ static void set_intercept_indicators_io(struct kvm_vcpu *vcpu)