From: Douglas Freimuth <freimuth@linux.ibm.com>
To: borntraeger@linux.ibm.com, imbrenda@linux.ibm.com,
frankja@linux.ibm.com, david@kernel.org, hca@linux.ibm.com,
gor@linux.ibm.com, agordeev@linux.ibm.com, svens@linux.ibm.com,
kvm@vger.kernel.org, linux-s390@vger.kernel.org,
linux-kernel@vger.kernel.org
Cc: mjrosato@linux.ibm.com, freimuth@linux.ibm.com
Subject: [PATCH v5 3/4] KVM: s390: Change the fi->lock to a raw_spinlock for RT case
Date: Tue, 5 May 2026 19:37:27 +0200 [thread overview]
Message-ID: <20260505173728.160562-4-freimuth@linux.ibm.com> (raw)
In-Reply-To: <20260505173728.160562-1-freimuth@linux.ibm.com>
s390 needs to maintain support for an RT kernel. This requires the
floating interrupt lock, fi->lock to be changed to a raw spin lock
since the fi->lock maybe called with interrupts disabled in __inject_io.
Signed-off-by: Douglas Freimuth <freimuth@linux.ibm.com>
---
arch/s390/include/asm/kvm_host.h | 2 +-
arch/s390/kvm/intercept.c | 4 +-
arch/s390/kvm/interrupt.c | 68 ++++++++++++++++----------------
arch/s390/kvm/kvm-s390.c | 2 +-
4 files changed, 38 insertions(+), 38 deletions(-)
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index fbb2406b31d2..9dd8a4986592 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -353,7 +353,7 @@ struct kvm_s390_local_interrupt {
struct kvm_s390_float_interrupt {
unsigned long pending_irqs;
unsigned long masked_irqs;
- spinlock_t lock;
+ raw_spinlock_t lock;
struct list_head lists[FIRQ_LIST_COUNT];
int counters[FIRQ_MAX_COUNT];
struct kvm_s390_mchk_info mchk;
diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
index 39aff324203e..6e9ad58c0e90 100644
--- a/arch/s390/kvm/intercept.c
+++ b/arch/s390/kvm/intercept.c
@@ -518,7 +518,7 @@ static int handle_pv_sclp(struct kvm_vcpu *vcpu)
{
struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
- spin_lock(&fi->lock);
+ raw_spin_lock(&fi->lock);
/*
* 2 cases:
* a: an sccb answering interrupt was already pending or in flight.
@@ -534,7 +534,7 @@ static int handle_pv_sclp(struct kvm_vcpu *vcpu)
fi->srv_signal.ext_params |= 0x43000;
set_bit(IRQ_PEND_EXT_SERVICE, &fi->pending_irqs);
clear_bit(IRQ_PEND_EXT_SERVICE, &fi->masked_irqs);
- spin_unlock(&fi->lock);
+ raw_spin_unlock(&fi->lock);
return 0;
}
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 12d8d38c260d..49ccdeccc70c 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -625,7 +625,7 @@ static int __must_check __deliver_machine_check(struct kvm_vcpu *vcpu)
int deliver = 0;
int rc = 0;
- spin_lock(&fi->lock);
+ raw_spin_lock(&fi->lock);
spin_lock(&li->lock);
if (test_bit(IRQ_PEND_MCHK_EX, &li->pending_irqs) ||
test_bit(IRQ_PEND_MCHK_REP, &li->pending_irqs)) {
@@ -654,7 +654,7 @@ static int __must_check __deliver_machine_check(struct kvm_vcpu *vcpu)
deliver = 1;
}
spin_unlock(&li->lock);
- spin_unlock(&fi->lock);
+ raw_spin_unlock(&fi->lock);
if (deliver) {
VCPU_EVENT(vcpu, 3, "deliver: machine check mcic 0x%llx",
@@ -942,10 +942,10 @@ static int __must_check __deliver_service(struct kvm_vcpu *vcpu)
struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
struct kvm_s390_ext_info ext;
- spin_lock(&fi->lock);
+ raw_spin_lock(&fi->lock);
if (test_bit(IRQ_PEND_EXT_SERVICE, &fi->masked_irqs) ||
!(test_bit(IRQ_PEND_EXT_SERVICE, &fi->pending_irqs))) {
- spin_unlock(&fi->lock);
+ raw_spin_unlock(&fi->lock);
return 0;
}
ext = fi->srv_signal;
@@ -954,7 +954,7 @@ static int __must_check __deliver_service(struct kvm_vcpu *vcpu)
clear_bit(IRQ_PEND_EXT_SERVICE_EV, &fi->pending_irqs);
if (kvm_s390_pv_cpu_is_protected(vcpu))
set_bit(IRQ_PEND_EXT_SERVICE, &fi->masked_irqs);
- spin_unlock(&fi->lock);
+ raw_spin_unlock(&fi->lock);
if (!ext.ext_params)
return 0;
@@ -973,16 +973,16 @@ static int __must_check __deliver_service_ev(struct kvm_vcpu *vcpu)
struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
struct kvm_s390_ext_info ext;
- spin_lock(&fi->lock);
+ raw_spin_lock(&fi->lock);
if (!(test_bit(IRQ_PEND_EXT_SERVICE_EV, &fi->pending_irqs))) {
- spin_unlock(&fi->lock);
+ raw_spin_unlock(&fi->lock);
return 0;
}
ext = fi->srv_signal;
/* only clear the event bits */
fi->srv_signal.ext_params &= ~SCCB_EVENT_PENDING;
clear_bit(IRQ_PEND_EXT_SERVICE_EV, &fi->pending_irqs);
- spin_unlock(&fi->lock);
+ raw_spin_unlock(&fi->lock);
VCPU_EVENT(vcpu, 4, "%s", "deliver: sclp parameter event");
vcpu->stat.deliver_service_signal++;
@@ -998,7 +998,7 @@ static int __must_check __deliver_pfault_done(struct kvm_vcpu *vcpu)
struct kvm_s390_interrupt_info *inti;
int rc = 0;
- spin_lock(&fi->lock);
+ raw_spin_lock(&fi->lock);
inti = list_first_entry_or_null(&fi->lists[FIRQ_LIST_PFAULT],
struct kvm_s390_interrupt_info,
list);
@@ -1008,7 +1008,7 @@ static int __must_check __deliver_pfault_done(struct kvm_vcpu *vcpu)
}
if (list_empty(&fi->lists[FIRQ_LIST_PFAULT]))
clear_bit(IRQ_PEND_PFAULT_DONE, &fi->pending_irqs);
- spin_unlock(&fi->lock);
+ raw_spin_unlock(&fi->lock);
if (inti) {
trace_kvm_s390_deliver_interrupt(vcpu->vcpu_id,
@@ -1040,7 +1040,7 @@ static int __must_check __deliver_virtio(struct kvm_vcpu *vcpu)
struct kvm_s390_interrupt_info *inti;
int rc = 0;
- spin_lock(&fi->lock);
+ raw_spin_lock(&fi->lock);
inti = list_first_entry_or_null(&fi->lists[FIRQ_LIST_VIRTIO],
struct kvm_s390_interrupt_info,
list);
@@ -1058,7 +1058,7 @@ static int __must_check __deliver_virtio(struct kvm_vcpu *vcpu)
}
if (list_empty(&fi->lists[FIRQ_LIST_VIRTIO]))
clear_bit(IRQ_PEND_VIRTIO, &fi->pending_irqs);
- spin_unlock(&fi->lock);
+ raw_spin_unlock(&fi->lock);
if (inti) {
rc = put_guest_lc(vcpu, EXT_IRQ_CP_SERVICE,
@@ -1119,7 +1119,7 @@ static int __must_check __deliver_io(struct kvm_vcpu *vcpu,
fi = &vcpu->kvm->arch.float_int;
- spin_lock(&fi->lock);
+ raw_spin_lock(&fi->lock);
isc = irq_type_to_isc(irq_type);
isc_list = &fi->lists[isc];
inti = list_first_entry_or_null(isc_list,
@@ -1146,7 +1146,7 @@ static int __must_check __deliver_io(struct kvm_vcpu *vcpu,
}
if (list_empty(isc_list))
clear_bit(irq_type, &fi->pending_irqs);
- spin_unlock(&fi->lock);
+ raw_spin_unlock(&fi->lock);
if (inti) {
rc = __do_deliver_io(vcpu, &(inti->io));
@@ -1663,7 +1663,7 @@ static struct kvm_s390_interrupt_info *get_io_int(struct kvm *kvm,
u16 id = (schid & 0xffff0000U) >> 16;
u16 nr = schid & 0x0000ffffU;
- spin_lock(&fi->lock);
+ raw_spin_lock(&fi->lock);
list_for_each_entry(iter, isc_list, list) {
if (schid && (id != iter->io.subchannel_id ||
nr != iter->io.subchannel_nr))
@@ -1673,10 +1673,10 @@ static struct kvm_s390_interrupt_info *get_io_int(struct kvm *kvm,
fi->counters[FIRQ_CNTR_IO] -= 1;
if (list_empty(isc_list))
clear_bit(isc_to_irq_type(isc), &fi->pending_irqs);
- spin_unlock(&fi->lock);
+ raw_spin_unlock(&fi->lock);
return iter;
}
- spin_unlock(&fi->lock);
+ raw_spin_unlock(&fi->lock);
return NULL;
}
@@ -1771,7 +1771,7 @@ static int __inject_service(struct kvm *kvm,
struct kvm_s390_float_interrupt *fi = &kvm->arch.float_int;
kvm->stat.inject_service_signal++;
- spin_lock(&fi->lock);
+ raw_spin_lock(&fi->lock);
fi->srv_signal.ext_params |= inti->ext.ext_params & SCCB_EVENT_PENDING;
/* We always allow events, track them separately from the sccb ints */
@@ -1791,7 +1791,7 @@ static int __inject_service(struct kvm *kvm,
fi->srv_signal.ext_params |= inti->ext.ext_params & SCCB_MASK;
set_bit(IRQ_PEND_EXT_SERVICE, &fi->pending_irqs);
out:
- spin_unlock(&fi->lock);
+ raw_spin_unlock(&fi->lock);
kfree(inti);
return 0;
}
@@ -1802,15 +1802,15 @@ static int __inject_virtio(struct kvm *kvm,
struct kvm_s390_float_interrupt *fi = &kvm->arch.float_int;
kvm->stat.inject_virtio++;
- spin_lock(&fi->lock);
+ raw_spin_lock(&fi->lock);
if (fi->counters[FIRQ_CNTR_VIRTIO] >= KVM_S390_MAX_VIRTIO_IRQS) {
- spin_unlock(&fi->lock);
+ raw_spin_unlock(&fi->lock);
return -EBUSY;
}
fi->counters[FIRQ_CNTR_VIRTIO] += 1;
list_add_tail(&inti->list, &fi->lists[FIRQ_LIST_VIRTIO]);
set_bit(IRQ_PEND_VIRTIO, &fi->pending_irqs);
- spin_unlock(&fi->lock);
+ raw_spin_unlock(&fi->lock);
return 0;
}
@@ -1820,16 +1820,16 @@ static int __inject_pfault_done(struct kvm *kvm,
struct kvm_s390_float_interrupt *fi = &kvm->arch.float_int;
kvm->stat.inject_pfault_done++;
- spin_lock(&fi->lock);
+ raw_spin_lock(&fi->lock);
if (fi->counters[FIRQ_CNTR_PFAULT] >=
(ASYNC_PF_PER_VCPU * KVM_MAX_VCPUS)) {
- spin_unlock(&fi->lock);
+ raw_spin_unlock(&fi->lock);
return -EBUSY;
}
fi->counters[FIRQ_CNTR_PFAULT] += 1;
list_add_tail(&inti->list, &fi->lists[FIRQ_LIST_PFAULT]);
set_bit(IRQ_PEND_PFAULT_DONE, &fi->pending_irqs);
- spin_unlock(&fi->lock);
+ raw_spin_unlock(&fi->lock);
return 0;
}
@@ -1840,11 +1840,11 @@ static int __inject_float_mchk(struct kvm *kvm,
struct kvm_s390_float_interrupt *fi = &kvm->arch.float_int;
kvm->stat.inject_float_mchk++;
- spin_lock(&fi->lock);
+ raw_spin_lock(&fi->lock);
fi->mchk.cr14 |= inti->mchk.cr14 & (1UL << CR_PENDING_SUBCLASS);
fi->mchk.mcic |= inti->mchk.mcic;
set_bit(IRQ_PEND_MCHK_REP, &fi->pending_irqs);
- spin_unlock(&fi->lock);
+ raw_spin_unlock(&fi->lock);
kfree(inti);
return 0;
}
@@ -1873,9 +1873,9 @@ static int __inject_io(struct kvm *kvm, struct kvm_s390_interrupt_info *inti)
}
fi = &kvm->arch.float_int;
- spin_lock(&fi->lock);
+ raw_spin_lock(&fi->lock);
if (fi->counters[FIRQ_CNTR_IO] >= KVM_S390_MAX_FLOAT_IRQS) {
- spin_unlock(&fi->lock);
+ raw_spin_unlock(&fi->lock);
return -EBUSY;
}
fi->counters[FIRQ_CNTR_IO] += 1;
@@ -1890,7 +1890,7 @@ static int __inject_io(struct kvm *kvm, struct kvm_s390_interrupt_info *inti)
list = &fi->lists[FIRQ_LIST_IO_ISC_0 + isc];
list_add_tail(&inti->list, list);
set_bit(isc_to_irq_type(isc), &fi->pending_irqs);
- spin_unlock(&fi->lock);
+ raw_spin_unlock(&fi->lock);
return 0;
}
@@ -2181,7 +2181,7 @@ void kvm_s390_clear_float_irqs(struct kvm *kvm)
if (!kvm_s390_pv_is_protected(kvm))
fi->masked_irqs = 0;
mutex_unlock(&kvm->lock);
- spin_lock(&fi->lock);
+ raw_spin_lock(&fi->lock);
fi->pending_irqs = 0;
memset(&fi->srv_signal, 0, sizeof(fi->srv_signal));
memset(&fi->mchk, 0, sizeof(fi->mchk));
@@ -2189,7 +2189,7 @@ void kvm_s390_clear_float_irqs(struct kvm *kvm)
clear_irq_list(&fi->lists[i]);
for (i = 0; i < FIRQ_MAX_COUNT; i++)
fi->counters[i] = 0;
- spin_unlock(&fi->lock);
+ raw_spin_unlock(&fi->lock);
kvm_s390_gisa_clear(kvm);
};
@@ -2235,7 +2235,7 @@ static int get_all_floating_irqs(struct kvm *kvm, u8 __user *usrbuf, u64 len)
}
}
fi = &kvm->arch.float_int;
- spin_lock(&fi->lock);
+ raw_spin_lock(&fi->lock);
for (i = 0; i < FIRQ_LIST_COUNT; i++) {
list_for_each_entry(inti, &fi->lists[i], list) {
if (n == max_irqs) {
@@ -2272,7 +2272,7 @@ static int get_all_floating_irqs(struct kvm *kvm, u8 __user *usrbuf, u64 len)
}
out:
- spin_unlock(&fi->lock);
+ raw_spin_unlock(&fi->lock);
out_nolock:
if (!ret && n > 0) {
if (copy_to_user(usrbuf, buf, sizeof(struct kvm_s390_irq) * n))
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 74f453f039a3..d8011b6d6801 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -3263,7 +3263,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
}
mutex_init(&kvm->arch.float_int.ais_lock);
- spin_lock_init(&kvm->arch.float_int.lock);
+ raw_spin_lock_init(&kvm->arch.float_int.lock);
for (i = 0; i < FIRQ_LIST_COUNT; i++)
INIT_LIST_HEAD(&kvm->arch.float_int.lists[i]);
init_waitqueue_head(&kvm->arch.ipte_wq);
--
2.52.0
next prev parent reply other threads:[~2026-05-05 17:37 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-05 17:37 [PATCH v5 0/4] KVM: s390: Introducing kvm_arch_set_irq_inatomic Fast Inject Douglas Freimuth
2026-05-05 17:37 ` [PATCH v5 1/4] KVM: s390: Add map/unmap ioctl and clean mappings post-guest Douglas Freimuth
2026-05-05 17:37 ` [PATCH v5 2/4] KVM: s390: Enable adapter_indicators_set to use mapped pages Douglas Freimuth
2026-05-05 17:37 ` Douglas Freimuth [this message]
2026-05-06 4:57 ` [PATCH v5 3/4] KVM: s390: Change the fi->lock to a raw_spinlock for RT case Heiko Carstens
2026-05-06 14:50 ` Douglas Freimuth
2026-05-07 9:56 ` Heiko Carstens
2026-05-07 13:17 ` Matthew Rosato
2026-05-07 14:45 ` Heiko Carstens
2026-05-07 14:49 ` Peter Zijlstra
2026-05-08 2:46 ` Douglas Freimuth
2026-05-08 10:27 ` Heiko Carstens
2026-05-05 17:37 ` [PATCH v5 4/4] KVM: s390: Introducing kvm_arch_set_irq_inatomic fast inject Douglas Freimuth
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