KVM: s390: irq routing for adapter interrupts.
Introduce a new interrupt class for s390 adapter interrupts and enable
irqfds for s390.
This is depending on a new s390 specific vm capability, KVM_CAP_S390_IRQCHIP,
that needs to be enabled by userspace.
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig
index c8bacbc..10d529a 100644
--- a/arch/s390/kvm/Kconfig
+++ b/arch/s390/kvm/Kconfig
@@ -25,6 +25,8 @@
select HAVE_KVM_EVENTFD
select KVM_ASYNC_PF
select KVM_ASYNC_PF_SYNC
+ select HAVE_KVM_IRQCHIP
+ select HAVE_KVM_IRQ_ROUTING
---help---
Support hosting paravirtualized guest machines using the SIE
virtualization capability on the mainframe. This should work
diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile
index a47d2c3..d3adb37 100644
--- a/arch/s390/kvm/Makefile
+++ b/arch/s390/kvm/Makefile
@@ -7,7 +7,7 @@
# as published by the Free Software Foundation.
KVM := ../../../virt/kvm
-common-objs = $(KVM)/kvm_main.o $(KVM)/eventfd.o $(KVM)/async_pf.o
+common-objs = $(KVM)/kvm_main.o $(KVM)/eventfd.o $(KVM)/async_pf.o $(KVM)/irqchip.o
ccflags-y := -Ivirt/kvm -Iarch/s390/kvm
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 7ecef5a..2e2814e 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -13,6 +13,7 @@
#include <linux/interrupt.h>
#include <linux/kvm_host.h>
#include <linux/hrtimer.h>
+#include <linux/mmu_context.h>
#include <linux/signal.h>
#include <linux/slab.h>
#include <asm/asm-offsets.h>
@@ -1284,3 +1285,123 @@
.create = flic_create,
.destroy = flic_destroy,
};
+
+static unsigned long get_ind_bit(__u64 addr, unsigned long bit_nr, bool swap)
+{
+ unsigned long bit;
+
+ bit = bit_nr + (addr % PAGE_SIZE) * 8;
+
+ return swap ? (bit ^ (BITS_PER_LONG - 1)) : bit;
+}
+
+static struct s390_map_info *get_map_info(struct s390_io_adapter *adapter,
+ u64 addr)
+{
+ struct s390_map_info *map;
+
+ if (!adapter)
+ return NULL;
+
+ list_for_each_entry(map, &adapter->maps, list) {
+ if (map->guest_addr == addr)
+ return map;
+ }
+ return NULL;
+}
+
+static int adapter_indicators_set(struct kvm *kvm,
+ struct s390_io_adapter *adapter,
+ struct kvm_s390_adapter_int *adapter_int)
+{
+ unsigned long bit;
+ int summary_set, idx;
+ struct s390_map_info *info;
+ void *map;
+
+ info = get_map_info(adapter, adapter_int->ind_addr);
+ if (!info)
+ return -1;
+ map = page_address(info->page);
+ bit = get_ind_bit(info->addr, adapter_int->ind_offset, adapter->swap);
+ set_bit(bit, map);
+ idx = srcu_read_lock(&kvm->srcu);
+ mark_page_dirty(kvm, info->guest_addr >> PAGE_SHIFT);
+ set_page_dirty_lock(info->page);
+ info = get_map_info(adapter, adapter_int->summary_addr);
+ if (!info) {
+ srcu_read_unlock(&kvm->srcu, idx);
+ return -1;
+ }
+ map = page_address(info->page);
+ bit = get_ind_bit(info->addr, adapter_int->summary_offset,
+ adapter->swap);
+ summary_set = test_and_set_bit(bit, map);
+ mark_page_dirty(kvm, info->guest_addr >> PAGE_SHIFT);
+ set_page_dirty_lock(info->page);
+ srcu_read_unlock(&kvm->srcu, idx);
+ return summary_set ? 0 : 1;
+}
+
+/*
+ * < 0 - not injected due to error
+ * = 0 - coalesced, summary indicator already active
+ * > 0 - injected interrupt
+ */
+static int set_adapter_int(struct kvm_kernel_irq_routing_entry *e,
+ struct kvm *kvm, int irq_source_id, int level,
+ bool line_status)
+{
+ int ret;
+ struct s390_io_adapter *adapter;
+
+ /* We're only interested in the 0->1 transition. */
+ if (!level)
+ return 0;
+ adapter = get_io_adapter(kvm, e->adapter.adapter_id);
+ if (!adapter)
+ return -1;
+ down_read(&adapter->maps_lock);
+ ret = adapter_indicators_set(kvm, adapter, &e->adapter);
+ up_read(&adapter->maps_lock);
+ if ((ret > 0) && !adapter->masked) {
+ struct kvm_s390_interrupt s390int = {
+ .type = KVM_S390_INT_IO(1, 0, 0, 0),
+ .parm = 0,
+ .parm64 = (adapter->isc << 27) | 0x80000000,
+ };
+ ret = kvm_s390_inject_vm(kvm, &s390int);
+ if (ret == 0)
+ ret = 1;
+ }
+ return ret;
+}
+
+int kvm_set_routing_entry(struct kvm_irq_routing_table *rt,
+ struct kvm_kernel_irq_routing_entry *e,
+ const struct kvm_irq_routing_entry *ue)
+{
+ int ret;
+
+ switch (ue->type) {
+ case KVM_IRQ_ROUTING_S390_ADAPTER:
+ e->set = set_adapter_int;
+ e->adapter.summary_addr = ue->u.adapter.summary_addr;
+ e->adapter.ind_addr = ue->u.adapter.ind_addr;
+ e->adapter.summary_offset = ue->u.adapter.summary_offset;
+ e->adapter.ind_offset = ue->u.adapter.ind_offset;
+ e->adapter.adapter_id = ue->u.adapter.adapter_id;
+ ret = 0;
+ break;
+ default:
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+
+int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e, struct kvm *kvm,
+ int irq_source_id, int level, bool line_status)
+{
+ return -EINVAL;
+}
diff --git a/arch/s390/kvm/irq.h b/arch/s390/kvm/irq.h
new file mode 100644
index 0000000..d98e415
--- /dev/null
+++ b/arch/s390/kvm/irq.h
@@ -0,0 +1,22 @@
+/*
+ * s390 irqchip routines
+ *
+ * Copyright IBM Corp. 2014
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License (version 2 only)
+ * as published by the Free Software Foundation.
+ *
+ * Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
+ */
+#ifndef __KVM_IRQ_H
+#define __KVM_IRQ_H
+
+#include <linux/kvm_host.h>
+
+static inline int irqchip_in_kernel(struct kvm *kvm)
+{
+ return 1;
+}
+
+#endif
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 2e6fbb0..ce5b659 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -196,6 +196,10 @@
return -EINVAL;
switch (cap->cap) {
+ case KVM_CAP_S390_IRQCHIP:
+ kvm->arch.use_irqchip = 1;
+ r = 0;
+ break;
default:
r = -EINVAL;
break;
@@ -228,6 +232,18 @@
r = kvm_vm_ioctl_enable_cap(kvm, &cap);
break;
}
+ case KVM_CREATE_IRQCHIP: {
+ struct kvm_irq_routing_entry routing;
+
+ r = -EINVAL;
+ if (kvm->arch.use_irqchip) {
+ /* Set up dummy routing. */
+ memset(&routing, 0, sizeof(routing));
+ kvm_set_irq_routing(kvm, &routing, 0, 0);
+ r = 0;
+ }
+ break;
+ }
default:
r = -ENOTTY;
}
@@ -284,6 +300,7 @@
}
kvm->arch.css_support = 0;
+ kvm->arch.use_irqchip = 0;
return 0;
out_nogmap: