[PATCH 6/6] s390x/virtio-ccw: Wire up irq routing and irqfds.

Cornelia Huck
2014-02-25T17:25:20Z

Make use of the new s390 adapter irq routing support to enable real
in-kernel irqfds for virtio-ccw with adapter interrupts.

Note that s390 doesn't provide the common KVM_CAP_IRQCHIP capability, but
rather needs KVM_CAP_S390_IRQCHIP to be enabled. This is to ensure backward
compatibility.

Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
hw/s390x/virtio-ccw.c | 167 ++++++++++++++++++++++++++++++++++++++++----
hw/s390x/virtio-ccw.h | 2 +
include/hw/s390x/adapter.h | 23 ++++++
include/qemu/typedefs.h | 1 +
include/sysemu/kvm.h | 2 +
kvm-all.c | 38 +++++++++-
kvm-stub.c | 5 ++
target-s390x/kvm.c | 5 ++
8 files changed, 230 insertions(+), 13 deletions(-)
create mode 100644 include/hw/s390x/adapter.h

diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index c218acd..29f9762 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -21,6 +21,7 @@
#include "hw/sysbus.h"
#include "qemu/bitops.h"
#include "hw/virtio/virtio-bus.h"
+#include "hw/s390x/adapter.h"

#include "ioinst.h"
#include "css.h"
@@ -48,7 +49,7 @@ static IndAddr *get_indicator(hwaddr ind_addr, int len)
return indicator;
}

-static void release_indicator(IndAddr *indicator)
+static void release_indicator(uint32_t adapter_id, IndAddr *indicator)
{
assert(indicator->refcnt > 0);
indicator->refcnt--;
@@ -56,9 +57,33 @@ static void release_indicator(IndAddr *indicator)
return;
}
QTAILQ_REMOVE(&indicator_addresses, indicator, sibling);
+ if (indicator->map) {
+ s390_io_adapter_map(adapter_id,
+ (uint64_t)(unsigned long)indicator->map, false);
+ }
g_free(indicator);
}

+static int map_indicator(uint32_t adapter_id, IndAddr *indicator)
+{
+ int ret;
+
+ if (indicator->map) {
+ return 0; /* already mapped is not an error */
+ }
+ indicator->map = (void *)indicator->addr;
+ ret = s390_io_adapter_map(adapter_id,
+ (uint64_t)(unsigned long)indicator->map, true);
+ if ((ret != 0) && (ret != -ENOSYS)) {
+ goto out_err;
+ }
+ return 0;
+
+out_err:
+ indicator->map = 0;
+ return -EFAULT;
+}
+
static void virtio_ccw_bus_new(VirtioBusState *bus, size_t bus_size,
VirtioCcwDevice *dev);

@@ -733,7 +758,7 @@ static int virtio_ccw_exit(VirtioCcwDevice *dev)
g_free(sch);
}
if (dev->indicators) {
- release_indicator(dev->indicators);
+ release_indicator(dev->adapter_id, dev->indicators);
dev->indicators = NULL;
}
return 0;
@@ -1034,15 +1059,15 @@ static void virtio_ccw_reset(DeviceState *d)
virtio_reset(vdev);
css_reset_sch(dev->sch);
if (dev->indicators) {
- release_indicator(dev->indicators);
+ release_indicator(dev->adapter_id, dev->indicators);
dev->indicators = NULL;
}
if (dev->indicators2) {
- release_indicator(dev->indicators2);
+ release_indicator(dev->adapter_id, dev->indicators2);
dev->indicators2 = NULL;
}
if (dev->summary_indicator) {
- release_indicator(dev->summary_indicator);
+ release_indicator(dev->adapter_id, dev->summary_indicator);
dev->summary_indicator = NULL;
}
}
@@ -1078,6 +1103,100 @@ static int virtio_ccw_set_host_notifier(DeviceState *d, int n, bool assign)
return virtio_ccw_set_guest2host_notifier(dev, n, assign, false);
}

+static int virtio_ccw_get_adapter_info(VirtioCcwDevice *dev,
+ AdapterInfo *adapter)
+{
+ int r;
+
+ if (!dev->sch->thinint_active) {
+ return -EINVAL;
+ }
+
+ r = map_indicator(dev->adapter_id, dev->summary_indicator);
+ if (r) {
+ return r;
+ }
+ r = map_indicator(dev->adapter_id, dev->indicators);
+ if (r) {
+ return r;
+ }
+ adapter->summary_addr = (unsigned long)dev->summary_indicator->map;
+ adapter->ind_addr = (unsigned long)dev->indicators->map;
+ adapter->ind_offset = dev->ind_bit;
+ adapter->summary_offset = 7;
+ adapter->adapter_id = dev->adapter_id;
+
+ return 0;
+}
+
+static int virtio_ccw_setup_irqroutes(VirtioCcwDevice *dev, int nvqs)
+{
+ int i;
+ VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
+ int ret;
+ AdapterInfo adapter;
+
+ ret = virtio_ccw_get_adapter_info(dev, &adapter);
+ if (ret) {
+ return ret;
+ }
+ for (i = 0; i < nvqs; i++) {
+ if (!virtio_queue_get_num(vdev, i)) {
+ break;
+ }
+ ret = kvm_irqchip_add_adapter_route(kvm_state, &adapter);
+ if (ret < 0) {
+ goto out_undo;
+ }
+ dev->gsi[i] = ret;
+ adapter.ind_offset++;
+ }
+ return 0;
+out_undo:
+ while (--i >= 0) {
+ kvm_irqchip_release_virq(kvm_state, dev->gsi[i]);
+ dev->gsi[i] = -1;
+ }
+ return ret;
+}
+
+static void virtio_ccw_release_irqroutes(VirtioCcwDevice *dev, int nvqs)
+{
+ int i;
+ VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
+
+ for (i = 0; i < nvqs; i++) {
+ if (!virtio_queue_get_num(vdev, i)) {
+ break;
+ }
+ if (dev->gsi[i] >= 0) {
+ kvm_irqchip_release_virq(kvm_state, dev->gsi[i]);
+ dev->gsi[i] = -1;
+ }
+ }
+}
+
+static int virtio_ccw_add_irqfd(VirtioCcwDevice *dev, int n)
+{
+ VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
+ VirtQueue *vq = virtio_get_queue(vdev, n);
+ EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);
+
+ return kvm_irqchip_add_irqfd_notifier(kvm_state, notifier, NULL,
+ dev->gsi[n]);
+}
+
+static void virtio_ccw_remove_irqfd(VirtioCcwDevice *dev, int n)
+{
+ VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
+ VirtQueue *vq = virtio_get_queue(vdev, n);
+ EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);
+ int ret;
+
+ ret = kvm_irqchip_remove_irqfd_notifier(kvm_state, notifier, dev->gsi[n]);
+ assert(ret == 0);
+}
+
static int virtio_ccw_set_guest_notifier(VirtioCcwDevice *dev, int n,
bool assign, bool with_irqfd)
{
@@ -1093,11 +1212,17 @@ static int virtio_ccw_set_guest_notifier(VirtioCcwDevice *dev, int n,
return r;
}
virtio_queue_set_guest_notifier_fd_handler(vq, true, with_irqfd);
- /* We do not support irqfd for classic I/O interrupts, because the
- * classic interrupts are intermixed with the subchannel status, that
- * is queried with test subchannel. We want to use vhost, though.
- * Lets make sure to have vhost running and wire up the irq fd to
- * land in qemu (and only the irq fd) in this code.
+ if (with_irqfd) {
+ r = virtio_ccw_add_irqfd(dev, n);
+ if (r) {
+ virtio_queue_set_guest_notifier_fd_handler(vq, false,
+ with_irqfd);
+ return r;
+ }
+ }
+ /*
+ * We do not support individual masking for channel devices, so we
+ * need to manually trigger any guest masking callbacks here.
*/
if (k->guest_notifier_mask) {
k->guest_notifier_mask(vdev, n, false);
@@ -1111,6 +1236,9 @@ static int virtio_ccw_set_guest_notifier(VirtioCcwDevice *dev, int n,
if (k->guest_notifier_mask) {
k->guest_notifier_mask(vdev, n, true);
}
+ if (with_irqfd) {
+ virtio_ccw_remove_irqfd(dev, n);
+ }
virtio_queue_set_guest_notifier_fd_handler(vq, false, with_irqfd);
event_notifier_cleanup(notifier);
}
@@ -1122,24 +1250,39 @@ static int virtio_ccw_set_guest_notifiers(DeviceState *d, int nvqs,
{
VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
VirtIODevice *vdev = virtio_bus_get_device(&dev->bus);
+ bool with_irqfd = dev->sch->thinint_active && kvm_irqfds_enabled();
int r, n;

+ if (with_irqfd && assigned) {
+ /* irq routes need to be set up before assigning irqfds */
+ r = virtio_ccw_setup_irqroutes(dev, nvqs);
+ if (r < 0) {
+ goto irqroute_error;
+ }
+ }
for (n = 0; n < nvqs; n++) {
if (!virtio_queue_get_num(vdev, n)) {
break;
}
- /* false -> true, as soon as irqfd works */
- r = virtio_ccw_set_guest_notifier(dev, n, assigned, false);
+ r = virtio_ccw_set_guest_notifier(dev, n, assigned, with_irqfd);
if (r < 0) {
goto assign_error;
}
}
+ if (with_irqfd && !assigned) {
+ /* release irq routes after irqfds have been released */
+ virtio_ccw_release_irqroutes(dev, nvqs);
+ }
return 0;

assign_error:
while (--n >= 0) {
virtio_ccw_set_guest_notifier(dev, n, !assigned, false);
}
+irqroute_error:
+ if (with_irqfd && assigned) {
+ virtio_ccw_release_irqroutes(dev, nvqs);
+ }
return r;
}

diff --git a/hw/s390x/virtio-ccw.h b/hw/s390x/virtio-ccw.h
index d340bf4..7977a3e 100644
--- a/hw/s390x/virtio-ccw.h
+++ b/hw/s390x/virtio-ccw.h
@@ -77,6 +77,7 @@ typedef struct VirtIOCCWDeviceClass {

typedef struct IndAddr {
hwaddr addr;
+ void *map;
unsigned long refcnt;
int len;
QTAILQ_ENTRY(IndAddr) sibling;
@@ -93,6 +94,7 @@ struct VirtioCcwDevice {
uint32_t flags;
uint8_t thinint_isc;
uint32_t adapter_id;
+ int gsi[VIRTIO_PCI_QUEUE_MAX];
/* Guest provided values: */
IndAddr *indicators;
IndAddr *indicators2;
diff --git a/include/hw/s390x/adapter.h b/include/hw/s390x/adapter.h
new file mode 100644
index 0000000..7e56724
--- /dev/null
+++ b/include/hw/s390x/adapter.h
@@ -0,0 +1,23 @@
+/*
+ * s390 adapter definitions
+ *
+ * Copyright 2013 IBM Corp.
+ * Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at
+ * your option) any later version. See the COPYING file in the top-level
+ * directory.
+ */
+
+#ifndef S390X_ADAPTER_H
+#define S390X_ADAPTER_H
+
+struct AdapterInfo {
+ uint64_t ind_addr;
+ uint64_t summary_addr;
+ uint64_t ind_offset;
+ uint32_t summary_offset;
+ uint32_t adapter_id;
+};
+
+#endif
diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h
index 83c9b16..76e6d43 100644
--- a/include/qemu/typedefs.h
+++ b/include/qemu/typedefs.h
@@ -72,5 +72,6 @@ typedef struct SHPCDevice SHPCDevice;
typedef struct FWCfgState FWCfgState;
typedef struct PcGuestInfo PcGuestInfo;
typedef struct Range Range;
+typedef struct AdapterInfo AdapterInfo;

#endif /* QEMU_TYPEDEFS_H */
diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index 9d2df88..7a0c18a 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -317,6 +317,8 @@ int kvm_irqchip_add_msi_route(KVMState *s, MSIMessage msg);
int kvm_irqchip_update_msi_route(KVMState *s, int virq, MSIMessage msg);
void kvm_irqchip_release_virq(KVMState *s, int virq);

+int kvm_irqchip_add_adapter_route(KVMState *s, AdapterInfo *adapter);
+
int kvm_irqchip_add_irqfd_notifier(KVMState *s, EventNotifier *n,
EventNotifier *rn, int virq);
int kvm_irqchip_remove_irqfd_notifier(KVMState *s, EventNotifier *n, int virq);
diff --git a/kvm-all.c b/kvm-all.c
index 6e6a804..9d6cd45 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -27,6 +27,7 @@
#include "sysemu/sysemu.h"
#include "hw/hw.h"
#include "hw/pci/msi.h"
+#include "hw/s390x/adapter.h"
#include "exec/gdbstub.h"
#include "sysemu/kvm.h"
#include "qemu/bswap.h"
@@ -1262,6 +1263,35 @@ static int kvm_irqchip_assign_irqfd(KVMState *s, int fd, int rfd, int virq,
return kvm_vm_ioctl(s, KVM_IRQFD, &irqfd);
}

+int kvm_irqchip_add_adapter_route(KVMState *s, AdapterInfo *adapter)
+{
+ struct kvm_irq_routing_entry kroute;
+ int virq;
+
+ if (!kvm_gsi_routing_enabled()) {
+ return -ENOSYS;
+ }
+
+ virq = kvm_irqchip_get_virq(s);
+ if (virq < 0) {
+ return virq;
+ }
+
+ kroute.gsi = virq;
+ kroute.type = KVM_IRQ_ROUTING_S390_ADAPTER;
+ kroute.flags = 0;
+ kroute.u.adapter.summary_addr = adapter->summary_addr;
+ kroute.u.adapter.ind_addr = adapter->ind_addr;
+ kroute.u.adapter.summary_offset = adapter->summary_offset;
+ kroute.u.adapter.ind_offset = adapter->ind_offset;
+ kroute.u.adapter.adapter_id = adapter->adapter_id;
+
+ kvm_add_routing_entry(s, &kroute);
+ kvm_irqchip_commit_routes(s);
+
+ return virq;
+}
+
#else /* !KVM_CAP_IRQ_ROUTING */

void kvm_init_irq_routing(KVMState *s)
@@ -1282,6 +1312,11 @@ int kvm_irqchip_add_msi_route(KVMState *s, MSIMessage msg)
return -ENOSYS;
}

+int kvm_irqchip_add_adapter_route(KVMState *s, AdapterInfo *adapter)
+{
+ return -ENOSYS;
+}
+
static int kvm_irqchip_assign_irqfd(KVMState *s, int fd, int virq, bool assign)
{
abort();
@@ -1311,7 +1346,8 @@ static int kvm_irqchip_create(KVMState *s)
int ret;

if (!qemu_opt_get_bool(qemu_get_machine_opts(), "kernel_irqchip", true) ||
- !kvm_check_extension(s, KVM_CAP_IRQCHIP)) {
+ (!kvm_check_extension(s, KVM_CAP_IRQCHIP) &&
+ kvm_enable_cap_vm(s, KVM_CAP_S390_IRQCHIP))) {
return 0;
}

diff --git a/kvm-stub.c b/kvm-stub.c
index e979f76..c329ab5 100644
--- a/kvm-stub.c
+++ b/kvm-stub.c
@@ -136,6 +136,11 @@ int kvm_irqchip_update_msi_route(KVMState *s, int virq, MSIMessage msg)
return -ENOSYS;
}

+int kvm_irqchip_add_adapter_route(KVMState *s, AdapterInfo *adapter)
+{
+ return -ENOSYS;
+}
+
int kvm_irqchip_add_irqfd_notifier(KVMState *s, EventNotifier *n,
EventNotifier *rn, int virq)
{
diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
index 7e8321e..6b7e5db 100644
--- a/target-s390x/kvm.c
+++ b/target-s390x/kvm.c
@@ -898,6 +898,11 @@ void kvm_s390_enable_css_support(S390CPU *cpu)

void kvm_arch_init_irq_routing(KVMState *s)
{
+ if (kvm_check_extension(s, KVM_CAP_IRQ_ROUTING)) {
+ kvm_irqfds_allowed = true;
+ kvm_gsi_routing_allowed = true;
+ kvm_halt_in_kernel_allowed = false;
+ }
}

int kvm_s390_assign_subch_ioeventfd(EventNotifier *notifier, uint32_t sch,
--
1.7.9.5