[Qemu-devel] [RFC][PATCH 15/16] kvm: x86: Add user space part for in-kernel IOAPIC

[Jan Kiszka]

From: Jan Kiszka <address@hidden>

This introduces the KVM-accelerated IOAPIC model 'kvm-ioapic' and
extends the IRQ routing setup by the 0->2 redirection when needed.

The kvm-ioapic model has a property that allows to define its GSI base
for injecting interrupts into the kernel model. This will allow to
disentangle PIC and IOAPIC pins for chipsets that support more
sophisticated IRQ routes than the PIIX3. So far the base is kept at 0,
i.e. PIC and IOAPIC share pins 0..15.

Signed-off-by: Jan Kiszka <address@hidden>
---
 Makefile.target      |    2 +-
 hw/ioapic_internal.h |    1 +
 hw/kvm/ioapic.c      |  120 ++++++++++++++++++++++++++++++++++++++++++++++++++
 hw/pc_piix.c         |   15 ++++++-
 4 files changed, 136 insertions(+), 2 deletions(-)
 create mode 100644 hw/kvm/ioapic.c

diff --git a/Makefile.target b/Makefile.target
index 850b80f..2f3407b 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -231,7 +231,7 @@ obj-i386-y += vmport.o
 obj-i386-y += device-hotplug.o pci-hotplug.o smbios.o wdt_ib700.o
 obj-i386-y += debugcon.o multiboot.o
 obj-i386-y += pc_piix.o
-obj-i386-$(CONFIG_KVM) += kvm/clock.o kvm/apic.o kvm/i8259.o
+obj-i386-$(CONFIG_KVM) += kvm/clock.o kvm/apic.o kvm/i8259.o kvm/ioapic.o
 obj-i386-$(CONFIG_SPICE) += qxl.o qxl-logger.o qxl-render.o
 
 # shared objects
diff --git a/hw/ioapic_internal.h b/hw/ioapic_internal.h
index bda3608..7d5f735 100644
--- a/hw/ioapic_internal.h
+++ b/hw/ioapic_internal.h
@@ -83,6 +83,7 @@ struct IOAPICState {
 
     void (*pre_save)(IOAPICState *s);
     void (*post_load)(IOAPICState *s);
+    uint32_t kvm_gsi_base;
 };
 
 extern const VMStateDescription vmstate_ioapic;
diff --git a/hw/kvm/ioapic.c b/hw/kvm/ioapic.c
new file mode 100644
index 0000000..680229b
--- /dev/null
+++ b/hw/kvm/ioapic.c
@@ -0,0 +1,120 @@
+/*
+ * KVM in-kernel IOPIC support
+ *
+ * Copyright (c) 2011 Siemens AG
+ *
+ * Authors:
+ *  Jan Kiszka          <address@hidden>
+ *
+ * This work is licensed under the terms of the GNU GPL version 2.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include <hw/pc.h>
+#include <hw/ioapic_internal.h>
+#include <hw/apic_internal.h>
+#include <kvm.h>
+
+static void kvm_ioapic_get(IOAPICState *s)
+{
+    struct kvm_irqchip chip;
+    struct kvm_ioapic_state *kioapic;
+    int ret, i;
+
+    chip.chip_id = KVM_IRQCHIP_IOAPIC;
+    ret = kvm_vm_ioctl(kvm_state, KVM_GET_IRQCHIP, &chip);
+    if (ret < 0) {
+        fprintf(stderr, "KVM_GET_IRQCHIP failed: %s\n", strerror(ret));
+        abort();
+    }
+
+    kioapic = &chip.chip.ioapic;
+
+    s->id = kioapic->id;
+    s->ioregsel = kioapic->ioregsel;
+    s->irr = kioapic->irr;
+    for (i = 0; i < IOAPIC_NUM_PINS; i++) {
+        s->ioredtbl[i] = kioapic->redirtbl[i].bits;
+    }
+}
+
+static void kvm_ioapic_put(IOAPICState *s)
+{
+    struct kvm_irqchip chip;
+    struct kvm_ioapic_state *kioapic;
+    int ret, i;
+
+    chip.chip_id = KVM_IRQCHIP_IOAPIC;
+    kioapic = &chip.chip.ioapic;
+
+    kioapic->id = s->id;
+    kioapic->ioregsel = s->ioregsel;
+    kioapic->base_address = s->busdev.mmio[0].addr;
+    kioapic->irr = s->irr;
+    for (i = 0; i < IOAPIC_NUM_PINS; i++) {
+        kioapic->redirtbl[i].bits = s->ioredtbl[i];
+    }
+
+    ret = kvm_vm_ioctl(kvm_state, KVM_SET_IRQCHIP, &chip);
+    if (ret < 0) {
+        fprintf(stderr, "KVM_GET_IRQCHIP failed: %s\n", strerror(ret));
+        abort();
+    }
+}
+
+static void kvm_ioapic_reset(DeviceState *d)
+{
+    IOAPICState *s = DO_UPCAST(IOAPICState, busdev.qdev, d);
+
+    ioapic_reset_internal(s);
+
+    kvm_ioapic_put(s);
+}
+
+static void kvm_ioapic_set_irq(void *opaque, int irq, int level)
+{
+    IOAPICState *s = opaque;
+    int delivered;
+
+    delivered = kvm_irqchip_set_irq(kvm_state, s->kvm_gsi_base + irq, level);
+    apic_set_irq_delivered(delivered);
+}
+
+static int kvm_ioapic_init(SysBusDevice *dev)
+{
+    IOAPICState *s = FROM_SYSBUS(IOAPICState, dev);
+
+    memory_region_init_reservation(&s->io_memory, "kvm-ioapic", 0x1000);
+
+    if (ioapic_init_common(s) < 0) {
+        memory_region_destroy(&s->io_memory);
+        return -1;
+    }
+
+    s->pre_save = kvm_ioapic_get;
+    s->post_load = kvm_ioapic_put;
+
+    qdev_init_gpio_in(&dev->qdev, kvm_ioapic_set_irq, IOAPIC_NUM_PINS);
+
+    return 0;
+}
+
+static SysBusDeviceInfo kvm_ioapic_info = {
+    .init = kvm_ioapic_init,
+    .qdev.name = "kvm-ioapic",
+    .qdev.size = sizeof(IOAPICState),
+    .qdev.vmsd = &vmstate_ioapic,
+    .qdev.reset = kvm_ioapic_reset,
+    .qdev.no_user = 1,
+    .qdev.props = (Property[]) {
+        DEFINE_PROP_UINT32("gsi_base", IOAPICState, kvm_gsi_base, 0),
+        DEFINE_PROP_END_OF_LIST(),
+    }
+};
+
+static void kvm_ioapic_register_devices(void)
+{
+    sysbus_register_withprop(&kvm_ioapic_info);
+}
+
+device_init(kvm_ioapic_register_devices)
diff --git a/hw/pc_piix.c b/hw/pc_piix.c
index 351b032..624aecd 100644
--- a/hw/pc_piix.c
+++ b/hw/pc_piix.c
@@ -68,6 +68,15 @@ static void kvm_piix3_setup_irq_routing(bool pci_enabled)
         for (i = 8; i < 16; ++i) {
             kvm_irqchip_add_route(s, i, KVM_IRQCHIP_PIC_SLAVE, i - 8);
         }
+        if (pci_enabled) {
+            for (i = 0; i < 24; ++i) {
+                if (i == 0) {
+                    kvm_irqchip_add_route(s, i, KVM_IRQCHIP_IOAPIC, 2);
+                } else if (i != 2) {
+                    kvm_irqchip_add_route(s, i, KVM_IRQCHIP_IOAPIC, i);
+                }
+            }
+        }
         ret = kvm_irqchip_commit_routes(s);
         if (ret < 0) {
             hw_error("KVM IRQ routing setup failed");
@@ -93,7 +102,11 @@ static void ioapic_init(GSIState *gsi_state)
     SysBusDevice *d;
     unsigned int i;
 
-    dev = qdev_create(NULL, "ioapic");
+    if (kvm_enabled() && kvm_irqchip_in_kernel()) {
+        dev = qdev_create(NULL, "kvm-ioapic");
+    } else {
+        dev = qdev_create(NULL, "ioapic");
+    }
     qdev_init_nofail(dev);
     d = sysbus_from_qdev(dev);
     sysbus_mmio_map(d, 0, 0xfec00000);
-- 
1.7.3.4