kvm: x86: Add user space part for in-kernel i8259

Introduce the alternative 'kvm-i8259' device model that exploits KVM
in-kernel acceleration.

The PIIX3 initialization code is furthermore extended by KVM specific
IRQ route setup. GSI injection differs in KVM mode from the user space
model. As we can dispatch ISA-range IRQs to both IOAPIC and PIC inside
the kernel, we do not need to inject them separately. This is reflected
by a KVM-specific GSI handler.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

diff --git a/Makefile.target b/Makefile.target
index 1a63a1c3e7e2a11f8e0e254f8ab322eae19d2712..701073d15598e254a3f076cfb1b45b20ec39764b 100644 (file)
--- a/Makefile.target
+++ b/Makefile.target
@@ -233,7 +233,7 @@ obj-i386-y += vmport.o
 obj-i386-y += pci-hotplug.o smbios.o wdt_ib700.o
 obj-i386-y += debugcon.o multiboot.o
 obj-i386-y += pc_piix.o
-obj-i386-$(CONFIG_KVM) += kvm/clock.o kvm/apic.o
+obj-i386-$(CONFIG_KVM) += kvm/clock.o kvm/apic.o kvm/i8259.o
 obj-i386-$(CONFIG_SPICE) += qxl.o qxl-logger.o qxl-render.o
 
 # shared objects

diff --git a/hw/kvm/i8259.c b/hw/kvm/i8259.c
new file mode 100644 (file)
index 0000000..64bb5c2
--- /dev/null
+++ b/hw/kvm/i8259.c
@@ -0,0 +1,128 @@
+/*
+ * KVM in-kernel PIC (i8259) support
+ *
+ * Copyright (c) 2011 Siemens AG
+ *
+ * Authors:
+ *  Jan Kiszka          <jan.kiszka@siemens.com>
+ *
+ * This work is licensed under the terms of the GNU GPL version 2.
+ * See the COPYING file in the top-level directory.
+ */
+#include "hw/i8259_internal.h"
+#include "hw/apic_internal.h"
+#include "kvm.h"
+
+static void kvm_pic_get(PICCommonState *s)
+{
+    struct kvm_irqchip chip;
+    struct kvm_pic_state *kpic;
+    int ret;
+
+    chip.chip_id = s->master ? KVM_IRQCHIP_PIC_MASTER : KVM_IRQCHIP_PIC_SLAVE;
+    ret = kvm_vm_ioctl(kvm_state, KVM_GET_IRQCHIP, &chip);
+    if (ret < 0) {
+        fprintf(stderr, "KVM_GET_IRQCHIP failed: %s\n", strerror(ret));
+        abort();
+    }
+
+    kpic = &chip.chip.pic;
+
+    s->last_irr = kpic->last_irr;
+    s->irr = kpic->irr;
+    s->imr = kpic->imr;
+    s->isr = kpic->isr;
+    s->priority_add = kpic->priority_add;
+    s->irq_base = kpic->irq_base;
+    s->read_reg_select = kpic->read_reg_select;
+    s->poll = kpic->poll;
+    s->special_mask = kpic->special_mask;
+    s->init_state = kpic->init_state;
+    s->auto_eoi = kpic->auto_eoi;
+    s->rotate_on_auto_eoi = kpic->rotate_on_auto_eoi;
+    s->special_fully_nested_mode = kpic->special_fully_nested_mode;
+    s->init4 = kpic->init4;
+    s->elcr = kpic->elcr;
+    s->elcr_mask = kpic->elcr_mask;
+}
+
+static void kvm_pic_put(PICCommonState *s)
+{
+    struct kvm_irqchip chip;
+    struct kvm_pic_state *kpic;
+    int ret;
+
+    chip.chip_id = s->master ? KVM_IRQCHIP_PIC_MASTER : KVM_IRQCHIP_PIC_SLAVE;
+
+    kpic = &chip.chip.pic;
+
+    kpic->last_irr = s->last_irr;
+    kpic->irr = s->irr;
+    kpic->imr = s->imr;
+    kpic->isr = s->isr;
+    kpic->priority_add = s->priority_add;
+    kpic->irq_base = s->irq_base;
+    kpic->read_reg_select = s->read_reg_select;
+    kpic->poll = s->poll;
+    kpic->special_mask = s->special_mask;
+    kpic->init_state = s->init_state;
+    kpic->auto_eoi = s->auto_eoi;
+    kpic->rotate_on_auto_eoi = s->rotate_on_auto_eoi;
+    kpic->special_fully_nested_mode = s->special_fully_nested_mode;
+    kpic->init4 = s->init4;
+    kpic->elcr = s->elcr;
+    kpic->elcr_mask = s->elcr_mask;
+
+    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_pic_reset(DeviceState *dev)
+{
+    PICCommonState *s = DO_UPCAST(PICCommonState, dev.qdev, dev);
+
+    pic_reset_common(s);
+    s->elcr = 0;
+
+    kvm_pic_put(s);
+}
+
+static void kvm_pic_set_irq(void *opaque, int irq, int level)
+{
+    int delivered;
+
+    delivered = kvm_irqchip_set_irq(kvm_state, irq, level);
+    apic_report_irq_delivered(delivered);
+}
+
+static void kvm_pic_init(PICCommonState *s)
+{
+    memory_region_init_reservation(&s->base_io, "kvm-pic", 2);
+    memory_region_init_reservation(&s->elcr_io, "kvm-elcr", 1);
+}
+
+qemu_irq *kvm_i8259_init(ISABus *bus)
+{
+    i8259_init_chip("kvm-i8259", bus, true);
+    i8259_init_chip("kvm-i8259", bus, false);
+
+    return qemu_allocate_irqs(kvm_pic_set_irq, NULL, ISA_NUM_IRQS);
+}
+
+static PICCommonInfo kvm_i8259_info = {
+    .isadev.qdev.name  = "kvm-i8259",
+    .isadev.qdev.reset = kvm_pic_reset,
+    .init       = kvm_pic_init,
+    .pre_save   = kvm_pic_get,
+    .post_load  = kvm_pic_put,
+};
+
+static void kvm_pic_register(void)
+{
+    pic_qdev_register(&kvm_i8259_info);
+}
+
+device_init(kvm_pic_register)

diff --git a/hw/pc.h b/hw/pc.h
index ece069ad1f6e7c8cc4d24297cfe60082450c7c31..5e913dbf857511b50bd20f6c6b964307e7881bd1 100644 (file)
--- a/hw/pc.h
+++ b/hw/pc.h
@@ -64,6 +64,7 @@ bool parallel_mm_init(MemoryRegion *address_space,
 
 extern DeviceState *isa_pic;
 qemu_irq *i8259_init(ISABus *bus, qemu_irq parent_irq);
+qemu_irq *kvm_i8259_init(ISABus *bus);
 int pic_read_irq(DeviceState *d);
 int pic_get_output(DeviceState *d);
 void pic_info(Monitor *mon);

diff --git a/hw/pc_piix.c b/hw/pc_piix.c
index cde810db2767f712aecfb58f8857743db8c37230..297c04a9ab20d1ee87cd6eb8778e9690e5fcfda0 100644 (file)
--- a/hw/pc_piix.c
+++ b/hw/pc_piix.c
@@ -53,6 +53,42 @@ static const int ide_iobase[MAX_IDE_BUS] = { 0x1f0, 0x170 };
 static const int ide_iobase2[MAX_IDE_BUS] = { 0x3f6, 0x376 };
 static const int ide_irq[MAX_IDE_BUS] = { 14, 15 };
 
+static void kvm_piix3_setup_irq_routing(bool pci_enabled)
+{
+#ifdef CONFIG_KVM
+    KVMState *s = kvm_state;
+    int ret, i;
+
+    if (kvm_check_extension(s, KVM_CAP_IRQ_ROUTING)) {
+        for (i = 0; i < 8; ++i) {
+            if (i == 2) {
+                continue;
+            }
+            kvm_irqchip_add_route(s, i, KVM_IRQCHIP_PIC_MASTER, i);
+        }
+        for (i = 8; i < 16; ++i) {
+            kvm_irqchip_add_route(s, i, KVM_IRQCHIP_PIC_SLAVE, i - 8);
+        }
+        ret = kvm_irqchip_commit_routes(s);
+        if (ret < 0) {
+            hw_error("KVM IRQ routing setup failed");
+        }
+    }
+#endif /* CONFIG_KVM */
+}
+
+static void kvm_piix3_gsi_handler(void *opaque, int n, int level)
+{
+    GSIState *s = opaque;
+
+    if (n < ISA_NUM_IRQS) {
+        /* Kernel will forward to both PIC and IOAPIC */
+        qemu_set_irq(s->i8259_irq[n], level);
+    } else {
+        qemu_set_irq(s->ioapic_irq[n], level);
+    }
+}
+
 static void ioapic_init(GSIState *gsi_state)
 {
     DeviceState *dev;
@@ -134,7 +170,13 @@ static void pc_init1(MemoryRegion *system_memory,
     }
 
     gsi_state = g_malloc0(sizeof(*gsi_state));
-    gsi = qemu_allocate_irqs(gsi_handler, gsi_state, GSI_NUM_PINS);
+    if (kvm_enabled() && kvm_irqchip_in_kernel()) {
+        kvm_piix3_setup_irq_routing(pci_enabled);
+        gsi = qemu_allocate_irqs(kvm_piix3_gsi_handler, gsi_state,
+                                 GSI_NUM_PINS);
+    } else {
+        gsi = qemu_allocate_irqs(gsi_handler, gsi_state, GSI_NUM_PINS);
+    }
 
     if (pci_enabled) {
         pci_bus = i440fx_init(&i440fx_state, &piix3_devfn, &isa_bus, gsi,
@@ -154,11 +196,13 @@ static void pc_init1(MemoryRegion *system_memory,
     }
     isa_bus_irqs(isa_bus, gsi);
 
-    if (!xen_enabled()) {
+    if (kvm_enabled() && kvm_irqchip_in_kernel()) {
+        i8259 = kvm_i8259_init(isa_bus);
+    } else if (xen_enabled()) {
+        i8259 = xen_interrupt_controller_init();
+    } else {
         cpu_irq = pc_allocate_cpu_irq();
         i8259 = i8259_init(isa_bus, cpu_irq[0]);
-    } else {
-        i8259 = xen_interrupt_controller_init();
     }
 
     for (i = 0; i < ISA_NUM_IRQS; i++) {