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>

1 files changed, 128 insertions, 0 deletions

diff --git a/hw/kvm/i8259.c b/hw/kvm/i8259.c
new file mode 100644
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)