[Qemu-devel] [PATCH 4/8] provide i8259-kvm

[Glauber Costa]

This patch provides the file i8259-kvm.c, which implements a schim over
the kvm in-kernel PIC.

Signed-off-by: Glauber Costa <address@hidden>
---
 Makefile.target |    2 +-
 hw/i8259-kvm.c  |  112 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 hw/pc.c         |    8 +++-
 hw/pc.h         |    1 +
 kvm-all.c       |   26 ++++++++++++-
 kvm.h           |    2 +
 6 files changed, 147 insertions(+), 4 deletions(-)
 create mode 100644 hw/i8259-kvm.c

diff --git a/Makefile.target b/Makefile.target
index ca9ae66..37b692e 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -197,7 +197,7 @@ obj-i386-y += usb-uhci.o vmmouse.o vmport.o vmware_vga.o 
hpet.o
 obj-i386-y += device-hotplug.o pci-hotplug.o smbios.o wdt_ib700.o
 obj-i386-y += ne2000-isa.o
 
-obj-i386-$(CONFIG_KVM) += ioapic-kvm.o
+obj-i386-$(CONFIG_KVM) += ioapic-kvm.o i8259-kvm.o
 
 # shared objects
 obj-ppc-y = ppc.o ide/core.o ide/qdev.o ide/isa.o ide/pci.o ide/macio.o
diff --git a/hw/i8259-kvm.c b/hw/i8259-kvm.c
new file mode 100644
index 0000000..bd6387b
--- /dev/null
+++ b/hw/i8259-kvm.c
@@ -0,0 +1,112 @@
+#include "hw.h"
+#include "pc.h"
+#include "isa.h"
+#include "monitor.h"
+#include "qemu-timer.h"
+#include "kvm.h"
+
+static void kvm_i8259_set_irq(void *opaque, int irq, int level)
+{
+    int pic_ret;
+
+    if (kvm_set_irq(irq, level, &pic_ret)) {
+        if (pic_ret != 0)
+            /* In theory, we should not be using any apic state, but we need
+             * to warn devices such as the rtc about state of delivery. Since 
this
+             * one is just a marker, it is no big deal */
+            apic_set_irq_delivered();
+        return;
+    }
+}
+
+static void kvm_pic_reset(void *opaque)
+{
+    struct kvm_pic_state *s = opaque;
+    struct kvm_irqchip *chip;
+
+    s->last_irr = 0;
+    s->irr = 0;
+    s->imr = 0;
+    s->isr = 0;
+    s->priority_add = 0;
+    s->irq_base = 0;
+    s->read_reg_select = 0;
+    s->poll = 0;
+    s->special_mask = 0;
+    s->init_state = 0;
+    s->auto_eoi = 0;
+    s->rotate_on_auto_eoi = 0;
+    s->special_fully_nested_mode = 0;
+    s->init4 = 0;
+
+    chip = container_of(s, struct kvm_irqchip, chip.pic);
+    kvm_set_irqchip(chip);
+}
+
+static void pic_pre_save(void *opaque)
+{
+    struct kvm_pic_state *s = opaque;
+    struct kvm_irqchip *chip;
+
+    chip = container_of(s, struct kvm_irqchip, chip.pic);
+
+    kvm_get_irqchip(chip);
+}
+
+static int pic_post_load(void *opaque, int version_id)
+{
+    struct kvm_pic_state *s = opaque;
+    struct kvm_irqchip *chip;
+
+    chip = container_of(s, struct kvm_irqchip, chip.pic);
+
+    return kvm_set_irqchip(chip);
+}
+
+static const VMStateDescription vmstate_kvm_pic = {
+    .name = "i8259-kvm",
+    .version_id = 1,
+    .pre_save = pic_pre_save,
+    .post_load = pic_post_load,
+    .minimum_version_id = 1,
+    .fields      = (VMStateField []) {
+        VMSTATE_UINT8(last_irr, struct kvm_pic_state),
+        VMSTATE_UINT8(irr, struct kvm_pic_state),
+        VMSTATE_UINT8(imr, struct kvm_pic_state),
+        VMSTATE_UINT8(isr, struct kvm_pic_state),
+        VMSTATE_UINT8(priority_add, struct kvm_pic_state),
+        VMSTATE_UINT8(irq_base, struct kvm_pic_state),
+        VMSTATE_UINT8(read_reg_select, struct kvm_pic_state),
+        VMSTATE_UINT8(poll, struct kvm_pic_state),
+        VMSTATE_UINT8(special_mask, struct kvm_pic_state),
+        VMSTATE_UINT8(init_state, struct kvm_pic_state),
+        VMSTATE_UINT8(auto_eoi, struct kvm_pic_state),
+        VMSTATE_UINT8(rotate_on_auto_eoi, struct kvm_pic_state),
+        VMSTATE_UINT8(special_fully_nested_mode, struct kvm_pic_state),
+        VMSTATE_UINT8(init4, struct kvm_pic_state),
+        VMSTATE_UINT8(elcr, struct kvm_pic_state),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void kvm_pic_init1(int io_addr, struct kvm_pic_state *s)
+{
+    vmstate_register(io_addr, &vmstate_kvm_pic, s);
+    qemu_register_reset(kvm_pic_reset, s);
+}
+
+qemu_irq *kvm_i8259_init(qemu_irq parent_irq)
+{
+    struct kvm_irqchip *master, *slave;
+
+    master = qemu_mallocz(sizeof(*master));
+    slave = qemu_mallocz(sizeof(*slave));
+
+    master->chip_id = KVM_IRQCHIP_PIC_MASTER;
+    slave->chip_id = KVM_IRQCHIP_PIC_SLAVE;
+
+    kvm_pic_init1(0x20, &master->chip.pic);
+    kvm_pic_init1(0xa0, &slave->chip.pic);
+
+    return qemu_allocate_irqs(kvm_i8259_set_irq, master, 16);
+}
diff --git a/hw/pc.c b/hw/pc.c
index b7a1734..003ae11 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -1154,8 +1154,14 @@ static void pc_init1(ram_addr_t ram_size,
     }
 
     cpu_irq = qemu_allocate_irqs(pic_irq_request, NULL, 1);
-    i8259 = i8259_init(cpu_irq[0]);
     isa_irq_state = qemu_mallocz(sizeof(*isa_irq_state));
+
+    if (kvm_enabled() && kvm_irqchip_in_kernel()) {
+        i8259 = kvm_i8259_init(cpu_irq[0]);
+    } else {
+        i8259 = i8259_init(cpu_irq[0]);
+    }
+
     isa_irq_state->i8259 = i8259;
     isa_irq = qemu_allocate_irqs(isa_irq_handler, isa_irq_state, 24);
 
diff --git a/hw/pc.h b/hw/pc.h
index 478f70c..7493760 100644
--- a/hw/pc.h
+++ b/hw/pc.h
@@ -33,6 +33,7 @@ uint32_t pic_intack_read(PicState2 *s);
 void pic_info(Monitor *mon);
 void irq_info(Monitor *mon);
 
+qemu_irq *kvm_i8259_init(qemu_irq parent_irq);
 /* APIC */
 typedef struct IOAPICState IOAPICState;
 void apic_deliver_irq(uint8_t dest, uint8_t dest_mode,
diff --git a/kvm-all.c b/kvm-all.c
index d795285..7684957 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -411,7 +411,6 @@ int kvm_check_extension(KVMState *s, unsigned int extension)
     return ret;
 }
 
-#ifdef KVM_CAP_IRQCHIP
 int kvm_set_irqchip(struct kvm_irqchip *chip)
 {
     if (!kvm_state->irqchip_in_kernel) {
@@ -429,7 +428,30 @@ int kvm_get_irqchip(struct kvm_irqchip *chip)
 
     return kvm_vm_ioctl(kvm_state, KVM_GET_IRQCHIP, chip);
 }
-#endif
+
+int kvm_set_irq(int irq, int level, int *status)
+{
+    struct kvm_irq_level event;
+    int r;
+
+    if (!kvm_state->irqchip_in_kernel) {
+        return 0;
+    }
+
+    event.level = level;
+    event.irq = irq;
+
+    r = kvm_vm_ioctl(kvm_state, KVM_IRQ_LINE_STATUS, &event);
+
+    if (r < 0)
+        return 0;
+
+    if (status) {
+        *status = event.status;
+    }
+
+    return 1;
+}
 
 int kvm_init(int smp_cpus)
 {
diff --git a/kvm.h b/kvm.h
index 8d4afa0..2765352 100644
--- a/kvm.h
+++ b/kvm.h
@@ -67,6 +67,8 @@ int kvm_irqchip_in_kernel(void);
 int kvm_set_irqchip(struct kvm_irqchip *chip);
 int kvm_get_irqchip(struct kvm_irqchip *chip);
 
+int kvm_set_irq(int irq, int level, int *status);
+
 /* internal API */
 
 struct KVMState;
-- 
1.6.2.5