Having a proxy PIC allows for ISA PICs to be created and wired up in
southbridges. This is especially useful for PIIX3 for two reasons:
First, the southbridge doesn't need to care about the virtualization
technology used (KVM, TCG, Xen) due to in-IRQs (where devices get
attached) and out-IRQs (which will trigger the IRQs of the respective
virtualization technology) are separated. Second, since the in-IRQs are
populated with fully initialized qemu_irq's, they can already be wired
up inside PIIX3.
Signed-off-by: Bernhard Beschow <shen...@gmail.com>
Reviewed-by: Michael S. Tsirkin <m...@redhat.com>
Message-Id: <20221022150508.26830-15-shen...@gmail.com>
---
Changes since v4:
* Change license to GPL-2.0-or-later and use SPDX-License-Identifier
* Fix typo in commit message
---
include/hw/core/proxy-pic.h | 38 ++++++++++++++++++++++++++
hw/core/proxy-pic.c | 54 +++++++++++++++++++++++++++++++++++++
MAINTAINERS | 2 ++
hw/core/Kconfig | 3 +++
hw/core/meson.build | 1 +
5 files changed, 98 insertions(+)
create mode 100644 include/hw/core/proxy-pic.h
create mode 100644 hw/core/proxy-pic.c
diff --git a/include/hw/core/proxy-pic.h b/include/hw/core/proxy-pic.h
new file mode 100644
index 0000000000..32bc7936bd
--- /dev/null
+++ b/include/hw/core/proxy-pic.h
@@ -0,0 +1,38 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * Proxy interrupt controller device.
+ *
+ * Copyright (c) 2022 Bernhard Beschow <shen...@gmail.com>
+ */
+
+#ifndef HW_PROXY_PIC_H
+#define HW_PROXY_PIC_H
+
+#include "hw/qdev-core.h"
+#include "qom/object.h"
+#include "hw/irq.h"
+
+#define TYPE_PROXY_PIC "proxy-pic"
+OBJECT_DECLARE_SIMPLE_TYPE(ProxyPICState, PROXY_PIC)
+
+#define MAX_PROXY_PIC_LINES 16
+
+/**
+ * This is a simple device which has 16 pairs of GPIO input and output lines.
+ * Any change on an input line is forwarded to the respective output.
+ *
+ * QEMU interface:
+ * + 16 unnamed GPIO inputs: the input lines
+ * + 16 unnamed GPIO outputs: the output lines
+ */
+struct ProxyPICState {
+ /*< private >*/
+ struct DeviceState parent_obj;
+ /*< public >*/
+
+ qemu_irq in_irqs[MAX_PROXY_PIC_LINES];
+ qemu_irq out_irqs[MAX_PROXY_PIC_LINES];
+};
+
+#endif /* HW_PROXY_PIC_H */
diff --git a/hw/core/proxy-pic.c b/hw/core/proxy-pic.c
new file mode 100644
index 0000000000..40fd70b9e2
--- /dev/null
+++ b/hw/core/proxy-pic.c
@@ -0,0 +1,54 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * Proxy interrupt controller device.
+ *
+ * Copyright (c) 2022 Bernhard Beschow <shen...@gmail.com>
+ */
+
+#include "qemu/osdep.h"
+#include "hw/core/proxy-pic.h"
+
+static void proxy_pic_set_irq(void *opaque, int irq, int level)
+{
+ ProxyPICState *s = opaque;
+
+ qemu_set_irq(s->out_irqs[irq], level);
+}
+
+static void proxy_pic_realize(DeviceState *dev, Error **errp)
+{
+ ProxyPICState *s = PROXY_PIC(dev);
+
+ qdev_init_gpio_in(DEVICE(s), proxy_pic_set_irq, MAX_PROXY_PIC_LINES);
+ qdev_init_gpio_out(DEVICE(s), s->out_irqs, MAX_PROXY_PIC_LINES);
+
+ for (int i = 0; i < MAX_PROXY_PIC_LINES; ++i) {
+ s->in_irqs[i] = qdev_get_gpio_in(DEVICE(s), i);
+ }
+}
+
+static void proxy_pic_class_init(ObjectClass *klass, void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+
+ /* No state to reset or migrate */
+ dc->realize = proxy_pic_realize;
+
+ /* Reason: Needs to be wired up to work */
+ dc->user_creatable = false;
+}
+
+static const TypeInfo proxy_pic_info = {
+ .name = TYPE_PROXY_PIC,
+ .parent = TYPE_DEVICE,
+ .instance_size = sizeof(ProxyPICState),
+ .class_init = proxy_pic_class_init,
+};
+
+static void split_irq_register_types(void)
+{
+ type_register_static(&proxy_pic_info);
+}
+
+type_init(split_irq_register_types)
diff --git a/MAINTAINERS b/MAINTAINERS
index 7a40d4d865..295a76bfbd 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1674,6 +1674,7 @@ S: Supported
F: hw/char/debugcon.c
F: hw/char/parallel*
F: hw/char/serial*
+F: hw/core/proxy-pic.c
F: hw/dma/i8257*
F: hw/i2c/pm_smbus.c
F: hw/input/pckbd.c
@@ -1690,6 +1691,7 @@ F: hw/watchdog/wdt_ib700.c
F: hw/watchdog/wdt_i6300esb.c
F: include/hw/display/vga.h
F: include/hw/char/parallel.h
+F: include/hw/core/proxy-pic.h
F: include/hw/dma/i8257.h
F: include/hw/i2c/pm_smbus.h
F: include/hw/input/i8042.h
diff --git a/hw/core/Kconfig b/hw/core/Kconfig
index 9397503656..a7224f4ca0 100644
--- a/hw/core/Kconfig
+++ b/hw/core/Kconfig
@@ -22,6 +22,9 @@ config OR_IRQ
config PLATFORM_BUS
bool
+config PROXY_PIC
+ bool
+
config REGISTER
bool
diff --git a/hw/core/meson.build b/hw/core/meson.build
index 7a4d02b6c0..e86aef6ec3 100644
--- a/hw/core/meson.build
+++ b/hw/core/meson.build
@@ -30,6 +30,7 @@ softmmu_ss.add(when: ['CONFIG_GUEST_LOADER', fdt], if_true:
files('guest-loader.
softmmu_ss.add(when: 'CONFIG_OR_IRQ', if_true: files('or-irq.c'))
softmmu_ss.add(when: 'CONFIG_PLATFORM_BUS', if_true: files('platform-bus.c'))
softmmu_ss.add(when: 'CONFIG_PTIMER', if_true: files('ptimer.c'))
+softmmu_ss.add(when: 'CONFIG_PROXY_PIC', if_true: files('proxy-pic.c'))
softmmu_ss.add(when: 'CONFIG_REGISTER', if_true: files('register.c'))
softmmu_ss.add(when: 'CONFIG_SPLIT_IRQ', if_true: files('split-irq.c'))
softmmu_ss.add(when: 'CONFIG_XILINX_AXI', if_true: files('stream.c'))
--
2.39.0
