[RFC PATCH 4/5] hw/i386/q35: Wire virtual SMI# lines to ICH9 chipset

[Philippe Mathieu-Daudé]

We use virtual SMI lines for the virtualized q35 machine
(see commit 5ce45c7a2b "hw/isa/lpc_ich9: add broadcast
SMI feature").

Expose them as QDev GPIO at the machine level. Wire them
to the ICH9 chipset. This allows removing a pair of calls
to cpu_interrupt() from the ICH9 model and make it target
agnostic.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 include/hw/isa/ich9_lpc.h     | 12 ++++++++++++
 include/hw/southbridge/ich9.h |  1 +
 hw/i386/pc_q35.c              | 26 ++++++++++++++++++++++++++
 hw/isa/ich9_lpc.c             | 10 ++++------
 hw/southbridge/ich9.c         |  1 +
 5 files changed, 44 insertions(+), 6 deletions(-)

diff --git a/include/hw/isa/ich9_lpc.h b/include/hw/isa/ich9_lpc.h
index b64d88b395..f11ae7e762 100644
--- a/include/hw/isa/ich9_lpc.h
+++ b/include/hw/isa/ich9_lpc.h
@@ -21,6 +21,17 @@ OBJECT_DECLARE_SIMPLE_TYPE(ICH9LPCState, ICH9_LPC_DEVICE)
 
 #define ICH9_CC_SIZE (16 * 1024) /* 16KB. Chipset configuration registers */
 
+/*
+ * Real ICH9 contains a single SMI output line and doesn't broadcast CPUs.
+ * Virtualized ICH9 allows broadcasting upon negatiation with guest, see
+ * commit 5ce45c7a2b.
+ */
+enum {
+    ICH9_VIRT_SMI_BROADCAST,
+    ICH9_VIRT_SMI_CURRENT,
+#define ICH9_VIRT_SMI_COUNT 2
+};
+
 struct ICH9LPCState {
     /* ICH9 LPC PCI to ISA bridge */
     PCIDevice d;
@@ -71,6 +82,7 @@ struct ICH9LPCState {
     Notifier machine_ready;
 
     qemu_irq gsi[IOAPIC_NUM_PINS];
+    qemu_irq virt_smi[ICH9_VIRT_SMI_COUNT];
 };
 
 #define ICH9_MASK(bit, ms_bit, ls_bit) \
diff --git a/include/hw/southbridge/ich9.h b/include/hw/southbridge/ich9.h
index a8da4a8665..48a4212ed8 100644
--- a/include/hw/southbridge/ich9.h
+++ b/include/hw/southbridge/ich9.h
@@ -17,6 +17,7 @@ OBJECT_DECLARE_SIMPLE_TYPE(ICH9State, ICH9_SOUTHBRIDGE)
 #define ICH9_PCIE_FUNC_MAX                      6
 
 #define ICH9_GPIO_GSI "gsi"
+#define ICH9_VIRT_SMI "x-virt-smi"
 
 #define ICH9_LPC_SMI_NEGOTIATED_FEAT_PROP "x-smi-negotiated-features"
 
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 31ab0ae77b..77fe8932e8 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -50,6 +50,7 @@
 #include "hw/ide/ahci-pci.h"
 #include "hw/intc/ioapic.h"
 #include "hw/southbridge/ich9.h"
+#include "hw/isa/ich9_lpc.h"
 #include "qapi/error.h"
 #include "qemu/error-report.h"
 #include "sysemu/numa.h"
@@ -58,6 +59,25 @@
 #include "hw/i386/acpi-build.h"
 #include "target/i386/cpu.h"
 
+/*
+ * Kludge IRQ handler for ICH9 virtual SMI delivery.
+ * IRQ#0: broadcast
+ * IRQ#1: deliver to current CPU
+ */
+static void pc_q35_ich9_virt_smi(void *opaque, int irq, int level)
+{
+    assert(level);
+    if (irq) {
+        cpu_interrupt(current_cpu, CPU_INTERRUPT_SMI);
+    } else {
+        CPUState *cs;
+
+        CPU_FOREACH(cs) {
+            cpu_interrupt(cs, CPU_INTERRUPT_SMI);
+        }
+    }
+}
+
 /* PC hardware initialisation */
 static void pc_q35_init(MachineState *machine)
 {
@@ -65,6 +85,7 @@ static void pc_q35_init(MachineState *machine)
     PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
     X86MachineState *x86ms = X86_MACHINE(machine);
     Object *phb;
+    qemu_irq *smi_irq;
     DeviceState *ich9;
     Object *lpc_obj;
     MemoryRegion *system_memory = get_system_memory();
@@ -160,6 +181,8 @@ static void pc_q35_init(MachineState *machine)
 
     /* irq lines */
     gsi_state = pc_gsi_create(&x86ms->gsi, true);
+    smi_irq = qemu_allocate_irqs(pc_q35_ich9_virt_smi, NULL,
+                                 ICH9_VIRT_SMI_COUNT);
 
     ich9 = qdev_new(TYPE_ICH9_SOUTHBRIDGE);
     object_property_add_child(OBJECT(machine), "ich9", OBJECT(ich9));
@@ -168,6 +191,9 @@ static void pc_q35_init(MachineState *machine)
     for (i = 0; i < IOAPIC_NUM_PINS; i++) {
         qdev_connect_gpio_out_named(ich9, ICH9_GPIO_GSI, i, x86ms->gsi[i]);
     }
+    for (i = 0; i < ICH9_VIRT_SMI_COUNT; i++) {
+        qdev_connect_gpio_out_named(ich9, ICH9_VIRT_SMI, i, smi_irq[i]);
+    }
     qdev_prop_set_bit(ich9, "d2p-enabled", false);
     qdev_prop_set_bit(ich9, "smm-enabled", x86_machine_is_smm_enabled(x86ms));
     qdev_prop_set_bit(ich9, "sata-enabled", pcms->sata_enabled);
diff --git a/hw/isa/ich9_lpc.c b/hw/isa/ich9_lpc.c
index b1f41158c5..599cb0ee86 100644
--- a/hw/isa/ich9_lpc.c
+++ b/hw/isa/ich9_lpc.c
@@ -30,7 +30,6 @@
 
 #include "qemu/osdep.h"
 #include "qemu/log.h"
-#include "cpu.h"
 #include "qapi/error.h"
 #include "qapi/visitor.h"
 #include "qemu/range.h"
@@ -495,12 +494,9 @@ static void ich9_apm_ctrl_changed(uint32_t val, void *arg)
     if (lpc->pm.smi_en & ICH9_PMIO_SMI_EN_APMC_EN) {
         if (lpc->smi_negotiated_features &
             (UINT64_C(1) << ICH9_LPC_SMI_F_BROADCAST_BIT)) {
-            CPUState *cs;
-            CPU_FOREACH(cs) {
-                cpu_interrupt(cs, CPU_INTERRUPT_SMI);
-            }
+            qemu_irq_raise(lpc->virt_smi[ICH9_VIRT_SMI_BROADCAST]);
         } else {
-            cpu_interrupt(current_cpu, CPU_INTERRUPT_SMI);
+            qemu_irq_raise(lpc->virt_smi[ICH9_VIRT_SMI_CURRENT]);
         }
     }
 }
@@ -700,6 +696,8 @@ static void ich9_lpc_initfn(Object *obj)
 
     qdev_init_gpio_out_named(DEVICE(lpc), lpc->gsi, ICH9_GPIO_GSI,
                              IOAPIC_NUM_PINS);
+    qdev_init_gpio_out_named(DEVICE(lpc), lpc->virt_smi,
+                             ICH9_VIRT_SMI, ARRAY_SIZE(lpc->virt_smi));
 
     object_property_add_uint8_ptr(obj, ACPI_PM_PROP_SCI_INT,
                                   &lpc->sci_gsi, OBJ_PROP_FLAG_READ);
diff --git a/hw/southbridge/ich9.c b/hw/southbridge/ich9.c
index 521925b462..d5e131cff3 100644
--- a/hw/southbridge/ich9.c
+++ b/hw/southbridge/ich9.c
@@ -64,6 +64,7 @@ static void ich9_init(Object *obj)
 
     object_initialize_child(obj, "lpc", &s->lpc, TYPE_ICH9_LPC_DEVICE);
     qdev_pass_gpios(DEVICE(&s->lpc), DEVICE(s), ICH9_GPIO_GSI);
+    qdev_pass_gpios(DEVICE(&s->lpc), DEVICE(s), ICH9_VIRT_SMI);
     qdev_prop_set_int32(DEVICE(&s->lpc), "addr", ICH9_LPC_DEVFN);
     qdev_prop_set_bit(DEVICE(&s->lpc), "multifunction", true);
     object_property_add_alias(obj, "smm-enabled",
-- 
2.41.0