hw/ide/ahci: Decouple from PCI

In some adhoc profiling booting Linux VMs, it's observed that ahci_irq_lower()
can be a hot path (10000+ triggers until login prompt appears). Even though the
parent device never changes, this method re-determines whether the parent device
is a PCI device or not using the rather expensive object_dynamic_cast()
function. Avoid this overhead by pushing the interrupt handling to the parent
device, essentially turning AHCIState into an "IP block".

Note that this change also frees AHCIState from the PCI dependency which wasn't
reflected in Kconfig.

Reported-by: Peter Xu <peterx@redhat.com>
Inspired-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Bernhard Beschow <shentey@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20241212110926.23548-2-shentey@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

diff --git a/hw/ide/ahci-internal.h b/hw/ide/ahci-internal.h
index 7e63ea231020dc745bf3dea0bb8d6260b76f7b0f..a318f36811c7d1e2ea6ab1425fe41df99e4847d3 100644 (file)
--- a/hw/ide/ahci-internal.h
+++ b/hw/ide/ahci-internal.h
@@ -25,7 +25,6 @@
 #define HW_IDE_AHCI_INTERNAL_H
 
 #include "hw/ide/ahci.h"
-#include "hw/pci/pci_device.h"
 #include "ide-internal.h"
 
 #define AHCI_MEM_BAR_SIZE         0x1000

diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
index 0eb24304eef21da60a755a56010c07fc43803dae..5836aa924bb280e3fbaee174c69f74975022fe14 100644 (file)
--- a/hw/ide/ahci.c
+++ b/hw/ide/ahci.c
@@ -23,8 +23,6 @@
 
 #include "qemu/osdep.h"
 #include "hw/irq.h"
-#include "hw/pci/msi.h"
-#include "hw/pci/pci.h"
 #include "hw/qdev-properties.h"
 #include "migration/vmstate.h"
 
@@ -34,8 +32,6 @@
 #include "qemu/module.h"
 #include "sysemu/block-backend.h"
 #include "sysemu/dma.h"
-#include "hw/ide/pci.h"
-#include "hw/ide/ahci-pci.h"
 #include "hw/ide/ahci-sysbus.h"
 #include "ahci-internal.h"
 #include "ide-internal.h"
@@ -179,34 +175,6 @@ static uint32_t ahci_port_read(AHCIState *s, int port, int offset)
     return val;
 }
 
-static void ahci_irq_raise(AHCIState *s)
-{
-    DeviceState *dev_state = s->container;
-    PCIDevice *pci_dev = (PCIDevice *) object_dynamic_cast(OBJECT(dev_state),
-                                                           TYPE_PCI_DEVICE);
-
-    trace_ahci_irq_raise(s);
-
-    if (pci_dev && msi_enabled(pci_dev)) {
-        msi_notify(pci_dev, 0);
-    } else {
-        qemu_irq_raise(s->irq);
-    }
-}
-
-static void ahci_irq_lower(AHCIState *s)
-{
-    DeviceState *dev_state = s->container;
-    PCIDevice *pci_dev = (PCIDevice *) object_dynamic_cast(OBJECT(dev_state),
-                                                           TYPE_PCI_DEVICE);
-
-    trace_ahci_irq_lower(s);
-
-    if (!pci_dev || !msi_enabled(pci_dev)) {
-        qemu_irq_lower(s->irq);
-    }
-}
-
 static void ahci_check_irq(AHCIState *s)
 {
     int i;
@@ -222,9 +190,11 @@ static void ahci_check_irq(AHCIState *s)
     trace_ahci_check_irq(s, old_irq, s->control_regs.irqstatus);
     if (s->control_regs.irqstatus &&
         (s->control_regs.ghc & HOST_CTL_IRQ_EN)) {
-            ahci_irq_raise(s);
+        trace_ahci_irq_raise(s);
+        qemu_irq_raise(s->irq);
     } else {
-        ahci_irq_lower(s);
+        trace_ahci_irq_lower(s);
+        qemu_irq_lower(s->irq);
     }
 }
 
@@ -1608,7 +1578,6 @@ static const IDEDMAOps ahci_dma_ops = {
 
 void ahci_init(AHCIState *s, DeviceState *qdev)
 {
-    s->container = qdev;
     /* XXX BAR size should be 1k, but that breaks, so bump it to 4k for now */
     memory_region_init_io(&s->mem, OBJECT(qdev), &ahci_mem_ops, s,
                           "ahci", AHCI_MEM_BAR_SIZE);

diff --git a/hw/ide/ich.c b/hw/ide/ich.c
index b311450c12dc33ff31b8138c59365c204201cfa3..c99a44df8e1cea491e0e8c53d5a33c486d46e079 100644 (file)
--- a/hw/ide/ich.c
+++ b/hw/ide/ich.c
@@ -61,7 +61,6 @@
  */
 
 #include "qemu/osdep.h"
-#include "hw/irq.h"
 #include "hw/pci/msi.h"
 #include "hw/pci/pci.h"
 #include "migration/vmstate.h"
@@ -91,6 +90,19 @@ static const VMStateDescription vmstate_ich9_ahci = {
     },
 };
 
+static void pci_ich9_ahci_update_irq(void *opaque, int irq_num, int level)
+{
+    PCIDevice *pci_dev = opaque;
+
+    if (msi_enabled(pci_dev)) {
+        if (level) {
+            msi_notify(pci_dev, 0);
+        }
+    } else {
+        pci_set_irq(pci_dev, level);
+    }
+}
+
 static void pci_ich9_reset(DeviceState *dev)
 {
     AHCIPCIState *d = ICH9_AHCI(dev);
@@ -102,7 +114,9 @@ static void pci_ich9_ahci_init(Object *obj)
 {
     AHCIPCIState *d = ICH9_AHCI(obj);
 
+    qemu_init_irq(&d->irq, pci_ich9_ahci_update_irq, d, 0);
     ahci_init(&d->ahci, DEVICE(obj));
+    d->ahci.irq = &d->irq;
 }
 
 static void pci_ich9_ahci_realize(PCIDevice *dev, Error **errp)
@@ -125,8 +139,6 @@ static void pci_ich9_ahci_realize(PCIDevice *dev, Error **errp)
     /* XXX Software should program this register */
     dev->config[0x90]   = 1 << 6; /* Address Map Register - AHCI mode */
 
-    d->ahci.irq = pci_allocate_irq(dev);
-
     pci_register_bar(dev, ICH9_IDP_BAR, PCI_BASE_ADDRESS_SPACE_IO,
                      &d->ahci.idp);
     pci_register_bar(dev, ICH9_MEM_BAR, PCI_BASE_ADDRESS_SPACE_MEMORY,
@@ -161,7 +173,6 @@ static void pci_ich9_uninit(PCIDevice *dev)
 
     msi_uninit(dev);
     ahci_uninit(&d->ahci);
-    qemu_free_irq(d->ahci.irq);
 }
 
 static void ich_ahci_class_init(ObjectClass *klass, void *data)

diff --git a/include/hw/ide/ahci-pci.h b/include/hw/ide/ahci-pci.h
index c2ee6169625c86b79b3df21590aca89d54b56d1f..face1a9a4a47e6ea457d90a252f056d4db8491c7 100644 (file)
--- a/include/hw/ide/ahci-pci.h
+++ b/include/hw/ide/ahci-pci.h
@@ -9,6 +9,7 @@
 #include "qom/object.h"
 #include "hw/ide/ahci.h"
 #include "hw/pci/pci_device.h"
+#include "hw/irq.h"
 
 #define TYPE_ICH9_AHCI "ich9-ahci"
 OBJECT_DECLARE_SIMPLE_TYPE(AHCIPCIState, ICH9_AHCI)
@@ -17,6 +18,7 @@ struct AHCIPCIState {
     PCIDevice parent_obj;
 
     AHCIState ahci;
+    IRQState irq;
 };
 
 #endif

diff --git a/include/hw/ide/ahci.h b/include/hw/ide/ahci.h
index ba31e75ff9b2ebc8ec33fa33d9c2aeba1f1c38f6..ac0292c634f7b6a121b7334c9140e6d0a90bcbd0 100644 (file)
--- a/include/hw/ide/ahci.h
+++ b/include/hw/ide/ahci.h
@@ -37,8 +37,6 @@ typedef struct AHCIControlRegs {
 } AHCIControlRegs;
 
 typedef struct AHCIState {
-    DeviceState *container;
-
     AHCIDevice *dev;
     AHCIControlRegs control_regs;
     MemoryRegion mem;