Patchwork [2/2] acpi_piix4: expose no_hotplug attribute via i/o port

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Submitter Marcelo Tosatti
Date Jan. 10, 2011, 6:55 p.m.
Message ID <20110110185906.946280027@redhat.com>
Download mbox | patch
Permalink /patch/78194/
State New
Headers show

Comments

Marcelo Tosatti - Jan. 10, 2011, 6:55 p.m.
Expose no_hotplug attribute via I/O port, so ACPI BIOS can indicate
removability status to guest OS.

An updated seabios is required to make use of this feature (seabios.git
commit ID 3c241edf3d7ef29c21).

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Tested-by: Gleb Natapov <gleb@redhat.com>
Michael S. Tsirkin - Jan. 10, 2011, 9:25 p.m.
On Mon, Jan 10, 2011 at 04:55:03PM -0200, Marcelo Tosatti wrote:
> Expose no_hotplug attribute via I/O port, so ACPI BIOS can indicate
> removability status to guest OS.
> 
> An updated seabios is required to make use of this feature (seabios.git
> commit ID 3c241edf3d7ef29c21).
> 
> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
> Tested-by: Gleb Natapov <gleb@redhat.com>
> 
> Index: qemu/hw/acpi_piix4.c
> ===================================================================
> --- qemu.orig/hw/acpi_piix4.c
> +++ qemu/hw/acpi_piix4.c
> @@ -37,6 +37,7 @@
>  #define GPE_BASE 0xafe0
>  #define PCI_BASE 0xae00
>  #define PCI_EJ_BASE 0xae08
> +#define PCI_RMV_BASE 0xae0c
>  
>  #define PIIX4_PCI_HOTPLUG_STATUS 2
>  
> @@ -73,6 +74,7 @@ typedef struct PIIX4PMState {
>      /* for pci hotplug */
>      struct gpe_regs gpe;
>      struct pci_status pci0_status;
> +    uint32_t pci0_hotplug_enable;
>  } PIIX4PMState;
>  
>  static void piix4_acpi_system_hot_add_init(PCIBus *bus, PIIX4PMState *s);
> @@ -322,6 +324,25 @@ static const VMStateDescription vmstate_
>      }
>  };
>  
> +static void piix4_update_hotplug(PIIX4PMState *s)
> +{
> +    PCIDevice *dev = &s->dev;
> +    BusState *bus = qdev_get_parent_bus(&dev->qdev);
> +    DeviceState *qdev, *next;
> +
> +    s->pci0_hotplug_enable = 0;
> +
> +    QLIST_FOREACH_SAFE(qdev, &bus->children, sibling, next) {
> +        PCIDeviceInfo *info = container_of(qdev->info, PCIDeviceInfo, qdev);
> +        PCIDevice *pdev = DO_UPCAST(PCIDevice, qdev, qdev);
> +        int slot = PCI_SLOT(pdev->devfn);
> +
> +        if (!info->no_hotplug) {
> +            s->pci0_hotplug_enable |= (1 << slot);
> +        }
> +    }
> +}
> +

So a slot starts as non-removable and becomes removable when you add a
hotpluggable device?  Isn't this a bit strange?
I would say all slots should be removable unless there's a
non hotpluggable device there ...

>  static void piix4_reset(void *opaque)
>  {
>      PIIX4PMState *s = opaque;
> @@ -336,6 +357,7 @@ static void piix4_reset(void *opaque)
>          /* Mark SMM as already inited (until KVM supports SMM). */
>          pci_conf[0x5B] = 0x02;
>      }
> +    piix4_update_hotplug(s);
>  }
>  
>  static void piix4_powerdown(void *opaque, int irq, int power_failing)
> @@ -576,6 +598,18 @@ static void pciej_write(void *opaque, ui
>      PIIX4_DPRINTF("pciej write %x <== %d\n", addr, val);
>  }
>  
> +static uint32_t pcirmv_read(void *opaque, uint32_t addr)
> +{
> +    PIIX4PMState *s = opaque;
> +
> +    return s->pci0_hotplug_enable;
> +}
> +
> +static void pcirmv_write(void *opaque, uint32_t addr, uint32_t val)
> +{
> +    return;
> +}
> +
>  static int piix4_device_hotplug(DeviceState *qdev, PCIDevice *dev,
>                                  PCIHotplugState state);
>  
> @@ -592,6 +626,9 @@ static void piix4_acpi_system_hot_add_in
>      register_ioport_write(PCI_EJ_BASE, 4, 4, pciej_write, bus);
>      register_ioport_read(PCI_EJ_BASE, 4, 4,  pciej_read, bus);
>  
> +    register_ioport_write(PCI_RMV_BASE, 4, 4, pcirmv_write, s);
> +    register_ioport_read(PCI_RMV_BASE, 4, 4,  pcirmv_read, s);
> +
>      pci_bus_hotplug(bus, piix4_device_hotplug, &s->dev.qdev);
>  }
>  
>
Marcelo Tosatti - Jan. 11, 2011, 4:20 p.m.
Indicate PCI removability through ACPI _RMV method, so that Windows
guests does not expose non-hotpluggable PCI devices as "hot removable".

v2:
- Mark slots with no present devices as hotpluggable.
Marcelo Tosatti - Jan. 11, 2011, 4:25 p.m.
On Mon, Jan 10, 2011 at 11:25:48PM +0200, Michael S. Tsirkin wrote:
> On Mon, Jan 10, 2011 at 04:55:03PM -0200, Marcelo Tosatti wrote:
> > Expose no_hotplug attribute via I/O port, so ACPI BIOS can indicate
> > removability status to guest OS.
> > 
> > An updated seabios is required to make use of this feature (seabios.git
> > commit ID 3c241edf3d7ef29c21).
> > 
> > Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
> > Tested-by: Gleb Natapov <gleb@redhat.com>
> > 
> > Index: qemu/hw/acpi_piix4.c
> > ===================================================================
> > --- qemu.orig/hw/acpi_piix4.c
> > +++ qemu/hw/acpi_piix4.c
> > @@ -37,6 +37,7 @@
> >  #define GPE_BASE 0xafe0
> >  #define PCI_BASE 0xae00
> >  #define PCI_EJ_BASE 0xae08
> > +#define PCI_RMV_BASE 0xae0c
> >  
> >  #define PIIX4_PCI_HOTPLUG_STATUS 2
> >  
> > @@ -73,6 +74,7 @@ typedef struct PIIX4PMState {
> >      /* for pci hotplug */
> >      struct gpe_regs gpe;
> >      struct pci_status pci0_status;
> > +    uint32_t pci0_hotplug_enable;
> >  } PIIX4PMState;
> >  
> >  static void piix4_acpi_system_hot_add_init(PCIBus *bus, PIIX4PMState *s);
> > @@ -322,6 +324,25 @@ static const VMStateDescription vmstate_
> >      }
> >  };
> >  
> > +static void piix4_update_hotplug(PIIX4PMState *s)
> > +{
> > +    PCIDevice *dev = &s->dev;
> > +    BusState *bus = qdev_get_parent_bus(&dev->qdev);
> > +    DeviceState *qdev, *next;
> > +
> > +    s->pci0_hotplug_enable = 0;
> > +
> > +    QLIST_FOREACH_SAFE(qdev, &bus->children, sibling, next) {
> > +        PCIDeviceInfo *info = container_of(qdev->info, PCIDeviceInfo, qdev);
> > +        PCIDevice *pdev = DO_UPCAST(PCIDevice, qdev, qdev);
> > +        int slot = PCI_SLOT(pdev->devfn);
> > +
> > +        if (!info->no_hotplug) {
> > +            s->pci0_hotplug_enable |= (1 << slot);
> > +        }
> > +    }
> > +}
> > +
> 
> So a slot starts as non-removable and becomes removable when you add a
> hotpluggable device?  Isn't this a bit strange?
> I would say all slots should be removable unless there's a
> non hotpluggable device there ...

Ugh, thats right, thanks.

Patch

Index: qemu/hw/acpi_piix4.c
===================================================================
--- qemu.orig/hw/acpi_piix4.c
+++ qemu/hw/acpi_piix4.c
@@ -37,6 +37,7 @@ 
 #define GPE_BASE 0xafe0
 #define PCI_BASE 0xae00
 #define PCI_EJ_BASE 0xae08
+#define PCI_RMV_BASE 0xae0c
 
 #define PIIX4_PCI_HOTPLUG_STATUS 2
 
@@ -73,6 +74,7 @@  typedef struct PIIX4PMState {
     /* for pci hotplug */
     struct gpe_regs gpe;
     struct pci_status pci0_status;
+    uint32_t pci0_hotplug_enable;
 } PIIX4PMState;
 
 static void piix4_acpi_system_hot_add_init(PCIBus *bus, PIIX4PMState *s);
@@ -322,6 +324,25 @@  static const VMStateDescription vmstate_
     }
 };
 
+static void piix4_update_hotplug(PIIX4PMState *s)
+{
+    PCIDevice *dev = &s->dev;
+    BusState *bus = qdev_get_parent_bus(&dev->qdev);
+    DeviceState *qdev, *next;
+
+    s->pci0_hotplug_enable = 0;
+
+    QLIST_FOREACH_SAFE(qdev, &bus->children, sibling, next) {
+        PCIDeviceInfo *info = container_of(qdev->info, PCIDeviceInfo, qdev);
+        PCIDevice *pdev = DO_UPCAST(PCIDevice, qdev, qdev);
+        int slot = PCI_SLOT(pdev->devfn);
+
+        if (!info->no_hotplug) {
+            s->pci0_hotplug_enable |= (1 << slot);
+        }
+    }
+}
+
 static void piix4_reset(void *opaque)
 {
     PIIX4PMState *s = opaque;
@@ -336,6 +357,7 @@  static void piix4_reset(void *opaque)
         /* Mark SMM as already inited (until KVM supports SMM). */
         pci_conf[0x5B] = 0x02;
     }
+    piix4_update_hotplug(s);
 }
 
 static void piix4_powerdown(void *opaque, int irq, int power_failing)
@@ -576,6 +598,18 @@  static void pciej_write(void *opaque, ui
     PIIX4_DPRINTF("pciej write %x <== %d\n", addr, val);
 }
 
+static uint32_t pcirmv_read(void *opaque, uint32_t addr)
+{
+    PIIX4PMState *s = opaque;
+
+    return s->pci0_hotplug_enable;
+}
+
+static void pcirmv_write(void *opaque, uint32_t addr, uint32_t val)
+{
+    return;
+}
+
 static int piix4_device_hotplug(DeviceState *qdev, PCIDevice *dev,
                                 PCIHotplugState state);
 
@@ -592,6 +626,9 @@  static void piix4_acpi_system_hot_add_in
     register_ioport_write(PCI_EJ_BASE, 4, 4, pciej_write, bus);
     register_ioport_read(PCI_EJ_BASE, 4, 4,  pciej_read, bus);
 
+    register_ioport_write(PCI_RMV_BASE, 4, 4, pcirmv_write, s);
+    register_ioport_read(PCI_RMV_BASE, 4, 4,  pcirmv_read, s);
+
     pci_bus_hotplug(bus, piix4_device_hotplug, &s->dev.qdev);
 }