xen: implement unplug protocol in xen_platform

The unplug protocol is necessary to support PV drivers in the guest: the
drivers expect to be able to "unplug" emulated disks and nics before
initializing the Xen PV interfaces.
It is responsibility of the guest to make sure that the unplug is done
before the emulated devices or the PV interface start to be used.

We use pci_for_each_device to walk the PCI bus, identify the devices and
disks that we want to disable and dynamically unplug them.

Changes in v2:

- use PCI_CLASS constants;

- replace pci_unplug_device with qdev_unplug;

- do not import hw/ide/internal.h in xen_platform.c;

Changes in v3:

- introduce piix3-ide-xen, that support hot-unplug;

- move the unplug code to hw/ide/piix.c;

- just call qdev_unplug from xen_platform.c to unplug the IDE disks;

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

diff --git a/hw/ide.h b/hw/ide.h
index 34d9394bcce3803398874f103c307920fa57848f..a490cbb6c5360262ce1dcbd8a08e890844994319 100644 (file)
--- a/hw/ide.h
+++ b/hw/ide.h
@@ -13,6 +13,7 @@ ISADevice *isa_ide_init(int iobase, int iobase2, int isairq,
 /* ide-pci.c */
 void pci_cmd646_ide_init(PCIBus *bus, DriveInfo **hd_table,
                          int secondary_ide_enabled);
+PCIDevice *pci_piix3_xen_ide_init(PCIBus *bus, DriveInfo **hd_table, int devfn);
 PCIDevice *pci_piix3_ide_init(PCIBus *bus, DriveInfo **hd_table, int devfn);
 PCIDevice *pci_piix4_ide_init(PCIBus *bus, DriveInfo **hd_table, int devfn);
 void vt82c686b_ide_init(PCIBus *bus, DriveInfo **hd_table, int devfn);

diff --git a/hw/ide/piix.c b/hw/ide/piix.c
index 84f72b0a66e5fccccfc4a9261220c376ac14c439..f527dbd57e0e424b5819aa3a69b380a7ab5639d1 100644 (file)
--- a/hw/ide/piix.c
+++ b/hw/ide/piix.c
@@ -149,6 +149,42 @@ static int pci_piix_ide_initfn(PCIDevice *dev)
     return 0;
 }
 
+static int pci_piix3_xen_ide_unplug(DeviceState *dev)
+{
+    PCIDevice *pci_dev;
+    PCIIDEState *pci_ide;
+    DriveInfo *di;
+    int i = 0;
+
+    pci_dev = DO_UPCAST(PCIDevice, qdev, dev);
+    pci_ide = DO_UPCAST(PCIIDEState, dev, pci_dev);
+
+    for (; i < 3; i++) {
+        di = drive_get_by_index(IF_IDE, i);
+        if (di != NULL && di->bdrv != NULL && !di->bdrv->removable) {
+            DeviceState *ds = bdrv_get_attached(di->bdrv);
+            if (ds) {
+                bdrv_detach(di->bdrv, ds);
+            }
+            bdrv_close(di->bdrv);
+            pci_ide->bus[di->bus].ifs[di->unit].bs = NULL;
+            drive_put_ref(di);
+        }
+    }
+    qdev_reset_all(&(pci_ide->dev.qdev));
+    return 0;
+}
+
+PCIDevice *pci_piix3_xen_ide_init(PCIBus *bus, DriveInfo **hd_table, int devfn)
+{
+    PCIDevice *dev;
+
+    dev = pci_create_simple(bus, devfn, "piix3-ide-xen");
+    dev->qdev.info->unplug = pci_piix3_xen_ide_unplug;
+    pci_ide_create_devs(dev, hd_table);
+    return dev;
+}
+
 /* hd_table must contain 4 block drivers */
 /* NOTE: for the PIIX3, the IRQs and IOports are hardcoded */
 PCIDevice *pci_piix3_ide_init(PCIBus *bus, DriveInfo **hd_table, int devfn)
@@ -181,6 +217,14 @@ static PCIDeviceInfo piix_ide_info[] = {
         .vendor_id    = PCI_VENDOR_ID_INTEL,
         .device_id    = PCI_DEVICE_ID_INTEL_82371SB_1,
         .class_id     = PCI_CLASS_STORAGE_IDE,
+    },{
+        .qdev.name    = "piix3-ide-xen",
+        .qdev.size    = sizeof(PCIIDEState),
+        .qdev.no_user = 1,
+        .init         = pci_piix_ide_initfn,
+        .vendor_id    = PCI_VENDOR_ID_INTEL,
+        .device_id    = PCI_DEVICE_ID_INTEL_82371SB_1,
+        .class_id     = PCI_CLASS_STORAGE_IDE,
     },{
         .qdev.name    = "piix4-ide",
         .qdev.size    = sizeof(PCIIDEState),

diff --git a/hw/pc_piix.c b/hw/pc_piix.c
index c5c16b45718ada66fabfc02298494fabc65c03bc..40b73ea25c2cfcb55183b2679a2e49b7cfe304f7 100644 (file)
--- a/hw/pc_piix.c
+++ b/hw/pc_piix.c
@@ -155,7 +155,11 @@ static void pc_init1(ram_addr_t ram_size,
     ide_drive_get(hd, MAX_IDE_BUS);
     if (pci_enabled) {
         PCIDevice *dev;
-        dev = pci_piix3_ide_init(pci_bus, hd, piix3_devfn + 1);
+        if (xen_enabled()) {
+            dev = pci_piix3_xen_ide_init(pci_bus, hd, piix3_devfn + 1);
+        } else {
+            dev = pci_piix3_ide_init(pci_bus, hd, piix3_devfn + 1);
+        }
         idebus[0] = qdev_get_child_bus(&dev->qdev, "ide.0");
         idebus[1] = qdev_get_child_bus(&dev->qdev, "ide.1");
     } else {

diff --git a/hw/xen_platform.c b/hw/xen_platform.c
index f43e175b4e2442cd7b5980641b1021007f2fc65a..fb6be6a464c6cb533251c5dfbe60ceec1e371e27 100644 (file)
--- a/hw/xen_platform.c
+++ b/hw/xen_platform.c
@@ -76,6 +76,35 @@ static void log_writeb(PCIXenPlatformState *s, char val)
 }
 
 /* Xen Platform, Fixed IOPort */
+#define UNPLUG_ALL_IDE_DISKS 1
+#define UNPLUG_ALL_NICS 2
+#define UNPLUG_AUX_IDE_DISKS 4
+
+static void unplug_nic(PCIBus *b, PCIDevice *d)
+{
+    if (pci_get_word(d->config + PCI_CLASS_DEVICE) ==
+            PCI_CLASS_NETWORK_ETHERNET) {
+        qdev_unplug(&(d->qdev));
+    }
+}
+
+static void pci_unplug_nics(PCIBus *bus)
+{
+    pci_for_each_device(bus, 0, unplug_nic);
+}
+
+static void unplug_disks(PCIBus *b, PCIDevice *d)
+{
+    if (pci_get_word(d->config + PCI_CLASS_DEVICE) ==
+            PCI_CLASS_STORAGE_IDE) {
+        qdev_unplug(&(d->qdev));
+    }
+}
+
+static void pci_unplug_disks(PCIBus *bus)
+{
+    pci_for_each_device(bus, 0, unplug_disks);
+}
 
 static void platform_fixed_ioport_writew(void *opaque, uint32_t addr, uint32_t val)
 {
@@ -83,10 +112,22 @@ static void platform_fixed_ioport_writew(void *opaque, uint32_t addr, uint32_t v
 
     switch (addr - XEN_PLATFORM_IOPORT) {
     case 0:
-        /* TODO: */
         /* Unplug devices.  Value is a bitmask of which devices to
            unplug, with bit 0 the IDE devices, bit 1 the network
            devices, and bit 2 the non-primary-master IDE devices. */
+        if (val & UNPLUG_ALL_IDE_DISKS) {
+            DPRINTF("unplug disks\n");
+            qemu_aio_flush();
+            bdrv_flush_all();
+            pci_unplug_disks(s->pci_dev.bus);
+        }
+        if (val & UNPLUG_ALL_NICS) {
+            DPRINTF("unplug nics\n");
+            pci_unplug_nics(s->pci_dev.bus);
+        }
+        if (val & UNPLUG_AUX_IDE_DISKS) {
+            DPRINTF("unplug auxiliary disks not supported\n");
+        }
         break;
     case 2:
         switch (val) {