[PATCH v3 21/28] xen-platform: unplug AHCI disks

David Woodhouse
2023-10-25T14:51:24Z

From: David Woodhouse <dwmw@amazon.co.uk>

To support Xen guests using the Q35 chipset, the unplug protocol needs
to also remove AHCI disks.

Make pci_xen_ide_unplug() more generic, iterating over the children
of the PCI device and destroying the "ide-hd" devices. That works the
same for both AHCI and IDE, as does the detection of the primary disk
as unit 0 on the bus named "ide.0".

Then pci_xen_ide_unplug() can be used for both AHCI and IDE devices.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
---
hw/i386/xen/xen_platform.c | 68 +++++++++++++++++++++++++-------------
1 file changed, 45 insertions(+), 23 deletions(-)

diff --git a/hw/i386/xen/xen_platform.c b/hw/i386/xen/xen_platform.c
index e2dd1b536a..ef7d3fc05f 100644
--- a/hw/i386/xen/xen_platform.c
+++ b/hw/i386/xen/xen_platform.c
@@ -169,39 +169,60 @@ static void pci_unplug_nics(PCIBus *bus)
*
* [1] https://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=docs/misc/hvm-emulated-unplug.pandoc
*/
-static void pci_xen_ide_unplug(PCIDevice *d, bool aux)
+struct ide_unplug_state {
+ bool aux;
+ int nr_unplugged;
+};
+
+static int ide_dev_unplug(DeviceState *dev, void *_st)
{
- DeviceState *dev = DEVICE(d);
- PCIIDEState *pci_ide;
- int i;
+ struct ide_unplug_state *st = _st;
IDEDevice *idedev;
IDEBus *idebus;
BlockBackend *blk;
+ int unit;
+
+ idedev = IDE_DEVICE(object_dynamic_cast(OBJECT(dev), "ide-hd"));
+ if (!idedev) {
+ return 0;
+ }

- pci_ide = PCI_IDE(dev);
+ idebus = IDE_BUS(qdev_get_parent_bus(dev));

- for (i = aux ? 1 : 0; i < 4; i++) {
- idebus = &pci_ide->bus[i / 2];
- blk = idebus->ifs[i % 2].blk;
+ unit = (idedev == idebus->slave);
+ assert(unit || idedev == idebus->master);

- if (blk && idebus->ifs[i % 2].drive_kind != IDE_CD) {
- if (!(i % 2)) {
- idedev = idebus->master;
- } else {
- idedev = idebus->slave;
- }
+ if (st->aux && !unit && !strcmp(BUS(idebus)->name, "ide.0")) {
+ return 0;
+ }

- blk_drain(blk);
- blk_flush(blk);
+ blk = idebus->ifs[unit].blk;
+ if (blk) {
+ blk_drain(blk);
+ blk_flush(blk);

- blk_detach_dev(blk, DEVICE(idedev));
- idebus->ifs[i % 2].blk = NULL;
- idedev->conf.blk = NULL;
- monitor_remove_blk(blk);
- blk_unref(blk);
- }
+ blk_detach_dev(blk, DEVICE(idedev));
+ idebus->ifs[unit].blk = NULL;
+ idedev->conf.blk = NULL;
+ monitor_remove_blk(blk);
+ blk_unref(blk);
+ }
+
+ object_unparent(OBJECT(dev));
+ st->nr_unplugged++;
+
+ return 0;
+}
+
+static void pci_xen_ide_unplug(PCIDevice *d, bool aux)
+{
+ struct ide_unplug_state st = { aux, 0 };
+ DeviceState *dev = DEVICE(d);
+
+ qdev_walk_children(dev, NULL, NULL, ide_dev_unplug, NULL, &st);
+ if (st.nr_unplugged) {
+ pci_device_reset(d);
}
- pci_device_reset(d);
}

static void unplug_disks(PCIBus *b, PCIDevice *d, void *opaque)
@@ -216,6 +237,7 @@ static void unplug_disks(PCIBus *b, PCIDevice *d, void *opaque)

switch (pci_get_word(d->config + PCI_CLASS_DEVICE)) {
case PCI_CLASS_STORAGE_IDE:
+ case PCI_CLASS_STORAGE_SATA:
pci_xen_ide_unplug(d, aux);
break;

--
2.40.1