[Qemu-devel] [PULL 3/3] xen_platform: SUSE xenlinux unplug for emulated PCI

[Stefano Stabellini <sstabellini@kernel.org>]

From: Olaf Hering <olaf@aepfle.de>

Implement SUSE specific unplug protocol for emulated PCI devices
in PVonHVM guests. Its a simple 'outl(1, (ioaddr + 4));'.
This protocol was implemented and used since Xen 3.0.4.
It is used in all SUSE/SLES/openSUSE releases up to SLES11SP3 and
openSUSE 12.3.
In addition old (pre-2011) VMDP versions are handled as well.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
---
 hw/i386/xen/xen_platform.c | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/hw/i386/xen/xen_platform.c b/hw/i386/xen/xen_platform.c
index 91d8a7a..2e1e543 100644
--- a/hw/i386/xen/xen_platform.c
+++ b/hw/i386/xen/xen_platform.c
@@ -311,13 +311,38 @@ static void xen_platform_ioport_writeb(void *opaque, hwaddr addr,
                                        uint64_t val, unsigned int size)
 {
     PCIXenPlatformState *s = opaque;
+    PCIDevice *pci_dev = PCI_DEVICE(s);
 
     switch (addr) {
     case 0: /* Platform flags */
         platform_fixed_ioport_writeb(opaque, 0, (uint32_t)val);
         break;
+    case 4:
+        if (val == 1) {
+            /*
+             * SUSE unplug for Xenlinux
+             * xen-kmp used this since xen-3.0.4, instead the official protocol
+             * from xen-3.3+ It did an unconditional "outl(1, (ioaddr + 4));"
+             * Pre VMDP 1.7 used 4 and 8 depending on how VMDP was configured.
+             * If VMDP was to control both disk and LAN it would use 4.
+             * If it controlled just disk or just LAN, it would use 8 below.
+             */
+            pci_unplug_disks(pci_dev->bus);
+            pci_unplug_nics(pci_dev->bus);
+        }
+        break;
     case 8:
-        log_writeb(s, (uint32_t)val);
+        switch (val) {
+        case 1:
+            pci_unplug_disks(pci_dev->bus);
+            break;
+        case 2:
+            pci_unplug_nics(pci_dev->bus);
+            break;
+        default:
+            log_writeb(s, (uint32_t)val);
+            break;
+        }
         break;
     default:
         break;
-- 
1.9.1