xhci PCIe endpoint migration compatibility fix

Add back the PCIe config capabilities on XHCI cards in non-PCIe slots,
but only for machine types before 2.1.

This fixes a migration incompatibility in the XHCI PCI devices
caused by:
   058fdcf52cdbf57b67e7 - xhci: add endpoint cap on express bus only

Note that in fixing it for compatibility with older QEMUs, it breaks
compatibility with existing QEMU 2.1's on older machine types.

The status before this patch was (if it used an XHCI adapter):
   machine type | source qemu
     any           pre-2.1     - FAIL
     any           2.1...      - PASS

With this patch:
   machine type | source qemu
     any           pre-2.1    - PASS
     pre-2.1       2.1...     - FAIL
     2.1           2.1...     - PASS

A test to trigger it is to add '-device nec-usb-xhci,id=xhci,addr=0x12'
to the command line.

Cc: qemu-stable@nongnu.org
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

diff --git a/hw/usb/hcd-xhci.c b/hw/usb/hcd-xhci.c
index bbe4c5fb85ba15c09481f8bffadaf31ee62f0cb3..73ced1f5f8309863f36857ba726dd506cc30d4d0 100644 (file)
--- a/hw/usb/hcd-xhci.c
+++ b/hw/usb/hcd-xhci.c
@@ -499,6 +499,7 @@ enum xhci_flags {
     XHCI_FLAG_USE_MSI = 1,
     XHCI_FLAG_USE_MSI_X,
     XHCI_FLAG_SS_FIRST,
+    XHCI_FLAG_FORCE_PCIE_ENDCAP,
 };
 
 static void xhci_kick_ep(XHCIState *xhci, unsigned int slotid,
@@ -3626,7 +3627,8 @@ static int usb_xhci_initfn(struct PCIDevice *dev)
                      PCI_BASE_ADDRESS_SPACE_MEMORY|PCI_BASE_ADDRESS_MEM_TYPE_64,
                      &xhci->mem);
 
-    if (pci_bus_is_express(dev->bus)) {
+    if (pci_bus_is_express(dev->bus) ||
+        xhci_get_flag(xhci, XHCI_FLAG_FORCE_PCIE_ENDCAP)) {
         ret = pcie_endpoint_cap_init(dev, 0xa0);
         assert(ret >= 0);
     }
@@ -3855,6 +3857,8 @@ static Property xhci_properties[] = {
     DEFINE_PROP_BIT("msix",     XHCIState, flags, XHCI_FLAG_USE_MSI_X, true),
     DEFINE_PROP_BIT("superspeed-ports-first",
                     XHCIState, flags, XHCI_FLAG_SS_FIRST, true),
+    DEFINE_PROP_BIT("force-pcie-endcap", XHCIState, flags,
+                    XHCI_FLAG_FORCE_PCIE_ENDCAP, false),
     DEFINE_PROP_UINT32("intrs", XHCIState, numintrs, MAXINTRS),
     DEFINE_PROP_UINT32("slots", XHCIState, numslots, MAXSLOTS),
     DEFINE_PROP_UINT32("p2",    XHCIState, numports_2, 4),

diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index a39cb42290ed803e2e8aaed8f92d67021ec3e908..77316d55c896e52ed4bcd038f926dd33fd715239 100644 (file)
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -329,6 +329,11 @@ bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *);
             .property = "superspeed-ports-first",\
             .value    = "off",\
         },\
+        {\
+            .driver   = "nec-usb-xhci",\
+            .property = "force-pcie-endcap",\
+            .value    = "on",\
+        },\
         {\
             .driver   = "pci-serial",\
             .property = "prog_if",\