diff mbox series

[v3,3/6] hw/usb/hcd-xhci-pci: Use event ring 0 if mapping unsupported

Message ID 20241227121336.25838-4-phil@philjordan.eu (mailing list archive)
State New
Headers show
Series hw/usb/hcd-xhci: Fixes, improvements, and macOS workaround | expand

Commit Message

Phil Dennis-Jordan Dec. 27, 2024, 12:13 p.m. UTC 
The XHCI specification, section 4.17.1 specifies that "If the
Number of Interrupters (MaxIntrs) field is greater than 1, then
Interrupter Mapping shall be supported." and "If Interrupter
Mapping is not supported, the Interrupter Target field shall be
ignored by the xHC and all Events targeted at Interrupter 0."

QEMU's XHCI device has so far not specially addressed this case,
so we add a check to xhci_event() to redirect to event ring and
interrupt 0 if mapping is disabled.

Signed-off-by: Phil Dennis-Jordan <phil@philjordan.eu>
---
 hw/usb/hcd-xhci.c | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox series

Patch

diff --git a/hw/usb/hcd-xhci.c b/hw/usb/hcd-xhci.c
index 3719c0f190..011c445443 100644
--- a/hw/usb/hcd-xhci.c
+++ b/hw/usb/hcd-xhci.c
@@ -644,6 +644,10 @@  static void xhci_event(XHCIState *xhci, XHCIEvent *event, int v)
     dma_addr_t erdp;
     unsigned int dp_idx;
 
+    if (xhci->numintrs == 1) {
+        v = 0;
+    }
+
     if (v >= xhci->numintrs) {
         DPRINTF("intr nr out of range (%d >= %d)\n", v, xhci->numintrs);
         return;