On May 12, 21, Greg Kroah-Hartman wrote: > On Tue, May 11, 2021 at 06:18:21PM -0600, Connor Davis wrote: > > When running as a dom0 guest on Xen, check if the USB3 debug > > capability is enabled before xHCI reset, suspend, and resume. If it > > is, call xen_dbgp_reset_prep() to notify Xen that it is unsafe to touch > > MMIO registers until the next xen_dbgp_external_startup(). > > > > This notification allows Xen to avoid undefined behavior resulting > > from MMIO access when the host controller's CNR bit is set or when > > the device transitions to D3hot. > > > > Signed-off-by: Connor Davis <connojdavis@xxxxxxxxx> > > --- > > drivers/usb/host/xhci-dbgcap.h | 6 ++++ > > drivers/usb/host/xhci.c | 57 ++++++++++++++++++++++++++++++++++ > > drivers/usb/host/xhci.h | 1 + > > 3 files changed, 64 insertions(+) > > > > diff --git a/drivers/usb/host/xhci-dbgcap.h b/drivers/usb/host/xhci-dbgcap.h > > index c70b78d504eb..24784b82a840 100644 > > --- a/drivers/usb/host/xhci-dbgcap.h > > +++ b/drivers/usb/host/xhci-dbgcap.h > > @@ -227,4 +227,10 @@ static inline int xhci_dbc_resume(struct xhci_hcd *xhci) > > return 0; > > } > > #endif /* CONFIG_USB_XHCI_DBGCAP */ > > + > > +#ifdef CONFIG_XEN_DOM0 > > +int xen_dbgp_reset_prep(struct usb_hcd *hcd); > > +int xen_dbgp_external_startup(struct usb_hcd *hcd); > > +#endif /* CONFIG_XEN_DOM0 */ > > + > > #endif /* __LINUX_XHCI_DBGCAP_H */ > > diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c > > index ca9385d22f68..afe44169183f 100644 > > --- a/drivers/usb/host/xhci.c > > +++ b/drivers/usb/host/xhci.c > > @@ -37,6 +37,57 @@ static unsigned long long quirks; > > module_param(quirks, ullong, S_IRUGO); > > MODULE_PARM_DESC(quirks, "Bit flags for quirks to be enabled as default"); > > > > +#ifdef CONFIG_XEN_DOM0 > > +#include <xen/xen.h> > > <snip> > > Can't this #ifdef stuff go into a .h file? > Yep, will clean that up in v2. > thanks, > > greg k-h Thanks, Connor
