Re: [PATCH v2 2/2] drivers/char: Use sub-page ro API to make just xhci dbc cap RO

2023-07-05 Thread Jan Beulich
On 01.07.2023 00:38, Marek Marczykowski-Górecki wrote: > On Tue, May 30, 2023 at 02:04:26PM +0200, Jan Beulich wrote: >> On 05.05.2023 23:25, Marek Marczykowski-Górecki wrote: >>> --- a/xen/drivers/char/xhci-dbc.c >>> +++ b/xen/drivers/char/xhci-dbc.c >>> @@ -1221,14 +1221,12 @@ static void __init

Re: [PATCH v2 2/2] drivers/char: Use sub-page ro API to make just xhci dbc cap RO

2023-06-30 Thread Marek Marczykowski-Górecki
On Tue, May 30, 2023 at 02:04:26PM +0200, Jan Beulich wrote: > On 05.05.2023 23:25, Marek Marczykowski-Górecki wrote: > > Not the whole page, which may contain other registers too. In fact > > on Tiger Lake and newer (at least), this page do contain other registers > > that Linux tries to use. >

Re: [PATCH v2 2/2] drivers/char: Use sub-page ro API to make just xhci dbc cap RO

2023-05-30 Thread Jan Beulich
On 05.05.2023 23:25, Marek Marczykowski-Górecki wrote: > Not the whole page, which may contain other registers too. In fact > on Tiger Lake and newer (at least), this page do contain other registers > that Linux tries to use. Please can you clarify whether this is with spec or an erratum? I ask

[PATCH v2 2/2] drivers/char: Use sub-page ro API to make just xhci dbc cap RO

2023-05-05 Thread Marek Marczykowski-Górecki
Not the whole page, which may contain other registers too. In fact on Tiger Lake and newer (at least), this page do contain other registers that Linux tries to use. And with share=yes, a domU would use them too. Without this patch, PV dom0 would fail to initialize the controller, while HVM would