Re: [XEN v1] xen/arm: io: Check ESR_EL2.ISV != 0 before searching for a MMIO handler

2022-01-31 Thread Ayan Kumar Halder
Hi Stefano/Julien, On 29/01/2022 17:40, Julien Grall wrote: Hi Stefano, On 28/01/2022 20:23, Stefano Stabellini wrote: On Fri, 28 Jan 2022, Julien Grall wrote: On 28/01/2022 01:20, Stefano Stabellini wrote: On Thu, 27 Jan 2022, Julien Grall wrote: On Thu, 27 Jan 2022 at 23:05, Julien Grall

Re: [XEN v1] xen/arm: io: Check ESR_EL2.ISV != 0 before searching for a MMIO handler

2022-01-29 Thread Julien Grall
Hi Stefano, On 28/01/2022 20:23, Stefano Stabellini wrote: On Fri, 28 Jan 2022, Julien Grall wrote: On 28/01/2022 01:20, Stefano Stabellini wrote: On Thu, 27 Jan 2022, Julien Grall wrote: On Thu, 27 Jan 2022 at 23:05, Julien Grall wrote: On Thu, 27 Jan 2022 at 22:40, Stefano Stabellini

Re: [XEN v1] xen/arm: io: Check ESR_EL2.ISV != 0 before searching for a MMIO handler

2022-01-29 Thread Julien Grall
Hi, Replying to Ayan's e-mail at the same time. On 28/01/2022 20:30, Stefano Stabellini wrote: On Fri, 28 Jan 2022, Ayan Kumar Halder wrote: Hi Julien/Stefano, Good discussion to learn about Xen (from a newbie's perspective). :) I am trying to clarify my understanding. Some queries as below

Re: [XEN v1] xen/arm: io: Check ESR_EL2.ISV != 0 before searching for a MMIO handler

2022-01-28 Thread Stefano Stabellini
On Fri, 28 Jan 2022, Ayan Kumar Halder wrote: > Hi Julien/Stefano, > > Good discussion to learn about Xen (from a newbie's perspective). :) > > I am trying to clarify my understanding. Some queries as below :- > > On 28/01/2022 09:46, Julien Grall wrote: > > > > > > On 28/01/2022 01:20,

Re: [XEN v1] xen/arm: io: Check ESR_EL2.ISV != 0 before searching for a MMIO handler

2022-01-28 Thread Stefano Stabellini
On Fri, 28 Jan 2022, Julien Grall wrote: > On 28/01/2022 01:20, Stefano Stabellini wrote: > > On Thu, 27 Jan 2022, Julien Grall wrote: > > > On Thu, 27 Jan 2022 at 23:05, Julien Grall > > > wrote: > > > > > > > > On Thu, 27 Jan 2022 at 22:40, Stefano Stabellini > > > > wrote: > > > > > I am

Re: [XEN v1] xen/arm: io: Check ESR_EL2.ISV != 0 before searching for a MMIO handler

2022-01-28 Thread Ayan Kumar Halder
Hi Julien/Stefano, Good discussion to learn about Xen (from a newbie's perspective). :) I am trying to clarify my understanding. Some queries as below :- On 28/01/2022 09:46, Julien Grall wrote: On 28/01/2022 01:20, Stefano Stabellini wrote: On Thu, 27 Jan 2022, Julien Grall wrote: On Thu,

Re: [XEN v1] xen/arm: io: Check ESR_EL2.ISV != 0 before searching for a MMIO handler

2022-01-28 Thread Julien Grall
On 28/01/2022 01:20, Stefano Stabellini wrote: On Thu, 27 Jan 2022, Julien Grall wrote: On Thu, 27 Jan 2022 at 23:05, Julien Grall wrote: On Thu, 27 Jan 2022 at 22:40, Stefano Stabellini wrote: I am with you on both points. One thing I noticed is that the code today is not able to deal

Re: [XEN v1] xen/arm: io: Check ESR_EL2.ISV != 0 before searching for a MMIO handler

2022-01-27 Thread Stefano Stabellini
On Thu, 27 Jan 2022, Julien Grall wrote: > On Thu, 27 Jan 2022 at 23:05, Julien Grall wrote: > > > > On Thu, 27 Jan 2022 at 22:40, Stefano Stabellini > > wrote: > > > I am with you on both points. > > > > > > One thing I noticed is that the code today is not able to deal with > > > IO_UNHANDLED

Re: [XEN v1] xen/arm: io: Check ESR_EL2.ISV != 0 before searching for a MMIO handler

2022-01-27 Thread Julien Grall
On Thu, 27 Jan 2022 at 23:05, Julien Grall wrote: > > On Thu, 27 Jan 2022 at 22:40, Stefano Stabellini > wrote: > > I am with you on both points. > > > > One thing I noticed is that the code today is not able to deal with > > IO_UNHANDLED for MMIO regions handled by IOREQ servers or Xen MMIO >

Re: [XEN v1] xen/arm: io: Check ESR_EL2.ISV != 0 before searching for a MMIO handler

2022-01-27 Thread Julien Grall
On Thu, 27 Jan 2022 at 22:40, Stefano Stabellini wrote: > I am with you on both points. > > One thing I noticed is that the code today is not able to deal with > IO_UNHANDLED for MMIO regions handled by IOREQ servers or Xen MMIO > emulator handlers. p2m_resolve_translation_fault and try_map_mmio

Re: [XEN v1] xen/arm: io: Check ESR_EL2.ISV != 0 before searching for a MMIO handler

2022-01-27 Thread Stefano Stabellini
On Thu, 27 Jan 2022, Julien Grall wrote: > On 27/01/2022 15:48, Ayan Kumar Halder wrote: > > On 27/01/2022 13:57, Julien Grall wrote: > > > > > > > > > On 27/01/2022 13:20, Ayan Kumar Halder wrote: > > > > Hi, > > > > > > > > Asking here as well (might not have been clear on irc). > > > > > >

Re: [XEN v1] xen/arm: io: Check ESR_EL2.ISV != 0 before searching for a MMIO handler

2022-01-27 Thread Julien Grall
On 27/01/2022 15:48, Ayan Kumar Halder wrote: Hi Julien, Hi, On 27/01/2022 13:57, Julien Grall wrote: On 27/01/2022 13:20, Ayan Kumar Halder wrote: Hi, Asking here as well (might not have been clear on irc). On 27/01/2022 00:10, Julien Grall wrote: Hi, On Wed, 26 Jan 2022, 17:56 Ayan

Re: [XEN v1] xen/arm: io: Check ESR_EL2.ISV != 0 before searching for a MMIO handler

2022-01-27 Thread Ayan Kumar Halder
Hi Julien, Thanks a lot for your clarification. Appreciate your help. I have a concern as below:- On 27/01/2022 13:57, Julien Grall wrote: On 27/01/2022 13:20, Ayan Kumar Halder wrote: Hi, Asking here as well (might not have been clear on irc). On 27/01/2022 00:10, Julien Grall wrote:

Re: [XEN v1] xen/arm: io: Check ESR_EL2.ISV != 0 before searching for a MMIO handler

2022-01-27 Thread Julien Grall
On 27/01/2022 13:20, Ayan Kumar Halder wrote: Hi, Asking here as well (might not have been clear on irc). On 27/01/2022 00:10, Julien Grall wrote: Hi, On Wed, 26 Jan 2022, 17:56 Ayan Kumar Halder, wrote:     Hi Julien,     On 26/01/2022 17:22, Julien Grall wrote:     Hi,     On

Re: [XEN v1] xen/arm: io: Check ESR_EL2.ISV != 0 before searching for a MMIO handler

2022-01-27 Thread Ayan Kumar Halder
Hi, Asking here as well (might not have been clear on irc). On 27/01/2022 00:10, Julien Grall wrote: Hi, On Wed, 26 Jan 2022, 17:56 Ayan Kumar Halder, wrote: Hi Julien, On 26/01/2022 17:22, Julien Grall wrote: Hi, On Wed, 26 Jan 2022, 16:58 Ayan Kumar Halder,

Re: [XEN v1] xen/arm: io: Check ESR_EL2.ISV != 0 before searching for a MMIO handler

2022-01-26 Thread Julien Grall
Hi, On Wed, 26 Jan 2022, 17:56 Ayan Kumar Halder, wrote: > Hi Julien, > On 26/01/2022 17:22, Julien Grall wrote: > > Hi, > > On Wed, 26 Jan 2022, 16:58 Ayan Kumar Halder, < > ayan.kumar.hal...@xilinx.com> wrote: > >> Refer to Armv8 ARM DDI 0487G.b, Page D13-3219 "ISS encoding for an >>

Re: [XEN v1] xen/arm: io: Check ESR_EL2.ISV != 0 before searching for a MMIO handler

2022-01-26 Thread Ayan Kumar Halder
Hi Julien, On 26/01/2022 17:22, Julien Grall wrote: Hi, On Wed, 26 Jan 2022, 16:58 Ayan Kumar Halder, wrote: Refer to Armv8 ARM DDI 0487G.b, Page D13-3219 "ISS encoding for an exception from a Data Abort" :- ISV - ISS[23:14] holds a valid instruction syndrome When the

Re: [XEN v1] xen/arm: io: Check ESR_EL2.ISV != 0 before searching for a MMIO handler

2022-01-26 Thread Julien Grall
Hi, On Wed, 26 Jan 2022, 16:58 Ayan Kumar Halder, wrote: > Refer to Armv8 ARM DDI 0487G.b, Page D13-3219 "ISS encoding for an > exception > from a Data Abort" :- > ISV - ISS[23:14] holds a valid instruction syndrome > > When the ISV is 0, the instruction could not be decoded by the hardware >

[XEN v1] xen/arm: io: Check ESR_EL2.ISV != 0 before searching for a MMIO handler

2022-01-26 Thread Ayan Kumar Halder
Refer to Armv8 ARM DDI 0487G.b, Page D13-3219 "ISS encoding for an exception from a Data Abort" :- ISV - ISS[23:14] holds a valid instruction syndrome When the ISV is 0, the instruction could not be decoded by the hardware (ie ISS is invalid). One should immediately return an error to the caller