Hi Ayan, > On 28 Feb 2025, at 12:51, Ayan Kumar Halder <ayank...@amd.com> wrote: > > > On 28/02/2025 08:56, Julien Grall wrote: >> Hi, > Hi Julien/Bertrand, >> >> On 27/02/2025 15:09, Ayan Kumar Halder wrote: >>> In the current patch, we have defined the requirements which are common for >>> all the commands. >>> >>> Signed-off-by: Ayan Kumar Halder <ayan.kumar.hal...@amd.com> >>> --- >>> Changes from - >>> >>> v1 - 1. Fixed `XenProd~version_hyp_ret_val~1` requirement as Xen does not >>> return >>> 0 for success in all the cases. >>> 2. Reworded the requirements so as to write them from Xen's perspective (not >>> domain's perspective). >>> >>> .../fusa/reqs/design-reqs/arm64/hypercall.rst | 55 +++++++++++++++++ >>> docs/fusa/reqs/index.rst | 2 + >>> docs/fusa/reqs/market-reqs/reqs.rst | 16 +++++ >>> .../reqs/product-reqs/version_hypercall.rst | 61 +++++++++++++++++++ >>> 4 files changed, 134 insertions(+) >>> create mode 100644 docs/fusa/reqs/design-reqs/arm64/hypercall.rst >>> create mode 100644 docs/fusa/reqs/product-reqs/version_hypercall.rst >>> >>> diff --git a/docs/fusa/reqs/design-reqs/arm64/hypercall.rst >>> b/docs/fusa/reqs/design-reqs/arm64/hypercall.rst >>> new file mode 100644 >>> index 0000000000..ffd883260c >>> --- /dev/null >>> +++ b/docs/fusa/reqs/design-reqs/arm64/hypercall.rst >>> @@ -0,0 +1,55 @@ >>> +.. SPDX-License-Identifier: CC-BY-4.0 >>> + >>> +Hypercall >>> +========= >>> + >>> +Instruction >>> +----------- >>> + >>> +`XenSwdgn~arm64_hyp_instr~1` >>> + >>> +Description: >>> +Xen shall treat domain hypercall exception as hypercall requests. >>> + >>> +Rationale: >>> + >>> +Comments: >>> +Hypercall is one of the communication mechanism between Xen and domains. >>> +Domains use hypercalls for various requests to Xen. >>> +Domains use 'hvc' instruction to invoke hypercalls. >> >> Are you trying to describe any hypercalls (e.g. SMCCC, Xen...) or just the >> Xen one? If the latter, only "hvc #0xEA1" will be used for Xen hypercalls. >> Other immediate/space will be used for something different (i.e. #0 is used >> for SMCCC). > Yes, only the Xen one. I will mention "hvc #0xEA1". >> >> > +> +Covers: >>> + - `XenProd~version_hyp_first_param~1` >>> + - `XenProd~version_hyp_second_param~1` >>> + >>> +Parameters >>> +---------- >>> + >>> +`XenSwdgn~arm64_hyp_param~1` >>> + >>> +Description: >>> +Xen shall use x0 to read the first parameter, x1 for second parameter and >>> so >>> +on, for domain hypercall requests. >> >> This implies we are supporting a large number of parameters. However, Xen is >> only support 5 arguments. So I would just list all the registers. > > Xen shall use the first five cpu core registers to obtain the arguments for > domain hypercall requests. Xen shall read the first register for the first > argument, second register for the second argument and so on. > > @Bertrand :- Does this look ok to you ? I deliberately changed from x0 to > first register so that this can be valid for both arm64 and arm32. Please > comment.
Yes we should mention the 5 registers as those are the one supported by Xen and also the register where the hypercall number is passed as mentioned after Cheers Bertrand > >> >>> + >>> +Rationale: >>> + >>> +Comments: >>> + >>> +Covers: >>> + - `XenProd~version_hyp_first_param~1` >>> + - `XenProd~version_hyp_second_param~1` >>> + >> >> You don't seem to describe how the hypercall number is passed. Is this >> intended? > > Good catch. I will add a requirement. > > Xen shall read x16 to obtain the hypercall number. > > Xen shall read r12 to obtain the hypercall number. > >> >>> +Return value >>> +------------ >>> + >>> +`XenSwdgn~arm64_ret_val~1` >>> + >>> +Description: >>> +Xen shall store the return value in x0 register. >>> + >>> +Rationale: >>> + >>> +Comments: >>> + >>> +Covers: >>> + - `XenProd~version_hyp_ret_val~1` >>> diff --git a/docs/fusa/reqs/index.rst b/docs/fusa/reqs/index.rst >>> index 1088a51d52..d8683edce7 100644 >>> --- a/docs/fusa/reqs/index.rst >>> +++ b/docs/fusa/reqs/index.rst >>> @@ -10,5 +10,7 @@ Requirements documentation >>> market-reqs/reqs >>> product-reqs/reqs >>> product-reqs/arm64/reqs >>> + product-reqs/version_hypercall >>> design-reqs/arm64/generic-timer >>> design-reqs/arm64/sbsa-uart >>> + design-reqs/arm64/hypercall >>> diff --git a/docs/fusa/reqs/market-reqs/reqs.rst >>> b/docs/fusa/reqs/market-reqs/reqs.rst >>> index 2d297ecc13..0e29fe5362 100644 >>> --- a/docs/fusa/reqs/market-reqs/reqs.rst >>> +++ b/docs/fusa/reqs/market-reqs/reqs.rst >>> @@ -79,3 +79,19 @@ Comments: >>> Needs: >>> - XenProd >>> + >>> +Version hypercall >>> +----------------- >>> + >>> +`XenMkt~version_hypercall~1` >>> + >>> +Description: >>> +Xen shall provide an interface for the domains to retrieve Xen's version, >>> type >>> +and compilation information. >>> + >>> +Rationale: >>> + >>> +Comments: >>> + >>> +Needs: >>> + - XenProd >>> diff --git a/docs/fusa/reqs/product-reqs/version_hypercall.rst >>> b/docs/fusa/reqs/product-reqs/version_hypercall.rst >>> new file mode 100644 >>> index 0000000000..03221f70c3 >>> --- /dev/null >>> +++ b/docs/fusa/reqs/product-reqs/version_hypercall.rst >>> @@ -0,0 +1,61 @@ >>> +.. SPDX-License-Identifier: CC-BY-4.0 >>> + >>> +Version hypercall >>> +================= >>> + >>> +First Parameter >>> +--------------- >>> + >>> +`XenProd~version_hyp_first_param~1` >>> + >>> +Description: >>> +Xen shall treat the first argument (as an integer) to denote the command >>> number >>> +for the hypercall. >>> + >>> +Rationale: >>> + >>> +Comments: >>> + >>> +Covers: >>> + - `XenMkt~version_hypercall~1` >>> + >>> +Needs: >>> + - XenSwdgn >>> + >>> +Second Parameter >>> +---------------- >>> + >>> +`XenProd~version_hyp_second_param~1` >>> + >>> +Description: >>> +Xen shall treat the second argument as a virtual address to buffer in >>> domain's >>> +memory. >> >> We don't support any VA. The VA will need to be mapped with specifc >> attributes (see include/public/arch-arm.h). Should this be mentioned in the >> requirement? > > ....as a virtual address (mapped as Normal Inner Write-Back Outer Write-Back > Inner-Shareable) to buffer in domain's .... > > - Ayan > >> >>> + >>> +Rationale: >>> + >>> +Comments: >>> + >>> +Covers: >>> + - `XenMkt~version_hypercall~1` >>> + >>> +Needs: >>> + - XenSwdgn >>> + >>> +Return Value >>> +------------ >>> + >>> +`XenProd~version_hyp_ret_val~1` >>> + >>> +Description: >>> +In case the hypercall fails, Xen shall return one of the error codes >>> defined >>> +in >>> http://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=xen/include/public/errno.h. >>> + >>> +Rationale: >>> + >>> +Comments: >>> + >>> +Covers: >>> + - `XenMkt~version_hypercall~1` >>> + >>> +Needs: >>> + - XenSwdgn >>> \ No newline at end of file
