Re: [PATCH] x86/mem_sharing: Fix build folloing VM Fork work

[Tamas K Lengyel <tamas@xxxxxxxxxxxxx>]

On Thu, Apr 9, 2020 at 5:00 PM Andrew Cooper <andrew.cooper3@xxxxxxxxxx> wrote:
>
> On 09/04/2020 23:38, Tamas K Lengyel wrote:
> > On Thu, Apr 9, 2020 at 4:05 PM Andrew Cooper <andrew.cooper3@xxxxxxxxxx> 
> > wrote:
> >> On 09/04/2020 22:24, Tamas K Lengyel wrote:
> >>> On Thu, Apr 9, 2020 at 2:48 PM Andrew Cooper <andrew.cooper3@xxxxxxxxxx> 
> >>> wrote:
> >>>> A default build fails with:
> >>>>
> >>>>   mem_sharing.c: In function ‘copy_special_pages’:
> >>>>   mem_sharing.c:1649:9: error: ‘HVM_PARAM_STORE_PFN’ undeclared (first 
> >>>> use in this function)
> >>>>            HVM_PARAM_STORE_PFN,
> >>>>            ^~~~~~~~~~~~~~~~~~~
> >>>>
> >>>> I suspect this is a rebasing issue with respect to c/s 12f0c69f2709 
> >>>> "x86/HVM:
> >>>> reduce hvm.h include dependencies".
> >>>>
> >>>> Fixes: 41548c5472a "mem_sharing: VM forking"
> >>>> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> >>> So staging definitely compiles for me both with and without
> >>> CONFIG_MEM_SHARING enabled. By default its off, so this shouldn't even
> >>> be compiled so I'm curious what's happening in your build. That said,
> >>> I have no objection to the extra include if it turns out to be
> >>> actually necessary.
> >> Exact config attached.  I've just double checked that staging fails.
> >>
> >> We should get  to the bottom of exactly what is going on here, if it
> >> isn't the obvious thing.
> > Strange, with your config it does produce the error. With "echo
> > CONFIG_MEM_SHARING=y > .config && XEN_CONFIG_EXPERT=y make
> > olddefconfig && make" it does compile.
>
> You lose XEN_CONFIG_EXPERT=y in the second make, so it rewrites your
> .config behind your back.  (This behaviour is totally obnoxious).

I also compiled with export XEN_CONFIG_EXPERT=y and it compiles fine.

> Diff the current config against original?

drt@t0:~/workspace/xen/xen$ diff .config .config-debug
6c6
< CONFIG_GCC_VERSION=80300
---
> CONFIG_GCC_VERSION=60300
25,28c25,32
< CONFIG_XEN_ALIGN_DEFAULT=y
< # CONFIG_XEN_ALIGN_2M is not set
< # CONFIG_XEN_GUEST is not set
< # CONFIG_HYPERV_GUEST is not set
---
> # CONFIG_XEN_ALIGN_DEFAULT is not set
> CONFIG_XEN_ALIGN_2M=y
> CONFIG_GUEST=y
> CONFIG_XEN_GUEST=y
> CONFIG_PVH_GUEST=y
> CONFIG_PV_SHIM=y
> # CONFIG_PV_SHIM_EXCLUSIVE is not set
> CONFIG_HYPERV_GUEST=y
61,62c65,74
< # CONFIG_XSM is not set
< # CONFIG_ARGO is not set
---
> CONFIG_XSM=y
> CONFIG_XSM_FLASK=y
> CONFIG_XSM_FLASK_AVC_STATS=y
> CONFIG_XSM_FLASK_POLICY=y
> CONFIG_XSM_SILO=y
> # CONFIG_XSM_DUMMY_DEFAULT is not set
> # CONFIG_XSM_FLASK_DEFAULT is not set
> CONFIG_XSM_SILO_DEFAULT=y
> # CONFIG_LATE_HWDOM is not set
> CONFIG_ARGO=y
72,73c84,85
< # CONFIG_SCHED_CREDIT_DEFAULT is not set
< CONFIG_SCHED_CREDIT2_DEFAULT=y
---
> CONFIG_SCHED_CREDIT_DEFAULT=y
> # CONFIG_SCHED_CREDIT2_DEFAULT is not set
77c89
< CONFIG_SCHED_DEFAULT="credit2"
---
> CONFIG_SCHED_DEFAULT="credit"

Tamas