Re: [PATCH v2 2/4] Add the NetBSD Virtual Machine Monitor accelerator.

[Kamil Rytarowski]

On 02.03.2020 20:40, Paolo Bonzini wrote:
>
>
> Il lun 2 mar 2020, 20:14 Maxime Villard <address@hidden
> <mailto:address@hidden>> ha scritto:
>
>     Le 02/03/2020 à 19:05, Kamil Rytarowski a écrit :
>     > On 02.03.2020 18:12, Paolo Bonzini wrote:
>     >> On 03/02/20 12:56, Kamil Rytarowski wrote:
>     >>> On 03.02.2020 12:41, Philippe Mathieu-Daudé wrote:
>     >>>>> @@ -1768,6 +1785,7 @@ disabled with --disable-FEATURE, default is
>     >>>>> enabled if available:
>     >>>>>     hax             HAX acceleration support
>     >>>>>     hvf             Hypervisor.framework acceleration support
>     >>>>>     whpx            Windows Hypervisor Platform acceleration
>     support
>     >>>>> +  nvmm            NetBSD Virtual Machine Monitor acceleration
>     support
>     >>>>>     rdma            Enable RDMA-based migration
>     >>>>>     pvrdma          Enable PVRDMA support
>     >>>>>     vde             support for vde network
>     >>>>> @@ -2757,6 +2775,20 @@ if test "$whpx" != "no" ; then
>     >>>>>       fi
>     >>>>>   fi
>     >>>>>
>     >>>>
>     >>>> Maybe you can add something like:
>     >>>>
>     >>>> if test "$targetos" = "NetBSD"; then
>     >>>>     nvmm="check"
>     >>>> fi
>     >>>>
>     >>>> to build by default with NVMM if available.
>     >>>
>     >>> I will add nvmm=yes to the NetBSD) targetos check section.
>     >>
>     >> No, nvmm=yes instead should fail the build if nvmm.h is not
>     available.
>     >> That is not a good default.
>     >>
>     >> Paolo
>     >>
>     >>
>     >
>     > Most users will get nvmm.h in place now and this is still a tunable.
>     >
>     > I have got no opinion what to put there, nvmm=check still works.
>
>     I would keep "yes", for consistency with the other entries. Changing all
>     entries to "check" should be done in a separate commit, unrelated to
>     NVMM.
>
>
> The difference is that KVM for example does not need external includes
> or libraries.
>
> Paolo
>

We don't support this scenario and after a year there might be no
supported release without NVMM.

The only concern is about using qemu on !amd64, but we have there not
many users of qemu for understandable reasons.

For AArch64 we plan to implement a dedicated NVMM backend.

>
>     > diff --git a/configure b/configure
>     > index d4a837cf9d..b3560d88bb 100755
>     > --- a/configure
>     > +++ b/configure
>     > @@ -836,7 +836,7 @@ DragonFly)
>     >  NetBSD)
>     >    bsd="yes"
>     >    hax="yes"
>     > -  nvmm="yes"
>     > +  nvmm="check"
>     >    make="${MAKE-gmake}"
>     >    audio_drv_list="oss try-sdl"
>     >    audio_possible_drivers="oss sdl"
>     >
>