Re: [RFC PATCH v2 1/9] Add Rust SEV library as subproject

[Tyler Fanelli]

Hi Manos,

Thanks for the heads up, I was using rust 1.71.1. Will update the series 
with 1.72.1

Stefan, Philippe, or Daniel: is there a specific policy for the Rust 
version we should be developing on for crates in qemu?

Tyler

On 10/13/23 2:09 PM, Manos Pitsidianakis wrote:
> Hello Tyler!
>
> With Rust stable 1.72.1, I get:
>
> error: unneeded `return` statement
>     --> tests/launch.rs:103:26
>      |
> 103 |         VcpuExit::Hlt => return,
>      |                          ^^^^^^
>      |
>      = help: for further information visit
> https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
>      = note: `-D clippy::needless-return` implied by `-D warnings`
> help: replace `return` with a unit value
>      |
> 103 |         VcpuExit::Hlt => (),
>      |                          ~~
>
> error: could not compile `sev` (test "launch") due to previous error
> warning: build failed, waiting for other jobs to finish...
>
>
> When doing make.
>
> --
> Manos
>
> On Wed, 11 Oct 2023 at 06:11, Tyler Fanelli <tfanelli@redhat.com> wrote:
> > On 10/5/23 11:54 AM, Stefan Hajnoczi wrote:
> > > On Wed, Oct 04, 2023 at 04:34:10PM -0400, Tyler Fanelli wrote:
> > > > The Rust sev library provides a C API for the AMD SEV launch ioctls, as
> > > > well as the ability to build with meson. Add the Rust sev library as a
> > > > QEMU subproject with the goal of outsourcing all SEV launch ioctls to C
> > > > APIs provided by it.
> > > >
> > > > Signed-off-by: Tyler Fanelli <tfanelli@redhat.com>
> > > > ---
> > > >    meson.build                   | 8 ++++++++
> > > >    meson_options.txt             | 2 ++
> > > >    scripts/meson-buildoptions.sh | 3 +++
> > > >    subprojects/sev.wrap          | 6 ++++++
> > > >    target/i386/meson.build       | 2 +-
> > > >    5 files changed, 20 insertions(+), 1 deletion(-)
> > > >    create mode 100644 subprojects/sev.wrap
> > > >
> > > > diff --git a/meson.build b/meson.build
> > > > index 20ceeb8158..8a17c29de8 100644
> > > > --- a/meson.build
> > > > +++ b/meson.build
> > > > @@ -960,6 +960,13 @@ if not get_option('slirp').auto() or have_system
> > > >      endif
> > > >    endif
> > > >
> > > > +sev = not_found
> > > > +if not get_option('sev').auto()
> > > When 'sev' is auto, then it won't be built. That seems strange. The
> > > auto-detection part is missing! I did you test this on a system that
> > > doesn't have libsev installed system-wide?
> > My testing environment had libsev installed system-wide. Thanks for
> > pointing this out.
> >
> > > I guess the auto-detection would look something like:
> > >
> > >     cargo = find_program('cargo', required: true)
> > >
> > >     if not get_option('sev').auto() or cargo.found()
> > >         ...
> > >
> > > That way 'sev' is only built automatically on systems that have cargo
> > > installed.
> > >
> > > > +  sev = dependency('sev',
> > > > +                   method: 'pkg-config',
> > > > +                   required: get_option('sev'))
> > > > +endif
> > > If you update the auto logic, see the documentation about fallbacks to
> > > subprojects for optional dependencies:
> > > https://mesonbuild.com/Wrap-dependency-system-manual.html#provide-section
> > >
> > > It might be necessary to add dependency(..., fallback='sev').
> > Noted. Thanks!
> >
> > > > +
> > > >    vde = not_found
> > > >    if not get_option('vde').auto() or have_system or have_tools
> > > >      vde = cc.find_library('vdeplug', has_headers: ['libvdeplug.h'],
> > > > @@ -4331,6 +4338,7 @@ summary_info += {'libudev':           libudev}
> > > >    # Dummy dependency, keep .found()
> > > >    summary_info += {'FUSE lseek':        fuse_lseek.found()}
> > > >    summary_info += {'selinux':           selinux}
> > > > +summary_info += {'sev':               sev}
> > > >    summary_info += {'libdw':             libdw}
> > > >    summary(summary_info, bool_yn: true, section: 'Dependencies')
> > > >
> > > > diff --git a/meson_options.txt b/meson_options.txt
> > > > index 57e265c871..5b8d283717 100644
> > > > --- a/meson_options.txt
> > > > +++ b/meson_options.txt
> > > > @@ -204,6 +204,8 @@ option('sdl_image', type : 'feature', value : 'auto',
> > > >           description: 'SDL Image support for icons')
> > > >    option('seccomp', type : 'feature', value : 'auto',
> > > >           description: 'seccomp support')
> > > > +option('sev', type : 'feature', value : 'auto',
> > > > +        description: 'Rust AMD SEV library')
> > > >    option('smartcard', type : 'feature', value : 'auto',
> > > >           description: 'CA smartcard emulation support')
> > > >    option('snappy', type : 'feature', value : 'auto',
> > > > diff --git a/scripts/meson-buildoptions.sh b/scripts/meson-buildoptions.sh
> > > > index e4b46d5715..e585a548fa 100644
> > > > --- a/scripts/meson-buildoptions.sh
> > > > +++ b/scripts/meson-buildoptions.sh
> > > > @@ -161,6 +161,7 @@ meson_options_help() {
> > > >      printf "%s\n" '  sdl-image       SDL Image support for icons'
> > > >      printf "%s\n" '  seccomp         seccomp support'
> > > >      printf "%s\n" '  selinux         SELinux support in qemu-nbd'
> > > > +  printf "%s\n" '  sev             SEV library support'
> > > >      printf "%s\n" '  slirp           libslirp user mode network backend 
> > > > support'
> > > >      printf "%s\n" '  slirp-smbd      use smbd (at path --smbd=*) in slirp 
> > > > networking'
> > > >      printf "%s\n" '  smartcard       CA smartcard emulation support'
> > > > @@ -440,6 +441,8 @@ _meson_option_parse() {
> > > >        --disable-seccomp) printf "%s" -Dseccomp=disabled ;;
> > > >        --enable-selinux) printf "%s" -Dselinux=enabled ;;
> > > >        --disable-selinux) printf "%s" -Dselinux=disabled ;;
> > > > +    --enable-sev) printf "%s" -Dsev=enabled ;;
> > > > +    --disable-sev) printf "%s" -Dsev=disabled ;;
> > > >        --enable-slirp) printf "%s" -Dslirp=enabled ;;
> > > >        --disable-slirp) printf "%s" -Dslirp=disabled ;;
> > > >        --enable-slirp-smbd) printf "%s" -Dslirp_smbd=enabled ;;
> > > > diff --git a/subprojects/sev.wrap b/subprojects/sev.wrap
> > > > new file mode 100644
> > > > index 0000000000..5be1faccf6
> > > > --- /dev/null
> > > > +++ b/subprojects/sev.wrap
> > > > @@ -0,0 +1,6 @@
> > > > +[wrap-git]
> > > > +url = https://github.com/tylerfanelli/sev
> > > > +revision = b81b1da5df50055600a5b0349b0c4afda677cccb
> > > > +
> > > > +[provide]
> > > > +sev = sev_dep
> > > > diff --git a/target/i386/meson.build b/target/i386/meson.build
> > > > index 6f1036d469..8972a4fb17 100644
> > > > --- a/target/i386/meson.build
> > > > +++ b/target/i386/meson.build
> > > > @@ -20,7 +20,7 @@ i386_system_ss.add(files(
> > > >      'monitor.c',
> > > >      'cpu-sysemu.c',
> > > >    ))
> > > > -i386_system_ss.add(when: 'CONFIG_SEV', if_true: files('sev.c'), if_false: 
> > > > files('sev-sysemu-stub.c'))
> > > > +i386_system_ss.add(when: 'CONFIG_SEV', if_true: [sev, files('sev.c')], 
> > > > if_false: files('sev-sysemu-stub.c'))
> > > >
> > > >    i386_user_ss = ss.source_set()
> > > >
> > > > --
> > > > 2.40.1
> > Tyler