Hi all,
On Wed, May 3, 2023 at 2:09 PM Daniel P. Berrangé <berra...@redhat.com> wrote:
>
> On Mon, May 01, 2023 at 10:21:00AM +0300, Andrew Melnychenko wrote:
> > Added command "request-ebpf". This command returns
> > eBPF program encoded base64. The program taken from the
> > skeleton and essentially is an ELF object that can be
> > loaded in the future with libbpf.
> >
> > Signed-off-by: Andrew Melnychenko <and...@daynix.com>
> > ---
> > monitor/qmp-cmds.c | 16 ++++++++++++++++
> > qapi/misc.json | 28 ++++++++++++++++++++++++++++
> > 2 files changed, 44 insertions(+)
> >
> > diff --git a/monitor/qmp-cmds.c b/monitor/qmp-cmds.c
> > index b0f948d3376..f7641bb55b9 100644
> > --- a/monitor/qmp-cmds.c
> > +++ b/monitor/qmp-cmds.c
> > @@ -32,6 +32,7 @@
> > #include "hw/mem/memory-device.h"
> > #include "hw/intc/intc.h"
> > #include "hw/rdma/rdma.h"
> > +#include "ebpf/ebpf.h"
> >
> > NameInfo *qmp_query_name(Error **errp)
> > {
> > @@ -209,3 +210,18 @@ static void __attribute__((__constructor__))
> > monitor_init_qmp_commands(void)
> > qmp_marshal_qmp_capabilities,
> > QCO_ALLOW_PRECONFIG, 0);
> > }
> > +
> > +EbpfObject *qmp_request_ebpf(const char *id, Error **errp)
> > +{
> > + EbpfObject *ret = NULL;
> > + size_t size = 0;
> > + const void *data = ebpf_find_binary_by_id(id, &size, errp);
> > + if (!data) {
> > + return NULL;
> > + }
> > +
> > + ret = g_new0(EbpfObject, 1);
> > + ret->object = g_base64_encode(data, size);
> > +
> > + return ret;
> > +}
> > diff --git a/qapi/misc.json b/qapi/misc.json
> > index 6ddd16ea283..81613fd1b13 100644
> > --- a/qapi/misc.json
> > +++ b/qapi/misc.json
> > @@ -618,3 +618,31 @@
> > { 'event': 'VFU_CLIENT_HANGUP',
> > 'data': { 'vfu-id': 'str', 'vfu-qom-path': 'str',
> > 'dev-id': 'str', 'dev-qom-path': 'str' } }
> > +
> > +##
> > +# @EbpfObject:
> > +#
> > +# Structure that holds eBPF ELF object encoded in base64.
> > +#
> > +# Since: 8.1
> > +#
> > +##
> > +{ 'struct': 'EbpfObject',
> > + 'data': {'object': 'str'} }
> > +
> > +##
> > +# @request-ebpf:
> > +#
> > +# Function returns eBPF object that can be loaded with libbpf.
> > +# Management applications (g.e. libvirt) may load it and pass file
> > +# descriptors to QEMU. Which allows running QEMU without BPF capabilities.
> > +#
> > +# Returns: RSS eBPF object encoded in base64.
> > +#
> > +# Since: 8.1
> > +#
> > +##
> > +{ 'command': 'request-ebpf',
> > + 'data': { 'id': 'str' },
>
> Since the number of EBPF program IDs is finite and known at build
> time, I think we'd be better using an enum instead of str. That
> will let apps introspect the QAPI schema to query whether the
> particular EBPF program ID is known to this version fo QEMU.
>
I've researched that issue a bit. I'll add the qapi enum.
> > + 'returns': 'EbpfObject' }
> > +
> > --
> > 2.39.1
> >
>
> With regards,
> Daniel
> --
> |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
> |: https://libvirt.org -o- https://fstop138.berrange.com :|
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>
