From: Laurent Vivier <lvivier@redhat.com>
To: qemu-devel@nongnu.org
Cc: "Laurent Vivier" <lvivier@redhat.com>,
"Daniel P . Berrangé" <berrange@redhat.com>,
"Kashyap Chamarthy" <kchamart@redhat.com>,
"Amit Shah" <amit@kernel.org>,
"Richard Henderson" <richard.henderson@linaro.org>,
"Richard W . M . Jones" <rjones@redhat.com>,
"Markus Armbruster" <armbru@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>
Subject: [Qemu-devel] [PATCH v7 2/4] rng-builtin: add an RNG backend that uses qemu_guest_getrandom()
Date: Wed, 29 May 2019 16:31:04 +0200 [thread overview]
Message-ID: <20190529143106.11789-3-lvivier@redhat.com> (raw)
In-Reply-To: <20190529143106.11789-1-lvivier@redhat.com>
Add a new RNG backend using QEMU builtin getrandom function.
It can be created and used with something like:
... -object rng-builtin,id=rng0 -device virtio-rng,rng=rng0 ...
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
backends/Makefile.objs | 2 +-
backends/rng-builtin.c | 78 ++++++++++++++++++++++++++++++++++++++++++
qemu-options.hx | 7 ++++
3 files changed, 86 insertions(+), 1 deletion(-)
create mode 100644 backends/rng-builtin.c
diff --git a/backends/Makefile.objs b/backends/Makefile.objs
index 981e8e122f2c..f0691116e86e 100644
--- a/backends/Makefile.objs
+++ b/backends/Makefile.objs
@@ -1,4 +1,4 @@
-common-obj-y += rng.o rng-egd.o
+common-obj-y += rng.o rng-egd.o rng-builtin.o
common-obj-$(CONFIG_POSIX) += rng-random.o
common-obj-$(CONFIG_TPM) += tpm.o
diff --git a/backends/rng-builtin.c b/backends/rng-builtin.c
new file mode 100644
index 000000000000..3381d47174df
--- /dev/null
+++ b/backends/rng-builtin.c
@@ -0,0 +1,78 @@
+/*
+ * QEMU Builtin Random Number Generator Backend
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "sysemu/rng.h"
+#include "qemu/main-loop.h"
+#include "qemu/guest-random.h"
+
+#define TYPE_RNG_BUILTIN "rng-builtin"
+#define RNG_BUILTIN(obj) OBJECT_CHECK(RngBuiltin, (obj), TYPE_RNG_BUILTIN)
+
+typedef struct RngBuiltin {
+ RngBackend parent;
+ QEMUBH *bh;
+} RngBuiltin;
+
+static void rng_builtin_receive_entropy_bh(void *opaque)
+{
+ RngBuiltin *s = opaque;
+
+ while (!QSIMPLEQ_EMPTY(&s->parent.requests)) {
+ RngRequest *req = QSIMPLEQ_FIRST(&s->parent.requests);
+
+ qemu_guest_getrandom_nofail(req->data, req->size);
+
+ req->receive_entropy(req->opaque, req->data, req->size);
+
+ rng_backend_finalize_request(&s->parent, req);
+ }
+}
+
+static void rng_builtin_request_entropy(RngBackend *b, RngRequest *req)
+{
+ RngBuiltin *s = RNG_BUILTIN(b);
+
+ qemu_bh_schedule(s->bh);
+}
+
+static void rng_builtin_init(Object *obj)
+{
+ RngBuiltin *s = RNG_BUILTIN(obj);
+
+ s->bh = qemu_bh_new(rng_builtin_receive_entropy_bh, s);
+}
+
+static void rng_builtin_finalize(Object *obj)
+{
+ RngBuiltin *s = RNG_BUILTIN(obj);
+
+ qemu_bh_delete(s->bh);
+}
+
+static void rng_builtin_class_init(ObjectClass *klass, void *data)
+{
+ RngBackendClass *rbc = RNG_BACKEND_CLASS(klass);
+
+ rbc->request_entropy = rng_builtin_request_entropy;
+}
+
+static const TypeInfo rng_builtin_info = {
+ .name = TYPE_RNG_BUILTIN,
+ .parent = TYPE_RNG_BACKEND,
+ .instance_size = sizeof(RngBuiltin),
+ .instance_init = rng_builtin_init,
+ .instance_finalize = rng_builtin_finalize,
+ .class_init = rng_builtin_class_init,
+};
+
+static void register_types(void)
+{
+ type_register_static(&rng_builtin_info);
+}
+
+type_init(register_types);
diff --git a/qemu-options.hx b/qemu-options.hx
index f6e9bd1d9c42..4e6a6828d7ce 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -4322,6 +4322,13 @@ other options.
The @option{share} boolean option is @var{on} by default with memfd.
+@item -object rng-builtin,id=@var{id}
+
+Creates a random number generator backend which obtains entropy from
+QEMU builtin functions. The @option{id} parameter is a unique ID that
+will be used to reference this entropy backend from the @option{virtio-rng}
+device.
+
@item -object rng-random,id=@var{id},filename=@var{/dev/random}
Creates a random number generator backend which obtains entropy from
--
2.20.1
next prev parent reply other threads:[~2019-05-29 14:35 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-29 14:31 [Qemu-devel] [PATCH v7 0/4] rng-builtin: add an RNG backend that uses qemu_guest_getrandom() Laurent Vivier
2019-05-29 14:31 ` [Qemu-devel] [PATCH v7 1/4] VirtIO-RNG: Update default entropy source to `/dev/urandom` Laurent Vivier
2019-06-26 20:29 ` Laurent Vivier
2019-07-02 7:41 ` Laurent Vivier
2019-07-03 14:26 ` Philippe Mathieu-Daudé
2019-05-29 14:31 ` Laurent Vivier [this message]
2019-06-06 4:46 ` [Qemu-devel] [PATCH v7 2/4] rng-builtin: add an RNG backend that uses qemu_guest_getrandom() Markus Armbruster
2019-05-29 14:31 ` [Qemu-devel] [PATCH v7 3/4] virtio-rng: Keep the default backend out of VirtIORNGConf Laurent Vivier
2019-05-29 14:31 ` [Qemu-devel] [PATCH v7 4/4] virtio-rng: change default backend to rng-builtin Laurent Vivier
2019-06-05 13:05 ` [Qemu-devel] [PATCH v7 0/4] rng-builtin: add an RNG backend that uses qemu_guest_getrandom() Markus Armbruster
2019-06-05 13:58 ` Laurent Vivier
2019-06-05 17:56 ` Markus Armbruster
2019-06-05 18:36 ` Laurent Vivier
2019-06-06 4:45 ` Markus Armbruster
2019-06-11 8:42 ` Laurent Vivier
2019-06-17 12:09 ` Laurent Vivier
2019-07-02 13:21 ` Michael S. Tsirkin
2019-07-02 16:48 ` Laurent Vivier
2019-07-03 14:23 ` Amit Shah
2019-07-03 14:57 ` Laurent Vivier
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190529143106.11789-3-lvivier@redhat.com \
--to=lvivier@redhat.com \
--cc=amit@kernel.org \
--cc=armbru@redhat.com \
--cc=berrange@redhat.com \
--cc=kchamart@redhat.com \
--cc=mst@redhat.com \
--cc=qemu-devel@nongnu.org \
--cc=richard.henderson@linaro.org \
--cc=rjones@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).