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charset=utf-8 Content-Transfer-Encoding: 8bit Content-Disposition: inline Received-SPF: pass client-ip=207.211.31.81; envelope-from=berrange@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/21 04:44:45 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -10 X-Spam_score: -1.1 X-Spam_bar: - X-Spam_report: (-1.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FROM_EXCESS_BASE64=0.979, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, May 20, 2020 at 03:20:23PM +0200, Marek Marczykowski-Górecki wrote: > In case of not using random-number needing feature, it makes sense to > skip RNG init too. This is especially helpful when QEMU is sandboxed in > Stubdomain under Xen, where there is very little entropy so initial > getrandom() call delays the startup several seconds. In that setup, no > random bytes are needed at all. > > Signed-off-by: Marek Marczykowski-Górecki > --- > configure | 11 +++++++++++ > crypto/Makefile.objs | 3 ++- > crypto/random-none.c | 38 ++++++++++++++++++++++++++++++++++++++ > 3 files changed, 51 insertions(+), 1 deletion(-) > create mode 100644 crypto/random-none.c > > diff --git a/configure b/configure > index 26084fc53a..79a3affe70 100755 > --- a/configure > +++ b/configure > @@ -509,6 +509,7 @@ libpmem="" > default_devices="yes" > plugins="no" > fuzzing="no" > +rng_none="no" > > supported_cpu="no" > supported_os="no" > @@ -1601,6 +1602,10 @@ for opt do > ;; > --gdb=*) gdb_bin="$optarg" > ;; > + --enable-rng-none) rng_none=yes > + ;; > + --disable-rng-none) rng_none=no > + ;; > *) > echo "ERROR: unknown option $opt" > echo "Try '$0 --help' for more information" > @@ -1894,6 +1899,7 @@ disabled with --disable-FEATURE, default is enabled if available: > debug-mutex mutex debugging support > libpmem libpmem support > xkbcommon xkbcommon support > + rng-none dummy RNG, avoid using /dev/(u)random and getrandom() > > NOTE: The object files are built at the place where configure is launched > EOF > @@ -6733,6 +6739,7 @@ echo "default devices $default_devices" > echo "plugin support $plugins" > echo "fuzzing support $fuzzing" > echo "gdb $gdb_bin" > +echo "rng-none $rng_none" > > if test "$supported_cpu" = "no"; then > echo > @@ -7705,6 +7712,10 @@ if test "$edk2_blobs" = "yes" ; then > echo "DECOMPRESS_EDK2_BLOBS=y" >> $config_host_mak > fi > > +if test "$rng_none" = "yes"; then > + echo "CONFIG_RNG_NONE=y" >> $config_host_mak > +fi > + > # use included Linux headers > if test "$linux" = "yes" ; then > mkdir -p linux-headers > diff --git a/crypto/Makefile.objs b/crypto/Makefile.objs > index c2a371b0b4..cdee92b4e5 100644 > --- a/crypto/Makefile.objs > +++ b/crypto/Makefile.objs > @@ -35,5 +35,6 @@ crypto-obj-y += block-luks.o > > util-obj-$(CONFIG_GCRYPT) += random-gcrypt.o > util-obj-$(if $(CONFIG_GCRYPT),n,$(CONFIG_GNUTLS)) += random-gnutls.o > -util-obj-$(if $(CONFIG_GCRYPT),n,$(if $(CONFIG_GNUTLS),n,y)) += random-platform.o > +util-obj-$(if $(CONFIG_GCRYPT),n,$(if $(CONFIG_GNUTLS),n,$(CONFIG_RNG_NONE))) += random-none.o > +util-obj-$(if $(CONFIG_GCRYPT),n,$(if $(CONFIG_GNUTLS),n,$(if $(CONFIG_RNG_NONE),n,y))) += random-platform.o > util-obj-y += aes.o init.o > diff --git a/crypto/random-none.c b/crypto/random-none.c > new file mode 100644 > index 0000000000..102f8a4dce > --- /dev/null > +++ b/crypto/random-none.c > @@ -0,0 +1,38 @@ > +/* > + * QEMU Crypto "none" random number provider > + * > + * Copyright (c) 2020 Marek Marczykowski-Górecki > + * > + * > + * This library is free software; you can redistribute it and/or > + * modify it under the terms of the GNU Lesser General Public > + * License as published by the Free Software Foundation; either > + * version 2.1 of the License, or (at your option) any later version. > + * > + * This library is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + * Lesser General Public License for more details. > + * > + * You should have received a copy of the GNU Lesser General Public > + * License along with this library; if not, see . > + * > + */ > + > +#include "qemu/osdep.h" > + > +#include "crypto/random.h" > +#include "qapi/error.h" > + > +int qcrypto_random_init(Error **errp) > +{ > + return 0; > +} > + > +int qcrypto_random_bytes(void *buf, > + size_t buflen, > + Error **errp) > +{ > + error_setg(errp, "Random bytes not available with \"none\" rng"); > + return -1; > +} Reviewed-by: Daniel P. Berrangé and queued. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|