Re: [Qemu-devel] Questions about gcc linker errors in crypto sub-directory

[Gonglei (Arei)]

> -----Original Message-----
> From: Daniel P. Berrange [mailto:address@hidden
> Sent: Tuesday, September 27, 2016 8:52 PM
> To: Gonglei (Arei)
> Cc: address@hidden
> Subject: Re: Questions about gcc linker errors in crypto sub-directory
> 
> On Mon, Sep 26, 2016 at 09:19:36AM +0000, Gonglei (Arei) wrote:
> > > -----Original Message-----
> > > From: Daniel P. Berrange [mailto:address@hidden
> > > Sent: Monday, September 26, 2016 5:14 PM
> > > To: Gonglei (Arei)
> > > Cc: address@hidden
> > > Subject: Re: Questions about gcc linker errors in crypto sub-directory
> > >
> > > On Mon, Sep 26, 2016 at 09:03:45AM +0000, Gonglei (Arei) wrote:
> > > > Hi Daniel,
> > > >
> > > > I'm coding cryptodev-vhost-user.c as a new cryptodev backend,
> > > > but the gcc report some linker errors:
> > > >
> > > > crypto/cryptodev-vhost-user.o: In function
> > > `qcrypto_cryptodev_vhost_crypto_cleanup':
> > > > /mnt/sdb/gonglei/qemu.git/qemu/crypto/cryptodev-vhost-user.c:87:
> > > undefined reference to `vhost_dev_cleanup'
> > > > crypto/cryptodev-vhost-user.o: In function
> > > `qcrypto_cryptodev_vhost_crypto_init':
> > > > /mnt/sdb/gonglei/qemu.git/qemu/crypto/cryptodev-vhost-user.c:126:
> > > undefined reference to `vhost_dev_init'
> > > > crypto/cryptodev-vhost-user.o: In function
> > > `qcrypto_cryptodev_vhost_user_opened':
> > > > /mnt/sdb/gonglei/qemu.git/qemu/crypto/cryptodev-vhost-user.c:187:
> > > undefined reference to `qemu_chr_find'
> > > > /mnt/sdb/gonglei/qemu.git/qemu/crypto/cryptodev-vhost-user.c:194:
> > > undefined reference to `qemu_chr_fe_claim_no_fail'
> > > > crypto/cryptodev-vhost-user.o: In function
> > > `qcrypto_cryptodev_vhost_user_event':
> > > > /mnt/sdb/gonglei/qemu.git/qemu/crypto/cryptodev-vhost-user.c:213:
> > > undefined reference to `qemu_chr_set_reconnect_time'
> > > > crypto/cryptodev-vhost-user.o: In function
> > > `qcrypto_cryptodev_vhost_user_init':
> > > > /mnt/sdb/gonglei/qemu.git/qemu/crypto/cryptodev-vhost-user.c:257:
> > > undefined reference to `qemu_chr_add_handlers'
> > > > crypto/cryptodev-vhost-user.o: In function
> > > `qcrypto_cryptodev_vhost_user_finalize':
> > > > /mnt/sdb/gonglei/qemu.git/qemu/crypto/cryptodev-vhost-user.c:353:
> > > undefined reference to `qemu_chr_add_handlers'
> > > > /mnt/sdb/gonglei/qemu.git/qemu/crypto/cryptodev-vhost-user.c:354:
> > > undefined reference to `qemu_chr_fe_release'
> > > > collect2: ld returned 1 exit status
> > > > make: *** [qemu-nbd] Error 1
> > > >
> > > > Currently I only change the crypto/Makefile.objs:
> > > >
> > > > diff --git a/crypto/Makefile.objs b/crypto/Makefile.objs
> > > > index b9ad26a..575f64e 100644
> > > > --- a/crypto/Makefile.objs
> > > > +++ b/crypto/Makefile.objs
> > > > @@ -28,6 +28,7 @@ crypto-obj-y += block-qcow.o
> > > >  crypto-obj-y += block-luks.o
> > > >  crypto-obj-y += cryptodev.o
> > > >  crypto-obj-y += cryptodev-builtin.o
> > > > +crypto-obj-y += cryptodev-vhost-user.o
> > >
> > > The $(crypto-obj-y) variable is intended to only contain general purpose
> > > crypto code, since it needs to be linked to all QEMU programs. Your
> > > cryptodev file is specific to system emulators, so must only be linked
> > > to the system emulator targets. Thus, it should not be added to the
> > > crypto-obj-y variable.
> > >
> > > It probably needs to be added to either common-obj-y or obj-y - I can't
> > > remember which is "best"
> > >
> > common-obj-y is fine! So all cryptodev stuff should be use
> > $( crypto-obj-y) variable, right? I'll change them in the next version.
> 
> Looking at this again, it actually makes me think that your
> cryptodev stuff would be better in the backends/ directory.
> 
> That would mean the crypto/ directory is kept as the place for
> generic crypto infrastructure, and avoiding system emulator
> specific device backend code. The backends/Makefile.objs is
> already setup to use common-obj-y and builds various other
> device backend models.
> 
Sounds reasonable and make senses. At present situation, I need
to do below changes for crypto subdirectory:

diff --git a/Makefile.objs b/Makefile.objs
index 6d5ddcf..f1a8f13 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -78,6 +78,7 @@ common-obj-$(CONFIG_SECCOMP) += qemu-seccomp.o
 
 common-obj-$(CONFIG_FDT) += device_tree.o
 
+common-obj-y += crypto/
 ######################################################################
 # qapi
 
diff --git a/crypto/Makefile.objs b/crypto/Makefile.objs
index a36d2d9..2632cbc 100644
--- a/crypto/Makefile.objs
+++ b/crypto/Makefile.objs
@@ -27,6 +27,10 @@ crypto-obj-y += block.o
 crypto-obj-y += block-qcow.o
 crypto-obj-y += block-luks.o
 
+# cryptodev file is specific to system emulators, so must only be linked
+# to the system emulator targets. 
+common-obj-y += cryptodev.o
+
 # Let the userspace emulators avoid linking gnutls/etc
 crypto-aes-obj-y = aes.o

I'll move them to backends/ directory.  But I still hope you can help to
review cryptdoev stuff in the following virtio-crypto patch serial versions, 
thanks in advance :)

Regards,
-Gonglei