Re: [Qemu-devel] Failure to compile latest git (target-i386/kvm.c:953:29: error: variable ‘fop’ set but not used)
On 04/21/2011 06:43 PM, Jan Kiszka wrote: On 2011-04-21 16:10, Yaniv Kaul wrote: Fedora 15beta/x64, latest git: [ykaul@ykaul qemu]$ make CCx86_64-softmmu/kvm.o /home/ykaul/qemu/target-i386/kvm.c: In function ‘kvm_get_xsave’: /home/ykaul/qemu/target-i386/kvm.c:953:29: error: variable ‘fop’ set but not used [-Werror=unused-but-set-variable] cc1: all warnings being treated as errors make[1]: *** [kvm.o] Error 1 make: *** [subdir-x86_64-softmmu] Error 2 This one looks a bit suspicious: Avi, why do we have kvm_fpu::last_* in the ABI, copying that information from/to user land, but do not handle it otherwise? We have in in the ABI because it is part of the FPU state. We don't handle it, because likely qemu tcg never emulated it and thus we never had anywhere to stow it. To trigger a bug here you'd need a live migration that happens after an x87 fpu instruction that causes an exception but before the next fpu instruction (which would trigger an exception), plus an exception handler that reads this information (I think Linux doesn't), plus an application that cares about the data... Note the kernel does handle it correctly. To my understanding this fop here in xsave corresponds to kvm_fpu::last_opcode in the SET/GET_FPU case, right? It's set to 0 on SET_XSAVE and ignored on GET_XSAVE as this warnings tells us. We have exactly the same issue in kvm_get_fpu(), just with no warning. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.
[Qemu-devel] Failure to compile latest git (target-i386/kvm.c:953:29: error: variable ‘fop’ set but not used)
Fedora 15beta/x64, latest git: [ykaul@ykaul qemu]$ make CCx86_64-softmmu/kvm.o /home/ykaul/qemu/target-i386/kvm.c: In function ‘kvm_get_xsave’: /home/ykaul/qemu/target-i386/kvm.c:953:29: error: variable ‘fop’ set but not used [-Werror=unused-but-set-variable] cc1: all warnings being treated as errors make[1]: *** [kvm.o] Error 1 make: *** [subdir-x86_64-softmmu] Error 2 [ykaul@ykaul qemu]$ gcc --version gcc (GCC) 4.6.0 20110419 (Red Hat 4.6.0-5) - Does happen even though I've used --target-list=x86_64-softmmu - Doesn't happen with --disable-kvm in ./configure. Then I'm getting: /home/ykaul/qemu/tcg/tcg.c: In function ‘tcg_gen_callN’: /home/ykaul/qemu/tcg/tcg.c:589:9: error: variable ‘call_type’ set but not used [-Werror=unused-but-set-variable]
Re: [Qemu-devel] Failure to compile latest git (target-i386/kvm.c:953:29: error: variable ‘fop’ set but not used)
On Thu, Apr 21, 2011 at 3:10 PM, Yaniv Kaul yk...@redhat.com wrote: Fedora 15beta/x64, latest git: [ykaul@ykaul qemu]$ make CC x86_64-softmmu/kvm.o /home/ykaul/qemu/target-i386/kvm.c: In function ‘kvm_get_xsave’: /home/ykaul/qemu/target-i386/kvm.c:953:29: error: variable ‘fop’ set but not used [-Werror=unused-but-set-variable] cc1: all warnings being treated as errors make[1]: *** [kvm.o] Error 1 make: *** [subdir-x86_64-softmmu] Error 2 [ykaul@ykaul qemu]$ gcc --version gcc (GCC) 4.6.0 20110419 (Red Hat 4.6.0-5) - Does happen even though I've used --target-list=x86_64-softmmu - Doesn't happen with --disable-kvm in ./configure. Then I'm getting: /home/ykaul/qemu/tcg/tcg.c: In function ‘tcg_gen_callN’: /home/ykaul/qemu/tcg/tcg.c:589:9: error: variable ‘call_type’ set but not used [-Werror=unused-but-set-variable] Hi Yaniv, Do you want to take a stab at fixing these warnings and sending patches? http://wiki.qemu.org/Contribute/SubmitAPatch If these warnings are preventing you from using QEMU, try: $ ./configure --disable-werror Stefan
Re: [Qemu-devel] Failure to compile latest git (target-i386/kvm.c:953:29: error: variable ‘fop’ set but not used)
On 2011-04-21 16:10, Yaniv Kaul wrote: Fedora 15beta/x64, latest git: [ykaul@ykaul qemu]$ make CCx86_64-softmmu/kvm.o /home/ykaul/qemu/target-i386/kvm.c: In function ‘kvm_get_xsave’: /home/ykaul/qemu/target-i386/kvm.c:953:29: error: variable ‘fop’ set but not used [-Werror=unused-but-set-variable] cc1: all warnings being treated as errors make[1]: *** [kvm.o] Error 1 make: *** [subdir-x86_64-softmmu] Error 2 This one looks a bit suspicious: Avi, why do we have kvm_fpu::last_* in the ABI, copying that information from/to user land, but do not handle it otherwise? To my understanding this fop here in xsave corresponds to kvm_fpu::last_opcode in the SET/GET_FPU case, right? It's set to 0 on SET_XSAVE and ignored on GET_XSAVE as this warnings tells us. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux
