arch/mips/kvm/vz.c:1552: warning: expecting prototype for kvm_trap_vz_handle_cop_unusuable(). Prototype was for kvm_trap_vz_handle_cop_unusable() instead

From: kernel test robot
Date: Mon Sep 06 2021 - 09:47:14 EST

Hi Thomas,

First bad commit (maybe != root cause):

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 27151f177827d478508e756c7657273261aaf8a9
commit: 45c7e8af4a5e3f0bea4ac209eea34118dd57ac64 MIPS: Remove KVM_TE support
date: 6 months ago
config: mips-randconfig-r004-20210906 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 6fe2beba7d2a41964af658c8c59dd172683ef739)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install mips cross compiling tool for clang build
# apt-get install binutils-mips-linux-gnu
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=45c7e8af4a5e3f0bea4ac209eea34118dd57ac64
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 45c7e8af4a5e3f0bea4ac209eea34118dd57ac64
# save the attached .config to linux build tree
mkdir build_dir
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross O=build_dir ARCH=mips SHELL=/bin/bash arch/mips/kvm/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

arch/mips/kvm/vz.c:471: warning: Function parameter or member 'out_compare' not described in '_kvm_vz_save_htimer'
arch/mips/kvm/vz.c:471: warning: Function parameter or member 'out_cause' not described in '_kvm_vz_save_htimer'
arch/mips/kvm/vz.c:471: warning: Excess function parameter 'compare' description in '_kvm_vz_save_htimer'
arch/mips/kvm/vz.c:471: warning: Excess function parameter 'cause' description in '_kvm_vz_save_htimer'
>> arch/mips/kvm/vz.c:1552: warning: expecting prototype for kvm_trap_vz_handle_cop_unusuable(). Prototype was for kvm_trap_vz_handle_cop_unusable() instead


vim +1552 arch/mips/kvm/vz.c

c992a4f6a9b0a3 James Hogan 2017-03-14 1543
c992a4f6a9b0a3 James Hogan 2017-03-14 1544 /**
c992a4f6a9b0a3 James Hogan 2017-03-14 1545 * kvm_trap_vz_handle_cop_unusuable() - Guest used unusable coprocessor.
c992a4f6a9b0a3 James Hogan 2017-03-14 1546 * @vcpu: Virtual CPU context.
c992a4f6a9b0a3 James Hogan 2017-03-14 1547 *
c992a4f6a9b0a3 James Hogan 2017-03-14 1548 * Handle when the guest attempts to use a coprocessor which hasn't been allowed
c992a4f6a9b0a3 James Hogan 2017-03-14 1549 * by the root context.
c992a4f6a9b0a3 James Hogan 2017-03-14 1550 */
c992a4f6a9b0a3 James Hogan 2017-03-14 1551 static int kvm_trap_vz_handle_cop_unusable(struct kvm_vcpu *vcpu)
c992a4f6a9b0a3 James Hogan 2017-03-14 @1552 {
c992a4f6a9b0a3 James Hogan 2017-03-14 1553 u32 cause = vcpu->arch.host_cp0_cause;
c992a4f6a9b0a3 James Hogan 2017-03-14 1554 enum emulation_result er = EMULATE_FAIL;
c992a4f6a9b0a3 James Hogan 2017-03-14 1555 int ret = RESUME_GUEST;
c992a4f6a9b0a3 James Hogan 2017-03-14 1556
c992a4f6a9b0a3 James Hogan 2017-03-14 1557 if (((cause & CAUSEF_CE) >> CAUSEB_CE) == 1) {
c992a4f6a9b0a3 James Hogan 2017-03-14 1558 /*
c992a4f6a9b0a3 James Hogan 2017-03-14 1559 * If guest FPU not present, the FPU operation should have been
c992a4f6a9b0a3 James Hogan 2017-03-14 1560 * treated as a reserved instruction!
c992a4f6a9b0a3 James Hogan 2017-03-14 1561 * If FPU already in use, we shouldn't get this at all.
c992a4f6a9b0a3 James Hogan 2017-03-14 1562 */
c992a4f6a9b0a3 James Hogan 2017-03-14 1563 if (WARN_ON(!kvm_mips_guest_has_fpu(&vcpu->arch) ||
c992a4f6a9b0a3 James Hogan 2017-03-14 1564 vcpu->arch.aux_inuse & KVM_MIPS_AUX_FPU)) {
c992a4f6a9b0a3 James Hogan 2017-03-14 1565 preempt_enable();
c992a4f6a9b0a3 James Hogan 2017-03-14 1566 return EMULATE_FAIL;
c992a4f6a9b0a3 James Hogan 2017-03-14 1567 }
c992a4f6a9b0a3 James Hogan 2017-03-14 1568
c992a4f6a9b0a3 James Hogan 2017-03-14 1569 kvm_own_fpu(vcpu);
c992a4f6a9b0a3 James Hogan 2017-03-14 1570 er = EMULATE_DONE;
c992a4f6a9b0a3 James Hogan 2017-03-14 1571 }
c992a4f6a9b0a3 James Hogan 2017-03-14 1572 /* other coprocessors not handled */
c992a4f6a9b0a3 James Hogan 2017-03-14 1573
c992a4f6a9b0a3 James Hogan 2017-03-14 1574 switch (er) {
c992a4f6a9b0a3 James Hogan 2017-03-14 1575 case EMULATE_DONE:
c992a4f6a9b0a3 James Hogan 2017-03-14 1576 ret = RESUME_GUEST;
c992a4f6a9b0a3 James Hogan 2017-03-14 1577 break;
c992a4f6a9b0a3 James Hogan 2017-03-14 1578
c992a4f6a9b0a3 James Hogan 2017-03-14 1579 case EMULATE_FAIL:
c34b26b98caca4 Tianjia Zhang 2020-06-23 1580 vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
c992a4f6a9b0a3 James Hogan 2017-03-14 1581 ret = RESUME_HOST;
c992a4f6a9b0a3 James Hogan 2017-03-14 1582 break;
c992a4f6a9b0a3 James Hogan 2017-03-14 1583
c992a4f6a9b0a3 James Hogan 2017-03-14 1584 default:
c992a4f6a9b0a3 James Hogan 2017-03-14 1585 BUG();
c992a4f6a9b0a3 James Hogan 2017-03-14 1586 }
c992a4f6a9b0a3 James Hogan 2017-03-14 1587 return ret;
c992a4f6a9b0a3 James Hogan 2017-03-14 1588 }
c992a4f6a9b0a3 James Hogan 2017-03-14 1589

:::::: The code at line 1552 was first introduced by commit
:::::: c992a4f6a9b0a37c8bd7dfc727ecc3fed125c16b KVM: MIPS: Implement VZ support

:::::: TO: James Hogan <james.hogan@xxxxxxxxxx>
:::::: CC: James Hogan <james.hogan@xxxxxxxxxx>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

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