[kvm:tdp-mmu 41/57] arch/x86/kvm/mmu/tdp_mmu.c:281:8: error: implicit declaration of function 'spte_to_child_pt'

[kvm:tdp-mmu 41/57] arch/x86/kvm/mmu/tdp_mmu.c:281:8: error: implicit declaration of function 'spte_to_child_pt'

[kernel test robot]

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tree:   https://git.kernel.org/pub/scm/virt/kvm/kvm.git tdp-mmu
head:   1eb10c8be32298671cee78789ce32c3851f2e1f7
commit: 0fbfee5a26646c2c3e361ba1f7d6c3adee7d09a5 [41/57] kvm: mmu: Add functions to handle changed TDP SPTEs
config: x86_64-rhel-7.6-kselftests (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/virt/kvm/kvm.git/commit/?id=0fbfee5a26646c2c3e361ba1f7d6c3adee7d09a5
        git remote add kvm https://git.kernel.org/pub/scm/virt/kvm/kvm.git
        git fetch --no-tags kvm tdp-mmu
        git checkout 0fbfee5a26646c2c3e361ba1f7d6c3adee7d09a5
        # save the attached .config to linux build tree
        make W=1 ARCH=x86_64 

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

Note: the kvm/tdp-mmu HEAD 1eb10c8be32298671cee78789ce32c3851f2e1f7 builds fine.
      It only hurts bisectibility.

All error/warnings (new ones prefixed by >>):

   arch/x86/kvm/mmu/tdp_mmu.c: In function 'handle_changed_spte':
>> arch/x86/kvm/mmu/tdp_mmu.c:281:8: error: implicit declaration of function 'spte_to_child_pt' [-Werror=implicit-function-declaration]
     281 |   pt = spte_to_child_pt(old_spte, level);
         |        ^~~~~~~~~~~~~~~~
>> arch/x86/kvm/mmu/tdp_mmu.c:281:6: warning: assignment to 'u64 *' {aka 'long long unsigned int *'} from 'int' makes pointer from integer without a cast [-Wint-conversion]
     281 |   pt = spte_to_child_pt(old_spte, level);
         |      ^
   At top level:
   arch/x86/kvm/mmu/tdp_mmu.c:208:13: warning: 'handle_changed_spte' defined but not used [-Wunused-function]
     208 | static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
         |             ^~~~~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors

vim +/spte_to_child_pt +281 arch/x86/kvm/mmu/tdp_mmu.c

   192	
   193	static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
   194					u64 old_spte, u64 new_spte, int level);
   195	
   196	/**
   197	 * handle_changed_spte - handle bookkeeping associated with an SPTE change
   198	 * @kvm: kvm instance
   199	 * @as_id: the address space of the paging structure the SPTE was a part of
   200	 * @gfn: the base GFN that was mapped by the SPTE
   201	 * @old_spte: The value of the SPTE before the change
   202	 * @new_spte: The value of the SPTE after the change
   203	 * @level: the level of the PT the SPTE is part of in the paging structure
   204	 *
   205	 * Handle bookkeeping that might result from the modification of a SPTE.
   206	 * This function must be called for all TDP SPTE modifications.
   207	 */
   208	static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
   209					u64 old_spte, u64 new_spte, int level)
   210	{
   211		bool was_present = is_shadow_present_pte(old_spte);
   212		bool is_present = is_shadow_present_pte(new_spte);
   213		bool was_leaf = was_present && is_last_spte(old_spte, level);
   214		bool is_leaf = is_present && is_last_spte(new_spte, level);
   215		bool pfn_changed = spte_to_pfn(old_spte) != spte_to_pfn(new_spte);
   216		u64 *pt;
   217		u64 old_child_spte;
   218		int i;
   219	
   220		WARN_ON(level > PT64_ROOT_MAX_LEVEL);
   221		WARN_ON(level < PG_LEVEL_4K);
   222		WARN_ON(gfn % KVM_PAGES_PER_HPAGE(level));
   223	
   224		/*
   225		 * If this warning were to trigger it would indicate that there was a
   226		 * missing MMU notifier or a race with some notifier handler.
   227		 * A present, leaf SPTE should never be directly replaced with another
   228		 * present leaf SPTE pointing to a differnt PFN. A notifier handler
   229		 * should be zapping the SPTE before the main MM's page table is
   230		 * changed, or the SPTE should be zeroed, and the TLBs flushed by the
   231		 * thread before replacement.
   232		 */
   233		if (was_leaf && is_leaf && pfn_changed) {
   234			pr_err("Invalid SPTE change: cannot replace a present leaf\n"
   235			       "SPTE with another present leaf SPTE mapping a\n"
   236			       "different PFN!\n"
   237			       "as_id: %d gfn: %llx old_spte: %llx new_spte: %llx level: %d",
   238			       as_id, gfn, old_spte, new_spte, level);
   239	
   240			/*
   241			 * Crash the host to prevent error propagation and guest data
   242			 * courruption.
   243			 */
   244			BUG();
   245		}
   246	
   247		if (old_spte == new_spte)
   248			return;
   249	
   250		/*
   251		 * The only times a SPTE should be changed from a non-present to
   252		 * non-present state is when an MMIO entry is installed/modified/
   253		 * removed. In that case, there is nothing to do here.
   254		 */
   255		if (!was_present && !is_present) {
   256			/*
   257			 * If this change does not involve a MMIO SPTE, it is
   258			 * unexpected. Log the change, though it should not impact the
   259			 * guest since both the former and current SPTEs are nonpresent.
   260			 */
   261			if (WARN_ON(!is_mmio_spte(old_spte) && !is_mmio_spte(new_spte)))
   262				pr_err("Unexpected SPTE change! Nonpresent SPTEs\n"
   263				       "should not be replaced with another,\n"
   264				       "different nonpresent SPTE, unless one or both\n"
   265				       "are MMIO SPTEs.\n"
   266				       "as_id: %d gfn: %llx old_spte: %llx new_spte: %llx level: %d",
   267				       as_id, gfn, old_spte, new_spte, level);
   268			return;
   269		}
   270	
   271	
   272		if (was_leaf && is_dirty_spte(old_spte) &&
   273		    (!is_dirty_spte(new_spte) || pfn_changed))
   274			kvm_set_pfn_dirty(spte_to_pfn(old_spte));
   275	
   276		/*
   277		 * Recursively handle child PTs if the change removed a subtree from
   278		 * the paging structure.
   279		 */
   280		if (was_present && !was_leaf && (pfn_changed || !is_present)) {
 > 281			pt = spte_to_child_pt(old_spte, level);

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

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