Subject: Re: [PATCH v1 2/4] KVM: PPC: Book3S HV: track shared GFNs of secure VMs

From: kbuild test robot <[email-masked]>
Date: Mon, 1 Jun 2020 12:12:29 +0800

Hi Ram,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on powerpc/next]
[also build test WARNING on v5.7 next-20200529]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Ram-Pai/Migrate-non-migrated-pages-of-a-SVM/20200601-034649
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: powerpc-allyesconfig (attached as .config)
compiler: powerpc64-linux-gcc (GCC) 9.3.0
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
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=powerpc 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <[email-masked]>

All warnings (new ones prefixed by >>, old ones prefixed by <<):

arch/powerpc/kvm/book3s_hv_uvmem.c:158:6: warning: no previous prototype for 'kvmppc_uvmem_available' [-Wmissing-prototypes]
158 | bool kvmppc_uvmem_available(void)
|      ^~~~~~~~~~~~~~~~~~~~~~
arch/powerpc/kvm/book3s_hv_uvmem.c:167:5: warning: no previous prototype for 'kvmppc_uvmem_slot_init' [-Wmissing-prototypes]
167 | int kvmppc_uvmem_slot_init(struct kvm *kvm, const struct kvm_memory_slot *slot)
|     ^~~~~~~~~~~~~~~~~~~~~~
arch/powerpc/kvm/book3s_hv_uvmem.c:192:6: warning: no previous prototype for 'kvmppc_uvmem_slot_free' [-Wmissing-prototypes]
192 | void kvmppc_uvmem_slot_free(struct kvm *kvm, const struct kvm_memory_slot *slot)
|      ^~~~~~~~~~~~~~~~~~~~~~
>> arch/powerpc/kvm/book3s_hv_uvmem.c:279:6: warning: no previous prototype for 'kvmppc_gfn_is_uvmem_shared' [-Wmissing-prototypes]
279 | bool kvmppc_gfn_is_uvmem_shared(unsigned long gfn, struct kvm *kvm)
|      ^~~~~~~~~~~~~~~~~~~~~~~~~~
arch/powerpc/kvm/book3s_hv_uvmem.c:293:15: warning: no previous prototype for 'kvmppc_h_svm_init_start' [-Wmissing-prototypes]
293 | unsigned long kvmppc_h_svm_init_start(struct kvm *kvm)
|               ^~~~~~~~~~~~~~~~~~~~~~~
arch/powerpc/kvm/book3s_hv_uvmem.c:335:15: warning: no previous prototype for 'kvmppc_h_svm_init_done' [-Wmissing-prototypes]
335 | unsigned long kvmppc_h_svm_init_done(struct kvm *kvm)
|               ^~~~~~~~~~~~~~~~~~~~~~
arch/powerpc/kvm/book3s_hv_uvmem.c:356:6: warning: no previous prototype for 'kvmppc_uvmem_drop_pages' [-Wmissing-prototypes]
356 | void kvmppc_uvmem_drop_pages(const struct kvm_memory_slot *free,
|      ^~~~~~~~~~~~~~~~~~~~~~~
arch/powerpc/kvm/book3s_hv_uvmem.c:397:15: warning: no previous prototype for 'kvmppc_h_svm_init_abort' [-Wmissing-prototypes]
397 | unsigned long kvmppc_h_svm_init_abort(struct kvm *kvm)
|               ^~~~~~~~~~~~~~~~~~~~~~~
arch/powerpc/kvm/book3s_hv_uvmem.c:599:15: warning: no previous prototype for 'kvmppc_h_svm_page_in' [-Wmissing-prototypes]
599 | unsigned long kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gpa,
|               ^~~~~~~~~~~~~~~~~~~~
arch/powerpc/kvm/book3s_hv_uvmem.c:784:1: warning: no previous prototype for 'kvmppc_h_svm_page_out' [-Wmissing-prototypes]
784 | kvmppc_h_svm_page_out(struct kvm *kvm, unsigned long gpa,
| ^~~~~~~~~~~~~~~~~~~~~
arch/powerpc/kvm/book3s_hv_uvmem.c:822:5: warning: no previous prototype for 'kvmppc_send_page_to_uv' [-Wmissing-prototypes]
822 | int kvmppc_send_page_to_uv(struct kvm *kvm, unsigned long gfn)
|     ^~~~~~~~~~~~~~~~~~~~~~
arch/powerpc/kvm/book3s_hv_uvmem.c:867:5: warning: no previous prototype for 'kvmppc_uvmem_init' [-Wmissing-prototypes]
867 | int kvmppc_uvmem_init(void)
|     ^~~~~~~~~~~~~~~~~
arch/powerpc/kvm/book3s_hv_uvmem.c:922:6: warning: no previous prototype for 'kvmppc_uvmem_free' [-Wmissing-prototypes]
922 | void kvmppc_uvmem_free(void)
|      ^~~~~~~~~~~~~~~~~

vim +/kvmppc_gfn_is_uvmem_shared +279 arch/powerpc/kvm/book3s_hv_uvmem.c

   157	
 > 158	bool kvmppc_uvmem_available(void)
   159	{
   160		/*
   161		 * If kvmppc_uvmem_bitmap != NULL, then there is an ultravisor
   162		 * and our data structures have been initialized successfully.
   163		 */
   164		return !!kvmppc_uvmem_bitmap;
   165	}
   166	
   167	int kvmppc_uvmem_slot_init(struct kvm *kvm, const struct kvm_memory_slot *slot)
   168	{
   169		struct kvmppc_uvmem_slot *p;
   170	
   171		p = kzalloc(sizeof(*p), GFP_KERNEL);
   172		if (!p)
   173			return -ENOMEM;
   174		p->pfns = vzalloc(array_size(slot->npages, sizeof(*p->pfns)));
   175		if (!p->pfns) {
   176			kfree(p);
   177			return -ENOMEM;
   178		}
   179		p->nr_pfns = slot->npages;
   180		p->base_pfn = slot->base_gfn;
   181	
   182		mutex_lock(&kvm->arch.uvmem_lock);
   183		list_add(&p->list, &kvm->arch.uvmem_pfns);
   184		mutex_unlock(&kvm->arch.uvmem_lock);
   185	
   186		return 0;
   187	}
   188	
   189	/*
   190	 * All device PFNs are already released by the time we come here.
   191	 */
   192	void kvmppc_uvmem_slot_free(struct kvm *kvm, const struct kvm_memory_slot *slot)
   193	{
   194		struct kvmppc_uvmem_slot *p, *next;
   195	
   196		mutex_lock(&kvm->arch.uvmem_lock);
   197		list_for_each_entry_safe(p, next, &kvm->arch.uvmem_pfns, list) {
   198			if (p->base_pfn == slot->base_gfn) {
   199				vfree(p->pfns);
   200				list_del(&p->list);
   201				kfree(p);
   202				break;
   203			}
   204		}
   205		mutex_unlock(&kvm->arch.uvmem_lock);
   206	}
   207	
   208	static void kvmppc_uvmem_pfn_insert(unsigned long gfn, unsigned long uvmem_pfn,
   209					    struct kvm *kvm)
   210	{
   211		struct kvmppc_uvmem_slot *p;
   212	
   213		list_for_each_entry(p, &kvm->arch.uvmem_pfns, list) {
   214			if (gfn >= p->base_pfn && gfn < p->base_pfn + p->nr_pfns) {
   215				unsigned long index = gfn - p->base_pfn;
   216	
   217				p->pfns[index] = uvmem_pfn | KVMPPC_UVMEM_PFN;
   218				return;
   219			}
   220		}
   221	}
   222	
   223	static void kvmppc_uvmem_pfn_remove(unsigned long gfn, struct kvm *kvm)
   224	{
   225		struct kvmppc_uvmem_slot *p;
   226	
   227		list_for_each_entry(p, &kvm->arch.uvmem_pfns, list) {
   228			if (gfn >= p->base_pfn && gfn < p->base_pfn + p->nr_pfns) {
   229				/*
   230				 * Reset everything, but keep the KVMPPC_UVMEM_SHARED
   231				 * flag intact.  A gfn continues to be shared or
   232				 * unshared, with or without an associated device pfn.
   233				 */
   234				p->pfns[gfn - p->base_pfn] &= KVMPPC_UVMEM_SHARED;
   235				return;
   236			}
   237		}
   238	}
   239	
   240	static bool kvmppc_gfn_is_uvmem_pfn(unsigned long gfn, struct kvm *kvm,
   241					    unsigned long *uvmem_pfn)
   242	{
   243		struct kvmppc_uvmem_slot *p;
   244	
   245		list_for_each_entry(p, &kvm->arch.uvmem_pfns, list) {
   246			if (gfn >= p->base_pfn && gfn < p->base_pfn + p->nr_pfns) {
   247				unsigned long index = gfn - p->base_pfn;
   248	
   249				if (p->pfns[index] & KVMPPC_UVMEM_PFN) {
   250					if (uvmem_pfn)
   251						*uvmem_pfn = p->pfns[index] &
   252							     KVMPPC_UVMEM_PFN_MASK;
   253					return true;
   254				} else
   255					return false;
   256			}
   257		}
   258		return false;
   259	}
   260	
   261	static void kvmppc_gfn_uvmem_shared(unsigned long gfn, struct kvm *kvm,
   262			bool set)
   263	{
   264		struct kvmppc_uvmem_slot *p;
   265	
   266		list_for_each_entry(p, &kvm->arch.uvmem_pfns, list) {
   267			if (gfn >= p->base_pfn && gfn < p->base_pfn + p->nr_pfns) {
   268				unsigned long index = gfn - p->base_pfn;
   269	
   270				if (set)
   271					p->pfns[index] |= KVMPPC_UVMEM_SHARED;
   272				else
   273					p->pfns[index] &= ~KVMPPC_UVMEM_SHARED;
   274				return;
   275			}
   276		}
   277	}
   278	
 > 279	bool kvmppc_gfn_is_uvmem_shared(unsigned long gfn, struct kvm *kvm)
   280	{
   281		struct kvmppc_uvmem_slot *p;
   282	
   283		list_for_each_entry(p, &kvm->arch.uvmem_pfns, list) {
   284			if (gfn >= p->base_pfn && gfn < p->base_pfn + p->nr_pfns) {
   285				unsigned long index = gfn - p->base_pfn;
   286	
   287				return (p->pfns[index] & KVMPPC_UVMEM_SHARED);
   288			}
   289		}
   290		return false;
   291	}
   292	

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