[arm-platforms:kvm-arm64/nv-5.16 38/71] arch/arm64/kvm/mmu.c:178: warning: expecting prototype for kvm_unmap_stage2_range(). Prototype was for __unmap_stage2_range() instead
kernel test robot
lkp at intel.com
Sun Nov 28 09:25:19 PST 2021
tree: https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git kvm-arm64/nv-5.16
head: 6162310e2419353608acd8f247bde3fc848d4f64
commit: cd6a3361a2f89c063eb12cead9808136d54cd18f [38/71] KVM: arm64: nv: Support multiple nested Stage-2 mmu structures
config: arm64-allyesconfig (https://download.01.org/0day-ci/archive/20211129/202111290109.52igH1P0-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 11.2.0
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
# https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git/commit/?id=cd6a3361a2f89c063eb12cead9808136d54cd18f
git remote add arm-platforms https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git
git fetch --no-tags arm-platforms kvm-arm64/nv-5.16
git checkout cd6a3361a2f89c063eb12cead9808136d54cd18f
# save the config file to linux build tree
mkdir build_dir
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=arm64 SHELL=/bin/bash arch/arm64/kvm/
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp at intel.com>
All warnings (new ones prefixed by >>):
>> arch/arm64/kvm/mmu.c:178: warning: expecting prototype for kvm_unmap_stage2_range(). Prototype was for __unmap_stage2_range() instead
vim +178 arch/arm64/kvm/mmu.c
378e6a9c78a02b arch/arm64/kvm/mmu.c Yanan Wang 2021-06-17 139
363ef89f8e9bce arch/arm/kvm/mmu.c Marc Zyngier 2014-12-19 140 /*
363ef89f8e9bce arch/arm/kvm/mmu.c Marc Zyngier 2014-12-19 141 * Unmapping vs dcache management:
363ef89f8e9bce arch/arm/kvm/mmu.c Marc Zyngier 2014-12-19 142 *
363ef89f8e9bce arch/arm/kvm/mmu.c Marc Zyngier 2014-12-19 143 * If a guest maps certain memory pages as uncached, all writes will
363ef89f8e9bce arch/arm/kvm/mmu.c Marc Zyngier 2014-12-19 144 * bypass the data cache and go directly to RAM. However, the CPUs
363ef89f8e9bce arch/arm/kvm/mmu.c Marc Zyngier 2014-12-19 145 * can still speculate reads (not writes) and fill cache lines with
363ef89f8e9bce arch/arm/kvm/mmu.c Marc Zyngier 2014-12-19 146 * data.
363ef89f8e9bce arch/arm/kvm/mmu.c Marc Zyngier 2014-12-19 147 *
363ef89f8e9bce arch/arm/kvm/mmu.c Marc Zyngier 2014-12-19 148 * Those cache lines will be *clean* cache lines though, so a
363ef89f8e9bce arch/arm/kvm/mmu.c Marc Zyngier 2014-12-19 149 * clean+invalidate operation is equivalent to an invalidate
363ef89f8e9bce arch/arm/kvm/mmu.c Marc Zyngier 2014-12-19 150 * operation, because no cache lines are marked dirty.
363ef89f8e9bce arch/arm/kvm/mmu.c Marc Zyngier 2014-12-19 151 *
363ef89f8e9bce arch/arm/kvm/mmu.c Marc Zyngier 2014-12-19 152 * Those clean cache lines could be filled prior to an uncached write
363ef89f8e9bce arch/arm/kvm/mmu.c Marc Zyngier 2014-12-19 153 * by the guest, and the cache coherent IO subsystem would therefore
363ef89f8e9bce arch/arm/kvm/mmu.c Marc Zyngier 2014-12-19 154 * end up writing old data to disk.
363ef89f8e9bce arch/arm/kvm/mmu.c Marc Zyngier 2014-12-19 155 *
363ef89f8e9bce arch/arm/kvm/mmu.c Marc Zyngier 2014-12-19 156 * This is why right after unmapping a page/section and invalidating
52bae936f0e7be arch/arm64/kvm/mmu.c Will Deacon 2020-09-11 157 * the corresponding TLBs, we flush to make sure the IO subsystem will
52bae936f0e7be arch/arm64/kvm/mmu.c Will Deacon 2020-09-11 158 * never hit in the cache.
e48d53a91f6e90 virt/kvm/arm/mmu.c Marc Zyngier 2018-04-06 159 *
e48d53a91f6e90 virt/kvm/arm/mmu.c Marc Zyngier 2018-04-06 160 * This is all avoided on systems that have ARM64_HAS_STAGE2_FWB, as
e48d53a91f6e90 virt/kvm/arm/mmu.c Marc Zyngier 2018-04-06 161 * we then fully enforce cacheability of RAM, no matter what the guest
e48d53a91f6e90 virt/kvm/arm/mmu.c Marc Zyngier 2018-04-06 162 * does.
363ef89f8e9bce arch/arm/kvm/mmu.c Marc Zyngier 2014-12-19 163 */
7a1c831ee8553b arch/arm/kvm/mmu.c Suzuki K Poulose 2016-03-23 164 /**
cd6a3361a2f89c arch/arm64/kvm/mmu.c Marc Zyngier 2021-04-26 165 * kvm_unmap_stage2_range -- Clear stage2 page table entries to unmap a range
c9c0279cc02b4e arch/arm64/kvm/mmu.c Xiaofei Tan 2020-09-17 166 * @mmu: The KVM stage-2 MMU pointer
7a1c831ee8553b arch/arm/kvm/mmu.c Suzuki K Poulose 2016-03-23 167 * @start: The intermediate physical base address of the range to unmap
7a1c831ee8553b arch/arm/kvm/mmu.c Suzuki K Poulose 2016-03-23 168 * @size: The size of the area to unmap
c9c0279cc02b4e arch/arm64/kvm/mmu.c Xiaofei Tan 2020-09-17 169 * @may_block: Whether or not we are permitted to block
7a1c831ee8553b arch/arm/kvm/mmu.c Suzuki K Poulose 2016-03-23 170 *
7a1c831ee8553b arch/arm/kvm/mmu.c Suzuki K Poulose 2016-03-23 171 * Clear a range of stage-2 mappings, lowering the various ref-counts. Must
7a1c831ee8553b arch/arm/kvm/mmu.c Suzuki K Poulose 2016-03-23 172 * be called while holding mmu_lock (unless for freeing the stage2 pgd before
7a1c831ee8553b arch/arm/kvm/mmu.c Suzuki K Poulose 2016-03-23 173 * destroying the VM), otherwise another faulting VCPU may come in and mess
7a1c831ee8553b arch/arm/kvm/mmu.c Suzuki K Poulose 2016-03-23 174 * with things behind our backs.
7a1c831ee8553b arch/arm/kvm/mmu.c Suzuki K Poulose 2016-03-23 175 */
b5331379bc6261 arch/arm64/kvm/mmu.c Will Deacon 2020-08-11 176 static void __unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size,
b5331379bc6261 arch/arm64/kvm/mmu.c Will Deacon 2020-08-11 177 bool may_block)
4f853a714bf163 arch/arm/kvm/mmu.c Christoffer Dall 2014-05-09 @178 {
cfb1a98de7a9aa arch/arm64/kvm/mmu.c Quentin Perret 2021-03-19 179 struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu);
52bae936f0e7be arch/arm64/kvm/mmu.c Will Deacon 2020-09-11 180 phys_addr_t end = start + size;
4f853a714bf163 arch/arm/kvm/mmu.c Christoffer Dall 2014-05-09 181
8b3405e345b5a0 arch/arm/kvm/mmu.c Suzuki K Poulose 2017-04-03 182 assert_spin_locked(&kvm->mmu_lock);
47a91b7232fa25 virt/kvm/arm/mmu.c Jia He 2018-05-21 183 WARN_ON(size & ~PAGE_MASK);
52bae936f0e7be arch/arm64/kvm/mmu.c Will Deacon 2020-09-11 184 WARN_ON(stage2_apply_range(kvm, start, end, kvm_pgtable_stage2_unmap,
52bae936f0e7be arch/arm64/kvm/mmu.c Will Deacon 2020-09-11 185 may_block));
342cd0ab0e6ca3 arch/arm/kvm/mmu.c Christoffer Dall 2013-01-20 186 }
000d399625b4b3 arch/arm/kvm/mmu.c Marc Zyngier 2013-03-05 187
:::::: The code at line 178 was first introduced by commit
:::::: 4f853a714bf16338ff5261128e6c7ae2569e9505 arm/arm64: KVM: Fix and refactor unmap_range
:::::: TO: Christoffer Dall <christoffer.dall at linaro.org>
:::::: CC: Christoffer Dall <christoffer.dall at linaro.org>
---
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