Hi Ben,

url:    https://github.com/0day-ci/linux/commits/Ben-Gardon/Introduce-the-TDP-MMU/20200926-052649
base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 6d28cf7dfede6cfca5119a0d415a6a447c68f3a0
config: x86_64-randconfig-m001-20201008 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0

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

smatch warnings:
arch/x86/kvm/mmu/mmu.c:3995 get_mmio_spte() error: uninitialized symbol 'root'.

vim +/root +3995 arch/x86/kvm/mmu/mmu.c

ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3974  static bool get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep)
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3975  {
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3976  	u64 sptes[PT64_ROOT_MAX_LEVEL];
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3977  	struct rsvd_bits_validate *rsvd_check;
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3978  	int root;

"root" is never initialized anywhere.  Part of the commit missing?

ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3979  	int leaf;
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3980  	int level;
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3981  	bool reserved = false;
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3982  
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3983  	if (!VALID_PAGE(vcpu->arch.mmu->root_hpa)) {
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3984  		*sptep = 0ull;
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3985  		return reserved;
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3986  	}
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3987  
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3988  	if (is_tdp_mmu_root(vcpu->kvm, vcpu->arch.mmu->root_hpa))
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3989  		leaf = kvm_tdp_mmu_get_walk(vcpu, addr, sptes);
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3990  	else
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3991  		leaf = get_walk(vcpu, addr, sptes);
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3992  
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3993  	rsvd_check = &vcpu->arch.mmu->shadow_zero_check;
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3994  
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25 @3995  	for (level = root; level >= leaf; level--) {
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3996  		if (!is_shadow_present_pte(sptes[level - 1]))
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  3997  			break;
b5c3c1b3c6e95cc arch/x86/kvm/mmu/mmu.c Sean Christopherson 2020-01-09  3998  		/*
b5c3c1b3c6e95cc arch/x86/kvm/mmu/mmu.c Sean Christopherson 2020-01-09  3999  		 * Use a bitwise-OR instead of a logical-OR to aggregate the
b5c3c1b3c6e95cc arch/x86/kvm/mmu/mmu.c Sean Christopherson 2020-01-09  4000  		 * reserved bit and EPT's invalid memtype/XWR checks to avoid
b5c3c1b3c6e95cc arch/x86/kvm/mmu/mmu.c Sean Christopherson 2020-01-09  4001  		 * adding a Jcc in the loop.
b5c3c1b3c6e95cc arch/x86/kvm/mmu/mmu.c Sean Christopherson 2020-01-09  4002  		 */
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  4003  		reserved |= __is_bad_mt_xwr(rsvd_check, sptes[level - 1]) |
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  4004  			    __is_rsvd_bits_set(rsvd_check, sptes[level - 1],
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  4005  					       level);
47ab8751695f71d arch/x86/kvm/mmu.c     Xiao Guangrong      2015-08-05  4006  	}
47ab8751695f71d arch/x86/kvm/mmu.c     Xiao Guangrong      2015-08-05  4007  
47ab8751695f71d arch/x86/kvm/mmu.c     Xiao Guangrong      2015-08-05  4008  	if (reserved) {
47ab8751695f71d arch/x86/kvm/mmu.c     Xiao Guangrong      2015-08-05  4009  		pr_err("%s: detect reserved bits on spte, addr 0x%llx, dump hierarchy:\n",
47ab8751695f71d arch/x86/kvm/mmu.c     Xiao Guangrong      2015-08-05  4010  		       __func__, addr);
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  4011  		for (level = root; level >= leaf; level--)
47ab8751695f71d arch/x86/kvm/mmu.c     Xiao Guangrong      2015-08-05  4012  			pr_err("------ spte 0x%llx level %d.\n",
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  4013  			       sptes[level - 1], level);
47ab8751695f71d arch/x86/kvm/mmu.c     Xiao Guangrong      2015-08-05  4014  	}
ddce6208217c1aa arch/x86/kvm/mmu/mmu.c Sean Christopherson 2019-12-06  4015  
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  4016  	*sptep = sptes[leaf - 1];
ea7e7c74afc3303 arch/x86/kvm/mmu/mmu.c Ben Gardon          2020-09-25  4017  
47ab8751695f71d arch/x86/kvm/mmu.c     Xiao Guangrong      2015-08-05  4018  	return reserved;
ce88decffd17bf9 arch/x86/kvm/mmu.c     Xiao Guangrong      2011-07-12  4019  }

---
0-DAY CI Kernel Test Service, Intel Corporation
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