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authorSean Christopherson <seanjc@google.com>2022-11-11 01:18:41 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2022-11-11 13:19:46 +0100
commit6d3085e4d89ad7e6c7f1c6cf929d903393565861 (patch)
treec777842fc7f1aab49ac04b147a737475ab0d2718
parentMerge tag 'kvm-s390-master-6.1-1' of https://git.kernel.org/pub/scm/linux/ker... (diff)
downloadlinux-6d3085e4d89ad7e6c7f1c6cf929d903393565861.tar.xz
linux-6d3085e4d89ad7e6c7f1c6cf929d903393565861.zip
KVM: x86/mmu: Block all page faults during kvm_zap_gfn_range()
When zapping a GFN range, pass 0 => ALL_ONES for the to-be-invalidated range to effectively block all page faults while the zap is in-progress. The invalidation helpers take a host virtual address, whereas zapping a GFN obviously provides a guest physical address and with the wrong unit of measurement (frame vs. byte). Alternatively, KVM could walk all memslots to get the associated HVAs, but thanks to SMM, that would require multiple lookups. And practically speaking, kvm_zap_gfn_range() usage is quite rare and not a hot path, e.g. MTRR and CR0.CD are almost guaranteed to be done only on vCPU0 during boot, and APICv inhibits are similarly infrequent operations. Fixes: edb298c663fc ("KVM: x86/mmu: bump mmu notifier count in kvm_zap_gfn_range") Reported-by: Chao Peng <chao.p.peng@linux.intel.com> Cc: stable@vger.kernel.org Cc: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221111001841.2412598-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--arch/x86/kvm/mmu/mmu.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 6f81539061d6..1ccb769f62af 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -6056,7 +6056,7 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end)
write_lock(&kvm->mmu_lock);
- kvm_mmu_invalidate_begin(kvm, gfn_start, gfn_end);
+ kvm_mmu_invalidate_begin(kvm, 0, -1ul);
flush = kvm_rmap_zap_gfn_range(kvm, gfn_start, gfn_end);
@@ -6070,7 +6070,7 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end)
kvm_flush_remote_tlbs_with_address(kvm, gfn_start,
gfn_end - gfn_start);
- kvm_mmu_invalidate_end(kvm, gfn_start, gfn_end);
+ kvm_mmu_invalidate_end(kvm, 0, -1ul);
write_unlock(&kvm->mmu_lock);
}