KVM: MMU: handle page removal with shadow mapping
Do not assume that a shadow mapping will always point to the same host frame number. Fixes crash with madvise(MADV_DONTNEED). [avi: move after first printk(), add another printk()] Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
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@ -892,14 +892,25 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
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int *ptwrite, gfn_t gfn, struct page *page)
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{
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u64 spte;
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int was_rmapped = is_rmap_pte(*shadow_pte);
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int was_rmapped = 0;
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int was_writeble = is_writeble_pte(*shadow_pte);
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hfn_t host_pfn = (*shadow_pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
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pgprintk("%s: spte %llx access %x write_fault %d"
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" user_fault %d gfn %lx\n",
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__FUNCTION__, *shadow_pte, pt_access,
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write_fault, user_fault, gfn);
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if (is_rmap_pte(*shadow_pte)) {
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if (host_pfn != page_to_pfn(page)) {
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pgprintk("hfn old %lx new %lx\n",
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host_pfn, page_to_pfn(page));
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rmap_remove(vcpu->kvm, shadow_pte);
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}
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else
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was_rmapped = 1;
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}
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/*
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* We don't set the accessed bit, since we sometimes want to see
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* whether the guest actually used the pte (in order to detect
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