Messages in this thread | | | Date | Wed, 15 Jun 2022 15:49:50 +0200 | From | Paolo Bonzini <> | Subject | Re: [PATCH v2 5/8] KVM: x86/mmu: Use separate namespaces for guest PTEs and shadow PTEs |
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On 6/15/22 01:33, Sean Christopherson wrote: > @@ -2027,8 +2013,8 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, > role.direct = direct; > role.access = access; > if (role.has_4_byte_gpte) { > - quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level)); > - quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1; > + quadrant = gaddr >> (PAGE_SHIFT + (SPTE_LEVEL_BITS * level)); > + quadrant &= (1 << ((PT32_LEVEL_BITS - SPTE_LEVEL_BITS) * level)) - 1; > role.quadrant = quadrant;
That's just a fancy 1, though, and this is just
/* * Isolate the bits of the address that have already been used by the * 8-byte shadow page table structures, but not yet in the 4-byte guest * page tables. For example, a 4-byte PDE consumes bits 31:22 and an * 8-byte PDE consumes bits 29:21, so bits 31:30 go in the hash * key. The hash table look up up ensures that each sPTE points to * the page for the correct portion of the guest page table structure. */ quadrant = gaddr >> (PAGE_SHIFT + (SPTE_LEVEL_BITS * level)); quadrant &= (1 << level) - 1;
(Not the best comment, understood).
Paolo
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