Messages in this thread | | | Date | Wed, 16 Aug 2023 15:01:51 -0700 | Subject | Re: [PATCH v10 7/9] KVM: VMX: Implement and wire get_untagged_addr() for LAM | From | Sean Christopherson <> |
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On Wed, Jul 19, 2023, Binbin Wu wrote: > + return (sign_extend64(gva, lam_bit) & ~BIT_ULL(63)) | (gva & BIT_ULL(63));
Almost forgot. Please add a comment explaning how LAM untags the address, specifically the whole bit 63 preservation. The logic is actually straightforward, but the above looks way more complex than it actually is. This?
/* * Untag the address by sign-extending the LAM bit, but NOT to bit 63. * Bit 63 is retained from the raw virtual address so that untagging * doesn't change a user access to a supervisor access, and vice versa. */
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