cr4_fixed1_update(X86_CR4_UMIP, ecx, feature_bit(UMIP));
cr4_fixed1_update(X86_CR4_LA57, ecx, feature_bit(LA57));
+ entry = kvm_find_cpuid_entry_index(vcpu, 0x7, 1);
+ cr4_fixed1_update(X86_CR4_LAM_SUP, eax, feature_bit(LAM));
+
#undef cr4_fixed1_update
}
free_pages((unsigned long)kvm_vmx->pid_table, vmx_get_pid_table_order(kvm));
}
+/*
+ * Note, the SDM states that the linear address is masked *after* the modified
+ * canonicality check, whereas KVM masks (untags) the address and then performs
+ * a "normal" canonicality check. Functionally, the two methods are identical,
+ * and when the masking occurs relative to the canonicality check isn't visible
+ * to software, i.e. KVM's behavior doesn't violate the SDM.
+ */
gva_t vmx_get_untagged_addr(struct kvm_vcpu *vcpu, gva_t gva, unsigned int flags)
{
- return gva;
+ int lam_bit;
+
+ if (flags & (X86EMUL_F_FETCH | X86EMUL_F_IMPLICIT | X86EMUL_F_INVLPG))
+ return gva;
+
+ if (!is_64_bit_mode(vcpu))
+ return gva;
+
+ /*
+ * Bit 63 determines if the address should be treated as user address
+ * or a supervisor address.
+ */
+ if (!(gva & BIT_ULL(63))) {
+ /* KVM doesn't yet virtualize LAM_U{48,57}. */
+ return gva;
+ } else {
+ if (!kvm_is_cr4_bit_set(vcpu, X86_CR4_LAM_SUP))
+ return gva;
+
+ lam_bit = kvm_is_cr4_bit_set(vcpu, X86_CR4_LA57) ? 56 : 47;
+ }
+
+ /*
+ * 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.
+ */
+ return (sign_extend64(gva, lam_bit) & ~BIT_ULL(63)) | (gva & BIT_ULL(63));
}
static struct kvm_x86_ops vmx_x86_ops __initdata = {