[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH v8 11/13] arm/mem_access: Add long-descriptor based gpt



Hi Sergej,

On 09/08/17 09:20, Sergej Proskurin wrote:
+    /*
+     * According to to ARM DDI 0487B.a J1-5927, we return an error if the found

Please drop one of the 'to'. The rest looks good to me.

+     * PTE is invalid or holds a reserved entry (PTE<1:0> == x0)) or if the PTE
+     * maps a memory block at level 3 (PTE<1:0> == 01).
+     */
+    if ( !lpae_is_page(pte, level) && !lpae_is_superpage(pte, level) )
+        return -EFAULT;
+
+    /* Make sure that the lower bits of the PTE's base address are zero. */
+    mask = GENMASK_ULL(47, grainsizes[gran]);
+    *ipa = (pfn_to_paddr(pte.walk.base) & mask) | (gva & masks[gran][level]);
+
+    /*
+     * Set permissions so that the caller can check the flags by herself. Note
+     * that stage 1 translations also inherit attributes from the tables
+     * (ARM DDI 0487B.a J1-5928).
+     */
+    if ( !pte.pt.ro && !ro_table )
+        *perms |= GV2M_WRITE;
+    if ( !pte.pt.xn && !xn_table )
+        *perms |= GV2M_EXEC;
+
+    return 0;
 }

Cheers,

--
Julien Grall

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel

 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.