Could anyone help me understand what the meaning of the hardcoded 3 in that macro is? With PGT_va_mask being an 11-bit mask I can''t seem to make any sense of this. And while at this, for 64-bits PGT_va_mask is defined as a 28-bit mask, but the comment there as well as my calculations say this should be only 27 bits. Thanks, Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Jan Beulich wrote:> Could anyone help me understand what the meaning of the hardcoded 3 in that > macro is?xen address space window is in l2 table #3 (of 4) ... cheers, Gerd -- Gerd Hoffmann <kraxel@suse.de> _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
>>> Gerd Hoffmann <kraxel@suse.de> 12.09.06 16:25 >>> >Jan Beulich wrote: >> Could anyone help me understand what the meaning of the hardcoded 3 in that >> macro is? > >xen address space window is in l2 table #3 (of 4) ...That''s why I pointed out that the mask is 11 bits (not 2) - what you say would mean that the constant should be 0x600 (the top 11 bits of such a va), and comparison should be >= rather than ==. Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Jan Beulich wrote:>>>> Gerd Hoffmann <kraxel@suse.de> 12.09.06 16:25 >>> >> Jan Beulich wrote: >>> Could anyone help me understand what the meaning of the hardcoded 3 in that >>> macro is? >> xen address space window is in l2 table #3 (of 4) ... > > That''s why I pointed out that the mask is 11 bits (not 2) - what you say would mean > that the constant should be 0x600 (the top 11 bits of such a va), and comparison > should be >= rather than ==.IIRC the full 11 bits are needed for L1 tables only (2 indexing into L3 and 9 indexing into L2). Has been quite some time I looked into this code ... cheers, Gerd -- Gerd Hoffmann <kraxel@suse.de> _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel