2014-09-18 19:46 GMT+04:00 Dave Hansen <[email protected]>: > > From: Dave Hansen <[email protected]> > > Peter Anvin says: >> 0xffff880000000000 is the lowest usable address because we have >> agreed to leave 0xffff800000000000-0xffff880000000000 for the >> hypervisor or other non-OS uses. > > Let's call this out in the documentation. > > This came up during the kernel address sanitizer discussions > where it was proposed to use this area for other kernel things. > > Signed-off-by: Dave Hansen <[email protected]> > Cc: Andrey Ryabinin <[email protected]> > Cc: Dmitry Vyukov <[email protected]> > Cc: Andi Kleen <[email protected]> > Cc: [email protected] > Cc: [email protected] > Cc: Thomas Gleixner <[email protected]> > Cc: Ingo Molnar <[email protected]> > --- > > b/Documentation/x86/x86_64/mm.txt | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff -puN Documentation/x86/x86_64/mm.txt~update-x86-mm-doc > Documentation/x86/x86_64/mm.txt > --- a/Documentation/x86/x86_64/mm.txt~update-x86-mm-doc 2014-09-17 > 21:44:10.499781092 -0700 > +++ b/Documentation/x86/x86_64/mm.txt 2014-09-17 21:44:31.852740822 -0700 > @@ -5,7 +5,7 @@ Virtual memory map with 4 level page tab > > 0000000000000000 - 00007fffffffffff (=47 bits) user space, different per mm > hole caused by [48:63] sign extension > -ffff800000000000 - ffff80ffffffffff (=40 bits) guard hole > +ffff800000000000 - ffff80ffffffffff (=40 bits) guard hole, reserved for > hypervisor
ffff800000000000 - ffff87ffffffffff (=43 bits) guard hole, reserved for hypervisor > ffff880000000000 - ffffc7ffffffffff (=64 TB) direct mapping of all phys. > memory > ffffc80000000000 - ffffc8ffffffffff (=40 bits) hole > ffffc90000000000 - ffffe8ffffffffff (=45 bits) vmalloc/ioremap space > _ -- Best regards, Andrey Ryabinin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
