Hi all, Beginning from commit 4138cc3418f5, ioremap_nocache() sets the _PAGE_PWT flag.
Lguest doesn't accept a guest pte with a _PWT flag and reports a "bad page table entry" in that case. I've removed check from lguest code and everything worked fine. Is this safe from the Lguest side ? Mentioned commit [*]: commit 4138cc3418f5eaa7524ff8e927102863f1ba0ea5 Author: Siddha, Suresh B <[EMAIL PROTECTED]> Date: Wed Jan 30 13:33:43 2008 +0100 x86: set strong uncacheable where UC is really desired Also use _PAGE_PWT for all the mappings which need uncache mapping. Instead of existing PAT2 which is UC- (and can be overwritten by MTRRs), we now use PAT3 which is strong uncacheable. This makes it consistent with pgprot_noncached() diff --git a/arch/x86/mm/ioremap_32.c b/arch/x86/mm/ioremap_32.c index 0b27831..ef0f6a4 100644 --- a/arch/x86/mm/ioremap_32.c +++ b/arch/x86/mm/ioremap_32.c @@ -119,7 +119,7 @@ EXPORT_SYMBOL(__ioremap); void __iomem *ioremap_nocache (unsigned long phys_addr, unsigned long size) { unsigned long last_addr; - void __iomem *p = __ioremap(phys_addr, size, _PAGE_PCD); + void __iomem *p = __ioremap(phys_addr, size, _PAGE_PCD | _PAGE_PWT); if (!p) return p; Thanks, [*]: latest pull calls set_memory_uc() which also sets the _PWT flag. -- Ahmed S. Darwish Homepage: http://darwish.07.googlepages.com Blog: http://darwish-07.blogspot.com -- 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/