# HG changeset patch # User Wei Wang # Node ID 848156536fda60540fe3f482a1fc1d34eeb3532d # Parent 3f00c5faa12aed4d0993391f71b7f12cf92f0208 AMD IOMMU hardware uses bit 9 - bit 11 to encode lower page levels. p2m type bits in p2m flags has to be shifted from bit 9 to bit 12. Also, bit 52 to bit 60 cannot be non-zero for iommu pde. So, the definition of p2m_ram_rw has to be swapped with p2m_invalid. Signed-off-by: Wei Wang diff -r 3f00c5faa12a -r 848156536fda xen/arch/x86/mm/p2m.c --- a/xen/arch/x86/mm/p2m.c Wed Apr 13 16:10:26 2011 +0100 +++ b/xen/arch/x86/mm/p2m.c Fri Apr 15 13:51:54 2011 +0200 @@ -80,7 +80,12 @@ unsigned long p2m_type_to_flags(p2m_type { unsigned long flags; #ifdef __x86_64__ - flags = (unsigned long)(t & 0x3fff) << 9; + /* + * AMD IOMMU: When we share p2m table with iommu, bit 9 - bit 11 will be + * used for iommu hardware to encode next io page level. Bit 59 - bit 62 + * are used for iommu flags, We could not use these bits to store p2m types. + */ + flags = (unsigned long)(t & 0x7f) << 12; #else flags = (t & 0x7UL) << 9; #endif @@ -1826,6 +1831,9 @@ static mfn_t p2m_gfn_to_mfn_current(stru p2mt = p2m_flags_to_type(l1e_get_flags(l1e)); ASSERT(l1e_get_pfn(l1e) != INVALID_MFN || !p2m_is_ram(p2mt)); + if ( l1e.l1 == 0 ) + p2mt = p2m_invalid; + if ( p2m_flags_to_type(l1e_get_flags(l1e)) == p2m_populate_on_demand ) { diff -r 3f00c5faa12a -r 848156536fda xen/include/asm-x86/p2m.h --- a/xen/include/asm-x86/p2m.h Wed Apr 13 16:10:26 2011 +0100 +++ b/xen/include/asm-x86/p2m.h Fri Apr 15 13:51:54 2011 +0200 @@ -63,9 +63,15 @@ * Further expansions of the type system will only be supported on * 64-bit Xen. */ + +/* + * AMD IOMMU: When we share p2m table with iommu, bit 52 -bit 58 in pte + * cannot be non-zero, otherwise, hardware generates io page faults when + * device access those pages. Therefore, p2m_ram_rw has to be defined as 0. + */ typedef enum { - p2m_invalid = 0, /* Nothing mapped here */ - p2m_ram_rw = 1, /* Normal read/write guest RAM */ + p2m_ram_rw = 0, /* Normal read/write guest RAM */ + p2m_invalid = 1, /* Nothing mapped here */ p2m_ram_logdirty = 2, /* Temporarily read-only for log-dirty */ p2m_ram_ro = 3, /* Read-only; writes are silently dropped */ p2m_mmio_dm = 4, /* Reads and write go to the device model */ @@ -375,7 +381,13 @@ static inline p2m_type_t p2m_flags_to_ty { /* Type is stored in the "available" bits */ #ifdef __x86_64__ - return (flags >> 9) & 0x3fff; + /* + * AMD IOMMU: When we share p2m table with iommu, bit 9 - bit 11 will be + * used for iommu hardware to encode next io page level. Bit 59 - bit 62 + * are used for iommu flags, We could not use these bits to store p2m types. + */ + + return (flags >> 12) & 0x7f; #else return (flags >> 9) & 0x7; #endif