When shadowing, we must make sure, that any changes to the GMAP inside guest N will also be directly reflected in our shadow GMAP. This is done by write-protecting guest N memory at the places where it stores DAT tables for guest N + 1. This still lacks EDAT1 support, so let's add it. Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxxxxxxx> --- arch/s390/mm/gmap.c | 82 ++++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 69 insertions(+), 13 deletions(-) diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c index c8296bc..f6a28d9 100644 --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -1289,6 +1289,56 @@ static inline void gmap_insert_rmap(struct gmap *sg, unsigned long vmaddr, } } +static int gmap_protect_rmap_large(struct gmap *sg, struct gmap_rmap *rmap, + unsigned long paddr, unsigned long vmaddr, + pmd_t *pmdp, int prot) +{ + int rc = 0; + + /* We have no upper segment, let's go back and fix this up. */ + if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID) + return -EAGAIN; + + spin_lock(&sg->guest_table_lock); + rc = gmap_protect_large(sg->parent, paddr, pmdp, + prot, GMAP_ENTRY_VSIE); + if (!rc) + gmap_insert_rmap(sg, vmaddr & HPAGE_MASK, rmap); + + spin_unlock(&sg->guest_table_lock); + return rc; +} + +static int gmap_protect_rmap_pte(struct gmap *sg, struct gmap_rmap *rmap, + unsigned long paddr, unsigned long vmaddr, + pmd_t *pmdp, int prot) +{ + int rc = 0; + pte_t *ptep = NULL; + spinlock_t *ptl = NULL; + + /* We have no upper segment, let's go back and fix this up. */ + if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID) + return -EAGAIN; + + if (gmap_is_shadow(sg->parent)) + ptep = pte_offset_map(pmdp, paddr); + else + ptep = pte_alloc_map_lock(sg->parent->mm, pmdp, paddr, &ptl); + + if (ptep) { + spin_lock(&sg->guest_table_lock); + rc = ptep_force_prot(sg->parent->mm, paddr, ptep, prot, + PGSTE_VSIE_BIT); + if (!rc) + gmap_insert_rmap(sg, vmaddr, rmap); + spin_unlock(&sg->guest_table_lock); + if (ptl) + gmap_pte_op_end(ptl); + } + return rc; +} + /** * gmap_protect_rmap - modify access rights to memory and create an rmap * @sg: pointer to the shadow guest address space structure @@ -1306,8 +1356,7 @@ static int gmap_protect_rmap(struct gmap *sg, unsigned long raddr, struct gmap *parent; struct gmap_rmap *rmap; unsigned long vmaddr; - spinlock_t *ptl; - pte_t *ptep; + pmd_t *pmdp; int rc; BUG_ON(!gmap_is_shadow(sg)); @@ -1326,15 +1375,24 @@ static int gmap_protect_rmap(struct gmap *sg, unsigned long raddr, return rc; } rc = -EAGAIN; - ptep = gmap_pte_op_walk(parent, paddr, &ptl); - if (ptep) { - spin_lock(&sg->guest_table_lock); - rc = ptep_force_prot(parent->mm, paddr, ptep, prot, - GMAP_ENTRY_VSIE); - if (!rc) - gmap_insert_rmap(sg, vmaddr, rmap); - spin_unlock(&sg->guest_table_lock); - gmap_pte_op_end(ptl); + pmdp = gmap_pmd_op_walk(parent, paddr); + if (pmdp) { + if (!pmd_large(*pmdp)) { + rc = gmap_protect_rmap_pte(sg, rmap, paddr, + vmaddr, pmdp, prot); + if (!rc) { + paddr += PAGE_SIZE; + len -= PAGE_SIZE; + } + } else { + rc = gmap_protect_rmap_large(sg, rmap, paddr, + vmaddr, pmdp, prot); + if (!rc) { + len = len < HPAGE_SIZE ? 0 : len - HPAGE_SIZE; + paddr = (paddr & HPAGE_MASK) + HPAGE_SIZE; + } + } + gmap_pmd_op_end(parent, pmdp); } radix_tree_preload_end(); if (rc) { @@ -1344,8 +1402,6 @@ static int gmap_protect_rmap(struct gmap *sg, unsigned long raddr, return rc; continue; } - paddr += PAGE_SIZE; - len -= PAGE_SIZE; } return 0; } -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html