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| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2014-04-30 16:04:25 +0200 |
|---|---|---|
| committer | Christian Borntraeger <borntraeger@de.ibm.com> | 2014-08-26 10:09:02 +0200 |
| commit | 527e30b41d8b86e9ae7f5b740de416958c0e574e (patch) | |
| tree | a19053eaa5ab6bb2f705006a0f7b5b90bb4a1a0b /arch/s390/mm/fault.c | |
| parent | 6e0a0431bf7d90ed0b8a0a974ad219617a70cc22 (diff) | |
| download | linux-527e30b41d8b86e9ae7f5b740de416958c0e574e.tar.bz2 | |
KVM: s390/mm: use radix trees for guest to host mappings
Store the target address for the gmap segments in a radix tree
instead of using invalid segment table entries. gmap_translate
becomes a simple radix_tree_lookup, gmap_fault is split into the
address translation with gmap_translate and the part that does
the linking of the gmap shadow page table with the process page
table.
A second radix tree is used to keep the pointers to the segment
table entries for segments that are mapped in the guest address
space. On unmap of a segment the pointer is retrieved from the
radix tree and is used to carry out the segment invalidation in
the gmap shadow page table. As the radix tree can only store one
pointer, each host segment may only be mapped to exactly one
guest location.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Diffstat (limited to 'arch/s390/mm/fault.c')
| -rw-r--r-- | arch/s390/mm/fault.c | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index 4880399d040e..a2b81d6ce8a5 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -442,18 +442,15 @@ static inline int do_exception(struct pt_regs *regs, int access) down_read(&mm->mmap_sem); #ifdef CONFIG_PGSTE - gmap = (struct gmap *) - ((current->flags & PF_VCPU) ? S390_lowcore.gmap : 0); + gmap = (current->flags & PF_VCPU) ? + (struct gmap *) S390_lowcore.gmap : NULL; if (gmap) { - address = __gmap_fault(gmap, address); + current->thread.gmap_addr = address; + address = __gmap_translate(gmap, address); if (address == -EFAULT) { fault = VM_FAULT_BADMAP; goto out_up; } - if (address == -ENOMEM) { - fault = VM_FAULT_OOM; - goto out_up; - } if (gmap->pfault_enabled) flags |= FAULT_FLAG_RETRY_NOWAIT; } @@ -530,6 +527,20 @@ retry: goto retry; } } +#ifdef CONFIG_PGSTE + if (gmap) { + address = __gmap_link(gmap, current->thread.gmap_addr, + address); + if (address == -EFAULT) { + fault = VM_FAULT_BADMAP; + goto out_up; + } + if (address == -ENOMEM) { + fault = VM_FAULT_OOM; + goto out_up; + } + } +#endif fault = 0; out_up: up_read(&mm->mmap_sem); |