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| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2016-06-14 12:56:01 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2017-07-25 06:55:28 +0200 |
| commit | c9b5ad546e7d486465a3dd8c89245ac3707a4384 (patch) | |
| tree | 5c073b778a64cfee1efc5e9f27b6a4caae82b764 /arch/s390/kernel/vdso.c | |
| parent | 520eccdfe187591a51ea9ab4c1a024ae4d0f68d9 (diff) | |
| download | linux-c9b5ad546e7d486465a3dd8c89245ac3707a4384.tar.bz2 | |
s390/mm: tag normal pages vs pages used in page tables
The ESSA instruction has a new option that allows to tag pages that
are not used as a page table. Without the tag the hypervisor has to
assume that any guest page could be used in a page table inside the
guest. This forces the hypervisor to flush all guest TLB entries
whenever a host page table entry is invalidated. With the tag
the host can skip the TLB flush if the page is tagged as normal page.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/vdso.c')
| -rw-r--r-- | arch/s390/kernel/vdso.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c index b89d19f6f2ab..eacda05b45d7 100644 --- a/arch/s390/kernel/vdso.c +++ b/arch/s390/kernel/vdso.c @@ -157,6 +157,8 @@ int vdso_alloc_per_cpu(struct lowcore *lowcore) page_frame = get_zeroed_page(GFP_KERNEL); if (!segment_table || !page_table || !page_frame) goto out; + arch_set_page_dat(virt_to_page(segment_table), SEGMENT_ORDER); + arch_set_page_dat(virt_to_page(page_table), 0); /* Initialize per-cpu vdso data page */ vd = (struct vdso_per_cpu_data *) page_frame; |