diff options
| author | Juergen Gross <jgross@suse.com> | 2018-08-20 17:24:20 +0200 |
|---|---|---|
| committer | Boris Ostrovsky <boris.ostrovsky@oracle.com> | 2018-08-20 14:46:26 -0400 |
| commit | 75f2d3a0cef5cd8cd41772c9f8ada37dee9c9369 (patch) | |
| tree | 89b3a7fa08753ecdf14490cf955152af3fe7d78f /arch/x86/mm | |
| parent | 00f53f758d9baffef9dc3efedf534bb0dc1872eb (diff) | |
x86/xen: enable early use of set_fixmap in 32-bit Xen PV guest
Commit 7b25b9cb0dad83 ("x86/xen/time: Initialize pv xen time in
init_hypervisor_platform()") moved the mapping of the shared info area
before pagetable_init(). This breaks booting as 32-bit PV guest as the
use of set_fixmap isn't possible at this time on 32-bit.
This can be worked around by populating the needed PMD on 32-bit
kernel earlier.
In order not to reimplement populate_extra_pte() using extend_brk()
for allocating new page tables extend alloc_low_pages() to do that in
case the early page table pool is not yet available.
Fixes: 7b25b9cb0dad83 ("x86/xen/time: Initialize pv xen time in init_hypervisor_platform()")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Diffstat (limited to 'arch/x86/mm')
| -rw-r--r-- | arch/x86/mm/init.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index acfab322fbe0..5c32a7665492 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -99,15 +99,22 @@ __ref void *alloc_low_pages(unsigned int num) } if ((pgt_buf_end + num) > pgt_buf_top || !can_use_brk_pgt) { - unsigned long ret; - if (min_pfn_mapped >= max_pfn_mapped) - panic("alloc_low_pages: ran out of memory"); - ret = memblock_find_in_range(min_pfn_mapped << PAGE_SHIFT, + unsigned long ret = 0; + + if (min_pfn_mapped < max_pfn_mapped) { + ret = memblock_find_in_range( + min_pfn_mapped << PAGE_SHIFT, max_pfn_mapped << PAGE_SHIFT, PAGE_SIZE * num , PAGE_SIZE); + } + if (ret) + memblock_reserve(ret, PAGE_SIZE * num); + else if (can_use_brk_pgt) + ret = __pa(extend_brk(PAGE_SIZE * num, PAGE_SIZE)); + if (!ret) panic("alloc_low_pages: can not alloc memory"); - memblock_reserve(ret, PAGE_SIZE * num); + pfn = ret >> PAGE_SHIFT; } else { pfn = pgt_buf_end; |