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| author | Juergen Gross <jgross@suse.com> | 2015-08-19 19:52:34 +0300 |
|---|---|---|
| committer | David Vrabel <david.vrabel@citrix.com> | 2015-09-08 18:28:04 +0300 |
| commit | eafd72e016c69df511b14a98b61e439c58ad9c51 (patch) | |
| tree | 451d001c8d85acad045a825304225bbb552b2787 | |
| parent | 724afaea2020f3bd98891b535f3ce5d3935bcf63 (diff) | |
| download | linux-eafd72e016c69df511b14a98b61e439c58ad9c51.tar.xz | |
xen: avoid early crash of memory limited dom0
Commit b1c9f169047b ("xen: split counting of extra memory pages...")
introduced an error when dom0 was started with limited memory.
The problem arises in case dom0 is started with initial memory and
maximum memory being the same and exactly a multiple of 1 GB. The
kernel must be configured without CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
for the problem to happen. In this case it will crash very early
during boot due to the virtual mapped p2m list not being large
enough to be able to remap any memory:
(XEN) Freed 304kB init memory.
mapping kernel into physical memory
about to get started...
(XEN) traps.c:459:d0v0 Unhandled invalid opcode fault/trap [#6] on VCPU 0 [ec=0000]
(XEN) domain_crash_sync called from entry.S: fault at ffff82d080229a93 create_bounce_frame+0x12b/0x13a
(XEN) Domain 0 (vcpu#0) crashed on cpu#0:
(XEN) ----[ Xen-4.5.2-pre x86_64 debug=n Not tainted ]----
(XEN) CPU: 0
(XEN) RIP: e033:[<ffffffff81d120cb>]
(XEN) RFLAGS: 0000000000000206 EM: 1 CONTEXT: pv guest (d0v0)
(XEN) rax: ffffffff81db2000 rbx: 000000004d000000 rcx: 0000000000000000
(XEN) rdx: 000000004d000000 rsi: 0000000000063000 rdi: 000000004d063000
(XEN) rbp: ffffffff81c03d78 rsp: ffffffff81c03d28 r8: 0000000000023000
(XEN) r9: 00000001040ff000 r10: 0000000000007ff0 r11: 0000000000000000
(XEN) r12: 0000000000063000 r13: 000000000004d000 r14: 0000000000000063
(XEN) r15: 0000000000000063 cr0: 0000000080050033 cr4: 00000000000006f0
(XEN) cr3: 0000000105c0f000 cr2: ffffc90000268000
(XEN) ds: 0000 es: 0000 fs: 0000 gs: 0000 ss: e02b cs: e033
(XEN) Guest stack trace from rsp=ffffffff81c03d28:
(XEN) 0000000000000000 0000000000000000 ffffffff81d120cb 000000010000e030
(XEN) 0000000000010006 ffffffff81c03d68 000000000000e02b ffffffffffffffff
(XEN) 0000000000000063 000000000004d063 ffffffff81c03de8 ffffffff81d130a7
(XEN) ffffffff81c03de8 000000000004d000 00000001040ff000 0000000000105db1
(XEN) 00000001040ff001 000000000004d062 ffff8800092d6ff8 0000000002027000
(XEN) ffff8800094d8340 ffff8800092d6ff8 00003ffffffff000 ffff8800092d7ff8
(XEN) ffffffff81c03e48 ffffffff81d13c43 ffff8800094d8000 ffff8800094d9000
(XEN) 0000000000000000 ffff8800092d6000 00000000092d6000 000000004cfbf000
(XEN) 00000000092d6000 00000000052d5442 0000000000000000 0000000000000000
(XEN) ffffffff81c03ed8 ffffffff81d185c1 0000000000000000 0000000000000000
(XEN) ffffffff81c03e78 ffffffff810f8ca4 ffffffff81c03ed8 ffffffff8171a15d
(XEN) 0000000000000010 ffffffff81c03ee8 0000000000000000 0000000000000000
(XEN) ffffffff81f0e402 ffffffffffffffff ffffffff81dae900 0000000000000000
(XEN) 0000000000000000 0000000000000000 ffffffff81c03f28 ffffffff81d0cf0f
(XEN) 0000000000000000 0000000000000000 0000000000000000 ffffffff81db82e0
(XEN) 0000000000000000 0000000000000000 0000000000000000 0000000000000000
(XEN) ffffffff81c03f38 ffffffff81d0c603 ffffffff81c03ff8 ffffffff81d11c86
(XEN) 0300000100000032 0000000000000005 0000000000000020 0000000000000000
(XEN) 0000000000000000 0000000000000000 0000000000000000 0000000000000000
(XEN) 0000000000000000 0000000000000000 0000000000000000 0000000000000000
(XEN) Domain 0 crashed: rebooting machine in 5 seconds.
This can be avoided by allocating aneough space for the p2m to cover
the maximum memory of dom0 plus the identity mapped holes required
for PCI space, BIOS etc.
Reported-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
| -rw-r--r-- | arch/x86/xen/setup.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index a1a77eabe858..ead0d363bfba 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -789,11 +789,12 @@ char * __init xen_memory_setup(void) &xen_e820_map_entries); max_pages = xen_get_max_pages(); - if (max_pages > max_pfn) - extra_pages += max_pages - max_pfn; /* How many extra pages do we need due to remapping? */ - extra_pages += xen_count_remap_pages(max_pfn); + max_pages += xen_count_remap_pages(max_pfn); + + if (max_pages > max_pfn) + extra_pages += max_pages - max_pfn; /* * Clamp the amount of extra memory to a EXTRA_MEM_RATIO |