The kdump-zlib data pages are not dumped from aarch64 host when the
'pvtime' is involved, that is, when the block->target_end is not aligned to
page_size. In the below example, it is expected to dump two blocks.
(qemu) info mtree -f
... ...
00000000090a0000-00000000090a0fff (prio 0, ram): pvtime KVM
... ...
0000000040000000-00000001bfffffff (prio 0, ram): mach-virt.ram KVM
... ...
However, there is an issue with get_next_page() so that the pages for
"mach-virt.ram" will not be dumped.
At line 1296, although we have reached at the end of the 'pvtime' block,
since it is not aligned to the page_size (e.g., 0x10000), it will not break
at line 1298.
1255 static bool get_next_page(GuestPhysBlock **blockptr, uint64_t *pfnptr,
1256 uint8_t **bufptr, DumpState *s)
... ...
1294 memcpy(buf + addr % page_size, hbuf, n);
1295 addr += n;
1296 if (addr % page_size == 0) {
1297 /* we filled up the page */
1298 break;
1299 }
As a result, get_next_page() will continue to the next
block ("mach-virt.ram"). Finally, when get_next_page() returns to the
caller:
- 'pfnptr' is referring to the 'pvtime'
- but 'blockptr' is referring to the "mach-virt.ram"
When get_next_page() is called the next time, "*pfnptr += 1" still refers
to the prior 'pvtime'. It will exit immediately because it is out of the
range of the current "mach-virt.ram".
The fix is to break when it is time to come to the next block, so that both
'pfnptr' and 'blockptr' refer to the same block.
Fixes: 94d788408d ("dump: fix kdump to work over non-aligned blocks")
Cc: Joe Jin <joe.jin@oracle.com>
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-ID: <20230713055819.30497-1-dongli.zhang@oracle.com>
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