From 8a64609eea8cb2bac015968c4b62da5bce266e22 Mon Sep 17 00:00:00 2001 From: Dongli Zhang Date: Wed, 12 Jul 2023 22:58:19 -0700 Subject: [PATCH] dump: kdump-zlib data pages not dumped with pvtime/aarch64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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: 94d788408d2d ("dump: fix kdump to work over non-aligned blocks") Cc: Joe Jin Signed-off-by: Dongli Zhang Reviewed-by: Marc-André Lureau Message-ID: <20230713055819.30497-1-dongli.zhang@oracle.com> --- dump/dump.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/dump/dump.c b/dump/dump.c index 1f1a6edcab..d4ef713cd0 100644 --- a/dump/dump.c +++ b/dump/dump.c @@ -1293,8 +1293,8 @@ static bool get_next_page(GuestPhysBlock **blockptr, uint64_t *pfnptr, memcpy(buf + addr % page_size, hbuf, n); addr += n; - if (addr % page_size == 0) { - /* we filled up the page */ + if (addr % page_size == 0 || addr >= block->target_end) { + /* we filled up the page or the current block is finished */ break; } } else {