From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: [PATCH] xl, e820_host, PV passthrough: Fix guests crashing when memory == maxmem Date: Fri, 24 May 2013 09:36:16 -0400 Message-ID: <1369402576-2958-1-git-send-email-konrad.wilk@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian.Campbell@citrix.com, david.vrabel@citrix.com, xen-devel@lists.xensource.com Cc: christian@holpert.de, Konrad Rzeszutek Wilk List-Id: xen-devel@lists.xenproject.org The code had an obvious bug where it would assume that the balloon amount would always be _something_ and add an E820_RAM entry at the end of the E820 array. The added E820_RAM would contain the balloon amount plus the delta of memory that had to be subtracted b/c of the various E820 entries. That assumption is certainly true when maxmem != mem, but if guest config has maxmem = memory that is incorrect (as balloon value is zero). The end result is that the E820 that is constructed is missing a swath of "delta" memory and in most cases ends up with only one E820_RAM entry that is of 512MB size on many Intel systems. Reported-by: Christian Holpert Signed-off-by: Konrad Rzeszutek Wilk --- tools/libxl/libxl_x86.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/tools/libxl/libxl_x86.c b/tools/libxl/libxl_x86.c index a17f6ae..a78c91d 100644 --- a/tools/libxl/libxl_x86.c +++ b/tools/libxl/libxl_x86.c @@ -182,7 +182,7 @@ static int e820_sanitize(libxl_ctx *ctx, struct e820entry src[], idx++; } /* At this point we have the mapped RAM + E820 entries from src. */ - if (balloon_kb) { + if (balloon_kb || delta_kb) { /* and if we truncated the RAM region, then add it to the end. */ e820[idx].type = E820_RAM; e820[idx].addr = (uint64_t)(1ULL << 32) > last ? -- 1.7.7.6