[Xen-changelog] [xen master] xl, e820_host, PV passthrough: Fix guests crashing when memory == maxmem

[patchbot@xxxxxxx]

commit d21b46e9b723b860ab6e32f6ad96dd4c650596c7
Author:     Konrad Rzeszutek Wilk <konrad@xxxxxxxxxx>
AuthorDate: Fri May 24 09:36:16 2013 -0400
Commit:     Ian Campbell <ian.campbell@xxxxxxxxxx>
CommitDate: Thu May 30 09:01:24 2013 +0100

    xl, e820_host, PV passthrough: Fix guests crashing when memory == maxmem
    
    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 <christian@xxxxxxxxxx>
    Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
    Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
---
 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 ?
--
generated by git-patchbot for /home/xen/git/xen.git#master

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