[Xen-changelog] [qemu-xen-unstable] [stubdom] fix the crash of HVM live migration with intensive disk access

[Ian Jackson <Ian.Jackson@xxxxxxxxxxxxx>]

commit 32710fbdc75e055f73a63d246737ce615b9109e9
Author: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Date:   Fri Sep 4 16:10:46 2009 +0100

    [stubdom] fix the crash of HVM live migration with intensive disk access
    
    Intensive disk access, e.g. sum of big file, during HVM live migration would
    cause guest error even file system crash. Guest dmesg said
    "attempt to access beyond end of device
    hda1: rw=0, want=10232032112, limit=10474317"
    
    Current map cache used by qemu dma doesn't mark the page dirty, so that 
these
    pages(probably holding DMA data struct) are not transferred in the last
    iteration during live migration.
    
    This patch fixes it, and also merges the qemu's original dirty bitmap used 
by
    other devices such as vga.
    
    Signed-Off-By: Zhai Edwin <edwin.zhai@xxxxxxxxx>
---
 cpu-all.h         |   10 ++++++++++
 i386-dm/exec-dm.c |   18 ++++++++++++++++++
 2 files changed, 28 insertions(+), 0 deletions(-)

diff --git a/cpu-all.h b/cpu-all.h
index c5c3ef2..9023127 100644
--- a/cpu-all.h
+++ b/cpu-all.h
@@ -975,6 +975,16 @@ static inline int cpu_physical_memory_get_dirty(ram_addr_t 
addr,
 static inline void cpu_physical_memory_set_dirty(ram_addr_t addr)
 {
     phys_ram_dirty[addr >> TARGET_PAGE_BITS] = 0xff;
+
+#ifndef CONFIG_STUBDOM
+    if (logdirty_bitmap != NULL) {
+        addr >>= TARGET_PAGE_BITS;
+        if (addr / 8 < logdirty_bitmap_size) {
+            logdirty_bitmap[addr / HOST_LONG_BITS]
+                |= 1UL << addr % HOST_LONG_BITS;
+        }
+    }
+#endif
 }
 
 void cpu_physical_memory_reset_dirty(ram_addr_t start, ram_addr_t end,
diff --git a/i386-dm/exec-dm.c b/i386-dm/exec-dm.c
index b8af55a..4fc26cd 100644
--- a/i386-dm/exec-dm.c
+++ b/i386-dm/exec-dm.c
@@ -806,6 +806,24 @@ void *cpu_physical_memory_map(target_phys_addr_t addr,
     if ((*plen) > l)
         *plen = l;
 #endif
+#ifndef CONFIG_STUBDOM
+    if (logdirty_bitmap != NULL) {
+        /* Record that we have dirtied this frame */
+        unsigned long pfn = addr >> TARGET_PAGE_BITS;
+        do {
+            if (pfn / 8 >= logdirty_bitmap_size) {
+                fprintf(logfile, "dirtying pfn %lx >= bitmap "
+                        "size %lx\n", pfn, logdirty_bitmap_size * 8);
+            } else {
+                logdirty_bitmap[pfn / HOST_LONG_BITS]
+                    |= 1UL << pfn % HOST_LONG_BITS;
+            }
+
+            pfn++;
+        } while ( (pfn << TARGET_PAGE_BITS) < addr + *plen );
+
+    }
+#endif
     return qemu_map_cache(addr, 1);
 }
 
--
generated by git-patchbot for /home/xen/git/qemu-xen-unstable.git

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