aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorJason Baron <jbaron@redhat.com>2012-08-02 15:44:16 -0400
committerAnthony Liguori <aliguori@us.ibm.com>2012-08-16 13:41:15 -0500
commitddb97f1debbb6be8d871f3b565f7b8befebf0f4f (patch)
treea81ce727e2c5f9d058d156b0754bdbaaafd00d25
parent3c4a4d0dcbf4269e125f92df06816db1c1e86d20 (diff)
memory: add -machine dump-guest-core=on|off
Add a new '[,dump-guest-core=on|off]' option to the '-machine' option. When 'dump-guest-core=off' is specified, guest memory is omitted from the core dump. The default behavior continues to be to include guest memory when a core dump is triggered. In my testing, this brought the core dump size down from 384MB to 6MB on a 2GB guest. Is anything additional required to preserve this setting for migration or savevm? I don't believe so. Changelog: v3: Eliminate globals as per Anthony's suggestion set no dump from qemu_ram_remap() as well v2: move the option from -m to -machine, rename option dump -> dump-guest-core Signed-off-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
-rw-r--r--exec.c21
-rw-r--r--osdep.h7
-rw-r--r--qemu-config.c4
-rw-r--r--qemu-options.hx5
4 files changed, 36 insertions, 1 deletions
diff --git a/exec.c b/exec.c
index 929db5cf0a..58347664b2 100644
--- a/exec.c
+++ b/exec.c
@@ -2475,6 +2475,24 @@ static ram_addr_t last_ram_offset(void)
return last;
}
+static void qemu_ram_setup_dump(void *addr, ram_addr_t size)
+{
+ int ret;
+ QemuOpts *machine_opts;
+
+ /* Use MADV_DONTDUMP, if user doesn't want the guest memory in the core */
+ machine_opts = qemu_opts_find(qemu_find_opts("machine"), 0);
+ if (machine_opts &&
+ !qemu_opt_get_bool(machine_opts, "dump-guest-core", true)) {
+ ret = qemu_madvise(addr, size, QEMU_MADV_DONTDUMP);
+ if (ret) {
+ perror("qemu_madvise");
+ fprintf(stderr, "madvise doesn't support MADV_DONTDUMP, "
+ "but dump_guest_core=off specified\n");
+ }
+ }
+}
+
void qemu_ram_set_idstr(ram_addr_t addr, const char *name, DeviceState *dev)
{
RAMBlock *new_block, *block;
@@ -2554,6 +2572,8 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
0, size >> TARGET_PAGE_BITS);
cpu_physical_memory_set_dirty_range(new_block->offset, size, 0xff);
+ qemu_ram_setup_dump(new_block->host, size);
+
if (kvm_enabled())
kvm_setup_guest_memory(new_block->host, size);
@@ -2670,6 +2690,7 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length)
exit(1);
}
qemu_madvise(vaddr, length, QEMU_MADV_MERGEABLE);
+ qemu_ram_setup_dump(vaddr, length);
}
return;
}
diff --git a/osdep.h b/osdep.h
index d4b887d542..cb213e0295 100644
--- a/osdep.h
+++ b/osdep.h
@@ -103,6 +103,11 @@ void qemu_vfree(void *ptr);
#else
#define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
#endif
+#ifdef MADV_DONTDUMP
+#define QEMU_MADV_DONTDUMP MADV_DONTDUMP
+#else
+#define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
+#endif
#elif defined(CONFIG_POSIX_MADVISE)
@@ -110,6 +115,7 @@ void qemu_vfree(void *ptr);
#define QEMU_MADV_DONTNEED POSIX_MADV_DONTNEED
#define QEMU_MADV_DONTFORK QEMU_MADV_INVALID
#define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
+#define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
#else /* no-op */
@@ -117,6 +123,7 @@ void qemu_vfree(void *ptr);
#define QEMU_MADV_DONTNEED QEMU_MADV_INVALID
#define QEMU_MADV_DONTFORK QEMU_MADV_INVALID
#define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
+#define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
#endif
diff --git a/qemu-config.c b/qemu-config.c
index 5c3296b8c6..6700de0c71 100644
--- a/qemu-config.c
+++ b/qemu-config.c
@@ -595,6 +595,10 @@ static QemuOptsList qemu_machine_opts = {
.name = "dt_compatible",
.type = QEMU_OPT_STRING,
.help = "Overrides the \"compatible\" property of the dt root node",
+ }, {
+ .name = "dump-guest-core",
+ .type = QEMU_OPT_BOOL,
+ .help = "Include guest memory in a core dump",
},
{ /* End of list */ }
},
diff --git a/qemu-options.hx b/qemu-options.hx
index 47cb5bd311..6aeef6a845 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -37,7 +37,8 @@ DEF("machine", HAS_ARG, QEMU_OPTION_machine, \
" property accel=accel1[:accel2[:...]] selects accelerator\n"
" supported accelerators are kvm, xen, tcg (default: tcg)\n"
" kernel_irqchip=on|off controls accelerated irqchip support\n"
- " kvm_shadow_mem=size of KVM shadow MMU\n",
+ " kvm_shadow_mem=size of KVM shadow MMU\n"
+ " dump-guest-core=on|off include guest memory in a core dump (default=on)\n",
QEMU_ARCH_ALL)
STEXI
@item -machine [type=]@var{name}[,prop=@var{value}[,...]]
@@ -54,6 +55,8 @@ to initialize.
Enables in-kernel irqchip support for the chosen accelerator when available.
@item kvm_shadow_mem=size
Defines the size of the KVM shadow MMU.
+@item dump-guest-core=on|off
+Include guest memory in a core dump. The default is on.
@end table
ETEXI