[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PULL 33/36] migration: do not rom_reset() during incoming
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PULL 33/36] migration: do not rom_reset() during incoming migration |
Date: |
Tue, 20 Aug 2019 08:59:52 +0200 |
From: Catherine Ho <address@hidden>
Commit 18269069c310 ("migration: Introduce ignore-shared capability")
addes ignore-shared capability to bypass the shared ramblock (e,g,
membackend + numa node). It does good to live migration.
As told by Yury,this commit expectes that QEMU doesn't write to guest RAM
until VM starts, but it does on aarch64 qemu:
Backtrace:
1 0x000055f4a296dd84 in address_space_write_rom_internal () at
exec.c:3458
2 0x000055f4a296de3a in address_space_write_rom () at exec.c:3479
3 0x000055f4a2d519ff in rom_reset () at hw/core/loader.c:1101
4 0x000055f4a2d475ec in qemu_devices_reset () at hw/core/reset.c:69
5 0x000055f4a2c90a28 in qemu_system_reset () at vl.c:1675
6 0x000055f4a2c9851d in main () at vl.c:4552
Actually, on arm64 virt marchine, ramblock "dtb" will be filled into ram
druing rom_reset. In ignore-shared incoming case, this rom filling
is not required since all the data has been stored in memory backend
file.
Further more, as suggested by Peter Xu, if we do rom_reset() now with
these ROMs then the RAM data should be re-filled again too with the
migration stream coming in.
Fixes: commit 18269069c310 ("migration: Introduce ignore-shared
capability")
Suggested-by: Yury Kotov <address@hidden>
Suggested-by: Peter Xu <address@hidden>
Signed-off-by: Catherine Ho <address@hidden>
Acked-by: Peter Xu <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
hw/core/loader.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/hw/core/loader.c b/hw/core/loader.c
index 9fb93a6..baa4448 100644
--- a/hw/core/loader.c
+++ b/hw/core/loader.c
@@ -1112,6 +1112,15 @@ static void rom_reset(void *unused)
{
Rom *rom;
+ /*
+ * We don't need to fill in the RAM with ROM data because we'll fill
+ * the data in during the next incoming migration in all cases. Note
+ * that some of those RAMs can actually be modified by the guest on ARM
+ * so this is probably the only right thing to do here.
+ */
+ if (runstate_check(RUN_STATE_INMIGRATE))
+ return;
+
QTAILQ_FOREACH(rom, &roms, next) {
if (rom->fw_file) {
continue;
--
1.8.3.1
- [Qemu-devel] [PULL 20/36] kconfig: do not select VMMOUSE, (continued)
- [Qemu-devel] [PULL 20/36] kconfig: do not select VMMOUSE, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 18/36] replay: Remove host_clock_last, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 25/36] replay: refine replay-time module, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 29/36] cpus-common: nuke finish_safe_work, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 27/36] icount: clean up cpu_can_io at the entry to the block, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 36/36] x86: Intel AVX512_BF16 feature enabling, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 28/36] icount: remove unnecessary gen_io_end calls, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 26/36] replay: rename step-related variables and functions, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 32/36] HACKING: Document 'struct' keyword usage, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 23/36] util/qemu-timer: refactor deadline calculation for external timers, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 33/36] migration: do not rom_reset() during incoming migration,
Paolo Bonzini <=
- [Qemu-devel] [PULL 34/36] test-bitmap: test set 1 bit case for bitmap_set, Paolo Bonzini, 2019/08/20
- [Qemu-devel] [PULL 35/36] scsi: lsi: exit infinite loop while executing script (CVE-2019-12068), Paolo Bonzini, 2019/08/20
- Re: [Qemu-devel] [PULL 00/36] QEMU patches for 2018-08-20, no-reply, 2019/08/20
- Re: [Qemu-devel] [PULL 00/36] QEMU patches for 2018-08-20, Peter Maydell, 2019/08/20
- Re: [Qemu-devel] [PULL 00/36] QEMU patches for 2018-08-20, no-reply, 2019/08/20