> -----Original Message----- > From: David Hildenbrand [mailto:da...@redhat.com] > Sent: 06 February 2020 10:56 > To: Shameerali Kolothum Thodi <shameerali.kolothum.th...@huawei.com>; > Igor Mammedov <imamm...@redhat.com> > Cc: peter.mayd...@linaro.org; xiaoguangrong.e...@gmail.com; > m...@redhat.com; shannon.zha...@gmail.com; qemu-devel@nongnu.org; > xuwei (O) <xuw...@huawei.com>; Linuxarm <linux...@huawei.com>; > eric.au...@redhat.com; qemu-...@nongnu.org; ler...@redhat.com > Subject: Re: [PATCH v2 1/7] exec: Fix for qemu_ram_resize() callback
[...] > > root@ubuntu:/# cat /dev/pmem > > pmem0 pmem1 > > > > From the logs, it looks like the ram_load_precopy() --> qemu_ram_resize() is > not > > called as length == used_length and both seems to be page aligned values. > > And from > https://github.com/qemu/qemu/blob/master/migration/ram.c#L3421 > > qemu_ram_resize() is called with length if length != used_length. > > Assume on your source, the old size is 12345 bytes. So 16384 aligned up > (4 pages). > > Assume on your target, the new size is 123456 bytes, so 126976 aligned > up (31 pages). > > If you migrate from source to destination, the migration code would > resize to 16384, although the "actual size" is 12345. The callback will > be called with the aligned size, not the actual size. Same the other way > around. That's what's inconsistent IMHO. Thanks. You are right. I didn’t consider the case where the target can be configured with a larger number of devices than the source. I can replicate the scenario now, Source: fw_cfg_add_file_callback: filename etc/boot-fail-wait size 0x4 fw_cfg_add_file_callback: filename etc/acpi/nvdimm-mem size 0x1000 fw_cfg_add_file_callback: filename etc/acpi/tables size 0x6210 Target: ram_load_precopy: Ram blk mem1 length 0x40000000 used_length 0x40000000 ram_load_precopy: Ram blk virt.flash0 length 0x4000000 used_length 0x4000000 ram_load_precopy: Ram blk virt.flash1 length 0x4000000 used_length 0x4000000 ram_load_precopy: Ram blk /rom@etc/acpi/tables length 0x7000 used_length 0x8000 fw_cfg_modify_file: filename etc/acpi/tables len 0x7000 Target updates FWCfgEntry with a page aligned size :(. I will look into this and see how we can solve this. Any pointers welcome. Cheers, Shameer
