Re: [Crash-utility] question about phys_base

At 02/17/2012 12:30 AM, Dave Anderson Wrote:

>> Yes. Even if the guest is linux, it is still impossible to do it. Because >> the guest maybe in the second kernel. >> >> qemu-dump walks all guest's page table and collect virtual address and >> physical address mapping. If the page is not used by guest, the virtual is set >> to 0. I create PT_LOAD according to such mapping. So if the guest linux, >> there may be a PT_LOAD segment that describes __START_KERNEL_map region. >> But the information stored in PT_LOAD maybe for the second kernel. If crash >> uses it, crash will see the second kernel, not the first kernel. > > Just to be clear -- what do you mean by the "second" kernel? Do you > mean that a guest kernel crashed guest, and did a kdump operation, > and that second kdump kernel failed somehow, and now you're trying > to do a "virsh dump" on the kdump kernel? Yes, the second kernel means kdump kernel. If kdump failed, the user can use it to dump the guest's memory.