Hi, tpm-crb creates a "tpm-crb-cmd" RAM memory region that is not page aligned. Apparently, this is not a problem for QEMU in general. However, it crashes kdump'ing in dump.c:get_next_page, as it expects GuestPhysBlock to be page-aligned. (see also bug https://bugzilla.redhat.com/show_bug.cgi?id=2120480)
Here is some relevant DEBUG_GUEST_PHYS_REGION_ADD log: guest_phys_block_add_section: target_start=00000000fd000000 target_end=00000000fe000000: added (count: 3) guest_phys_block_add_section: target_start=00000000fed40080 target_end=00000000fed41000: added (count: 4) guest_phys_block_add_section: target_start=00000000fffc0000 target_end=0000000100000000: added (count: 5) I am looking for ideas on how to solve this crash. Should qemu enforce that memory regions are target page-aligned? In which case, TPM CRB MMIO region would overlap with the RAM region, and I wonder how that turns out to be, and if other devices would be impacted etc Or should kdump learn to handle non-aligned blocks somehow? I think that option should make a reasonable solution, as long as we only have empty/zero-memory "gaps". Handling other cases of joint or overlapping regions seems more difficult. thanks -- Marc-André Lureau
