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63938e1708
To support memory devices under QEMU/KVM, such as virtio-mem, we have to prepare our kernel virtual address space accordingly and have to know the highest possible physical memory address we might see later: the storage limit. The good old SCLP interface is not suitable for this use case. In particular, memory owned by memory devices has no relationship to storage increments, it is always detected using the device driver, and unaware OSes (no driver) must never try making use of that memory. Consequently this memory is located outside of the "maximum storage increment"-indicated memory range. Let's use our new diag500 STORAGE_LIMIT subcode to query this storage limit that can exceed the "maximum storage increment", and use the existing interfaces (i.e., SCLP) to obtain information about the initial memory that is not owned+managed by memory devices. If a hypervisor does not support such memory devices, the address exposed through diag500 STORAGE_LIMIT will correspond to the maximum storage increment exposed through SCLP. To teach kdump on s390 to include memory owned by memory devices, there will be ways to query the relevant memory ranges from the device via a driver running in special kdump mode (like virtio-mem already implements to filter /proc/vmcore access so we don't end up reading from unplugged device blocks). Update setup_ident_map_size(), to clarify that there can be more than just online and standby memory. Tested-by: Mario Casquero <mcasquer@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Tested-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20241025141453.1210600-4-david@redhat.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com> |
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| .. | ||
| .gitignore | ||
| als.c | ||
| alternative.c | ||
| boot.h | ||
| clz_ctz.c | ||
| cmdline.c | ||
| ctype.c | ||
| decompressor.c | ||
| decompressor.h | ||
| ebcdic.c | ||
| head_kdump.S | ||
| head.S | ||
| install.sh | ||
| ipl_data.c | ||
| ipl_parm.c | ||
| ipl_report.c | ||
| ipl_vmparm.c | ||
| kaslr.c | ||
| kmsan.c | ||
| machine_kexec_reloc.c | ||
| Makefile | ||
| mem.S | ||
| pgm_check_info.c | ||
| physmem_info.c | ||
| printk.c | ||
| sclp_early_core.c | ||
| startup.c | ||
| string.c | ||
| uv.c | ||
| uv.h | ||
| version.c | ||
| vmem.c | ||
| vmlinux.lds.S | ||