On 03/22/21 at 05:01pm, David Hildenbrand wrote: > It used to be true that we can have busy system RAM only on the first level > in the resourc tree. However, this is no longer holds for driver-managed > system RAM (i.e., added via dax/kmem and virtio-mem), which gets added on > lower levels. > > We have two users of walk_system_ram_res(), which currently only > consideres the first level: > a) kernel/kexec_file.c:kexec_walk_resources() -- We properly skip > IORESOURCE_SYSRAM_DRIVER_MANAGED resources via > locate_mem_hole_callback(), so even after this change, we won't be > placing kexec images onto dax/kmem and virtio-mem added memory. No > change. > b) arch/x86/kernel/crash.c:fill_up_crash_elf_data() -- we're currently > not adding relevant ranges to the crash elf info, resulting in them > not getting dumped via kdump. > > This change fixes loading a crashkernel via kexec_file_load() and including > dax/kmem and virtio-mem added System RAM in the crashdump on x86-64. Note > that e.g,, arm64 relies on memblock data and, therefore, always considers > all added System RAM already. > > Let's find all busy IORESOURCE_SYSTEM_RAM resources, making the function > behave like walk_system_ram_range(). > > Cc: Andrew Morton <a...@linux-foundation.org> > Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org> > Cc: Dan Williams <dan.j.willi...@intel.com> > Cc: Daniel Vetter <daniel.vet...@ffwll.ch> > Cc: Andy Shevchenko <andriy.shevche...@linux.intel.com> > Cc: Mauro Carvalho Chehab <mchehab+hua...@kernel.org> > Cc: Signed-off-by: David Hildenbrand <da...@redhat.com> > Cc: Dave Young <dyo...@redhat.com> > Cc: Baoquan He <b...@redhat.com> > Cc: Vivek Goyal <vgo...@redhat.com> > Cc: Dave Hansen <dave.han...@linux.intel.com> > Cc: Keith Busch <keith.bu...@intel.com> > Cc: Michal Hocko <mho...@suse.com> > Cc: Qian Cai <c...@lca.pw> > Cc: Oscar Salvador <osalva...@suse.de> > Cc: Eric Biederman <ebied...@xmission.com> > Cc: Thomas Gleixner <t...@linutronix.de> > Cc: Ingo Molnar <mi...@redhat.com> > Cc: Borislav Petkov <b...@alien8.de> > Cc: "H. Peter Anvin" <h...@zytor.com> > Cc: Tom Lendacky <thomas.lenda...@amd.com> > Cc: Brijesh Singh <brijesh.si...@amd.com> > Cc: x...@kernel.org > Cc: ke...@lists.infradead.org > Signed-off-by: David Hildenbrand <da...@redhat.com> > --- > kernel/resource.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/resource.c b/kernel/resource.c > index 627e61b0c124..4efd6e912279 100644 > --- a/kernel/resource.c > +++ b/kernel/resource.c > @@ -457,7 +457,7 @@ int walk_system_ram_res(u64 start, u64 end, void *arg, > { > unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; > > - return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true, > + return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, false, > arg, func);
Thanks, David, this is a good fix. Acked-by: Baoquan He <b...@redhat.com> > } > > -- > 2.29.2 >