Messages in this thread | | | Date | Tue, 18 Sep 2018 19:15:14 +0800 | From | Dave Young <> | Subject | Re: [PATCH 2/2] x86/kexec_file: add reserved e820 ranges to 2nd kernel e820 table |
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On 09/18/18 at 06:20pm, lijiang wrote: > 在 2018年09月18日 11:20, Dave Young 写道: > > On 09/18/18 at 10:48am, Lianbo Jiang wrote: > >> e820 reserved ranges is useful in kdump kernel, we have added this in > >> kexec-tools code. > >> > >> One reason is PCI mmconf (extended mode) requires reserved region > >> otherwise it falls back to legacy mode. > >> > >> When AMD SME kdump support, it needs to map dmi table area as unencrypted. > >> For normal boot these ranges sit in e820 reserved ranges thus the early > >> ioremap code naturally map them as unencrypted. So if we have same e820 > >> reserve setup in kdump kernel then it will just work like normal kernel. > >> > >> Signed-off-by: Dave Young <dyoung@redhat.com> > >> Signed-off-by: Lianbo Jiang <lijiang@redhat.com> > >> --- > >> arch/x86/kernel/crash.c | 6 ++++++ > >> 1 file changed, 6 insertions(+) > >> > >> diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c > >> index 3c113e6545a3..db453e9c117b 100644 > >> --- a/arch/x86/kernel/crash.c > >> +++ b/arch/x86/kernel/crash.c > >> @@ -384,6 +384,12 @@ int crash_setup_memmap_entries(struct kimage *image, struct boot_params *params) > >> walk_iomem_res_desc(IORES_DESC_ACPI_NV_STORAGE, flags, 0, -1, &cmd, > >> memmap_entry_callback); > >> > >> + /* Add all reserved ranges */ > >> + cmd.type = E820_TYPE_RESERVED; > >> + flags = IORESOURCE_MEM; > > > > Lianbo, rethink about this, we will miss other io resource types if only > > match IORESOURCE_MEM here, can you redo the patch with just using "0" > > for the passing flags? > > > > This patches align on kexec-tools for e820 reserved ranges, if so, the kexec-tools also need to > be improved for the other type, such as IORESOURCE_IO/BUS/DMA(...), right?
Kexec-tools just go through /proc/iomem "reserved" items and add them these flags are not visible to it. So we have done same in kexec-tools.
> > I will improve these patches and post v2 tomorrow.
Thanks! Dave
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