[PATCH RESEND] kdump: pass e820 reserved region to 2nd kernel via e820 table or setup_data
horms at verge.net.au
Mon Apr 28 18:59:52 PDT 2014
On Mon, Apr 28, 2014 at 09:26:11PM +0800, WANG Chao wrote:
> e820 reserved region could be useful in 2nd kernel.
> For example, PCI mmconf (extended mode) requires reserved region
> otherwise it falls back to legacy mode. The following log is from Cliff
> Wickman <cpw at sgi.com>:
> PCI: MMCONFIG for domain 1003 [bus 3f-3f] at [mem 0xff0ff00000-0xff0fffffff] (base 0xff0c000000)
> [Firmware Bug]: PCI: MMCONFIG at [mem 0x80000000-0x80cfffff] not reserved in ACPI motherboard resources
> PCI: not using MMCONFIG
> PCI devices on segment 1 (>0) can't fall back to legacy mode, thus
> kernel probing fails and device can't be found.
> We don't pass reserved region because these regions could be too much
> and eat up our very limited kernel command line resource in
> memmap=exactmap case.
> However now we use e820 map and setup_data to pass memory map to 2nd
> kernel and the number of reserved regions should not be a problem any
> Signed-off-by: WANG Chao <chaowang at redhat.com>
More information about the kexec