Re: [PATCH 3/7] ppc/pnv: Use skiboot addresses to load kernel and ramfs

[David Gibson]

On Thu, Jan 28, 2021 at 08:02:41AM +0100, Cédric Le Goater wrote:
> On 1/28/21 1:45 AM, Joel Stanley wrote:
> > On Tue, 26 Jan 2021 at 17:11, Cédric Le Goater <clg@kaod.org> wrote:
> >>
> >> The current settings are useful to load large kernels (with debug) but
> >> it moves the initrd image in a memory region not protected by
> >> skiboot. If skiboot is compiled with DEBUG=1, memory poisoning will
> >> corrupt the initrd.
> >>
> >> Cc: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
> >> Signed-off-by: Cédric Le Goater <clg@kaod.org>
> > 
> > Reviewed-by: Joel Stanley <joel@jms.id.au>
> > 
> > Note that the machine's default ram size will change with this patch:
> > 
> >  mc->default_ram_size = INITRD_LOAD_ADDR + INITRD_MAX_SIZE;
> 
> Ah yes. I missed that.
> 
> > So we will go from 1.75GB to 768MB. Does anything break when the
> > machine has less than 1GB of ram?
> 
> There is a warning if the machine has less than 1GB but we should
> also change the default RAM size to 1G to be on the safe side.

I've merged the patch, but I'm happy to replace it with an updated
version, or fold in a change, if that helps.

> 
> Thanks,
> 
> C. 
> 
> > 
> >> ---
> >>
> >>  If we want to increase the kernel size limit as commit b45b56baeecd
> >>  ("ppc/pnv: increase kernel size limit to 256MiB") intented to do, I
> >>  think we should add a machine option.
> >>
> >>  hw/ppc/pnv.c | 6 +++---
> >>  1 file changed, 3 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
> >> index 14fc9758a973..e500c2e2437e 100644
> >> --- a/hw/ppc/pnv.c
> >> +++ b/hw/ppc/pnv.c
> >> @@ -65,9 +65,9 @@
> >>  #define FW_MAX_SIZE             (16 * MiB)
> >>
> >>  #define KERNEL_LOAD_ADDR        0x20000000
> >> -#define KERNEL_MAX_SIZE         (256 * MiB)
> >> -#define INITRD_LOAD_ADDR        0x60000000
> >> -#define INITRD_MAX_SIZE         (256 * MiB)
> >> +#define KERNEL_MAX_SIZE         (128 * MiB)
> >> +#define INITRD_LOAD_ADDR        0x28000000
> >> +#define INITRD_MAX_SIZE         (128 * MiB)
> >>
> >>  static const char *pnv_chip_core_typename(const PnvChip *o)
> >>  {
> >>
> >>
> 

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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