> From: JAN KISZKA <[email protected]> > Date: 1 May 2018 at 18:55 > Subject: Re: [PATCH 05/19] configs: arm: add comm_region to all inmates > To: Ralf Ramsauer <[email protected]>, > [email protected] > > On 2018-05-01 10:54, Ralf Ramsauer wrote: >> On 04/27/2018 08:27 PM, Jan Kiszka wrote: >>> On 2018-04-27 11:36, Ralf Ramsauer wrote: >>>> On x86, we already use the communication region to pass certain platform >>>> specific information to guests. So let's do this on all ARM >>>> architectures as well. This patch is a preparation for that. >>>> >>>> Let's use guest paddr 0x80000000 (2GiB) for the comm region, which >>>> doesn't seem to collide with any existing (MMIO) region of our current >>>> inmates. >>> >>> So you really checked them all? Also validated that there is no >>> collision with any of the virtual mmcfg region we define (that's in the >>> system config then)? >> >> I manually checked them, including the mmcfg region. But I think it's >> worth crosschecking them. >> >> Of course, 0x80000000 overlaps with physical RAM on most ARM platforms, >> but that's not an issue for the communication region in inmates. >> >> The point of this address is that on most platforms, MMIO regions are >> spread somewhere below 0x80000000, where it's on the one hand hard to >> find a common free region, and on the other it's likely to get a new >> board where that address might be in use. > > Hmm, may work for us - provided we never try to steal RAM for inmates > from that address onward... OK, will double-check the targets. > > Jan > > -- > You received this message because you are subscribed to the Google Groups > "Jailhouse" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout [1].
As per "Principles of ARM(R) Memory Maps White Paper", Document number: ARM DEN 0001C, http://infocenter.arm.com/help/topic/com.arm.doc.den0001c/DEN0001C_principles_of_arm_memory_maps.pdf I would say the selected location will never point to MMIO. -FF Links: ------ [1] https://groups.google.com/d/optout -- You received this message because you are subscribed to the Google Groups "Jailhouse" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
