On 28.07.20 11:31, Jakub Lužný wrote:
In the default configuration <https://github.com/siemens/jailhouse/blob/master/configs/arm64/rpi4.c>, Jailhouse allocates the memory range 0x0 - 0x3fa10000 (~1018M) for the cells. The rest of the first 0x40000000 (1024M) long memory space is used for the hypervisor itself and various shared memory regions. To avoid the Linux kernel using all of the memory, |mem=768M| kernel parameter is used <https://github.com/siemens/jailhouse-images/blob/master/recipes-bsp/rpi-firmware/files/cmdline.txt>. That makes the memory above 768M available for the non-root cells. Regarding the GPU memory, the |gpu_mem| parameter in Raspberry’s config.txt is not set <https://github.com/siemens/jailhouse-images/blob/master/recipes-bsp/rpi-firmware/files/config.txt>, so it defaults to 64M. Then, the area of 0x3b400000 (948M) - 0x40000000 (1024M) is reserved by the Raspberry firmware. I don’t know how they make sure that Jailhouse’s shared memory regions don’t interfere with the GPU, but it seems that they know what they’re doing.
That is actually a valid finding. The demo image is not using the GPU but this means that we are using GPU RAM for sharing?! Fix for that welcome.
Jan -- Siemens AG, Corporate Technology, CT RDA IOT SES-DE Corporate Competence Center Embedded Linux -- 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]. To view this discussion on the web visit https://groups.google.com/d/msgid/jailhouse-dev/f9395dda-b39c-0826-ff6a-8c60f4efac1b%40siemens.com.
