On 4/16/21 4:46 AM, Thanos Makatos wrote: > > >> -----Original Message----- >> From: Gerd Hoffmann <kra...@redhat.com> >> Sent: 16 April 2021 08:15 >> To: Thanos Makatos <thanos.maka...@nutanix.com> >> Cc: Kevin O'Connor <ke...@koconnor.net>; seabios@seabios.org; John >> Levon <john.le...@nutanix.com>; Swapnil Ingle >> <swapnil.in...@nutanix.com>; Liu, Changpeng <changpeng....@intel.com> >> Subject: Re: [SeaBIOS] SeaBIOS fails to boot from NVMe controller with lots >> of namespaces >> >> Hi, >> >>> Regarding the failure cases, will things break during build >> (BUILD_MIN_BIOSTABLE=16K), e.g: >>> >>> [seabios] Error! ROM doesn't fit (135584 > 131072) >>> [seabios] You have to either increase the size (CONFIG_ROM_SIZE) >>> [seabios] or turn off some features (such as hardware support not >>> [seabios] needed) to make it fit. Trying a more recent gcc version >>> [seabios] might work too. >>> [seabios] make: *** [out/bios.bin.prep] Error 1 >>> >>> Or do we expect undefined behavior at run time? >> >> Running out of memory can lead to undefined behavior at run time, >> depending on which allocations fail. Typical error pattern is that seabios >> can't >> initialize all devices, leading to boot failures. >> >>> 256 namespaces is not an insanely huge number. >> >> Well, back in the 80ies when the BIOS interfaces have been created >> 256 was an insanely huge number ... >> >> Given we have a number of real mode constrains for compatibility reasons >> (like some data structures must live in the f segment) there is no easy way >> out, we simply can't support an unlimited number of disks (which btw is one >> of the reasons why the "skip non-bootable disks" code exists). > > SeaBIOS only tries to boot from the first namespace; if that fails other > namespaces aren't tried > (https://mail.coreboot.org/hyperkitty/list/seabios@seabios.org/thread/72LFLT7KFMWE4GVZHWF4G34PKLVG5LRD/). > If we stick to the current behavior, then there's no reason to probe any > other namespace apart from the first one. This greatly reduces memory > requirements so we should be able to support the max number of namespaces. > >> >> Of course there is the option to leave behind the 80ies and go for UEFI. > > Or can just live with it as you suggest and simply document it 😊.
Sorry for thread necro, but CoreOS devs are hitting this issue too, but using plain emulated qemu nvme. Fedora bug: https://bugzilla.redhat.com/show_bug.cgi?id=1963255 Originally a `-device nvme,...` would report only 1 namespace, and seabios could boot from it fine. After '7f0f1acedf hw/block/nvme: support multiple namespaces', the device now reports 256 namespaces, and seabios fails like described in this thread. Where can I file this so it doesn't get lost? Anyone know a qemu command line workaround? Thanks, Cole _______________________________________________ SeaBIOS mailing list -- seabios@seabios.org To unsubscribe send an email to seabios-le...@seabios.org
