[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [PATCH v2] iscsi_ibft: Fix finding the iBFT under Xen Dom 0
On 5/30/23 08:01, Ross Lagerwall wrote: > Since firmware doesn't indicate the iBFT in the E820, add a reserved > region so that it gets identity mapped when running as Dom 0 so that it > is possible to search for it. Move the call to reserve_ibft_region() > later so that it is called after the Xen identity mapping adjustments > are applied. > > Finally, instead of using isa_bus_to_virt() which doesn't do the right > thing under Xen, use early_memremap() like the dmi_scan code does. This is connecting Xen, iSCSI and x86. Some background here would be *really* nice for dummies like me that deal heavily in only one of those three. One or two sentences like this: Firmware can provide an iSCSI-specific table called the iBFT which helps the OS boot from iSCSI devices. can go a long way for dummies like me. As could some background about why this: ... add a reserved region so that it gets identity mapped when running as Dom 0 so that it is possible to search for it. These are all English words, but off the top of my head, I have no idea why reserved regions get identity mapped when running as Dom 0 or why that makes it possible to search. The addresses and size here: > +#ifdef CONFIG_ISCSI_IBFT_FIND > + /* Reserve 0.5 MiB to 1 MiB region so iBFT can be found */ > + xen_e820_table.entries[xen_e820_table.nr_entries].addr = > 0x80000; > + xen_e820_table.entries[xen_e820_table.nr_entries].size = > 0x80000; > + xen_e820_table.entries[xen_e820_table.nr_entries].type = > E820_TYPE_RESERVED; > + xen_e820_table.nr_entries++; > +#endif also appear to be conjured out of thin air. As does the move of: > + reserve_ibft_region(); I'm sure I can go figure this all out with some research. But, I'd really appreciate some extra effort from you in this changelog to save me the time. I bet you can explain it a lot more efficiently than I can go figure it out.
|
![]() |
Lists.xenproject.org is hosted with RackSpace, monitoring our |