On Fri, Feb 21, 2020 at 04:55:32PM +0000, Andre Przywara wrote: > From: Raphael Gault <raphael.gault@xxxxxxx> > > The EDK II UEFI firmware implementation requires some storage for the EFI > variables, which is typically some flash storage. > Since this is already supported on the EDK II side, we add a CFI flash > emulation to kvmtool. > This is backed by a file, specified via the --flash or -F command line > option. Any flash writes done by the guest will immediately be reflected > into this file (kvmtool mmap's the file). > The flash will be limited to the nearest power-of-2 size, so only the > first 2 MB of a 3 MB file will be used. > > This implements a CFI flash using the "Intel/Sharp extended command > set", as specified in: > - JEDEC JESD68.01 > - JEDEC JEP137B > - Intel Application Note 646 > Some gaps in those specs have been filled by looking at real devices and > other implementations (QEMU, Linux kernel driver). > > At the moment this relies on DT to advertise the base address of the > flash memory (mapped into the MMIO address space) and is only enabled > for ARM/ARM64. The emulation itself is architecture agnostic, though. > > This is one missing piece toward a working UEFI boot with kvmtool on > ARM guests, the other is to provide writable PCI BARs, which is WIP. > > Signed-off-by: Raphael Gault <raphael.gault@xxxxxxx> > [Andre: rewriting and fixing] > Signed-off-by: Andre Przywra <andre.przywara@xxxxxxx> > --- > Hi, > > an update fixing Alexandru's review comments (many thanks for those!) > The biggest change code-wise is the split of the MMIO handler into three > different functions. Another significant change is the rounding *down* of > the present flash file size to the nearest power-of-two, to match flash > hardware chips and Linux' expectations. Alexandru -- are you happy with this now? Will
