Re: [PATCH v4 2/3] riscv/virt: Support using pflash via -blockdev option

[Sunil V L <sunilvl@ventanamicro.com>]

On Fri, May 26, 2023 at 11:53:18AM +0200, Philippe Mathieu-Daudé wrote:
> On 25/5/23 18:48, Sunil V L wrote:
> > Currently, pflash devices can be configured only via -pflash
> > or if=pflash options. This is the legacy way and the
> > better way is to use -blockdev as in other architectures.
> > libvirt also has moved to -blockdev method.
> > 
> > To support -blockdev option, pflash devices need to be
> > created in instance_init itself. So, update the code to
> > move the virt_flash_create() to instance_init. Also, use
> > standard interfaces to detect whether pflash0 is
> > configured or not.
> > 
> > Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
> > Reported-by: Andrea Bolognani <abologna@redhat.com>
> > ---
> >   hw/riscv/virt.c | 15 +++++++++------
> >   1 file changed, 9 insertions(+), 6 deletions(-)
> 
> 
> > @@ -1265,21 +1267,22 @@ static void virt_machine_done(Notifier *notifier, void *data)
> >       firmware_end_addr = riscv_find_and_load_firmware(machine, firmware_name,
> >                                                        start_addr, NULL);
> > -
> > -    if (drive_get(IF_PFLASH, 0, 0)) {
> > +    pflash_blk0 = pflash_cfi01_get_blk(s->flash[0]);
> > +    if (pflash_blk0) {
> > +        flash_mem = pflash_cfi01_get_memory(s->flash[0]);
> >           if (machine->firmware && !strcmp(machine->firmware, "none")) {
> >               /*
> >                * Pflash was supplied but bios is none, let's overwrite the
> >                * address we jump to after reset to the base of the flash.
> >                */
> > -            start_addr = virt_memmap[VIRT_FLASH].base;
> > +            start_addr = flash_mem->addr;
> 
> I don't understand this change. Besides you access MemoryRegion::addr
> which is an internal API field.
> 
Thanks Philip. This is not really required. I was trying to avoid
depending on memmap base addresses and dividing the memmap
range by 2 to get the second flash memory base etc. Since we have
created MemoryRegion already which has the actual base address for each
pflash, I was thinking to avoid this hardcoding. But I didn't realize I
am accessing the internal field.

Let me revert this particular change.

Thanks,
Sunil