Re: [SeaBIOS] [PATCH] vcpu hotplug: Setup vcpu add/remove infrastructure, including madt bios_info and dsdt

[Liu, Jinsong]

Connor and Gleb,

Thanks for comments and suggestions!

According to the discussion, I will update my patch as:
1. simplify method 'PRSC' definiation, move 'maxvcpus' to method 'NTFY' so that code is more direct and easy to understand;
2. remove unnecessary global variable 'madt_csum_addr, madt_lapic0_addr, max_cpus_byte, max_cpus_bit';
3. use VAR16FIXED() macro for a hardcode address, change hardcode address from '0xEA000' to '0x514' (same as old BOCHS);

Is it OK?

Thanks,
Jinsong

Gleb Natapov wrote:
> On Sat, Jan 23, 2010 at 06:46:18PM -0500, Kevin O'Connor wrote:
> > On Fri, Jan 22, 2010 at 09:35:55AM +0800, Liu, Jinsong wrote:
> > > From cb997030cba02e7e74a29b3d942aeba9808ed293 Mon Sep 17 00:00:00
> > > 2001 
> > > From: Liu, Jinsong 
> > > Date: Fri, 22 Jan 2010 03:18:46 +0800
> > > Subject: [PATCH]         Setup vcpu add/remove infrastructure,
> > > including madt bios_info and dsdt.
> > >     1. setup madt bios_info structure, so that static dsdt get
> > >        run-time madt info like checksum address, lapic address,
> > >        max cpu numbers, with least hardcode magic number
> > >        (realmode address of bios_info).
> > >     2. setup vcpu add/remove dsdt infrastructure, including
> > >        processor related acpi objects and control methods. vcpu
> > >        add/remove will trigger SCI and then control method
> > >        _L02. By matching madt, vcpu number and add/remove
> > >        action were found, then by notify control method, it
> > >
> > > will notify OS acpi driver.
> > >     Signed-off-by: Liu, Jinsong <[e-mail]>
> >
> > Thanks.
> >
> > I'd like to see Gleb's comments on the ACPI changes.
>
> I already commented on KVM list. Here is the link
> http://www.mail-archive.com/[e-mail]/msg27562.html
> > [...]
> > > diff --git a/src/acpi.c b/src/acpi.c
> > > index f613b03..037da46 100644
> > > --- a/src/acpi.c
> > > +++ b/src/acpi.c
> > > @@ -344,6 +344,9 @@ build_fadt(int bdf)
> > >      return fadt;
> > >  }
> > >
> > > +u32 madt_csum_addr, madt_lapic0_addr;
> > > +u32 max_cpus_byte, max_cpus_bit;
> > >
> > > static void*
> > >  build_madt(void)
> > >  {
> > > @@ -360,6 +363,10 @@ build_madt(void)
> > >      madt->local_apic_address = cpu_to_le32(BUILD_APIC_ADDR);
> > >      madt->flags = cpu_to_le32(1);
> > >      struct madt_processor_apic *apic = (void*)&madt[1];
> > > madt_csum_addr = (u32)&madt->checksum;
> > > madt_lapic0_addr = (u32)apic;
> > > max_cpus_byte = MaxCountCPUs / 8;
> > > max_cpus_bit = MaxCountCPUs % 8;
> >
> > I'm confused at why global variables are being created, exported, and
> > set, just to be copied to another location later on.
> > > +/*
> > > ***************************************************************** +
> > > use bios_info to enable dsdt get run-time madt and cpu info, + *
> > >
> > > and to avoid more hardcode magic number. +
> > > *******************************************************************/
> > > +#define BIOS_INFO_PHYSICAL_ADDRESS    0x000EA000
> >
> > That wont work - nothing stops 0xea000 from being used by an option
> > rom or the bios itself.  If a physical address is needed, the
> > VAR16FIXED() macro needs to be used.  However, I'm very reluctant to
> > add new hardcoded addresses - there has to be a very compelling
> > reason to do that.
> >
> > -Kevin
> >
> > SeaBIOS mailing list
> > [e-mail]
> > http://www.seabios.org/mailman/listinfo/seabios