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

[Gleb Natapov]

On Thu, Jan 28, 2010 at 11:16:17AM +0800, Liu, Jinsong wrote:
> Connor and Gleb,
>
> Thanks for comments and suggestions!
>
> According to the discussion, I will update my patch as:
> simplify method 'PRSC' definiation, move 'maxvcpus' to method 'NTFY' so that code is more direct and easy to understand;
> remove unnecessary global variable 'madt_csum_addr, madt_lapic0_addr, max_cpus_byte, max_cpus_bit';
> use VAR16FIXED() macro for a hardcode address, change hardcode address from '0xEA000' to '0x514' (same as old BOCHS);
>
> Is it OK?

The memory that is accessed from DSDT should be of type ACPI NVS in e820
map. Otherwise Windows7 checked build BSODs.
> 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