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

[Gleb Natapov <gleb@redhat.com>]

On Fri, Jan 22, 2010 at 10:15:44AM +0800, Liu, Jinsong wrote:
> Gleb Natapov wrote:
> > On Thu, Jan 21, 2010 at 07:48:23PM +0800, Liu, Jinsong wrote:
> >>> From cb997030cba02e7e74a29b3d942aeba9808ed293 Mon Sep 17 00:00:00
> >>> 2001 
> >> From: Liu, Jinsong <jinsong.liu@intel.com>
> >> 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 <jinsong.liu@intel.com>
> > It looks like AML code is a port of what we had in BOCHS bios with
> > minor changes. Can you detail what is changed and why for easy review
> > please? And this still doesn't work with Windows I assume.
> > 
> 
> Yes, my work is based on BOCHS infrastructure, thanks BOCHS :)
> I just change some minor points:
> 1. explicitly define returen value of '_MAT' as 'buffer', otherwise some linux acpi driver (i.e. linux 2.6.30) would parse error which will handle it as 'integer' not 'buffer';
> 2. keep correct 'checksum' of madt when vcpu add/remove, otherwise it will report 'checksum error' when using acpi tools to get madt info if we add/remove vcpu;
> 3. add '_EJ0' so that linux has acpi obj under /sys/devices/LNXSYSTM:00, which is need for vcpu remove;
> 4. on Method(PRSC, 0), just scan 'xxx' vcpus that qemu get from cmdline para 'maxcpus=xxx', not all 256 vcpus, otherwise under some dsdt processor define, it will result error;
What kind of errors? Qemu should never set bit over maxcpus in PRS.

> 5. use 1 hardcode address bios_info structure to replace '0x514', so that it can transfer more madt info to dsdt;
> 
> Thanks,
> Jinsong

--
			Gleb.