Re: [Qemu-devel] [PATCH] sparc32 machine specific maximums

[Blue Swirl]

On 12/4/07, Robert Reif <address@hidden> wrote:
> Blue Swirl wrote:
>
> >On 12/3/07, Robert Reif <address@hidden> wrote:
> >
> >
> >>This patch sets the maximum number of CPUs and memory to what is
> >>supported by the actual hardware.
> >>
> >>
> >
> >While it's not historically accurate to emulate a Sparcstation 5 with
> >16 CPUs and 2 gigabytes of memory, it doesn't break anything to have
> >this capability. We don't throttle the power of the CPU, speed of the
> >network, serial or disk devices either, so they may be unrealistically
> >fast. The timers are not accurate at all compared to CPU execution
> >speed.
> >
> >Currently the memory on SS-5 machine is limited by the location of
> >IOMMU and that the memory lies in one linear bank starting from zero.
> >With more advanced banking and >4G patches, the entire physical
> >address space could be filled with RAM.
> >
> >
> >
> I would be surprised if an SMP kernel actually worked on a multi CPU SS5.

Prepare for a surprise:

Loading initial ramdisk....
PROMLIB: obio_ranges 1
Booting Linux...
PROMLIB: Sun Boot Prom Version 3 Revision 2
Linux version 2.2.20pre2 (address@hidden) (gcc version egcs-2.91.66
19990314/Linux (egcs-1.1.2 release)) #1 SMP Wed May 30 10:44:52 PDT
2001
ARCH: SUN4M
TYPE: SPARCstation 5
Ethernet address: 52:54:0:12:34:56
Boot time fixup v1.6. 4/Mar/98 Jakub Jelinek (address@hidden).
Patching kernel for srmmu[Fujitsu TurboSparc]/iommu
[0]: v[f0000000,fd000000](d000000) p[00000000]
[1]: v[ed000000,eff2c000](2f2c000) p[0d000000]
Found CPU 0 <node=ffd56998,mid=0>
Found CPU 1 <node=ffd56d4c,mid=1>
Found CPU 2 <node=ffd57100,mid=2>
Found CPU 3 <node=ffd574b4,mid=3>
Found 4 CPU prom device tree node(s).
Power off control detected.
Calibrating delay loop... 235.92 BogoMIPS
Memory: 254792k available (1508k kernel code, 3372k data, 148k init)
[ed000000,fd000000]
Dentry hash table entries: 32768 (order 6, 256k)
Buffer cache hash table entries: 262144 (order 8, 1024k)
Page cache hash table entries: 65536 (order 6, 256k)
VFS: Diskquotas version dquot_6.4.0 initialized
POSIX conformance testing by UNIFIX
Entering SMP Mode...
Starting CPU 1 at f01c9dc4
Calibrating delay loop... 84.17 BogoMIPS
Starting CPU 2 at f01c9dd0
Calibrating delay loop... 77.00 BogoMIPS
Starting CPU 3 at f01c9ddc
Calibrating delay loop... 78.84 BogoMIPS
Total of 4 Processors activated (475.95 BogoMIPS).
IOMMU: impl 0 vers 4 page table at efe80000 of size 524288 bytes
sbus0: Clock 21.1250 MHz
dma0: Revision 2
dma1: Revision 0
Linux NET4.0 for Linux 2.2
Based upon Swansea University Computer Society NET3.039
NET4: Unix domain sockets 1.0 for Linux NET4.0.
NET4: Linux TCP/IP 1.0 for NET4.0
IP Protocols: ICMP, UDP, TCP, IGMP
TCP: Hash tables configured (ehash 262144 bhash 65536)
Linux IP multicast router 0.06 plus PIM-SM
Initializing RT netlink socket
Starting kswapd v 1.5
Sparc Zilog8530 serial driver version 1.41.2.8
tty00 at 0xffe97004 (irq = 44) is a Zilog8530
tty01 at 0xffe97000 (irq = 44) is a Zilog8530
tty02 at 0xffe98004 (irq = 44) is a Zilog8530
tty03 at 0xffe98000 (irq = 44) is a Zilog8530
Sun TYPE 4 keyboard detected without keyclick
Console: ttyS0 (Zilog8530)
pty: 512 Unix98 ptys configured
Sun Mouse-Systems mouse driver version 1.00
RAM disk driver initialized:  16 RAM disks of 5120K size
Floppy drive(s): fd0 is 1.44M
FDC 0 is a S82078B
md driver 0.36.6 MAX_MD_DEV=4, MAX_REAL=8
linear personality registered
raid0 personality registered
raid1 personality registered
raid5 personality registered
esp0: IRQ 36 SCSI ID 7 Clk 40MHz CCF=8 TOut 167 NCR53C90(esp100)
ESP: Total of 1 ESP hosts found, 1 actually in use.
scsi0 : Sparc ESP100 (NCR53C90)
scsi : 1 host.
  Vendor: QEMU      Model: QEMU HARDDISK     Rev: 0.9.
  Type:   Direct-Access                      ANSI SCSI revision: 03
Detected scsi disk sda at scsi0, channel 0, id 0, lun 0
  Vendor: QEMU      Model: QEMU CD-ROM       Rev: 0.9.
  Type:   CD-ROM                             ANSI SCSI revision: 03
Detected scsi CD-ROM sr0 at scsi0, channel 0, id 2, lun 0
scsi : detected 2 SCSI generics 1 SCSI cdrom 1 SCSI disk total.
sr0: scsi3-mmc drive: 16x/50x cd/rw xa/form2 cdda tray
Uniform CD-ROM driver Revision: 3.11
SCSI device sda: hdwr sector= 512 bytes. Sectors= 2097152 [1024 MB] [1.0 GB]
Partition check:
 sda: sda1 sda2 sda3
RAMDISK: Compressed image found at block 0
EXT2-fs warning: checktime reached, running e2fsck is recommended
VFS: Mounted root (ext2 filesystem).
serial console detected.  Disabling virtual terminals.
init started:  BusyBox v0.51 (2001.05.24-01:20+0000) multi-call binary
none on /proc type proc (rw)
chown[26]: Unimplemented SPARC system call 31
chown[38]: Unimplemented SPARC system call 31

> Currently OSs like solaris and bsd that actually use more than a minimal
> amount of hardware don't work in QEMU.  That's because QEMUs
> system emulation is both incomplete and inaccurate.  If you want to make

Please give concrete examples where the emulation is incomplete so we
can fix the problems. There are some well known areas where Qemu is by
design not accurate and some things are hard to implement.

> a 16
> CPU, 64 Gb machine, define a QEMU specific machine.  There are no real
> 32 bit sparc systems like that. I would like to see real sun openboot ROM

I can't imagine anybody forcing someone to put -smp 16 -m 64000 to the
command line.

> images work on realistic emulated hardware so QEMU could be used for
> real OS development.

How exactly does the _capability_ to specify more than 256M of memory
or more than one CPU break your ROM?