Re: [Qemu-devel] [Question]Support of China loogson processor

[Paolo Bonzini]

On 16/04/2015 17:05, Leon Alrae wrote:
> On 16/04/2015 13:02, Paolo Bonzini wrote:
>>
>>
>> On 16/04/2015 13:07, Leon Alrae wrote:
>>> Since I also haven't had a chance to test Loongson emulation, I thought
>>> I'd give it a try (TCG only, Loongson-2E cpu and fulong2e machine).
>>>
>>> Good news is that I'm able to get to the login prompt using ancient QEMU
>>> v1.0, kernel 2.6.33 (with additional patch from
>>> https://lists.gnu.org/archive/html/qemu-devel/2010-06/msg02566.html) and
>>> some old debian image I had handy. However, in any newer version
>>> starting from v1.1.0 of QEMU something goes horribly wrong and it just
>>> segfaults somewhere inside hw/bonito.c quite early during kernel
>>> booting.
>>
>> Where exactly?  If it's related to the memory API conversion, it may be
>> easy to fix.  I can look at a backtrace (or you can just put the Debian
>> image somewhere I can grab it).
> 
> Bisect points at: 5312bd8b3152f8d4fcf9389ba54e32b09f4b4093
> 
> Crash occurs during the first access, below there is backtrace from
> working and not working case:

This is my best guess...

diff --git a/hw/pci-host/bonito.c b/hw/pci-host/bonito.c
index 8bdd569..8134d0b 100644
--- a/hw/pci-host/bonito.c
+++ b/hw/pci-host/bonito.c
@@ -233,7 +233,7 @@ static void bonito_writel(void *opaque, hwaddr addr,
     uint32_t saddr;
     int reset = 0;
 
-    saddr = (addr - BONITO_REGBASE) >> 2;
+    saddr = addr >> 2;
 
     DPRINTF("bonito_writel "TARGET_FMT_plx" val %x saddr %x\n", addr, val, 
saddr);
     switch (saddr) {
@@ -295,7 +295,7 @@ static uint64_t bonito_readl(void *opaque, hwaddr addr,
     PCIBonitoState *s = opaque;
     uint32_t saddr;
 
-    saddr = (addr - BONITO_REGBASE) >> 2;
+    saddr = addr >> 2;
 
     DPRINTF("bonito_readl "TARGET_FMT_plx"\n", addr);
     switch (saddr) {


Paolo