On 19.08.2011, at 06:45, Aashish Mittal wrote: > Hi > I'm trying to emulate the lwzu instruction in e500 powerpc kvm for my project . > I've removed the read and write privileges from the tlb entries of guest's > certain pages . So when i'm trying to emulate lwzu instruction i'm getting a > kernel panic while mounting the guest filesystem while booting . > > attempt to access beyond end of device > ram0: rw=0, want=75703268, limit=262144 > > To make sure that the emulation is faulty what i'm trying to do now is at the > time of DATA STORAGE exit on a marked page by an lwzu instruction i'm patching > the next instruction with an instruction which will raise an INTERRUPT PROGRAM > EXCEPTION and will get trapped in kvm and then i'm reverting the old read and > write privileges of this page and resuming the guest so that this LWZU > instruction can run natively . I'm expecting the immediate next instruction to > raise the INTERRUPT PROGRAM EXCEPTION but all i'm getting are DATA STORAGE Exits > at other pages marked by me and DTLB and ITLB misses on other addresses . > > I've made sure to flush the icache after i patch using the instruction > flush_icache_range . > > Error Log : > Emulating a lwzu instruction on pc 0xc00161ac && eaddr 0xc05742f0 > Original Instruction is 0x90e60004 at pc: 0xc00161b0 > Modified Instruction is 0x7ce000a6 at pc: 0xc00161b0 > Exit : Interrupt DATA STORAGE at pc 0xc000f210 on eaddr:0xc000f228 instruction: > 0x8085001c > > Why i'm not getting any INTERRUPT PROGRAM EXCEPTION immediately in the next > instruction ? Hrm. Are you sure you're actually modifying the instruction? This looks like you're running Linux, so you could try and just put a "b ." instruction right after the instruction you're trying to patch up and examine memory from Qemu :) Alex -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
