| Message ID | 20100601201232.5908.51923.stgit@skyserv |
|---|---|
| State | New |
| Headers | show |
On 06/01/2010 10:12 PM, Igor V. Kovalenko wrote: > From: Igor V. Kovalenko<igor.v.kovalenko@gmail.com> > > - change return type of ldl_* to uint32_t to prevent unwanted sign extension > visible in sparc64 load alternate address space methods > - note this change makes ldl_* softmmu implementations match ldl_phys one This patch breaks -kernel/-initrd. Paolo
Am 03.06.2010 um 15:18 schrieb Paolo Bonzini <pbonzini@redhat.com>: > On 06/01/2010 10:12 PM, Igor V. Kovalenko wrote: >> From: Igor V. Kovalenko<igor.v.kovalenko@gmail.com> >> >> - change return type of ldl_* to uint32_t to prevent unwanted sign >> extension >> visible in sparc64 load alternate address space methods >> - note this change makes ldl_* softmmu implementations match >> ldl_phys one > > This patch breaks -kernel/-initrd. Breaks it where and when? Alex >
On 06/03/2010 05:25 PM, Alexander Graf wrote: > > Am 03.06.2010 um 15:18 schrieb Paolo Bonzini <pbonzini@redhat.com>: > >> On 06/01/2010 10:12 PM, Igor V. Kovalenko wrote: >>> From: Igor V. Kovalenko<igor.v.kovalenko@gmail.com> >>> >>> - change return type of ldl_* to uint32_t to prevent unwanted sign >>> extension >>> visible in sparc64 load alternate address space methods >>> - note this change makes ldl_* softmmu implementations match ldl_phys >>> one >> >> This patch breaks -kernel/-initrd. > > Breaks it where and when? x86_64 TCG reboots after the "Probing EDD" step. Paolo
On Thu, Jun 3, 2010 at 7:42 PM, Paolo Bonzini <pbonzini@redhat.com> wrote: > On 06/03/2010 05:25 PM, Alexander Graf wrote: >> >> Am 03.06.2010 um 15:18 schrieb Paolo Bonzini <pbonzini@redhat.com>: >> >>> On 06/01/2010 10:12 PM, Igor V. Kovalenko wrote: >>>> >>>> From: Igor V. Kovalenko<igor.v.kovalenko@gmail.com> >>>> >>>> - change return type of ldl_* to uint32_t to prevent unwanted sign >>>> extension >>>> visible in sparc64 load alternate address space methods >>>> - note this change makes ldl_* softmmu implementations match ldl_phys >>>> one >>> >>> This patch breaks -kernel/-initrd. >> >> Breaks it where and when? > > x86_64 TCG reboots after the "Probing EDD" step. My local build appears to work, qemu-system-x86_64 loads my gentoo linux setup. I use x86_64 host, gcc 4.4.3, qemu configured with ./configure --prefix=/inst --target-list=sparc64-softmmu,x86_64-softmmu
On 06/03/2010 09:59 PM, Igor Kovalenko wrote: > On Thu, Jun 3, 2010 at 7:42 PM, Paolo Bonzini<pbonzini@redhat.com> wrote: >> On 06/03/2010 05:25 PM, Alexander Graf wrote: >>> >>> Am 03.06.2010 um 15:18 schrieb Paolo Bonzini<pbonzini@redhat.com>: >>> >>>> On 06/01/2010 10:12 PM, Igor V. Kovalenko wrote: >>>>> >>>>> From: Igor V. Kovalenko<igor.v.kovalenko@gmail.com> >>>>> >>>>> - change return type of ldl_* to uint32_t to prevent unwanted sign >>>>> extension >>>>> visible in sparc64 load alternate address space methods >>>>> - note this change makes ldl_* softmmu implementations match ldl_phys >>>>> one >>>> >>>> This patch breaks -kernel/-initrd. >>> >>> Breaks it where and when? >> >> x86_64 TCG reboots after the "Probing EDD" step. > > My local build appears to work, qemu-system-x86_64 loads my gentoo linux setup. > I use x86_64 host, gcc 4.4.3, qemu configured with ./configure > --prefix=/inst --target-list=sparc64-softmmu,x86_64-softmmu Normal boot works. Only -kernel/-initrd fails. Paolo
On 06/04/2010 09:53 AM, Paolo Bonzini wrote: > On 06/03/2010 09:59 PM, Igor Kovalenko wrote: >> On Thu, Jun 3, 2010 at 7:42 PM, Paolo Bonzini<pbonzini@redhat.com> wrote: >>> On 06/03/2010 05:25 PM, Alexander Graf wrote: >>>> >>>> Am 03.06.2010 um 15:18 schrieb Paolo Bonzini<pbonzini@redhat.com>: >>>> >>>>> On 06/01/2010 10:12 PM, Igor V. Kovalenko wrote: >>>>>> >>>>>> From: Igor V. Kovalenko<igor.v.kovalenko@gmail.com> >>>>>> >>>>>> - change return type of ldl_* to uint32_t to prevent unwanted sign >>>>>> extension >>>>>> visible in sparc64 load alternate address space methods >>>>>> - note this change makes ldl_* softmmu implementations match ldl_phys >>>>>> one >>>>> >>>>> This patch breaks -kernel/-initrd. >>>> >>>> Breaks it where and when? >>> >>> x86_64 TCG reboots after the "Probing EDD" step. >> >> My local build appears to work, qemu-system-x86_64 loads my gentoo >> linux setup. >> I use x86_64 host, gcc 4.4.3, qemu configured with ./configure >> --prefix=/inst --target-list=sparc64-softmmu,x86_64-softmmu > > Normal boot works. Only -kernel/-initrd fails. Hmm, PEBKAC. Boot of Fedora and RHEL5 guests always fails, so it's not related to -kernel/-initrd. (Of course, without -kernel/-initrd it reboots into GRUB rather than looping quickly). I've placed a failing vmlinuz at http://people.redhat.com/people/vmlinuz-fail -- if it fails it should reboot continuously. The failure happens pretty soon after the kernel starts running. The sequence is: lock_kernel -> __lock_kernel -> preempt_disable -> current_thread_info() IN: 0xffffffff80063064: push %rbp 0xffffffff80063065: mov %rsp,%rbp 0xffffffff80063068: mov %gs:0x10,%rax 0xffffffff80063071: mov -0x1fc8(%rax),%eax 0xffffffff80063077: test $0x8,%al 0xffffffff80063079: je 0xffffffff800630a2 %rax is 0xffffffff803f1fd8, but it page faults with %cr2=0x00000000803f0010. The reason is that in the generated x86 assembly -0x1fc8 is erroneously zero extended: 0x4180347b: mov %rbp,%rbx 0x4180347e: mov $0xffffe038,%r12d 0x41803484: add %r12,%rbx so it gives the wrong address: (gdb) info reg rbp rbp 0xffffffff803f1fd8 0xffffffff803f1fd8 (gdb) info reg r12 r12 0xffffe038 4294959160 (gdb) info reg rbx rbx 0x803f0010 2151612432 From there it's obvious: general protection, double fault, general protection, triple fault. So it's a TCG bug that is expecting ldl_* to sign extend. I'll send a patch after I come back from lunch. Paolo
diff --git a/softmmu_header.h b/softmmu_header.h index 6a36e01..2f95c33 100644 --- a/softmmu_header.h +++ b/softmmu_header.h @@ -60,7 +60,7 @@ #if DATA_SIZE == 8 #define RES_TYPE uint64_t #else -#define RES_TYPE int +#define RES_TYPE uint32_t #endif #if ACCESS_TYPE == (NB_MMU_MODES + 1)