On Tue, 2009-01-27 at 19:42 +0200, Valtteri Kiviniemi wrote:
Hi,
I can confirm this. With NX enabled in BIOS the domU boots fine (tested with 2.6.28).
If I disable NX in BIOS the domU will crash.
Thanks for confirming. Did you get a chance to try the patch I sent?
Ian.
- Valtteri Kiviniemi
Virtualization kirjoitti:
Hi Ian,
Indeed nx is on one and not the other! However, that doesn't help...
Broken CPU: /proc/cpuinfo: model name : Intel(R) Xeon(TM) CPU 3.00GHz flags : fpu tsc msr pae mce cx8 apic mtrr mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall lm constant_tsc up pni monitor ds_cpl cid cx16 xtpr
Good CPU: model name : AMD Athlon(tm) 64 X2 Dual Core Processor 3600+ flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt rdtscp lm 3dnowext 3dnow rep_good pni cx16 lahf_lm cmp_legacy svm extapic cr8_legacy 3dnowprefetch
So, ran it again with noexec=0,
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kernel /vmlinuz-2.6.27.9-159.fc10.x86_64 ro root=LABEL=/ selinux=0 noipv6 nomodeset noexec=off
Results:
[ root@office64 xen ]# /usr/lib64/xen/bin/xenctx -s System.map-2.6.27.9-159.fc10.x86_64 119 rip: ffffffff8100b8a2 set_page_prot+0x6d rsp: ffffffff81575f08 rax: ffffffea rbx: 000016e4 rcx: 00000055 rdx: 00000000 rsi: 800000014a293061 rdi: ffffffff816e4000 rbp: ffffffff81575f68 r8: 0000000f r9: ffffffff817ee350 r10: ffffffff817ee550 r11: 00000010 r12: ffffffff816e4000 r13: 800000014a293061 r14: 8000000000000161 r15: 00002c00 cs: 0000e033 ds: 00000000 fs: 00000000 gs: 00000000
Stack: 0000000000000055 0000000000000010 ffffffff8100b8a2 000000010000e030 0000000000010082 ffffffff81575f48 000000000000e02b ffffffff8100b89e 0000000000000200 ffffffff816e7000 0000000000000800 0000000000000016 ffffffff81575ff8 ffffffff815a5c60 0000000000002c00 0000000000000000
Code: df 54 1d 00 4c 89 e7 4c 89 ee 31 d2 e8 22 d9 ff ff 85 c0 74 04 <0f> 0b eb fe 5b 41 5c 41 5d 41 5e
Call Trace: [<ffffffff8100b8a2>] set_page_prot+0x6d <-- [<ffffffff8100b8a2>] set_page_prot+0x6d [<ffffffff8100b89e>] set_page_prot+0x69 [<ffffffff815a5c60>] xen_start_kernel+0x5dd
Battling with bugzilla trying to get a new account. It doesn't like me :-(
Might have to leave it up to Jon to do the bugzilla thing.
Cheers Phill.
On Tue, 2009-01-20 at 17:03 +0000, Ian Campbell wrote:
(resending with original xen-devel thread participants on CC, please reply to this subthread, I'll forward you guys Mark's original mail in a second)
On Tue, 2009-01-20 at 10:27 +0000, Mark McLoughlin wrote:
if ( unlikely(l1e_get_flags(nl1e) & L1_DISALLOW_MASK) ) { MEM_LOG("Bad L1 flags %x", l1e_get_flags(nl1e) & L1_DISALLOW_MASK); return 0; }... }
the PTE flags are 800000 which corresponds to:
#define _PAGE_NX_BIT (1U<<23)
At least in xen-unstable (and I think for much longer) L1_DISALLOW_MASK contains _PAGE_NX_BIT dynamically depending on the processor capabilities.
#define _PAGE_NX (cpu_has_nx ? _PAGE_NX_BIT : 0) ... /* * Disallow unused flag bits plus PAT/PSE, PCD, PWT and GLOBAL. * Permit the NX bit if the hardware supports it. */ #define BASE_DISALLOW_MASK (0xFFFFF198U & ~_PAGE_NX) #define L1_DISALLOW_MASK (BASE_DISALLOW_MASK | _PAGE_GNTTAB)Does the hardware support NX? What does /proc/cpuinfo in dom0 think?
The guest kernel should be setting up __supported_pte_mask appropriately to match the hardware and hence shouldn't be using NX if it isn't available. There's a command line option to force NX, can you try noexec=off on the guest command line.
My guess would be that the guest is getting a wrong EFER from somewhere...
Ian.