Dietmar Maurer wrote: > 00000000000037c0 <svm_get_msr>: > ... > > 387e: 66 90 xchg %ax,%ax > 3880: 0f 84 8a 00 00 00 je 3910 <svm_get_msr+0x150> > 3886: 66 90 xchg %ax,%ax > 3888: 0f 86 c2 01 00 00 jbe 3a50 <svm_get_msr+0x290> > 388e: 48 8b 87 e0 27 00 00 mov 0x27e0(%rdi),%rax > 3895: 48 8b 80 08 06 00 00 mov 0x608(%rax),%rax > 389c: 48 89 02 mov %rax,(%rdx) > 389f: 90 nop > 38a0: 31 c0 xor %eax,%eax > 38a2: c3 retq > 38a3: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) > 38a8: 81 fe d9 01 00 00 cmp $0x1d9,%esi > 38ae: 0f 84 7c 00 00 00 je 3930 <svm_get_msr+0x170> > 38b4: 0f 86 46 01 00 00 jbe 3a00 <svm_get_msr+0x240> > 38ba: 81 fe db 01 00 00 cmp $0x1db,%esi > 38c0: 0f 84 ca 01 00 00 je 3a90 <svm_get_msr+0x2d0> > 38c6: 81 fe dc 01 00 00 cmp $0x1dc,%esi > 38cc: 0f 1f 40 00 nopl 0x0(%rax) > 38d0: 75 98 jne 386a <svm_get_msr+0xaa> > 38d2: 48 8b 87 e0 27 00 00 mov 0x27e0(%rdi),%rax > 38d9: 48 8b 80 80 06 00 00 mov 0x680(%rax),%rax > 38e0: 48 89 02 mov %rax,(%rdx) > 38e3: eb bb jmp 38a0 <svm_get_msr+0xe0> > 38e5: 0f 1f 00 nopl (%rax) > 38e8: 48 83 bf 78 28 00 00 cmpq $0x0,0x2878(%rdi) > 38ef: 00 > 38f0: 0f 85 82 01 00 00 jne 3a78 <svm_get_msr+0x2b8> > 38f6: 48 8b 87 e0 27 00 00 mov 0x27e0(%rdi),%rax > 38fd: 48 8b 48 50 mov 0x50(%rax),%rcx > 3901: 0f 31 rdtsc > 3903: 48 01 c8 add %rcx,%rax > > # this is svm_get_msr+0x146 > 3906: 48 89 02 mov %rax,(%rdx) > 3909: eb 95 jmp 38a0 <svm_get_msr+0xe0> > 390b: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) > 3910: 48 8b 87 e0 27 00 00 mov 0x27e0(%rdi),%rax > 3917: 48 8b 80 00 06 00 00 mov 0x600(%rax),%rax > 391e: 48 89 02 mov %rax,(%rdx) > 3921: e9 7a ff ff ff jmpq 38a0 <svm_get_msr+0xe0> > 3926: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1) > 392d: 00 00 00 > 3930: 48 8b 87 e0 27 00 00 mov 0x27e0(%rdi),%rax > 3937: 48 8b 80 70 06 00 00 mov 0x670(%rax),%rax > 393e: 48 89 02 mov %rax,(%rdx) > 3941: e9 5a ff ff ff jmpq 38a0 <svm_get_msr+0xe0> > 3946: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1) > 394d: 00 00 00 > 3950: 48 8b 87 e0 27 00 00 mov 0x27e0(%rdi),%rax > 3957: 48 8b 80 28 06 00 00 mov 0x628(%rax),%rax > 395e: 48 89 02 mov %rax,(%rdx) > 3961: e9 3a ff ff ff jmpq 38a0 <svm_get_msr+0xe0> > 3966: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1) > 396d: 00 00 00 > 3970: 48 c7 02 65 00 00 01 movq $0x1000065,(%rdx) > 3977: e9 24 ff ff ff jmpq 38a0 <svm_get_msr+0xe0> > 397c: 0f 1f 40 00 nopl 0x0(%rax) > 3980: 48 8b 87 e0 27 00 00 mov 0x27e0(%rdi),%rax > 3987: 48 8b 80 10 06 00 00 mov 0x610(%rax),%rax > 398e: 48 89 02 mov %rax,(%rdx) > 3991: e9 0a ff ff ff jmpq 38a0 <svm_get_msr+0xe0> > 3996: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1) > 399d: 00 00 00 > ... > > > We use the ubunto 2.6.24 kernel (http://kernel.ubuntu.com/git?p=ubuntu/ubuntu-hardy.git;a=summary) > > They have a few more patches applied: > > http://kernel.ubuntu.com/git?p=ubuntu/ubuntu-hardy.git;a=history;f=include/asm-x86/msr.h;h=cfe169475b5b50a448326ef3c34f50100ac83faf;hb=HEAD > > Maybe those last 2 patches can cause the problem? Nope, it was most probably a kvm-kmod bug. Patch below should fix it. Jan -----> Fix native_read_tsc wrapping for x86-64 Use register constraint macros so that the return values of rdtsc are properly picked up and no local variable is overwritten. This is supposed to fix an oops on x86-64 with a 2.6.24 host kernel. Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> --- x86/external-module-compat.h | 7 ++++--- 1 files changed, 4 insertions(+), 3 deletions(-) diff --git a/x86/external-module-compat.h b/x86/external-module-compat.h index b0b9f21..b0de024 100644 --- a/x86/external-module-compat.h +++ b/x86/external-module-compat.h @@ -94,9 +94,10 @@ static inline unsigned long long native_read_msr_safe(unsigned int msr, static inline unsigned long long kvm_native_read_tsc(void) { - unsigned long long val; - asm volatile("rdtsc" : "=A" (val)); - return val; + DECLARE_ARGS(val, low, high); + + asm volatile("rdtsc" : EAX_EDX_RET(val, low, high)); + return EAX_EDX_VAL(val, low, high); } #else /* >= 2.6.25 */ -- 1.6.0.2 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
