Re: [kvm-devel] [PATCH 2/3] kvmclock - the host part.

From: Glauber de Oliveira Costa
Date: Tue Nov 13 2007 - 07:17:58 EST


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Dong, Eddie escreveu:
>> +static void kvm_write_guest_time(struct kvm_vcpu *vcpu) +{
>> + struct timespec ts;
>> + int r;
>> +
>> + if (!vcpu->clock_gpa)
>> + return;
>> +
>> + /* Updates version to the next odd number, indicating
>> we're writing */
>> + vcpu->hv_clock.version++;
>> + kvm_write_guest(vcpu->kvm, vcpu->clock_gpa,
>> &vcpu->hv_clock, PAGE_SIZE);
>> +
>> + kvm_get_msr(vcpu, MSR_IA32_TIME_STAMP_COUNTER,
>> + &vcpu->hv_clock.last_tsc);
>> +
>> + ktime_get_ts(&ts);
>
> Do we need to disable preemption here?
After thinking for a little while, you are theoretically right.
In the current state, we could even be preempted between all operations
;-) Maybe after avi's suggestion of moving the call to it it will end up
in a preempt safe region, but anyway, it's safer to add the preempt
markers here.
I'll put it in next version, thanks

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.7 (GNU/Linux)
Comment: Using GnuPG with Remi - http://enigmail.mozdev.org

iD8DBQFHOZBrjYI8LaFUWXMRAo81AKCfbkzhLl7F6BUjzUHVyErCFeHxFACg1teB
eqsOnJiAqB3JiYf+2YdMZ4o=
=ENKU
-----END PGP SIGNATURE-----
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/