linux-kernel - Re: KVM: x86: zero kvmclock_offset when vcpu0 initializes kvmclock system MSR

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 22 May 2015 14:40:48 -0700
From:	Owen Hofmann <osh@...gle.com>
To:	Marcelo Tosatti <mtosatti@...hat.com>
Cc:	KVM General <kvm@...r.kernel.org>,
	Paolo Bonzini <pbonzini@...hat.com>,
	LKML <linux-kernel@...r.kernel.org>,
	Sasha Levin <sasha.levin@...cle.com>
Subject: Re: KVM: x86: zero kvmclock_offset when vcpu0 initializes kvmclock
 system MSR

Change as described sounds good, however:

> @@ -2188,6 +2188,8 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu,
> struct msr_data *msr_info)
>                                         &vcpu->requests);
>
>                         ka->boot_vcpu_runs_old_kvmclock = tmp;
> +
> +                       ka->kvmclock_offset = get_kernel_ns();
>                 }

Should this be ka->kvmclock_offset = -get_kernel_ns()?
kvm_guest_time_update() sets hv_clock.system_time = kernel_ns +
v->kvm->arch.kvmclock_offset, and similarly kvmclock_offset is added
to the value from get_kernel_ns() in the handler for
HV_X64_MSR_TIME_REF_COUNT.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/