From: Andi Kleen <ak@linux.intel.com>
To: speck@linutronix.de
Subject: [MODERATED] Re: [PATCH v2.1 4/6] [PATCH v2.1 4/6] Patch #4
Date: Thu, 21 Jun 2018 16:05:48 -0700 [thread overview]
Message-ID: <20180621230548.GV30690@tassilo.jf.intel.com> (raw)
In-Reply-To: <20180620204351.997227234@localhost.localdomain>
> + if (boot_cpu_has(X86_BUG_L1TF) && (cpu_smt_control == CPU_SMT_ENABLED)) {
> + printk(KERN_ERR "kvm: SMT enabled with L1TF CPU bug present. Refer to CVE-2018-3615 for details.\n");
Doesn't make sense if it's mitigated.
> + if (disallow_smt) {
> + r = -EOPNOTSUPP;
> + goto out;
> + }
> + printk(KERN_ERR "Without disabling SMT or setting disallow_smt=1 you risk untrusted guests\n"
> + "being able to snoop the host memory!");
This is not correct because the snooping can be also prevented in other ways,
e.g. using task affinity, cpu sets, interrupt binding etc.
I wouldn't give a specific recipe, it's far too complicated for an kernel
message.
Also all shouldn't be KERN_ERR, just _WARN
-Andi
next prev parent reply other threads:[~2018-06-21 23:05 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-20 20:43 [MODERATED] [PATCH v2.1 4/6] [PATCH v2.1 4/6] Patch #4 konrad.wilk
2018-06-21 8:43 ` [MODERATED] " Peter Zijlstra
2018-06-21 13:56 ` Konrad Rzeszutek Wilk
2018-06-21 17:19 ` Paolo Bonzini
2018-06-21 11:53 ` Paolo Bonzini
2018-06-21 23:05 ` Andi Kleen [this message]
2018-06-22 9:03 ` Paolo Bonzini
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