linux-kernel - [PATCH 05/18] Warn about unstable TSC

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

Message-Id: <1278987938-23873-6-git-send-email-zamsden@redhat.com>
Date:	Mon, 12 Jul 2010 16:25:25 -1000
From:	Zachary Amsden <zamsden@...hat.com>
To:	KVM <kvm@...r.kernel.org>, Avi Kivity <avi@...hat.com>,
	Marcelo Tosatti <mtosatti@...hat.com>,
	Glauber Costa <glommer@...hat.com>
Cc:	Linux-kernel <linux-kernel@...r.kernel.org>,
	Zachary Amsden <zamsden@...hat.com>,
	Avi Kivity <avi@...hat.com>,
	Marcelo Tosatti <mtosatti@...hat.com>,
	Glauber Costa <glommer@...hat.com>
Subject: [PATCH 05/18] Warn about unstable TSC

If creating an SMP guest with unstable host TSC, issue a warning

Signed-off-by: Zachary Amsden <zamsden@...hat.com>
---
 arch/x86/kvm/x86.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2d5b97a..36ef649 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5449,6 +5449,10 @@ void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
 struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
 						unsigned int id)
 {
+	if (check_tsc_unstable() && id != 0)
+		printk_once(KERN_WARNING
+		"kvm: SMP vm created on host with unstable TSC; "
+		"guest TSC will not be reliable\n");
 	return kvm_x86_ops->vcpu_create(kvm, id);
 }
 
-- 
1.7.1

--
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/