From: Paolo Bonzini <pbonzini@redhat.com>
To: Xiaoyao Li <xiaoyao.li@intel.com>,
Sean Christopherson <sean.j.christopherson@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Andy Lutomirski <luto@amacapital.net>
Cc: x86@kernel.org, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org,
David Laight <David.Laight@aculab.com>
Subject: Re: [PATCH v2 3/6] kvm: x86: Emulate split-lock access as a write
Date: Tue, 11 Feb 2020 13:20:45 +0100 [thread overview]
Message-ID: <95d29a81-62d5-f5b6-0eb6-9d002c0bba23@redhat.com> (raw)
In-Reply-To: <20200203151608.28053-4-xiaoyao.li@intel.com>
On 03/02/20 16:16, Xiaoyao Li wrote:
> A sane guest should never tigger emulation on a split-lock access, but
> it cannot prevent malicous guest from doing this. So just emulating the
> access as a write if it's a split-lock access to avoid malicous guest
> polluting the kernel log.
Saying that anything doing a split lock access is malicious makes little
sense.
Split lock detection is essentially a debugging feature, there's a
reason why the MSR is called "TEST_CTL". So you don't want to make the
corresponding behavior wrong. Just kill the guest with a
KVM_INTERNAL_ERROR userspace exit so people will notice quickly and
either disable the feature or see if they can fix the guest.
Paolo
next prev parent reply other threads:[~2020-02-11 12:20 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-03 15:16 [PATCH v2 0/6] kvm/split_lock: Add feature split lock detection support in kvm Xiaoyao Li
2020-02-03 15:16 ` [PATCH v2 1/6] x86/split_lock: Add and export get_split_lock_detect_state() Xiaoyao Li
2020-02-03 21:45 ` Sean Christopherson
2020-02-03 15:16 ` [PATCH v2 2/6] x86/split_lock: Add and export split_lock_detect_set() Xiaoyao Li
2020-02-03 15:16 ` [PATCH v2 3/6] kvm: x86: Emulate split-lock access as a write Xiaoyao Li
2020-02-03 20:54 ` Sean Christopherson
2020-02-04 2:55 ` Xiaoyao Li
2020-02-11 12:20 ` Paolo Bonzini [this message]
2020-02-11 13:22 ` Thomas Gleixner
2020-02-11 13:34 ` Paolo Bonzini
2020-02-11 14:02 ` Xiaoyao Li
2020-02-11 14:34 ` David Laight
2020-02-27 0:11 ` Sean Christopherson
2020-03-12 11:42 ` Xiaoyao Li
2020-03-12 15:00 ` Paolo Bonzini
2020-02-03 15:16 ` [PATCH v2 4/6] kvm: vmx: Extend VMX's #AC handding for split lock in guest Xiaoyao Li
2020-02-03 21:14 ` Sean Christopherson
2020-02-04 6:46 ` Xiaoyao Li
2020-02-10 21:30 ` Sean Christopherson
2020-02-03 15:16 ` [PATCH v2 5/6] kvm: x86: Emulate MSR IA32_CORE_CAPABILITIES Xiaoyao Li
2020-02-03 21:43 ` Sean Christopherson
2020-02-04 9:19 ` Xiaoyao Li
2020-02-04 9:37 ` Peter Zijlstra
2020-02-11 3:52 ` Andy Lutomirski
2020-02-11 12:38 ` Peter Zijlstra
2020-02-03 15:16 ` [PATCH v2 6/6] x86: vmx: virtualize split lock detection Xiaoyao Li
2020-02-03 15:58 ` Xiaoyao Li
2020-02-03 18:52 ` Andy Lutomirski
2020-02-03 21:42 ` Sean Christopherson
2020-02-04 2:52 ` Xiaoyao Li
2020-02-04 5:35 ` Sean Christopherson
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