From: Xiaoyao Li <xiaoyao.li@intel.com>
To: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
hpa@zytor.com, Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <sean.j.christopherson@intel.com>
Cc: x86@kernel.org, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org, Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Arvind Sankar <nivedita@alum.mit.edu>,
Fenghua Yu <fenghua.yu@intel.com>,
Tony Luck <tony.luck@intel.com>
Subject: Re: [PATCH v6 8/8] kvm: vmx: virtualize split lock detection
Date: Thu, 26 Mar 2020 14:41:14 +0800 [thread overview]
Message-ID: <88b01989-25cd-90af-bfe8-c236bd5d1dbf@intel.com> (raw)
In-Reply-To: <87eethz2p6.fsf@nanos.tec.linutronix.de>
On 3/25/2020 8:40 AM, Thomas Gleixner wrote:
> Xiaoyao Li <xiaoyao.li@intel.com> writes:
>> +static inline bool guest_cpu_split_lock_detect_on(struct vcpu_vmx *vmx)
>> +{
>> + return vmx->msr_test_ctrl & MSR_TEST_CTRL_SPLIT_LOCK_DETECT;
>> +}
>> +
>> static int handle_exception_nmi(struct kvm_vcpu *vcpu)
>> {
>> struct vcpu_vmx *vmx = to_vmx(vcpu);
>> @@ -4725,12 +4746,13 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu)
>> case AC_VECTOR:
>> /*
>> * Reflect #AC to the guest if it's expecting the #AC, i.e. has
>> - * legacy alignment check enabled. Pre-check host split lock
>> - * support to avoid the VMREADs needed to check legacy #AC,
>> - * i.e. reflect the #AC if the only possible source is legacy
>> - * alignment checks.
>> + * legacy alignment check enabled or split lock detect enabled.
>> + * Pre-check host split lock support to avoid further check of
>> + * guest, i.e. reflect the #AC if host doesn't enable split lock
>> + * detection.
>> */
>> if (!split_lock_detect_on() ||
>> + guest_cpu_split_lock_detect_on(vmx) ||
>> guest_cpu_alignment_check_enabled(vcpu)) {
>
> If the host has split lock detection disabled then how is the guest
> supposed to have it enabled in the first place?
>
It is ||
Thanks,
-Xiaoyao
next prev parent reply other threads:[~2020-03-26 6:41 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-24 15:18 [PATCH v6 0/8] x86/split_lock: Fix and virtualization of split lock detection Xiaoyao Li
2020-03-24 15:18 ` [PATCH v6 1/8] x86/split_lock: Rework the initialization flow " Xiaoyao Li
2020-03-24 15:18 ` [PATCH v6 2/8] x86/split_lock: Avoid runtime reads of the TEST_CTRL MSR Xiaoyao Li
2020-03-24 15:18 ` [PATCH v6 3/8] x86/split_lock: Export handle_user_split_lock() Xiaoyao Li
2020-03-24 15:18 ` [PATCH v6 4/8] kvm: x86: Emulate split-lock access as a write in emulator Xiaoyao Li
2020-03-25 0:00 ` Thomas Gleixner
2020-03-25 0:31 ` Xiaoyao Li
2020-03-24 15:18 ` [PATCH v6 5/8] kvm: vmx: Extend VMX's #AC interceptor to handle split lock #AC happens in guest Xiaoyao Li
2020-03-24 15:18 ` [PATCH v6 6/8] kvm: x86: Emulate MSR IA32_CORE_CAPABILITIES Xiaoyao Li
2020-03-24 15:18 ` [PATCH v6 7/8] kvm: vmx: Enable MSR_TEST_CTRL for intel guest Xiaoyao Li
2020-03-25 0:07 ` Thomas Gleixner
2020-03-24 15:18 ` [PATCH v6 8/8] kvm: vmx: virtualize split lock detection Xiaoyao Li
2020-03-25 0:40 ` Thomas Gleixner
2020-03-25 1:11 ` Xiaoyao Li
2020-03-25 1:41 ` Thomas Gleixner
2020-03-26 1:38 ` Xiaoyao Li
2020-03-26 11:08 ` Thomas Gleixner
2020-03-26 12:31 ` Xiaoyao Li
2020-03-26 6:41 ` Xiaoyao Li [this message]
2020-03-26 11:10 ` Thomas Gleixner
2020-03-26 12:43 ` Xiaoyao Li
2020-03-26 14:55 ` Thomas Gleixner
2020-03-26 15:09 ` Xiaoyao Li
2020-03-26 18:51 ` Thomas Gleixner
2020-03-24 17:47 ` [PATCH v6 0/8] x86/split_lock: Fix and virtualization of " Sean Christopherson
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