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From: Chao Gao <chao.gao@intel.com>
To: Robert Hoo <robert.hu@linux.intel.com>
Cc: <seanjc@google.com>, <pbonzini@redhat.com>,
	<yu.c.zhang@linux.intel.com>, <yuan.yao@linux.intel.com>,
	<jingqi.liu@intel.com>, <weijiang.yang@intel.com>,
	<isaku.yamahata@intel.com>, <kirill.shutemov@linux.intel.com>,
	<kvm@vger.kernel.org>
Subject: Re: [PATCH v4 6/9] KVM: x86: When KVM judges CR3 valid or not, consider LAM bits
Date: Tue, 14 Feb 2023 15:00:46 +0800	[thread overview]
Message-ID: <Y+sxniz6PBQTrVKy@gao-cwp> (raw)
In-Reply-To: <Y+sn09U4wTIxoDKN@gao-cwp>

On Tue, Feb 14, 2023 at 02:18:59PM +0800, Chao Gao wrote:
>>> > 	bool skip_tlb_flush = false;
>>> > @@ -1254,7 +1262,7 @@ int kvm_set_cr3(struct kvm_vcpu *vcpu,
>>> > unsigned long cr3)
>>> > 	 * stuff CR3, e.g. for RSM emulation, and there is no guarantee
>>> > that
>>> > 	 * the current vCPU mode is accurate.
>>> > 	 */
>>> > -	if (kvm_vcpu_is_illegal_gpa(vcpu, cr3))
>>> > +	if (!kvm_is_valid_cr3(vcpu, cr3))
>>> 
>>> There are other call sites of kvm_vcpu_is_illegal_gpa() to validate
>>> cr3.
>>> Do you need to modify them?
>>
>>I don't think so. Others are for gpa validation, no need to change.
>>Here is for CR3.
>
>how about the call in kvm_is_valid_sregs()? if you don't change it, when
>user space VMM tries to set a CR3 with any LAM bits, KVM thinks the CR3
>is illegal and returns an error. To me it means live migration probably
>is broken.
>
>And the call in nested_vmx_check_host_state()? L1 VMM should be allowed to
>program a CR3 with LAM bits set to VMCS's HOST_CR3 field. Actually, it
>is exactly what this patch 6 is doing.

Please disregard "Actually, it is exactly what this patch 6 is doing".
My brain just disconnected.

  reply	other threads:[~2023-02-14  7:00 UTC|newest]

Thread overview: 64+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-02-09  2:40 [PATCH v4 0/9] Linear Address Masking (LAM) KVM Enabling Robert Hoo
2023-02-09  2:40 ` [PATCH v4 1/9] KVM: x86: Intercept CR4.LAM_SUP when LAM feature is enabled in guest Robert Hoo
2023-02-09  9:21   ` Chao Gao
2023-02-09 12:48     ` Robert Hoo
2023-02-10  3:29   ` Yang, Weijiang
2023-02-10  5:02     ` Robert Hoo
2023-02-10 16:30       ` Sean Christopherson
2023-02-14  1:27   ` Binbin Wu
2023-02-14  6:11     ` Robert Hoo
2023-02-14  9:00       ` Binbin Wu
2023-02-14 12:24         ` Robert Hoo
2023-02-14 12:36           ` Robert Hoo
2023-02-16  5:31           ` Binbin Wu
2023-02-16  5:54             ` Robert Hoo
2023-02-09  2:40 ` [PATCH v4 2/9] KVM: x86: MMU: Clear CR3 LAM bits when allocate shadow root Robert Hoo
2023-02-09  9:55   ` Chao Gao
2023-02-09 13:02     ` Robert Hoo
2023-02-14  2:55       ` Binbin Wu
2023-02-15  1:17         ` Robert Hoo
2023-02-16  2:14         ` Robert Hoo
2023-02-10  3:38   ` Yang, Weijiang
2023-02-11  3:12     ` Robert Hoo
2023-02-09  2:40 ` [PATCH v4 3/9] KVM: x86: MMU: Commets update Robert Hoo
2023-02-10  6:59   ` Chao Gao
2023-02-10  7:55     ` Robert Hoo
2023-02-10 16:54       ` Sean Christopherson
2023-02-09  2:40 ` [PATCH v4 4/9] KVM: x86: MMU: Integrate LAM bits when build guest CR3 Robert Hoo
2023-02-10 14:04   ` Chao Gao
2023-02-11  6:24     ` Robert Hoo
2023-02-11  6:29       ` Robert Hoo
2023-02-09  2:40 ` [PATCH v4 5/9] KVM: x86: Untag LAM bits when applicable Robert Hoo
2023-02-10 15:04   ` Chao Gao
2023-02-11  5:57     ` Robert Hoo
2023-02-16  6:37       ` Binbin Wu
2023-02-09  2:40 ` [PATCH v4 6/9] KVM: x86: When KVM judges CR3 valid or not, consider LAM bits Robert Hoo
2023-02-13  2:01   ` Chao Gao
2023-02-13 13:25     ` Robert Hoo
2023-02-14  6:18       ` Chao Gao
2023-02-14  7:00         ` Chao Gao [this message]
2023-02-18  5:44         ` Robert Hoo
2023-02-09  2:40 ` [PATCH v4 7/9] KVM: x86: When guest set CR3, handle LAM bits semantics Robert Hoo
2023-02-13  3:31   ` Chao Gao
2023-02-14  5:28     ` Robert Hoo
2023-02-14  6:48       ` Chao Gao
2023-02-09  2:40 ` [PATCH v4 8/9] KVM: x86: emulation: Apply LAM when emulating data access Robert Hoo
2023-02-13  3:53   ` Chao Gao
2023-02-14  5:38     ` Robert Hoo
2023-02-09  2:40 ` [PATCH v4 9/9] KVM: x86: LAM: Expose LAM CPUID to user space VMM Robert Hoo
2023-02-21  5:47   ` Binbin Wu
2023-02-21  7:26     ` Robert Hoo
2023-02-21  8:26       ` Binbin Wu
2023-02-21 11:13         ` Yu Zhang
2023-02-21 13:18           ` Binbin Wu
2023-02-21 14:36             ` Robert Hoo
2023-02-09  6:15 ` [PATCH v4 0/9] Linear Address Masking (LAM) KVM Enabling Chao Gao
2023-02-09 12:25   ` Robert Hoo
2023-02-09 17:27     ` Sean Christopherson
2023-02-10  2:07       ` Robert Hoo
2023-02-10  3:17         ` Chao Gao
2023-02-10  8:41           ` Robert Hoo
2023-02-10  8:39         ` Robert Hoo
2023-02-10  9:22           ` Chao Gao
2023-02-13  9:02 ` Binbin Wu
2023-02-13 13:16   ` Robert Hoo

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