From: Chao Gao <chao.gao@intel.com>
To: Binbin Wu <binbin.wu@linux.intel.com>
Cc: Sean Christopherson <seanjc@google.com>, <kvm@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, <pbonzini@redhat.com>,
<kai.huang@intel.com>, <David.Laight@aculab.com>,
<robert.hu@linux.intel.com>
Subject: Re: [PATCH v9 4/6] KVM: x86: Introduce untag_addr() in kvm_x86_ops
Date: Thu, 29 Jun 2023 14:57:53 +0800 [thread overview]
Message-ID: <ZJ0rcVpSjbZInnIq@chao-email> (raw)
In-Reply-To: <bf5ef935-b676-4f2a-7df3-271eff24e6bb@linux.intel.com>
On Thu, Jun 29, 2023 at 02:12:27PM +0800, Binbin Wu wrote:
>> > + /*
>> > + * Check LAM_U48 in cr3_ctrl_bits to avoid guest_cpuid_has().
>> > + * If not set, vCPU doesn't supports LAM.
>> > + */
>> > + if (!(vcpu->arch.cr3_ctrl_bits & X86_CR3_LAM_U48) ||
>> This is unnecessary, KVM should never allow the LAM bits in CR3 to be set if LAM
>> isn't supported.
A corner case is:
If EPT is enabled, CR3 writes are not trapped. then guests can set the
LAM bits in CR3 if hardware supports LAM regardless whether or not guest
enumerates LAM.
next prev parent reply other threads:[~2023-06-29 6:58 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-06 9:18 [PATCH v9 0/6] Linear Address Masking (LAM) KVM Enabling Binbin Wu
2023-06-06 9:18 ` [PATCH v9 1/6] KVM: x86: Consolidate flags for __linearize() Binbin Wu
2023-06-06 9:18 ` [PATCH v9 2/6] KVM: x86: Virtualize CR4.LAM_SUP Binbin Wu
2023-06-07 3:40 ` Huang, Kai
2023-06-07 4:55 ` Binbin Wu
2023-06-07 9:20 ` Huang, Kai
2023-06-06 9:18 ` [PATCH v9 3/6] KVM: x86: Virtualize CR3.LAM_{U48,U57} Binbin Wu
2023-06-27 23:40 ` Sean Christopherson
2023-06-28 3:05 ` Binbin Wu
2023-06-28 17:40 ` Sean Christopherson
2023-07-03 7:56 ` Binbin Wu
2023-07-22 1:28 ` Sean Christopherson
2023-06-06 9:18 ` [PATCH v9 4/6] KVM: x86: Introduce untag_addr() in kvm_x86_ops Binbin Wu
2023-06-28 0:15 ` Sean Christopherson
2023-06-29 6:12 ` Binbin Wu
2023-06-29 6:57 ` Chao Gao [this message]
2023-06-29 7:22 ` Binbin Wu
2023-06-29 15:33 ` Sean Christopherson
2023-06-29 8:30 ` David Laight
2023-06-29 15:16 ` Sean Christopherson
2023-06-29 17:26 ` Binbin Wu
2023-06-06 9:18 ` [PATCH v9 5/6] KVM: x86: Untag address when LAM applicable Binbin Wu
2023-06-28 0:19 ` Sean Christopherson
2023-06-06 9:18 ` [PATCH v9 6/6] KVM: x86: Expose LAM feature to userspace VMM Binbin Wu
2023-06-07 3:52 ` Huang, Kai
2023-06-16 1:45 ` Binbin Wu
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