From: Sean Christopherson <seanjc@google.com>
To: Rick P Edgecombe <rick.p.edgecombe@intel.com>
Cc: "jmattson@google.com" <jmattson@google.com>,
Chao Gao <chao.gao@intel.com>,
Weijiang Yang <weijiang.yang@intel.com>,
Dave Hansen <dave.hansen@intel.com>,
"peterz@infradead.org" <peterz@infradead.org>,
"john.allen@amd.com" <john.allen@amd.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"mlevitsk@redhat.com" <mlevitsk@redhat.com>,
"pbonzini@redhat.com" <pbonzini@redhat.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>
Subject: Re: [PATCH v8 00/26] Enable CET Virtualization
Date: Fri, 5 Jan 2024 11:34:05 -0800 [thread overview]
Message-ID: <ZZhVzNb4QHzGJO6W@google.com> (raw)
In-Reply-To: <b6ed5961a3a73de532e2ff0610f43ca129151199.camel@intel.com>
On Fri, Jan 05, 2024, Rick P Edgecombe wrote:
> On Fri, 2024-01-05 at 10:09 -0800, Jim Mattson wrote:
> > > 3. Task switching
> >
> > Sigh. KVM is forced to emulate task switch, because the hardware is
> > incapable of virtualizing it. How hard would it be to make KVM's
> > task-switch emulation CET-aware?
>
> (I am not too familiar with this part of the arch).
>
> See SDM Vol 3a, chapter 7.3, number 8 and 15. The behavior is around
> actual task switching. At first glance, it looks annoying at least. It
> would need to do a CMPXCHG to guest memory at some points and take care
> to not implement the "Complex Shadow-Stack Updates" behavior.
>
> But, would anyone use it? I'm not aware of any 32 bit supervisor shadow
> stack support out there. So maybe it is ok to just punt to userspace in
> this case?
Yeah, I think KVM can punt.
next prev parent reply other threads:[~2024-01-05 19:34 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-21 14:02 [PATCH v8 00/26] Enable CET Virtualization Yang Weijiang
2023-12-21 14:02 ` [PATCH v8 01/26] x86/fpu/xstate: Always preserve non-user xfeatures/flags in __state_perm Yang Weijiang
2023-12-21 14:02 ` [PATCH v8 02/26] x86/fpu/xstate: Refine CET user xstate bit enabling Yang Weijiang
2024-01-02 22:24 ` Maxim Levitsky
2023-12-21 14:02 ` [PATCH v8 03/26] x86/fpu/xstate: Add CET supervisor mode state support Yang Weijiang
2023-12-21 14:02 ` [PATCH v8 04/26] x86/fpu/xstate: Introduce XFEATURE_MASK_KERNEL_DYNAMIC xfeature set Yang Weijiang
2024-01-02 22:25 ` Maxim Levitsky
2024-01-03 9:10 ` Yang, Weijiang
2024-01-04 22:26 ` Edgecombe, Rick P
2024-01-04 22:26 ` Edgecombe, Rick P
2023-12-21 14:02 ` [PATCH v8 05/26] x86/fpu/xstate: Introduce fpu_guest_cfg for guest FPU configuration Yang Weijiang
2024-01-02 22:32 ` Maxim Levitsky
2024-01-03 9:17 ` Yang, Weijiang
2024-01-04 22:42 ` Edgecombe, Rick P
2023-12-21 14:02 ` [PATCH v8 06/26] x86/fpu/xstate: Create guest fpstate with guest specific config Yang Weijiang
2024-01-02 22:32 ` Maxim Levitsky
2024-01-03 18:16 ` Edgecombe, Rick P
2024-01-04 2:16 ` Yang, Weijiang
2024-01-04 22:47 ` Edgecombe, Rick P
2024-01-05 8:16 ` Yang, Weijiang
2023-12-21 14:02 ` [PATCH v8 07/26] x86/fpu/xstate: Warn if kernel dynamic xfeatures detected in normal fpstate Yang Weijiang
2024-01-02 22:33 ` Maxim Levitsky
2023-12-21 14:02 ` [PATCH v8 08/26] KVM: x86: Rework cpuid_get_supported_xcr0() to operate on vCPU data Yang Weijiang
2024-01-02 22:33 ` Maxim Levitsky
2023-12-21 14:02 ` [PATCH v8 09/26] KVM: x86: Rename kvm_{g,s}et_msr() to menifest emulation operations Yang Weijiang
2023-12-21 14:02 ` [PATCH v8 10/26] KVM: x86: Refine xsave-managed guest register/MSR reset handling Yang Weijiang
2023-12-21 14:02 ` [PATCH v8 11/26] KVM: x86: Add kvm_msr_{read,write}() helpers Yang Weijiang
2023-12-21 14:02 ` [PATCH v8 12/26] KVM: x86: Report XSS as to-be-saved if there are supported features Yang Weijiang
2023-12-21 14:02 ` [PATCH v8 13/26] KVM: x86: Refresh CPUID on write to guest MSR_IA32_XSS Yang Weijiang
2023-12-21 14:02 ` [PATCH v8 14/26] KVM: x86: Initialize kvm_caps.supported_xss Yang Weijiang
2023-12-21 14:02 ` [PATCH v8 15/26] KVM: x86: Load guest FPU state when access XSAVE-managed MSRs Yang Weijiang
2023-12-21 14:02 ` [PATCH v8 16/26] KVM: x86: Add fault checks for guest CR4.CET setting Yang Weijiang
2023-12-21 14:02 ` [PATCH v8 17/26] KVM: x86: Report KVM supported CET MSRs as to-be-saved Yang Weijiang
2023-12-21 14:02 ` [PATCH v8 18/26] KVM: VMX: Introduce CET VMCS fields and control bits Yang Weijiang
2023-12-21 14:02 ` [PATCH v8 19/26] KVM: x86: Use KVM-governed feature framework to track "SHSTK/IBT enabled" Yang Weijiang
2023-12-21 14:02 ` [PATCH v8 20/26] KVM: VMX: Emulate read and write to CET MSRs Yang Weijiang
2023-12-21 14:02 ` [PATCH v8 21/26] KVM: x86: Save and reload SSP to/from SMRAM Yang Weijiang
2024-01-02 22:34 ` Maxim Levitsky
2023-12-21 14:02 ` [PATCH v8 22/26] KVM: VMX: Set up interception for CET MSRs Yang Weijiang
2024-01-02 22:34 ` Maxim Levitsky
2024-01-15 9:58 ` Yuan Yao
2024-01-17 1:41 ` Yang, Weijiang
2024-01-17 1:58 ` Yang, Weijiang
2024-01-17 5:31 ` Yuan Yao
2024-01-17 6:16 ` Yang, Weijiang
2023-12-21 14:02 ` [PATCH v8 23/26] KVM: VMX: Set host constant supervisor states to VMCS fields Yang Weijiang
2023-12-21 14:02 ` [PATCH v8 24/26] KVM: x86: Enable CET virtualization for VMX and advertise to userspace Yang Weijiang
2024-01-02 22:34 ` Maxim Levitsky
2024-01-16 7:25 ` Yuan Yao
2024-01-17 1:43 ` Yang, Weijiang
2023-12-21 14:02 ` [PATCH v8 25/26] KVM: nVMX: Introduce new VMX_BASIC bit for event error_code delivery to L1 Yang Weijiang
2023-12-21 14:02 ` [PATCH v8 26/26] KVM: nVMX: Enable CET support for nested guest Yang Weijiang
2024-01-02 22:35 ` Maxim Levitsky
2024-01-16 7:22 ` Yuan Yao
2024-01-17 1:53 ` Yang, Weijiang
2024-01-03 18:50 ` [PATCH v8 00/26] Enable CET Virtualization Edgecombe, Rick P
2024-01-04 7:11 ` Yang, Weijiang
2024-01-04 21:10 ` Edgecombe, Rick P
2024-01-05 0:22 ` Sean Christopherson
2024-01-05 0:34 ` Edgecombe, Rick P
2024-01-05 0:44 ` Jim Mattson
2024-01-05 0:54 ` Sean Christopherson
2024-01-05 9:28 ` Yang, Weijiang
2024-01-05 16:21 ` Sean Christopherson
2024-01-05 17:52 ` Edgecombe, Rick P
2024-01-05 18:09 ` Jim Mattson
2024-01-05 18:51 ` Edgecombe, Rick P
2024-01-05 19:34 ` Sean Christopherson [this message]
2024-01-08 14:17 ` Yang, Weijiang
2024-01-09 15:10 ` Sean Christopherson
2024-01-11 14:56 ` Yang, Weijiang
2024-01-15 1:55 ` Chao Gao
2024-01-17 0:53 ` Yang, Weijiang
2024-01-05 9:04 ` Yang, Weijiang
2024-01-04 22:29 ` Edgecombe, Rick P
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