From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Yang Weijiang <weijiang.yang@intel.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
pbonzini@redhat.com, jmattson@google.com,
yu.c.zhang@linux.intel.com
Subject: Re: [RESEND v13 02/11] KVM: VMX: Introduce CET VMCS fields and flags
Date: Wed, 22 Jul 2020 12:48:51 -0700 [thread overview]
Message-ID: <20200722194851.GC9114@linux.intel.com> (raw)
In-Reply-To: <20200716031627.11492-3-weijiang.yang@intel.com>
On Thu, Jul 16, 2020 at 11:16:18AM +0800, Yang Weijiang wrote:
> CET(Control-flow Enforcement Technology) is a CPU feature used to prevent
> Return/Jump-Oriented Programming(ROP/JOP) attacks. It provides the following
> sub-features to defend against ROP/JOP style control-flow subversion attacks:
>
> Shadow Stack (SHSTK):
> A second stack for program which is used exclusively for control transfer
> operations.
>
> Indirect Branch Tracking (IBT):
> Code branching protection to defend against jump/call oriented programming.
>
> Several new CET MSRs are defined in kernel to support CET:
> MSR_IA32_{U,S}_CET: Controls the CET settings for user mode and kernel mode
> respectively.
>
> MSR_IA32_PL{0,1,2,3}_SSP: Stores shadow stack pointers for CPL-0,1,2,3
> protection respectively.
>
> MSR_IA32_INT_SSP_TAB: Stores base address of shadow stack pointer table.
>
> Two XSAVES state bits are introduced for CET:
> IA32_XSS:[bit 11]: Control saving/restoring user mode CET states
> IA32_XSS:[bit 12]: Control saving/restoring kernel mode CET states.
>
> Six VMCS fields are introduced for CET:
> {HOST,GUEST}_S_CET: Stores CET settings for kernel mode.
> {HOST,GUEST}_SSP: Stores shadow stack pointer of current task/thread.
> {HOST,GUEST}_INTR_SSP_TABLE: Stores base address of shadow stack pointer
> table.
>
> If VM_EXIT_LOAD_HOST_CET_STATE = 1, the host CET states are restored from below
> VMCS fields at VM-Exit:
> HOST_S_CET
> HOST_SSP
> HOST_INTR_SSP_TABLE
>
> If VM_ENTRY_LOAD_GUEST_CET_STATE = 1, the guest CET states are loaded from below
> VMCS fields at VM-Entry:
> GUEST_S_CET
> GUEST_SSP
> GUEST_INTR_SSP_TABLE
No changes to the patch itself, but I tweaked the formatting of the changelog
a bit and expanded the introduction for SHSTK and IBT to provide a bit more
background.
next prev parent reply other threads:[~2020-07-22 19:48 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-16 3:16 [RESEND PATCH v13 00/11] Introduce support for guest CET feature Yang Weijiang
2020-07-16 3:16 ` [RESEND v13 01/11] KVM: x86: Include CET definitions for KVM test purpose Yang Weijiang
2020-07-16 3:16 ` [RESEND v13 02/11] KVM: VMX: Introduce CET VMCS fields and flags Yang Weijiang
2020-07-22 19:48 ` Sean Christopherson [this message]
2020-07-16 3:16 ` [RESEND v13 03/11] KVM: VMX: Set guest CET MSRs per KVM and host configuration Yang Weijiang
2020-07-22 20:14 ` Sean Christopherson
2020-07-16 3:16 ` [RESEND v13 04/11] KVM: VMX: Configure CET settings upon guest CR0/4 changing Yang Weijiang
2020-07-22 20:31 ` Sean Christopherson
2020-07-16 3:16 ` [RESEND v13 05/11] KVM: x86: Refresh CPUID once guest changes XSS bits Yang Weijiang
2020-07-22 20:32 ` Sean Christopherson
2020-07-16 3:16 ` [RESEND v13 06/11] KVM: x86: Load guest fpu state when access MSRs managed by XSAVES Yang Weijiang
2020-07-22 20:32 ` Sean Christopherson
2020-07-16 3:16 ` [RESEND v13 07/11] KVM: x86: Add userspace access interface for CET MSRs Yang Weijiang
2020-07-22 20:54 ` Sean Christopherson
2020-07-16 3:16 ` [RESEND v13 08/11] KVM: VMX: Enable CET support for nested VM Yang Weijiang
2020-07-22 21:20 ` Sean Christopherson
2020-07-16 3:16 ` [RESEND v13 09/11] KVM: VMX: Add VMCS dump and sanity check for CET states Yang Weijiang
2020-07-22 21:29 ` Sean Christopherson
2020-07-16 3:16 ` [RESEND v13 10/11] KVM: x86: Add #CP support in guest exception dispatch Yang Weijiang
2020-07-22 21:29 ` Sean Christopherson
2020-07-16 3:16 ` [RESEND v13 11/11] KVM: x86: Enable CET virtualization and advertise CET to userspace Yang Weijiang
2020-07-22 21:33 ` Sean Christopherson
2020-07-22 19:48 ` [RESEND PATCH v13 00/11] Introduce support for guest CET feature Sean Christopherson
2020-07-23 3:17 ` Yang Weijiang
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