linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Yang Weijiang <weijiang.yang@intel.com>
To: pbonzini@redhat.com, seanjc@google.com, jmattson@google.com,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: yu.c.zhang@linux.intel.com, Yang Weijiang <weijiang.yang@intel.com>
Subject: [PATCH v15 06/14] KVM: x86: Add fault checks for CR4.CET
Date: Wed,  3 Feb 2021 19:34:13 +0800	[thread overview]
Message-ID: <20210203113421.5759-7-weijiang.yang@intel.com> (raw)
In-Reply-To: <20210203113421.5759-1-weijiang.yang@intel.com>

Add the fault checks for CR4.CET, which is the master control for all
CET features (SHSTK and IBT).  In addition to basic support checks, CET
can be enabled if and only if CR0.WP==1, i.e. setting CR4.CET=1 faults
if CR0.WP==0 and setting CR0.WP=0 fails if CR4.CET==1.

Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
---
 arch/x86/kvm/x86.c | 6 ++++++
 arch/x86/kvm/x86.h | 3 +++
 2 files changed, 9 insertions(+)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d9d3bae40a8c..6af240d87a33 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -868,6 +868,9 @@ int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
 	if (!(cr0 & X86_CR0_PG) && kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE))
 		return 1;
 
+	if (!(cr0 & X86_CR0_WP) && kvm_read_cr4_bits(vcpu, X86_CR4_CET))
+		return 1;
+
 	kvm_x86_ops.set_cr0(vcpu, cr0);
 
 	kvm_post_set_cr0(vcpu, old_cr0, cr0);
@@ -1034,6 +1037,9 @@ int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
 			return 1;
 	}
 
+	if ((cr4 & X86_CR4_CET) && !(kvm_read_cr0(vcpu) & X86_CR0_WP))
+		return 1;
+
 	kvm_x86_ops.set_cr4(vcpu, cr4);
 
 	kvm_post_set_cr4(vcpu, old_cr4, cr4);
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index bdbd0b023ecc..fd8c46da2030 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -425,6 +425,9 @@ bool kvm_msr_allowed(struct kvm_vcpu *vcpu, u32 index, u32 type);
 		__reserved_bits |= X86_CR4_UMIP;        \
 	if (!__cpu_has(__c, X86_FEATURE_VMX))           \
 		__reserved_bits |= X86_CR4_VMXE;        \
+	if (!__cpu_has(__c, X86_FEATURE_SHSTK) &&	\
+	    !__cpu_has(__c, X86_FEATURE_IBT))		\
+		__reserved_bits |= X86_CR4_CET;		\
 	__reserved_bits;                                \
 })
 
-- 
2.26.2


  parent reply	other threads:[~2021-02-03 11:24 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-03 11:34 [PATCH v15 00/14] Introduce support for guest CET feature Yang Weijiang
2021-02-03 11:34 ` [PATCH v15 01/14] KVM: x86: Report XSS as an MSR to be saved if there are supported features Yang Weijiang
2021-02-03 11:34 ` [PATCH v15 02/14] KVM: x86: Refresh CPUID on writes to MSR_IA32_XSS Yang Weijiang
2021-02-03 11:34 ` [PATCH v15 03/14] KVM: x86: Load guest fpu state when accessing MSRs managed by XSAVES Yang Weijiang
2021-02-03 11:34 ` [PATCH v15 04/14] KVM: x86: Add #CP support in guest exception dispatch Yang Weijiang
2021-02-03 21:46   ` Sean Christopherson
2021-02-04  7:22     ` Yang Weijiang
2021-02-04  8:28       ` Paolo Bonzini
2021-02-04  8:24     ` Paolo Bonzini
2021-02-04 16:42       ` Sean Christopherson
2021-02-04 17:29         ` Paolo Bonzini
2021-02-03 11:34 ` [PATCH v15 05/14] KVM: VMX: Introduce CET VMCS fields and flags Yang Weijiang
2021-02-03 11:34 ` Yang Weijiang [this message]
2021-02-03 11:34 ` [PATCH v15 07/14] KVM: VMX: Emulate reads and writes to CET MSRs Yang Weijiang
2021-02-03 11:57   ` Paolo Bonzini
2021-02-03 12:50     ` Yang Weijiang
2022-05-18 15:55   ` John Allen
2022-05-18 16:16     ` Sean Christopherson
2022-05-19  8:49       ` Yang, Weijiang
2021-02-03 11:34 ` [PATCH v15 08/14] KVM: VMX: Add a synthetic MSR to allow userspace VMM to access GUEST_SSP Yang Weijiang
2021-02-03 11:34 ` [PATCH v15 09/14] KVM: x86: Report CET MSRs as to-be-saved if CET is supported Yang Weijiang
2021-02-03 11:34 ` [PATCH v15 10/14] KVM: x86: Enable CET virtualization for VMX and advertise CET to userspace Yang Weijiang
2021-02-03 11:34 ` [PATCH v15 11/14] KVM: VMX: Pass through CET MSRs to the guest when supported Yang Weijiang
2021-02-03 11:34 ` [PATCH v15 12/14] KVM: nVMX: Add helper to check the vmcs01 MSR bitmap for MSR pass-through Yang Weijiang
2021-02-03 11:34 ` [PATCH v15 13/14] KVM: nVMX: Enable CET support for nested VMX Yang Weijiang
2021-02-03 11:34 ` [PATCH v15 14/14] KVM: x86: Save/Restore GUEST_SSP to/from SMRAM Yang Weijiang
2021-02-03 12:07   ` Paolo Bonzini
2021-02-03 12:59     ` Yang Weijiang
2021-02-03 12:40 ` [PATCH v15 00/14] Introduce support for guest CET feature Paolo Bonzini

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210203113421.5759-7-weijiang.yang@intel.com \
    --to=weijiang.yang@intel.com \
    --cc=jmattson@google.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=pbonzini@redhat.com \
    --cc=seanjc@google.com \
    --cc=yu.c.zhang@linux.intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).