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From: Yang Weijiang <weijiang.yang@intel.com>
To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	pbonzini@redhat.com, sean.j.christopherson@intel.com,
	jmattson@google.com
Cc: yu.c.zhang@linux.intel.com, Yang Weijiang <weijiang.yang@intel.com>
Subject: [PATCH v13 11/11] KVM: x86: Enable CET virtualization and advertise CET to userspace
Date: Wed,  1 Jul 2020 16:04:11 +0800
Message-ID: <20200701080411.5802-12-weijiang.yang@intel.com> (raw)
In-Reply-To: <20200701080411.5802-1-weijiang.yang@intel.com>

Set the feature bits so that CET capabilities can be seen in guest via
CPUID enumeration. Add CR4.CET bit support in order to allow guest set CET
master control bit(CR4.CET).

Disable KVM CET feature once unrestricted_guest is turned off because
KVM cannot emulate guest CET behavior well in this case.

Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
---
 arch/x86/include/asm/kvm_host.h | 3 ++-
 arch/x86/kvm/cpuid.c            | 5 +++--
 arch/x86/kvm/vmx/vmx.c          | 5 +++++
 arch/x86/kvm/x86.c              | 5 +++++
 4 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index f68c825e94ad..21f3c89d8c70 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -95,7 +95,8 @@
 			  | X86_CR4_PGE | X86_CR4_PCE | X86_CR4_OSFXSR | X86_CR4_PCIDE \
 			  | X86_CR4_OSXSAVE | X86_CR4_SMEP | X86_CR4_FSGSBASE \
 			  | X86_CR4_OSXMMEXCPT | X86_CR4_LA57 | X86_CR4_VMXE \
-			  | X86_CR4_SMAP | X86_CR4_PKE | X86_CR4_UMIP))
+			  | X86_CR4_SMAP | X86_CR4_PKE | X86_CR4_UMIP \
+			  | X86_CR4_CET))
 
 #define CR8_RESERVED_BITS (~(unsigned long)X86_CR8_TPR)
 
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 984ab2b395b3..333a9e0d7cdf 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -344,7 +344,8 @@ void kvm_set_cpu_caps(void)
 		F(AVX512VBMI) | F(LA57) | 0 /*PKU*/ | 0 /*OSPKE*/ | F(RDPID) |
 		F(AVX512_VPOPCNTDQ) | F(UMIP) | F(AVX512_VBMI2) | F(GFNI) |
 		F(VAES) | F(VPCLMULQDQ) | F(AVX512_VNNI) | F(AVX512_BITALG) |
-		F(CLDEMOTE) | F(MOVDIRI) | F(MOVDIR64B) | 0 /*WAITPKG*/
+		F(CLDEMOTE) | F(MOVDIRI) | F(MOVDIR64B) | 0 /*WAITPKG*/ |
+		F(SHSTK)
 	);
 	/* Set LA57 based on hardware capability. */
 	if (cpuid_ecx(7) & F(LA57))
@@ -353,7 +354,7 @@ void kvm_set_cpu_caps(void)
 	kvm_cpu_cap_mask(CPUID_7_EDX,
 		F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) |
 		F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES) | F(INTEL_STIBP) |
-		F(MD_CLEAR) | F(AVX512_VP2INTERSECT) | F(FSRM)
+		F(MD_CLEAR) | F(AVX512_VP2INTERSECT) | F(FSRM) | F(IBT)
 	);
 
 	/* TSC_ADJUST and ARCH_CAPABILITIES are emulated in software. */
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 70cb2d4a1391..7dac5747adc8 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7411,6 +7411,11 @@ static __init void vmx_set_cpu_caps(void)
 	/* CPUID 0x80000001 */
 	if (!cpu_has_vmx_rdtscp())
 		kvm_cpu_cap_clear(X86_FEATURE_RDTSCP);
+
+	if (!enable_unrestricted_guest) {
+		kvm_cpu_cap_clear(X86_FEATURE_SHSTK);
+		kvm_cpu_cap_clear(X86_FEATURE_IBT);
+	}
 }
 
 static void vmx_request_immediate_exit(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 94ca5b56d233..a4cf5f3211f3 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9707,6 +9707,11 @@ int kvm_arch_hardware_setup(void *opaque)
 	if (kvm_cpu_cap_has(X86_FEATURE_XSAVES))
 		supported_xss = host_xss & KVM_SUPPORTED_XSS;
 
+	if (!kvm_cpu_cap_has(X86_FEATURE_SHSTK) &&
+	    !kvm_cpu_cap_has(X86_FEATURE_IBT))
+		supported_xss &= ~(XFEATURE_MASK_CET_USER |
+				   XFEATURE_MASK_CET_KERNEL);
+
 	cr4_reserved_bits = kvm_host_cr4_reserved_bits(&boot_cpu_data);
 
 	if (kvm_has_tsc_control) {
-- 
2.17.2


      parent reply index

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-01  8:04 [PATCH v13 00/11] Introduce support for guest CET feature Yang Weijiang
2020-07-01  8:04 ` [PATCH v13 01/11] KVM: x86: Include CET definitions for KVM test purpose Yang Weijiang
2020-07-01  8:04 ` [PATCH v13 02/11] KVM: VMX: Introduce CET VMCS fields and flags Yang Weijiang
2020-07-01  8:04 ` [PATCH v13 03/11] KVM: VMX: Set guest CET MSRs per KVM and host configuration Yang Weijiang
2020-07-02 15:13   ` Xiaoyao Li
2020-07-03 15:02     ` Yang Weijiang
2020-07-01  8:04 ` [PATCH v13 04/11] KVM: VMX: Configure CET settings upon guest CR0/4 changing Yang Weijiang
2020-07-01  8:04 ` [PATCH v13 05/11] KVM: x86: Refresh CPUID once guest changes XSS bits Yang Weijiang
2020-07-01  8:04 ` [PATCH v13 06/11] KVM: x86: Load guest fpu state when access MSRs managed by XSAVES Yang Weijiang
2020-07-01  8:04 ` [PATCH v13 07/11] KVM: x86: Add userspace access interface for CET MSRs Yang Weijiang
2020-07-01  8:04 ` [PATCH v13 08/11] KVM: VMX: Enable CET support for nested VM Yang Weijiang
2020-07-01  8:04 ` [PATCH v13 09/11] KVM: VMX: Add VMCS dump and sanity check for CET states Yang Weijiang
2020-07-01  8:04 ` [PATCH v13 10/11] KVM: x86: Add #CP support in guest exception dispatch Yang Weijiang
2020-07-01  8:04 ` Yang Weijiang [this message]

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