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From: Zeng Guang <guang.zeng@intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
	Sean Christopherson <seanjc@google.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	H Peter Anvin <hpa@zytor.com>,
	kvm@vger.kernel.org
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
	Zeng Guang <guang.zeng@intel.com>
Subject: [PATCH v2 8/8] KVM: x86: Advertise LASS CPUID to user space
Date: Wed, 19 Jul 2023 10:45:58 +0800	[thread overview]
Message-ID: <20230719024558.8539-9-guang.zeng@intel.com> (raw)
In-Reply-To: <20230719024558.8539-1-guang.zeng@intel.com>

Linear address space separation (LASS) is an independent mechanism
to enforce the mode-based protection that can prevent user-mode
accesses to supervisor-mode addresses, and vice versa. Because the
LASS protections are applied before paging, malicious software can
not acquire any paging-based timing information to compromise the
security of system.

The CPUID bit definition to support LASS:
CPUID.(EAX=07H.ECX=1):EAX.LASS[bit 6]

Advertise LASS to user space to support LASS virtualization.

Signed-off-by: Zeng Guang <guang.zeng@intel.com>
Tested-by: Xuelian Guo <xuelian.guo@intel.com>
---
 arch/x86/kvm/cpuid.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 0c9660a07b23..a7fafe99ffe4 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -646,9 +646,8 @@ void kvm_set_cpu_caps(void)
 		kvm_cpu_cap_set(X86_FEATURE_SPEC_CTRL_SSBD);
 
 	kvm_cpu_cap_mask(CPUID_7_1_EAX,
-		F(AVX_VNNI) | F(AVX512_BF16) | F(CMPCCXADD) |
-		F(FZRM) | F(FSRS) | F(FSRC) |
-		F(AMX_FP16) | F(AVX_IFMA)
+		F(AVX_VNNI) | F(AVX512_BF16) | F(LASS) | F(CMPCCXADD) |
+		F(FZRM) | F(FSRS) | F(FSRC) | F(AMX_FP16) | F(AVX_IFMA)
 	);
 
 	kvm_cpu_cap_init_kvm_defined(CPUID_7_1_EDX,
-- 
2.27.0


  parent reply	other threads:[~2023-07-19  3:27 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-19  2:45 [PATCH v2 0/8] LASS KVM virtualization support Zeng Guang
2023-07-19  2:45 ` [PATCH v2 1/8] KVM: x86: Consolidate flags for __linearize() Zeng Guang
2023-07-19  2:45 ` [PATCH v2 2/8] KVM: x86: Use a new flag for branch instructions Zeng Guang
2023-08-15 22:51   ` Sean Christopherson
2023-08-16  7:34     ` Binbin Wu
2023-08-16 14:38       ` Sean Christopherson
2023-08-17  1:38         ` Binbin Wu
2023-08-17 14:45           ` Sean Christopherson
2023-07-19  2:45 ` [PATCH v2 3/8] KVM: x86: Add an emulation flag for implicit system access Zeng Guang
2023-07-19  2:45 ` [PATCH v2 4/8] KVM: x86: Add X86EMUL_F_INVTLB and pass it in em_invlpg() Zeng Guang
2023-08-15 23:11   ` Sean Christopherson
2023-08-16  7:55     ` Binbin Wu
2023-08-16 14:27       ` Sean Christopherson
2023-07-19  2:45 ` [PATCH v2 5/8] KVM: emulator: Add emulation of LASS violation checks on linear address Zeng Guang
2023-07-19  2:45 ` [PATCH v2 6/8] KVM: VMX: Implement and apply vmx_is_lass_violation() for LASS protection Zeng Guang
2023-08-07  7:03   ` Binbin Wu
2023-08-15 23:46     ` Sean Christopherson
2023-08-17 16:15       ` Zeng Guang
2023-07-19  2:45 ` [PATCH v2 7/8] KVM: x86: Virtualize CR4.LASS Zeng Guang
2023-07-19  2:45 ` Zeng Guang [this message]
  -- strict thread matches above, loose matches on Subject: below --
2023-07-18 13:18 [PATCH v2 0/8] LASS KVM virtualization support Zeng Guang
2023-07-18 13:18 ` [PATCH v2 8/8] KVM: x86: Advertise LASS CPUID to user space Zeng Guang

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