linux-kernel - [PATCH v10 3/9] KVM: x86: Use KVM-governed feature framework to track "LAM enabled"

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20230719144131.29052-4-binbin.wu@linux.intel.com>
Date:   Wed, 19 Jul 2023 22:41:25 +0800
From:   Binbin Wu <binbin.wu@...ux.intel.com>
To:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     seanjc@...gle.com, pbonzini@...hat.com, chao.gao@...el.com,
        kai.huang@...el.com, David.Laight@...LAB.COM,
        robert.hu@...ux.intel.com, guang.zeng@...el.com,
        binbin.wu@...ux.intel.com
Subject: [PATCH v10 3/9] KVM: x86: Use KVM-governed feature framework to track "LAM enabled"

Use the governed feature framework to track if Linear Address Masking (LAM)
is "enabled", i.e. if LAM can be used by the guest. So that guest_can_use()
can be used to support LAM virtualization.

LAM modifies the checking that is applied to 64-bit linear addresses, allowing
software to use of the untranslated address bits for metadata and masks the
metadata bits before using them as linear addresses to access memory.

Signed-off-by: Binbin Wu <binbin.wu@...ux.intel.com>
---
 arch/x86/kvm/governed_features.h | 2 ++
 arch/x86/kvm/vmx/vmx.c           | 3 +++
 2 files changed, 5 insertions(+)

diff --git a/arch/x86/kvm/governed_features.h b/arch/x86/kvm/governed_features.h
index 40ce8e6608cd..708578d60e6f 100644
--- a/arch/x86/kvm/governed_features.h
+++ b/arch/x86/kvm/governed_features.h
@@ -5,5 +5,7 @@ BUILD_BUG()
 
 #define KVM_GOVERNED_X86_FEATURE(x) KVM_GOVERNED_FEATURE(X86_FEATURE_##x)
 
+KVM_GOVERNED_X86_FEATURE(LAM)
+
 #undef KVM_GOVERNED_X86_FEATURE
 #undef KVM_GOVERNED_FEATURE
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 0ecf4be2c6af..ae47303c88d7 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7783,6 +7783,9 @@ static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
 		vmx->msr_ia32_feature_control_valid_bits &=
 			~FEAT_CTL_SGX_LC_ENABLED;
 
+	if (boot_cpu_has(X86_FEATURE_LAM))
+		kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_LAM);
+
 	/* Refresh #PF interception to account for MAXPHYADDR changes. */
 	vmx_update_exception_bitmap(vcpu);
 }
-- 
2.25.1