public inbox for kvm@vger.kernel.org
 help / color / mirror / Atom feed
From: Binbin Wu <binbin.wu@linux.intel.com>
To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: seanjc@google.com, pbonzini@redhat.com, chao.gao@intel.com,
	kai.huang@intel.com, David.Laight@ACULAB.COM,
	robert.hu@linux.intel.com, guang.zeng@intel.com,
	binbin.wu@linux.intel.com
Subject: [PATCH v11 13/16] KVM: x86: Use KVM-governed feature framework to track "LAM enabled"
Date: Wed, 13 Sep 2023 20:42:24 +0800	[thread overview]
Message-ID: <20230913124227.12574-14-binbin.wu@linux.intel.com> (raw)
In-Reply-To: <20230913124227.12574-1-binbin.wu@linux.intel.com>

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

Using the framework to avoid the relative expensive call guest_cpuid_has()
during cr3 and vmexit handling paths for LAM.

No functional change intended.

Signed-off-by: Binbin Wu <binbin.wu@linux.intel.com>
Tested-by: Xuelian Guo <xuelian.guo@intel.com>
---
 arch/x86/kvm/cpuid.h             | 3 +--
 arch/x86/kvm/governed_features.h | 1 +
 arch/x86/kvm/mmu.h               | 3 +--
 arch/x86/kvm/vmx/vmx.c           | 1 +
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h
index 3c579ce2f60f..93c63ba29337 100644
--- a/arch/x86/kvm/cpuid.h
+++ b/arch/x86/kvm/cpuid.h
@@ -275,8 +275,7 @@ static __always_inline bool guest_can_use(struct kvm_vcpu *vcpu,
 
 static inline bool kvm_vcpu_is_legal_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
 {
-	if (kvm_cpu_cap_has(X86_FEATURE_LAM) &&
-	    guest_cpuid_has(vcpu, X86_FEATURE_LAM))
+	if (guest_can_use(vcpu, X86_FEATURE_LAM))
 		cr3 &= ~(X86_CR3_LAM_U48 | X86_CR3_LAM_U57);
 
 	return kvm_vcpu_is_legal_gpa(vcpu, cr3);
diff --git a/arch/x86/kvm/governed_features.h b/arch/x86/kvm/governed_features.h
index 423a73395c10..ad463b1ed4e4 100644
--- a/arch/x86/kvm/governed_features.h
+++ b/arch/x86/kvm/governed_features.h
@@ -16,6 +16,7 @@ KVM_GOVERNED_X86_FEATURE(PAUSEFILTER)
 KVM_GOVERNED_X86_FEATURE(PFTHRESHOLD)
 KVM_GOVERNED_X86_FEATURE(VGIF)
 KVM_GOVERNED_X86_FEATURE(VNMI)
+KVM_GOVERNED_X86_FEATURE(LAM)
 
 #undef KVM_GOVERNED_X86_FEATURE
 #undef KVM_GOVERNED_FEATURE
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index e700f1f854ae..f04cc5ade1cd 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -148,8 +148,7 @@ static inline unsigned long kvm_get_active_pcid(struct kvm_vcpu *vcpu)
 
 static inline unsigned long kvm_get_active_cr3_lam_bits(struct kvm_vcpu *vcpu)
 {
-	if (!kvm_cpu_cap_has(X86_FEATURE_LAM) ||
-	    !guest_cpuid_has(vcpu, X86_FEATURE_LAM))
+	if (!guest_can_use(vcpu, X86_FEATURE_LAM))
 		return 0;
 
 	return kvm_read_cr3(vcpu) & (X86_CR3_LAM_U48 | X86_CR3_LAM_U57);
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 23eac6bb4fac..3bdeebee71cc 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7767,6 +7767,7 @@ static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
 		kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_XSAVES);
 
 	kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_VMX);
+	kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_LAM);
 
 	vmx_setup_uret_msrs(vmx);
 
-- 
2.25.1


  parent reply	other threads:[~2023-09-13 15:41 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-09-13 12:42 [PATCH v11 00/16] LAM and LASS KVM Enabling Binbin Wu
2023-09-13 12:42 ` [PATCH v11 01/16] KVM: x86: Consolidate flags for __linearize() Binbin Wu
2023-09-13 12:42 ` [PATCH v11 02/16] KVM: x86: Use a new flag for branch targets Binbin Wu
2023-10-23 16:20   ` Sean Christopherson
2023-09-13 12:42 ` [PATCH v11 03/16] KVM: x86: Add an emulation flag for implicit system access Binbin Wu
2023-09-13 12:42 ` [PATCH v11 04/16] KVM: x86: Add X86EMUL_F_INVLPG and pass it in em_invlpg() Binbin Wu
2023-09-13 12:42 ` [PATCH v11 05/16] KVM: x86/mmu: Drop non-PA bits when getting GFN for guest's PGD Binbin Wu
2023-09-13 12:42 ` [PATCH v11 06/16] KVM: x86: Add & use kvm_vcpu_is_legal_cr3() to check CR3's legality Binbin Wu
2023-09-13 12:42 ` [PATCH v11 07/16] KVM: x86: Remove kvm_vcpu_is_illegal_gpa() Binbin Wu
2023-09-13 12:42 ` [PATCH v11 08/16] KVM: x86: Introduce get_untagged_addr() in kvm_x86_ops and call it in emulator Binbin Wu
2023-10-23 23:14   ` Sean Christopherson
2023-10-23 23:30   ` Sean Christopherson
2023-09-13 12:42 ` [PATCH v11 09/16] KVM: x86: Untag address for vmexit handlers when LAM applicable Binbin Wu
2023-09-13 12:42 ` [PATCH v11 10/16] KVM: x86: Virtualize LAM for supervisor pointer Binbin Wu
2023-09-13 12:42 ` [PATCH v11 11/16] KVM: x86: Virtualize LAM for user pointer Binbin Wu
2023-09-13 12:42 ` [PATCH v11 12/16] KVM: x86: Advertise and enable LAM (user and supervisor) Binbin Wu
2023-09-13 12:42 ` Binbin Wu [this message]
2023-09-13 12:42 ` [PATCH v11 14/16] KVM: emulator: Add emulation of LASS violation checks on linear address Binbin Wu
2023-09-13 12:42 ` [PATCH v11 15/16] KVM: VMX: Virtualize LASS Binbin Wu
2023-09-13 12:42 ` [PATCH v11 16/16] KVM: x86: Advertise LASS CPUID to user space Binbin Wu
2023-10-08  9:37 ` [PATCH v11 00/16] LAM and LASS KVM Enabling Binbin Wu
2023-10-10 23:48   ` Sean Christopherson
2023-10-21  0:26 ` Sean Christopherson
2023-10-21  0:34   ` Sean Christopherson
2023-10-22 12:35     ` Binbin Wu
2023-10-23 23:43 ` Sean Christopherson
2023-10-24  8:31   ` Binbin Wu

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=20230913124227.12574-14-binbin.wu@linux.intel.com \
    --to=binbin.wu@linux.intel.com \
    --cc=David.Laight@ACULAB.COM \
    --cc=chao.gao@intel.com \
    --cc=guang.zeng@intel.com \
    --cc=kai.huang@intel.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=pbonzini@redhat.com \
    --cc=robert.hu@linux.intel.com \
    --cc=seanjc@google.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