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Reply-To: Sean Christopherson <seanjc@google.com>
Date:   Fri, 21 Jul 2023 13:18:50 -0700
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Subject: [PATCH v4 10/19] x86/virt: KVM: Move VMXOFF helpers into KVM VMX
From:   Sean Christopherson <seanjc@google.com>
To:     Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        Sean Christopherson <seanjc@google.com>,
        Paolo Bonzini <pbonzini@redhat.com>
Cc:     linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        Andrew Cooper <Andrew.Cooper3@citrix.com>,
        Kai Huang <kai.huang@intel.com>, Chao Gao <chao.gao@intel.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Now that VMX is disabled in emergencies via the virt callbacks, move the
VMXOFF helpers into KVM, the only remaining user.

No functional change intended.

Reviewed-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/include/asm/virtext.h | 42 ----------------------------------
 arch/x86/kvm/vmx/vmx.c         | 29 ++++++++++++++++++++---
 2 files changed, 26 insertions(+), 45 deletions(-)

diff --git a/arch/x86/include/asm/virtext.h b/arch/x86/include/asm/virtext.h
index b1171a5ad452..a27801f2bc71 100644
--- a/arch/x86/include/asm/virtext.h
+++ b/arch/x86/include/asm/virtext.h
@@ -19,48 +19,6 @@
 #include <asm/svm.h>
 #include <asm/tlbflush.h>
 
-/*
- * VMX functions:
- */
-/**
- * cpu_vmxoff() - Disable VMX on the current CPU
- *
- * Disable VMX and clear CR4.VMXE (even if VMXOFF faults)
- *
- * Note, VMXOFF causes a #UD if the CPU is !post-VMXON, but it's impossible to
- * atomically track post-VMXON state, e.g. this may be called in NMI context.
- * Eat all faults as all other faults on VMXOFF faults are mode related, i.e.
- * faults are guaranteed to be due to the !post-VMXON check unless the CPU is
- * magically in RM, VM86, compat mode, or at CPL>0.
- */
-static inline int cpu_vmxoff(void)
-{
-	asm_volatile_goto("1: vmxoff\n\t"
-			  _ASM_EXTABLE(1b, %l[fault])
-			  ::: "cc", "memory" : fault);
-
-	cr4_clear_bits(X86_CR4_VMXE);
-	return 0;
-
-fault:
-	cr4_clear_bits(X86_CR4_VMXE);
-	return -EIO;
-}
-
-static inline int cpu_vmx_enabled(void)
-{
-	return __read_cr4() & X86_CR4_VMXE;
-}
-
-/** Disable VMX if it is enabled on the current CPU
- */
-static inline void __cpu_emergency_vmxoff(void)
-{
-	if (cpu_vmx_enabled())
-		cpu_vmxoff();
-}
-
-
 /*
  * SVM functions:
  */
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 71571cd9adbb..6f4fcd82fa6e 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -47,7 +47,6 @@
 #include <asm/mshyperv.h>
 #include <asm/mwait.h>
 #include <asm/spec-ctrl.h>
-#include <asm/virtext.h>
 #include <asm/vmx.h>
 
 #include "capabilities.h"
@@ -744,6 +743,29 @@ static int vmx_set_guest_uret_msr(struct vcpu_vmx *vmx,
 	return ret;
 }
 
+/*
+ * Disable VMX and clear CR4.VMXE (even if VMXOFF faults)
+ *
+ * Note, VMXOFF causes a #UD if the CPU is !post-VMXON, but it's impossible to
+ * atomically track post-VMXON state, e.g. this may be called in NMI context.
+ * Eat all faults as all other faults on VMXOFF faults are mode related, i.e.
+ * faults are guaranteed to be due to the !post-VMXON check unless the CPU is
+ * magically in RM, VM86, compat mode, or at CPL>0.
+ */
+static int kvm_cpu_vmxoff(void)
+{
+	asm_volatile_goto("1: vmxoff\n\t"
+			  _ASM_EXTABLE(1b, %l[fault])
+			  ::: "cc", "memory" : fault);
+
+	cr4_clear_bits(X86_CR4_VMXE);
+	return 0;
+
+fault:
+	cr4_clear_bits(X86_CR4_VMXE);
+	return -EIO;
+}
+
 static void vmx_emergency_disable(void)
 {
 	int cpu = raw_smp_processor_id();
@@ -753,7 +775,8 @@ static void vmx_emergency_disable(void)
 			    loaded_vmcss_on_cpu_link)
 		vmcs_clear(v->vmcs);
 
-	__cpu_emergency_vmxoff();
+	if (__read_cr4() & X86_CR4_VMXE)
+		kvm_cpu_vmxoff();
 }
 
 static void __loaded_vmcs_clear(void *arg)
@@ -2818,7 +2841,7 @@ static void vmx_hardware_disable(void)
 {
 	vmclear_local_loaded_vmcss();
 
-	if (cpu_vmxoff())
+	if (kvm_cpu_vmxoff())
 		kvm_spurious_fault();
 
 	hv_reset_evmcs();
-- 
2.41.0.487.g6d72f3e995-goog