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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>
Subject: [PATCH v2 10/18] x86/virt: KVM: Move VMXOFF helpers into KVM VMX
Date: Fri, 10 Mar 2023 13:42:24 -0800	[thread overview]
Message-ID: <20230310214232.806108-11-seanjc@google.com> (raw)
In-Reply-To: <20230310214232.806108-1-seanjc@google.com>

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.

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 58856e196536..158853ab0d1b 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"
@@ -743,6 +742,29 @@ 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();
@@ -752,7 +774,8 @@ 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)
@@ -2848,7 +2871,7 @@ static void vmx_hardware_disable(void)
 {
 	vmclear_local_loaded_vmcss();
 
-	if (cpu_vmxoff())
+	if (kvm_cpu_vmxoff())
 		kvm_spurious_fault();
 
 	hv_reset_evmcs();
-- 
2.40.0.rc1.284.g88254d51c5-goog


  parent reply	other threads:[~2023-03-10 21:43 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-10 21:42 [PATCH v2 00/18] x86/reboot: KVM: Clean up "emergency" virt code Sean Christopherson
2023-03-10 21:42 ` [PATCH v2 01/18] x86/reboot: VMCLEAR active VMCSes before emergency reboot Sean Christopherson
2023-03-10 21:42 ` [PATCH v2 02/18] x86/reboot: Expose VMCS crash hooks if and only if KVM_INTEL is enabled Sean Christopherson
2023-03-13  0:31   ` Huang, Kai
2023-03-13 18:31     ` Sean Christopherson
2023-03-14  1:19       ` Huang, Kai
2023-03-10 21:42 ` [PATCH v2 03/18] x86/reboot: Harden virtualization hooks for emergency reboot Sean Christopherson
2023-03-13  8:26   ` Chao Gao
2023-03-13 17:08     ` Sean Christopherson
2023-03-10 21:42 ` [PATCH v2 04/18] x86/reboot: KVM: Handle VMXOFF in KVM's reboot callback Sean Christopherson
2023-03-10 21:42 ` [PATCH v2 05/18] x86/reboot: KVM: Disable SVM during reboot via virt/KVM " Sean Christopherson
2023-03-13  0:52   ` Huang, Kai
2023-03-13 17:18     ` Sean Christopherson
2023-03-14  0:42       ` Huang, Kai
2023-03-15  0:47         ` Sean Christopherson
2023-03-15  1:30           ` Huang, Kai
2023-03-10 21:42 ` [PATCH v2 06/18] x86/reboot: Hoist "disable virt" helpers above "emergency reboot" path Sean Christopherson
2023-03-10 21:42 ` [PATCH v2 07/18] x86/reboot: Disable virtualization during reboot iff callback is registered Sean Christopherson
2023-03-13  0:54   ` Huang, Kai
2023-03-13 18:40     ` Sean Christopherson
2023-03-14  0:50       ` Huang, Kai
2023-03-10 21:42 ` [PATCH v2 08/18] x86/reboot: Assert that IRQs are disabled when turning off virtualization Sean Christopherson
2023-03-10 21:42 ` [PATCH v2 09/18] x86/virt: KVM: Open code cpu_has_vmx() in KVM VMX Sean Christopherson
2023-03-10 21:42 ` Sean Christopherson [this message]
2023-03-10 21:42 ` [PATCH v2 11/18] KVM: SVM: Make KVM_AMD depend on CPU_SUP_AMD or CPU_SUP_HYGON Sean Christopherson
2023-03-10 21:42 ` [PATCH v2 12/18] x86/virt: Drop unnecessary check on extended CPUID level in cpu_has_svm() Sean Christopherson
2023-03-10 21:42 ` [PATCH v2 13/18] x86/virt: KVM: Open code cpu_has_svm() into kvm_is_svm_supported() Sean Christopherson
2023-03-10 21:42 ` [PATCH v2 14/18] KVM: SVM: Check that the current CPU supports SVM in kvm_is_svm_supported() Sean Christopherson
2023-03-13  2:47   ` Huang, Kai
2023-03-13 17:29     ` Sean Christopherson
2023-03-14  0:17       ` Huang, Kai
2023-03-10 21:42 ` [PATCH v2 15/18] KVM: VMX: Ensure CPU is stable when probing basic VMX support Sean Christopherson
2023-03-10 21:42 ` [PATCH v2 16/18] x86/virt: KVM: Move "disable SVM" helper into KVM SVM Sean Christopherson
2023-03-10 21:42 ` [PATCH v2 17/18] KVM: x86: Force kvm_rebooting=true during emergency reboot/crash Sean Christopherson
2023-03-10 21:42 ` [PATCH v2 18/18] KVM: SVM: Use "standard" stgi() helper when disabling SVM Sean Christopherson

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