linux-kernel - [PATCH AUTOSEL 5.10 03/25] x86/kvm/vmx: Make noinstr clean

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Date:   Tue, 19 Jul 2022 21:15:54 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Peter Zijlstra <peterz@...radead.org>,
        Borislav Petkov <bp@...e.de>, Sasha Levin <sashal@...nel.org>,
        seanjc@...gle.com, pbonzini@...hat.com, tglx@...utronix.de,
        mingo@...hat.com, bp@...en8.de, dave.hansen@...ux.intel.com,
        x86@...nel.org, kvm@...r.kernel.org
Subject: [PATCH AUTOSEL 5.10 03/25] x86/kvm/vmx: Make noinstr clean

From: Peter Zijlstra <peterz@...radead.org>

[ Upstream commit 742ab6df974ae8384a2dd213db1a3a06cf6d8936 ]

The recent mmio_stale_data fixes broke the noinstr constraints:

  vmlinux.o: warning: objtool: vmx_vcpu_enter_exit+0x15b: call to wrmsrl.constprop.0() leaves .noinstr.text section
  vmlinux.o: warning: objtool: vmx_vcpu_enter_exit+0x1bf: call to kvm_arch_has_assigned_device() leaves .noinstr.text section

make it all happy again.

Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Signed-off-by: Borislav Petkov <bp@...e.de>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 arch/x86/kvm/vmx/vmx.c   | 6 +++---
 arch/x86/kvm/x86.c       | 4 ++--
 include/linux/kvm_host.h | 2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index cc647dcc228b..497d50c7fc00 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -380,9 +380,9 @@ static __always_inline void vmx_disable_fb_clear(struct vcpu_vmx *vmx)
 	if (!vmx->disable_fb_clear)
 		return;
 
-	rdmsrl(MSR_IA32_MCU_OPT_CTRL, msr);
+	msr = __rdmsr(MSR_IA32_MCU_OPT_CTRL);
 	msr |= FB_CLEAR_DIS;
-	wrmsrl(MSR_IA32_MCU_OPT_CTRL, msr);
+	native_wrmsrl(MSR_IA32_MCU_OPT_CTRL, msr);
 	/* Cache the MSR value to avoid reading it later */
 	vmx->msr_ia32_mcu_opt_ctrl = msr;
 }
@@ -393,7 +393,7 @@ static __always_inline void vmx_enable_fb_clear(struct vcpu_vmx *vmx)
 		return;
 
 	vmx->msr_ia32_mcu_opt_ctrl &= ~FB_CLEAR_DIS;
-	wrmsrl(MSR_IA32_MCU_OPT_CTRL, vmx->msr_ia32_mcu_opt_ctrl);
+	native_wrmsrl(MSR_IA32_MCU_OPT_CTRL, vmx->msr_ia32_mcu_opt_ctrl);
 }
 
 static void vmx_update_fb_clear_dis(struct kvm_vcpu *vcpu, struct vcpu_vmx *vmx)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index da547752580a..1003a46e4ddf 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11171,9 +11171,9 @@ void kvm_arch_end_assignment(struct kvm *kvm)
 }
 EXPORT_SYMBOL_GPL(kvm_arch_end_assignment);
 
-bool kvm_arch_has_assigned_device(struct kvm *kvm)
+bool noinstr kvm_arch_has_assigned_device(struct kvm *kvm)
 {
-	return atomic_read(&kvm->arch.assigned_device_count);
+	return arch_atomic_read(&kvm->arch.assigned_device_count);
 }
 EXPORT_SYMBOL_GPL(kvm_arch_has_assigned_device);
 
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index c66c702a4f07..439fbe0ee0c7 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -988,7 +988,7 @@ static inline void kvm_arch_end_assignment(struct kvm *kvm)
 {
 }
 
-static inline bool kvm_arch_has_assigned_device(struct kvm *kvm)
+static __always_inline bool kvm_arch_has_assigned_device(struct kvm *kvm)
 {
 	return false;
 }
-- 
2.35.1