Subject: linux-next: build failure after merge of the kvm tree

From: Stephen Rothwell <[email-masked]>
Date: Wed, 19 Dec 2018 15:33:20 +1100

Hi all,

After merging the kvm tree, today's linux-next build (x86_64 allmodconfig)
failed like this:

arch/x86/kvm/vmx/nested.c: In function 'prepare_vmcs02_full':
arch/x86/kvm/vmx/nested.c:2242:6: error: implicit declaration of function 'kvm_mpx_supported'; did you mean 'vmx_mpx_supported'? [-Werror=implicit-function-declaration]
  if (kvm_mpx_supported()) {
      ^~~~~~~~~~~~~~~~~
      vmx_mpx_supported

Caused by commit

  55d2375e58a6 ("KVM: nVMX: Move nested code to dedicated files")

interacting with commit

  eb012ef3b4e3 ("x86: Remove Intel MPX")

from the tip tree.

I applied the following merge fix patch for today:

From: Stephen Rothwell <[email-masked]>
Date: Wed, 19 Dec 2018 15:28:31 +1100
Subject: [PATCH] kvm: tidy up from MPX removal

Signed-off-by: Stephen Rothwell <[email-masked]>
---
 arch/x86/kvm/vmx/nested.c | 13 -------------
 arch/x86/kvm/vmx/vmx.c    | 40 +++------------------------------------
 2 files changed, 3 insertions(+), 50 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 3f019aa63341..59e6da4171a8 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -2238,14 +2238,6 @@ static void prepare_vmcs02_full(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)
 	vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, vmx->msr_autoload.guest.nr);
 
 	set_cr4_guest_host_mask(vmx);
-
-	if (kvm_mpx_supported()) {
-		if (vmx->nested.nested_run_pending &&
-			(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS))
-			vmcs_write64(GUEST_BNDCFGS, vmcs12->guest_bndcfgs);
-		else
-			vmcs_write64(GUEST_BNDCFGS, vmx->nested.vmcs01_guest_bndcfgs);
-	}
 }
 
 /*
@@ -2971,9 +2963,6 @@ int nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu, bool from_vmentry)
 
 	if (!(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS))
 		vmx->nested.vmcs01_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL);
-	if (kvm_mpx_supported() &&
-		!(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS))
-		vmx->nested.vmcs01_guest_bndcfgs = vmcs_read64(GUEST_BNDCFGS);
 
 	vmx_switch_vmcs(vcpu, &vmx->nested.vmcs02);
 
@@ -3496,8 +3485,6 @@ static void sync_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
 	vmcs12->guest_sysenter_cs = vmcs_read32(GUEST_SYSENTER_CS);
 	vmcs12->guest_sysenter_esp = vmcs_readl(GUEST_SYSENTER_ESP);
 	vmcs12->guest_sysenter_eip = vmcs_readl(GUEST_SYSENTER_EIP);
-	if (kvm_mpx_supported())
-		vmcs12->guest_bndcfgs = vmcs_read64(GUEST_BNDCFGS);
 }
 
 /*
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index c90fffdc5a93..ccab822be9cd 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1527,12 +1527,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		msr_info->data = vmcs_readl(GUEST_SYSENTER_ESP);
 		break;
 	case MSR_IA32_BNDCFGS:
-		if (!kvm_mpx_supported() ||
-		    (!msr_info->host_initiated &&
-		     !guest_cpuid_has(vcpu, X86_FEATURE_MPX)))
-			return 1;
-		msr_info->data = vmcs_read64(GUEST_BNDCFGS);
-		break;
+		return 1;
 	case MSR_IA32_MCG_EXT_CTL:
 		if (!msr_info->host_initiated &&
 		    !(vmx->msr_ia32_feature_control &
@@ -1610,15 +1605,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		vmcs_writel(GUEST_SYSENTER_ESP, data);
 		break;
 	case MSR_IA32_BNDCFGS:
-		if (!kvm_mpx_supported() ||
-		    (!msr_info->host_initiated &&
-		     !guest_cpuid_has(vcpu, X86_FEATURE_MPX)))
-			return 1;
-		if (is_noncanonical_address(data & PAGE_MASK, vcpu) ||
-		    (data & MSR_IA32_BNDCFGS_RSVD))
-			return 1;
-		vmcs_write64(GUEST_BNDCFGS, data);
-		break;
+		return 1;
 	case MSR_IA32_SPEC_CTRL:
 		if (!msr_info->host_initiated &&
 		    !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))
@@ -3868,8 +3855,6 @@ static void vmx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
 	vmcs_write32(GUEST_ACTIVITY_STATE, GUEST_ACTIVITY_ACTIVE);
 	vmcs_write32(GUEST_INTERRUPTIBILITY_INFO, 0);
 	vmcs_writel(GUEST_PENDING_DBG_EXCEPTIONS, 0);
-	if (kvm_mpx_supported())
-		vmcs_write64(GUEST_BNDCFGS, 0);
 
 	setup_msrs(vmx);
 
@@ -6636,23 +6621,6 @@ static void nested_vmx_cr_fixed1_bits_update(struct kvm_vcpu *vcpu)
 #undef cr4_fixed1_update
 }
 
-static void nested_vmx_entry_exit_ctls_update(struct kvm_vcpu *vcpu)
-{
-	struct vcpu_vmx *vmx = to_vmx(vcpu);
-
-	if (kvm_mpx_supported()) {
-		bool mpx_enabled = guest_cpuid_has(vcpu, X86_FEATURE_MPX);
-
-		if (mpx_enabled) {
-			vmx->nested.msrs.entry_ctls_high |= VM_ENTRY_LOAD_BNDCFGS;
-			vmx->nested.msrs.exit_ctls_high |= VM_EXIT_CLEAR_BNDCFGS;
-		} else {
-			vmx->nested.msrs.entry_ctls_high &= ~VM_ENTRY_LOAD_BNDCFGS;
-			vmx->nested.msrs.exit_ctls_high &= ~VM_EXIT_CLEAR_BNDCFGS;
-		}
-	}
-}
-
 static void vmx_cpuid_update(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
@@ -6669,10 +6637,8 @@ static void vmx_cpuid_update(struct kvm_vcpu *vcpu)
 		to_vmx(vcpu)->msr_ia32_feature_control_valid_bits &=
 			~FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX;
 
-	if (nested_vmx_allowed(vcpu)) {
+	if (nested_vmx_allowed(vcpu))
 		nested_vmx_cr_fixed1_bits_update(vcpu);
-		nested_vmx_entry_exit_ctls_update(vcpu);
-	}
 }
 
 static void vmx_set_supported_cpuid(u32 func, struct kvm_cpuid_entry2 *entry)
-- 
2.19.1

-- 
Cheers,
Stephen Rothwell