Re: [PATCH 21/61] KVM: x86: Use supported_xcr0 to detect MPX support

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 2/2/2020 2:51 AM, Sean Christopherson wrote:
Query supported_xcr0 when checking for MPX support instead of invoking
->mpx_supported() and drop ->mpx_supported() as kvm_mpx_supported() was
its last user.  Rename vmx_mpx_supported() to cpu_has_vmx_mpx() to
better align with VMX/VMCS nomenclature.

Modify VMX's adjustment of xcr0 to call cpus_has_vmx_mpx() (renamed from
vmx_mpx_supported()) directly to avoid reading supported_xcr0 before
it's fully configured.

No functional change intended.


Reviewed-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>

Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
---
  arch/x86/include/asm/kvm_host.h | 2 +-
  arch/x86/kvm/cpuid.c            | 3 +--
  arch/x86/kvm/svm.c              | 6 ------
  arch/x86/kvm/vmx/capabilities.h | 2 +-
  arch/x86/kvm/vmx/vmx.c          | 3 +--
  5 files changed, 4 insertions(+), 12 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 77d206a93658..85f0d96cfeb2 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1163,7 +1163,7 @@ struct kvm_x86_ops {
  			       enum x86_intercept_stage stage);
  	void (*handle_exit_irqoff)(struct kvm_vcpu *vcpu,
  		enum exit_fastpath_completion *exit_fastpath);
-	bool (*mpx_supported)(void);
+
  	bool (*xsaves_supported)(void);
  	bool (*umip_emulated)(void);
  	bool (*pt_supported)(void);
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index b9763eb711cb..84006cc4007c 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -47,8 +47,7 @@ static u32 xstate_required_size(u64 xstate_bv, bool compacted)
bool kvm_mpx_supported(void)
  {
-	return ((host_xcr0 & (XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR))
-		 && kvm_x86_ops->mpx_supported());
+	return supported_xcr0 & (XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR);
  }
  EXPORT_SYMBOL_GPL(kvm_mpx_supported);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index af096c4f9c5f..3c7ddaff405d 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6082,11 +6082,6 @@ static bool svm_invpcid_supported(void)
  	return false;
  }
-static bool svm_mpx_supported(void)
-{
-	return false;
-}
-
  static bool svm_xsaves_supported(void)
  {
  	return boot_cpu_has(X86_FEATURE_XSAVES);
@@ -7468,7 +7463,6 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
.rdtscp_supported = svm_rdtscp_supported,
  	.invpcid_supported = svm_invpcid_supported,
-	.mpx_supported = svm_mpx_supported,
  	.xsaves_supported = svm_xsaves_supported,
  	.umip_emulated = svm_umip_emulated,
  	.pt_supported = svm_pt_supported,
diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
index 1a6a99382e94..0a0b1494a934 100644
--- a/arch/x86/kvm/vmx/capabilities.h
+++ b/arch/x86/kvm/vmx/capabilities.h
@@ -100,7 +100,7 @@ static inline bool cpu_has_load_perf_global_ctrl(void)
  	       (vmcs_config.vmexit_ctrl & VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL);
  }
-static inline bool vmx_mpx_supported(void)
+static inline bool cpu_has_vmx_mpx(void)
  {
  	return (vmcs_config.vmexit_ctrl & VM_EXIT_CLEAR_BNDCFGS) &&
  		(vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_BNDCFGS);
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 32a84ec15064..98fd651f7f7e 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7590,7 +7590,7 @@ static __init int hardware_setup(void)
  		WARN_ONCE(host_bndcfgs, "KVM: BNDCFGS in host will be lost");
  	}
- if (!kvm_mpx_supported())
+	if (!cpu_has_vmx_mpx())
  		supported_xcr0 &= ~(XFEATURE_MASK_BNDREGS |
  				    XFEATURE_MASK_BNDCSR);
@@ -7857,7 +7857,6 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = { .check_intercept = vmx_check_intercept,
  	.handle_exit_irqoff = vmx_handle_exit_irqoff,
-	.mpx_supported = vmx_mpx_supported,
  	.xsaves_supported = vmx_xsaves_supported,
  	.umip_emulated = vmx_umip_emulated,
  	.pt_supported = vmx_pt_supported,





[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]

  Powered by Linux