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| author | Nicolai Stange <nstange@suse.de> | 2018-07-21 22:35:28 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-08-15 18:12:57 +0200 |
| commit | 0d6b3085975fafd909d26d37310c641f8e5e1be9 (patch) | |
| tree | 839cd2f17ad5a1875d901a707ce584492a7780b4 | |
| parent | 9baeea57aff241b5b454db99373479dae157a30f (diff) | |
| download | linux-0d6b3085975fafd909d26d37310c641f8e5e1be9.tar.gz linux-0d6b3085975fafd909d26d37310c641f8e5e1be9.tar.bz2 linux-0d6b3085975fafd909d26d37310c641f8e5e1be9.zip | |
x86/KVM/VMX: Move the l1tf_flush_l1d test to vmx_l1d_flush()
commit 5b6ccc6c3b1a477fbac9ec97a0b4c1c48e765209 upstream
Currently, vmx_vcpu_run() checks if l1tf_flush_l1d is set and invokes
vmx_l1d_flush() if so.
This test is unncessary for the "always flush L1D" mode.
Move the check to vmx_l1d_flush()'s conditional mode code path.
Notes:
- vmx_l1d_flush() is likely to get inlined anyway and thus, there's no
extra function call.
- This inverts the (static) branch prediction, but there hadn't been any
explicit likely()/unlikely() annotations before and so it stays as is.
Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/kvm/vmx.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 785d8169ecaa..60ffeb3c60ee 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -9168,12 +9168,16 @@ static void vmx_l1d_flush(struct kvm_vcpu *vcpu) * 'always' */ if (static_branch_likely(&vmx_l1d_flush_cond)) { + bool flush_l1d = vcpu->arch.l1tf_flush_l1d; + /* * Clear the flush bit, it gets set again either from * vcpu_run() or from one of the unsafe VMEXIT * handlers. */ vcpu->arch.l1tf_flush_l1d = false; + if (!flush_l1d) + return; } vcpu->stat.l1d_flush++; @@ -9703,10 +9707,8 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu) vmx->__launched = vmx->loaded_vmcs->launched; - if (static_branch_unlikely(&vmx_l1d_should_flush)) { - if (vcpu->arch.l1tf_flush_l1d) - vmx_l1d_flush(vcpu); - } + if (static_branch_unlikely(&vmx_l1d_should_flush)) + vmx_l1d_flush(vcpu); asm( /* Store host registers */ |