Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5b6ccc6c authored by Nicolai Stange's avatar Nicolai Stange Committed by Thomas Gleixner
Browse files

x86/KVM/VMX: Move the l1tf_flush_l1d test to vmx_l1d_flush() 



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: default avatarNicolai Stange <nstange@suse.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 427362a1

arch/x86/kvm/vmx.c

+6 −4
Original line number Diff line number Diff line
@@ -9693,12 +9693,16 @@ 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++;
@@ -10228,10 +10232,8 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu) 
	evmcs_rsp = static_branch_unlikely(&enable_evmcs) ?

		(unsigned long)&current_evmcs->host_rsp : 0;



	if (static_branch_unlikely(&vmx_l1d_should_flush)) {

		if (vcpu->arch.l1tf_flush_l1d)

	if (static_branch_unlikely(&vmx_l1d_should_flush))

		vmx_l1d_flush(vcpu);

	}



	asm(

		/* Store host registers */