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| author | Thomas Gleixner <tglx@linutronix.de> | 2018-07-13 16:23:20 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-08-15 17:37:30 +0200 |
| commit | 651f562081cc6386fbb181f863f6d95890714f7b (patch) | |
| tree | 5905c9311ba4769af82b9ac4a1c7293b82ae5d46 | |
| parent | cc1e6659990b3e7b33cc7d9439582bd9bfb7bb34 (diff) | |
| download | linux-651f562081cc6386fbb181f863f6d95890714f7b.tar.gz | |
x86/kvm: Add static key for flush always
commit 4c6523ec59fe895ea352a650218a6be0653910b1 upstream.
Avoid the conditional in the L1D flush control path.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20180713142322.790914912@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/kvm/vmx.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 7590b8688edeb0..4eb95cb0719b5a 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -192,6 +192,7 @@ module_param(ple_window_max, uint, 0444); extern const ulong vmx_return; static DEFINE_STATIC_KEY_FALSE(vmx_l1d_should_flush); +static DEFINE_STATIC_KEY_FALSE(vmx_l1d_flush_always); /* Storage for pre module init parameter parsing */ static enum vmx_l1d_flush_state __read_mostly vmentry_l1d_flush_param = VMENTER_L1D_FLUSH_AUTO; @@ -232,8 +233,12 @@ static int vmx_setup_l1d_flush(enum vmx_l1d_flush_state l1tf) l1tf_vmx_mitigation = l1tf; - if (l1tf != VMENTER_L1D_FLUSH_NEVER) - static_branch_enable(&vmx_l1d_should_flush); + if (l1tf == VMENTER_L1D_FLUSH_NEVER) + return 0; + + static_branch_enable(&vmx_l1d_should_flush); + if (l1tf == VMENTER_L1D_FLUSH_ALWAYS) + static_branch_enable(&vmx_l1d_flush_always); return 0; } @@ -9687,7 +9692,6 @@ static void *vmx_l1d_flush_pages; static void vmx_l1d_flush(struct kvm_vcpu *vcpu) { int size = PAGE_SIZE << L1D_CACHE_ORDER; - bool always; /* * This code is only executed when the the flush mode is 'cond' or @@ -9697,8 +9701,10 @@ static void vmx_l1d_flush(struct kvm_vcpu *vcpu) * it. The flush bit gets set again either from vcpu_run() or from * one of the unsafe VMEXIT handlers. */ - always = l1tf_vmx_mitigation == VMENTER_L1D_FLUSH_ALWAYS; - vcpu->arch.l1tf_flush_l1d = always; + if (static_branch_unlikely(&vmx_l1d_flush_always)) + vcpu->arch.l1tf_flush_l1d = true; + else + vcpu->arch.l1tf_flush_l1d = false; vcpu->stat.l1d_flush++; |