diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2020-05-29 23:27:36 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-06-11 15:15:22 +0200 |
| commit | 84b6a3491567a540f955e18d8e615493afa36df0 (patch) | |
| tree | 6cb78ccb03028398a87ffff420648ed4637c1488 /arch/x86/kvm/vmx | |
| parent | cd840e424f27fcc1ae8d14b7ec3ec4560ee6561a (diff) | |
x86/entry: Optimize local_db_save() for virt
Because DRn access is 'difficult' with virt; but the DR7 read is cheaper
than a cacheline miss on native, add a virt specific fast path to
local_db_save(), such that when breakpoints are not in use to avoid
touching DRn entirely.
Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200529213321.187833200@infradead.org
Diffstat (limited to 'arch/x86/kvm/vmx')
| -rw-r--r-- | arch/x86/kvm/vmx/nested.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 9c74a732b08d..2e7238a57fc1 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -3087,9 +3087,9 @@ static int nested_vmx_check_vmentry_hw(struct kvm_vcpu *vcpu) /* * VMExit clears RFLAGS.IF and DR7, even on a consistency check. */ - local_irq_enable(); if (hw_breakpoint_active()) set_debugreg(__this_cpu_read(cpu_dr7), 7); + local_irq_enable(); preempt_enable(); /* |