On 06/28/2010 12:31 PM, Gleb Natapov wrote:
On Mon, Jun 28, 2010 at 12:27:22PM +0300, Avi Kivity wrote:
nOn 06/28/2010 11:42 AM, Sheng Yang wrote:
Some guest device driver may leverage the "Non-Snoop" I/O, and explicitly
WBINVD or CLFLUSH to a RAM space. Since migration may occur before WBINVD or
CLFLUSH, we need to maintain data consistency either by:
1: flushing cache (wbinvd) when the guest is scheduled out if there is no
wbinvd exit, or
2: execute wbinvd on all dirty physical CPUs when guest wbinvd exits.


+int kvm_emulate_wbinvd(struct kvm_vcpu *vcpu)
+{
+       if (need_emulate_wbinvd(vcpu)&&   kvm_x86_ops->has_wbinvd_exit()) {
+               smp_call_function_many(vcpu->arch.wbinvd_dirty_mask,
+                               wbinvd_ipi, NULL, 1);
+               cpumask_clear(vcpu->arch.wbinvd_dirty_mask);
+       } else
+               wbinvd();
+       return X86EMUL_CONTINUE;
+}
+EXPORT_SYMBOL_GPL(kvm_emulate_wbinvd);
Why check for has_wbinvd_exit()?  If it's false, we don't get here anyway.

If !need_emulate_wbinvd(), why call wbinvd()?


The function is called from emulator too. I guess that is why.

Ah, yes.  But it needs to return, if !n_e_wbinvd(), not call wbinvd().


--
error compiling committee.c: too many arguments to function

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