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()?
+
int emulate_clts(struct kvm_vcpu *vcpu)
{
kvm_x86_ops->set_cr0(vcpu, kvm_read_cr0_bits(vcpu, ~X86_CR0_TS));
@@ -5255,6 +5287,7 @@ void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
vcpu->arch.time_page = NULL;
}
+ free_cpumask_var(vcpu->arch.wbinvd_dirty_mask);
fx_free(vcpu);
kvm_x86_ops->vcpu_free(vcpu);
}
@@ -5262,7 +5295,16 @@ void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
unsigned int id)
{
- return kvm_x86_ops->vcpu_create(kvm, id);
+ struct kvm_vcpu *vcpu = kvm_x86_ops->vcpu_create(kvm, id);
+
+ if (IS_ERR(vcpu))
+ return vcpu;
+
+ if (!zalloc_cpumask_var(&vcpu->arch.wbinvd_dirty_mask, GFP_KERNEL)) {
+ kvm_x86_ops->vcpu_free(vcpu);
+ return ERR_PTR(-ENOMEM);
+ }
+ return vcpu;
}
Better place is kvm_arch_vcpu_init().
--
error compiling committee.c: too many arguments to function
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