KVM: x86: Move Hyper-V partition assist page out of Hyper-V emulation context

[linux-2.6-block.git] / arch / x86 / kvm / kvm_onhyperv.h

diff --git a/arch/x86/kvm/kvm_onhyperv.h b/arch/x86/kvm/kvm_onhyperv.h
index f9ca3e7432b2e8fc983dd61bbc2887e38f4a93a2..eefab3dc8498b79cb083b827ec8c415315aaae14 100644 (file)
--- a/arch/x86/kvm/kvm_onhyperv.h
+++ b/arch/x86/kvm/kvm_onhyperv.h
@@ -10,6 +10,26 @@
 int hv_flush_remote_tlbs_range(struct kvm *kvm, gfn_t gfn, gfn_t nr_pages);
 int hv_flush_remote_tlbs(struct kvm *kvm);
 void hv_track_root_tdp(struct kvm_vcpu *vcpu, hpa_t root_tdp);
+static inline hpa_t hv_get_partition_assist_page(struct kvm_vcpu *vcpu)
+{
+       /*
+        * Partition assist page is something which Hyper-V running in L0
+        * requires from KVM running in L1 before direct TLB flush for L2
+        * guests can be enabled. KVM doesn't currently use the page but to
+        * comply with TLFS it still needs to be allocated. For now, this
+        * is a single page shared among all vCPUs.
+        */
+       struct hv_partition_assist_pg **p_hv_pa_pg =
+               &vcpu->kvm->arch.hv_pa_pg;
+
+       if (!*p_hv_pa_pg)
+               *p_hv_pa_pg = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);
+
+       if (!*p_hv_pa_pg)
+               return INVALID_PAGE;
+
+       return __pa(*p_hv_pa_pg);
+}
 #else /* !CONFIG_HYPERV */
 static inline int hv_flush_remote_tlbs(struct kvm *kvm)
 {