KVM: PPC: Book3S: Make magic page properly 4k mappable

[karo-tx-linux.git] / arch / powerpc / kvm / powerpc.c

diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 7efc2b71140404b9da1c5f289a10914899058847..fe0257a8e3351d7e63ad27452ecbf3979d5cd795 100644 (file)
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -190,6 +190,25 @@ int kvmppc_kvm_pv(struct kvm_vcpu *vcpu)
                vcpu->arch.magic_page_pa = param1 & ~0xfffULL;
                vcpu->arch.magic_page_ea = param2 & ~0xfffULL;
 
+#ifdef CONFIG_PPC_64K_PAGES
+               /*
+                * Make sure our 4k magic page is in the same window of a 64k
+                * page within the guest and within the host's page.
+                */
+               if ((vcpu->arch.magic_page_pa & 0xf000) !=
+                   ((ulong)vcpu->arch.shared & 0xf000)) {
+                       void *old_shared = vcpu->arch.shared;
+                       ulong shared = (ulong)vcpu->arch.shared;
+                       void *new_shared;
+
+                       shared &= PAGE_MASK;
+                       shared |= vcpu->arch.magic_page_pa & 0xf000;
+                       new_shared = (void*)shared;
+                       memcpy(new_shared, old_shared, 0x1000);
+                       vcpu->arch.shared = new_shared;
+               }
+#endif
+
                r2 = KVM_MAGIC_FEAT_SR | KVM_MAGIC_FEAT_MAS0_TO_SPRG7;
 
                r = EV_SUCCESS;