KVM: PPC: Introduce shared page
For transparent variable sharing between the hypervisor and guest, I introduce
a shared page. This shared page will contain all the registers the guest can
read and write safely without exiting guest context.
This patch only implements the stubs required for the basic structure of the
shared page. The actual register moving follows.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/powerpc/kvm/e500.c b/arch/powerpc/kvm/e500.c
index e8a00b0..71750f2 100644
--- a/arch/powerpc/kvm/e500.c
+++ b/arch/powerpc/kvm/e500.c
@@ -117,8 +117,14 @@
if (err)
goto uninit_vcpu;
+ vcpu->arch.shared = (void*)__get_free_page(GFP_KERNEL|__GFP_ZERO);
+ if (!vcpu->arch.shared)
+ goto uninit_tlb;
+
return vcpu;
+uninit_tlb:
+ kvmppc_e500_tlb_uninit(vcpu_e500);
uninit_vcpu:
kvm_vcpu_uninit(vcpu);
free_vcpu:
@@ -131,6 +137,7 @@
{
struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
+ free_page((unsigned long)vcpu->arch.shared);
kvmppc_e500_tlb_uninit(vcpu_e500);
kvm_vcpu_uninit(vcpu);
kmem_cache_free(kvm_vcpu_cache, vcpu_e500);