KVM: PPC: Book3S HV: Page table construction and page faults for radix guests

This adds the code to construct the second-level ("partition-scoped" in
architecturese) page tables for guests using the radix MMU.  Apart from
the PGD level, which is allocated when the guest is created, the rest
of the tree is all constructed in response to hypervisor page faults.

As well as hypervisor page faults for missing pages, we also get faults
for reference/change (RC) bits needing to be set, as well as various
other error conditions.  For now, we only set the R or C bit in the
guest page table if the same bit is set in the host PTE for the
backing page.

This code can take advantage of the guest being backed with either
transparent or ordinary 2MB huge pages, and insert 2MB page entries
into the guest page tables.  There is no support for 1GB huge pages
yet.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 16 insertions, 1 deletions

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index bb2854314ba4..d50251f9a3c9 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3356,7 +3356,10 @@ static void kvmppc_core_destroy_vm_hv(struct kvm *kvm)
 
 	kvmppc_free_vcores(kvm);
 
-	kvmppc_free_hpt(kvm);
+	if (kvm_is_radix(kvm))
+		kvmppc_free_radix(kvm);
+	else
+		kvmppc_free_hpt(kvm);
 
 	kvmppc_free_pimap(kvm);
 }
@@ -3768,6 +3771,11 @@ static int kvm_init_subcore_bitmap(void)
 	return 0;
 }
 
+static int kvmppc_radix_possible(void)
+{
+	return cpu_has_feature(CPU_FTR_ARCH_300) && radix_enabled();
+}
+
 static int kvmppc_book3s_init_hv(void)
 {
 	int r;
@@ -3807,12 +3815,19 @@ static int kvmppc_book3s_init_hv(void)
 	init_vcore_lists();
 
 	r = kvmppc_mmu_hv_init();
+	if (r)
+		return r;
+
+	if (kvmppc_radix_possible())
+		r = kvmppc_radix_init();
 	return r;
 }
 
 static void kvmppc_book3s_exit_hv(void)
 {
 	kvmppc_free_host_rm_ops();
+	if (kvmppc_radix_possible())
+		kvmppc_radix_exit();
 	kvmppc_hv_ops = NULL;
 }