KVM: PPC: Book3S PR: Allow guest to use 64k pages

This adds the code to interpret 64k HPTEs in the guest hashed page
table (HPT), 64k SLB entries, and to tell the guest about 64k pages
in kvm_vm_ioctl_get_smmu_info().  Guest 64k pages are still shadowed
by 4k pages.

This also adds another hash table to the four we have already in
book3s_mmu_hpte.c to allow us to find all the PTEs that we have
instantiated that match a given 64k guest page.

The tlbie instruction changed starting with POWER6 to use a bit in
the RB operand to indicate large page invalidations, and to use other
RB bits to indicate the base and actual page sizes and the segment
size.  64k pages came in slightly earlier, with POWER5++.
We use one bit in vcpu->arch.hflags to indicate that the emulated
cpu supports 64k pages, and another to indicate that it has the new
tlbie definition.

The KVM_PPC_GET_SMMU_INFO ioctl presents a bit of a problem, because
the MMU capabilities depend on which CPU model we're emulating, but it
is a VM ioctl not a VCPU ioctl and therefore doesn't get passed a VCPU
fd.  In addition, commonly-used userspace (QEMU) calls it before
setting the PVR for any VCPU.  Therefore, as a best effort we look at
the first vcpu in the VM and return 64k pages or not depending on its
capabilities.  We also make the PVR default to the host PVR on recent
CPUs that support 1TB segments (and therefore multiple page sizes as
well) so that KVM_PPC_GET_SMMU_INFO will include 64k page and 1TB
segment support on those CPUs.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 6 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index 40f22d9c704c..1d4a1202e2d5 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -58,6 +58,9 @@ struct hpte_cache {
 	struct hlist_node list_pte_long;
 	struct hlist_node list_vpte;
 	struct hlist_node list_vpte_long;
+#ifdef CONFIG_PPC_BOOK3S_64
+	struct hlist_node list_vpte_64k;
+#endif
 	struct rcu_head rcu_head;
 	u64 host_vpn;
 	u64 pfn;
@@ -99,6 +102,9 @@ struct kvmppc_vcpu_book3s {
 	struct hlist_head hpte_hash_pte_long[HPTEG_HASH_NUM_PTE_LONG];
 	struct hlist_head hpte_hash_vpte[HPTEG_HASH_NUM_VPTE];
 	struct hlist_head hpte_hash_vpte_long[HPTEG_HASH_NUM_VPTE_LONG];
+#ifdef CONFIG_PPC_BOOK3S_64
+	struct hlist_head hpte_hash_vpte_64k[HPTEG_HASH_NUM_VPTE_64K];
+#endif
 	int hpte_cache_count;
 	spinlock_t mmu_lock;
 };