kvm/powerpc: Add new ioctl to retreive server MMU infos

This is necessary for qemu to be able to pass the right information
to the guest, such as the supported page sizes and corresponding
encodings in the SLB and hash table, which can vary depending
on the processor type, the type of KVM used (PR vs HV) and the
version of KVM

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[agraf: fix compilation on hv, adjust for newer ioctl numbers]
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 225b452..8d696cf 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -449,6 +449,30 @@
 	__u8  pad[108];
 };
 
+/* for KVM_PPC_GET_SMMU_INFO */
+#define KVM_PPC_PAGE_SIZES_MAX_SZ	8
+
+struct kvm_ppc_one_page_size {
+	__u32 page_shift;	/* Page shift (or 0) */
+	__u32 pte_enc;		/* Encoding in the HPTE (>>12) */
+};
+
+struct kvm_ppc_one_seg_page_size {
+	__u32 page_shift;	/* Base page shift of segment (or 0) */
+	__u32 slb_enc;		/* SLB encoding for BookS */
+	struct kvm_ppc_one_page_size enc[KVM_PPC_PAGE_SIZES_MAX_SZ];
+};
+
+#define KVM_PPC_PAGE_SIZES_REAL		0x00000001
+#define KVM_PPC_1T_SEGMENTS		0x00000002
+
+struct kvm_ppc_smmu_info {
+	__u64 flags;
+	__u32 slb_size;
+	__u32 pad;
+	struct kvm_ppc_one_seg_page_size sps[KVM_PPC_PAGE_SIZES_MAX_SZ];
+};
+
 #define KVMIO 0xAE
 
 /* machine type bits, to be used as argument to KVM_CREATE_VM */
@@ -591,6 +615,7 @@
 #define KVM_CAP_PCI_2_3 75
 #define KVM_CAP_KVMCLOCK_CTRL 76
 #define KVM_CAP_SIGNAL_MSI 77
+#define KVM_CAP_PPC_GET_SMMU_INFO 78
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
@@ -800,6 +825,8 @@
 				       struct kvm_assigned_pci_dev)
 /* Available with KVM_CAP_SIGNAL_MSI */
 #define KVM_SIGNAL_MSI            _IOW(KVMIO,  0xa5, struct kvm_msi)
+/* Available with KVM_CAP_PPC_GET_SMMU_INFO */
+#define KVM_PPC_GET_SMMU_INFO	  _IOR(KVMIO,  0xa6, struct kvm_ppc_smmu_info)
 
 /*
  * ioctls for vcpu fds