target/ppc: Manage external HPT via virtual hypervisor

The pseries machine type implements the behaviour of a PAPR compliant
hypervisor, without actually executing such a hypervisor on the virtual
CPU.  To do this we need some hooks in the CPU code to make hypervisor
facilities get redirected to the machine instead of emulated internally.

For hypercalls this is managed through the cpu->vhyp field, which points
to a QOM interface with a method implementing the hypercall.

For the hashed page table (HPT) - also a hypervisor resource - we use an
older hack.  CPUPPCState has an 'external_htab' field which when non-NULL
indicates that the HPT is stored in qemu memory, rather than within the
guest's address space.

For consistency - and to make some future extensions easier - this merges
the external HPT mechanism into the vhyp mechanism.  Methods are added
to vhyp for the basic operations the core hash MMU code needs: map_hptes()
and unmap_hptes() for reading the HPT, store_hpte() for updating it and
hpt_mask() to retrieve its size.

To match this, the pseries machine now sets these vhyp fields in its
existing vhyp class, rather than reaching into the cpu object to set the
external_htab field.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
index aaf79f52b9..4e7fc2cfb6 100644
--- a/target/ppc/cpu.h
+++ b/target/ppc/cpu.h
@@ -999,8 +999,6 @@ struct CPUPPCState {
 #endif
     /* segment registers */
     target_ulong sr[32];
-    /* externally stored hash table */
-    uint8_t *external_htab;
     /* BATs */
     uint32_t nb_BATs;
     target_ulong DBAT[2][8];
@@ -1208,6 +1206,14 @@ struct PPCVirtualHypervisor {
 struct PPCVirtualHypervisorClass {
     InterfaceClass parent;
     void (*hypercall)(PPCVirtualHypervisor *vhyp, PowerPCCPU *cpu);
+    hwaddr (*hpt_mask)(PPCVirtualHypervisor *vhyp);
+    const ppc_hash_pte64_t *(*map_hptes)(PPCVirtualHypervisor *vhyp,
+                                         hwaddr ptex, int n);
+    void (*unmap_hptes)(PPCVirtualHypervisor *vhyp,
+                        const ppc_hash_pte64_t *hptes,
+                        hwaddr ptex, int n);
+    void (*store_hpte)(PPCVirtualHypervisor *vhyp, hwaddr ptex,
+                       uint64_t pte0, uint64_t pte1);
 };
 
 #define TYPE_PPC_VIRTUAL_HYPERVISOR "ppc-virtual-hypervisor"