target/ppc: Add ppc_hash64_filter_pagesizes()

The paravirtualized PAPR platform sometimes needs to restrict the guest to
using only some of the page sizes actually supported by the host's MMU.
At the moment this is handled in KVM specific code, but for consistency we
want to apply the same limitations to all accelerators.

This makes a start on this by providing a helper function in the cpu code
to allow platform code to remove some of the cpu's page size definitions
via a caller supplied callback.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>

diff --git a/target/ppc/mmu-hash64.c b/target/ppc/mmu-hash64.c
index aa200cba4cefe438e8e7c28fb34b2e7a858970cc..276d9015e7c427641a776d718ebc3e496d3d1261 100644 (file)
--- a/target/ppc/mmu-hash64.c
+++ b/target/ppc/mmu-hash64.c
@@ -1166,3 +1166,62 @@ const PPCHash64Options ppc_hash64_opts_POWER7 = {
         },
     }
 };
+
+void ppc_hash64_filter_pagesizes(PowerPCCPU *cpu,
+                                 bool (*cb)(void *, uint32_t, uint32_t),
+                                 void *opaque)
+{
+    PPCHash64Options *opts = cpu->hash64_opts;
+    int i;
+    int n = 0;
+    bool ci_largepage = false;
+
+    assert(opts);
+
+    n = 0;
+    for (i = 0; i < ARRAY_SIZE(opts->sps); i++) {
+        PPCHash64SegmentPageSizes *sps = &opts->sps[i];
+        int j;
+        int m = 0;
+
+        assert(n <= i);
+
+        if (!sps->page_shift) {
+            break;
+        }
+
+        for (j = 0; j < ARRAY_SIZE(sps->enc); j++) {
+            PPCHash64PageSize *ps = &sps->enc[j];
+
+            assert(m <= j);
+            if (!ps->page_shift) {
+                break;
+            }
+
+            if (cb(opaque, sps->page_shift, ps->page_shift)) {
+                if (ps->page_shift >= 16) {
+                    ci_largepage = true;
+                }
+                sps->enc[m++] = *ps;
+            }
+        }
+
+        /* Clear rest of the row */
+        for (j = m; j < ARRAY_SIZE(sps->enc); j++) {
+            memset(&sps->enc[j], 0, sizeof(sps->enc[j]));
+        }
+
+        if (m) {
+            n++;
+        }
+    }
+
+    /* Clear the rest of the table */
+    for (i = n; i < ARRAY_SIZE(opts->sps); i++) {
+        memset(&opts->sps[i], 0, sizeof(opts->sps[i]));
+    }
+
+    if (!ci_largepage) {
+        opts->flags &= ~PPC_HASH64_CI_LARGEPAGE;
+    }
+}

diff --git a/target/ppc/mmu-hash64.h b/target/ppc/mmu-hash64.h
index 53dcec5b93160a24fb3b5f6f6a76323584d7cc73..f11efc9cbc1fce6a5c48d8ba4394628171b60073 100644 (file)
--- a/target/ppc/mmu-hash64.h
+++ b/target/ppc/mmu-hash64.h
@@ -20,6 +20,9 @@ unsigned ppc_hash64_hpte_page_shift_noslb(PowerPCCPU *cpu,
 void ppc_store_lpcr(PowerPCCPU *cpu, target_ulong val);
 void ppc_hash64_init(PowerPCCPU *cpu);
 void ppc_hash64_finalize(PowerPCCPU *cpu);
+void ppc_hash64_filter_pagesizes(PowerPCCPU *cpu,
+                                 bool (*cb)(void *, uint32_t, uint32_t),
+                                 void *opaque);
 #endif
 
 /*