1 files changed, 311 insertions, 3 deletions

diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
index 6ea8fa7..f69ce4f 100644
--- a/hw/ppc/spapr_hcall.c
+++ b/hw/ppc/spapr_hcall.c
@@ -3,6 +3,7 @@
 #include "sysemu/hw_accel.h"
 #include "sysemu/sysemu.h"
 #include "qemu/log.h"
+#include "qemu/error-report.h"
 #include "cpu.h"
 #include "exec/exec-all.h"
 #include "helper_regs.h"
@@ -354,20 +355,291 @@ static target_ulong h_read(PowerPCCPU *cpu, sPAPRMachineState *spapr,
     return H_SUCCESS;
 }
 
+struct sPAPRPendingHPT {
+    /* These fields are read-only after initialization */
+    int shift;
+    QemuThread thread;
+
+    /* These fields are protected by the BQL */
+    bool complete;
+
+    /* These fields are private to the preparation thread if
+     * !complete, otherwise protected by the BQL */
+    int ret;
+    void *hpt;
+};
+
+static void free_pending_hpt(sPAPRPendingHPT *pending)
+{
+    if (pending->hpt) {
+        qemu_vfree(pending->hpt);
+    }
+
+    g_free(pending);
+}
+
+static void *hpt_prepare_thread(void *opaque)
+{
+    sPAPRPendingHPT *pending = opaque;
+    size_t size = 1ULL << pending->shift;
+
+    pending->hpt = qemu_memalign(size, size);
+    if (pending->hpt) {
+        memset(pending->hpt, 0, size);
+        pending->ret = H_SUCCESS;
+    } else {
+        pending->ret = H_NO_MEM;
+    }
+
+    qemu_mutex_lock_iothread();
+
+    if (SPAPR_MACHINE(qdev_get_machine())->pending_hpt == pending) {
+        /* Ready to go */
+        pending->complete = true;
+    } else {
+        /* We've been cancelled, clean ourselves up */
+        free_pending_hpt(pending);
+    }
+
+    qemu_mutex_unlock_iothread();
+    return NULL;
+}
+
+/* Must be called with BQL held */
+static void cancel_hpt_prepare(sPAPRMachineState *spapr)
+{
+    sPAPRPendingHPT *pending = spapr->pending_hpt;
+
+    /* Let the thread know it's cancelled */
+    spapr->pending_hpt = NULL;
+
+    if (!pending) {
+        /* Nothing to do */
+        return;
+    }
+
+    if (!pending->complete) {
+        /* thread will clean itself up */
+        return;
+    }
+
+    free_pending_hpt(pending);
+}
+
 static target_ulong h_resize_hpt_prepare(PowerPCCPU *cpu,
                                          sPAPRMachineState *spapr,
                                          target_ulong opcode,
                                          target_ulong *args)
 {
     target_ulong flags = args[0];
-    target_ulong shift = args[1];
+    int shift = args[1];
+    sPAPRPendingHPT *pending = spapr->pending_hpt;
+    uint64_t current_ram_size = MACHINE(spapr)->ram_size;
 
     if (spapr->resize_hpt == SPAPR_RESIZE_HPT_DISABLED) {
         return H_AUTHORITY;
     }
 
+    if (!spapr->htab_shift) {
+        /* Radix guest, no HPT */
+        return H_NOT_AVAILABLE;
+    }
+
     trace_spapr_h_resize_hpt_prepare(flags, shift);
-    return H_HARDWARE;
+
+    if (flags != 0) {
+        return H_PARAMETER;
+    }
+
+    if (shift && ((shift < 18) || (shift > 46))) {
+        return H_PARAMETER;
+    }
+
+    current_ram_size = pc_existing_dimms_capacity(&error_fatal);
+
+    /* We only allow the guest to allocate an HPT one order above what
+     * we'd normally give them (to stop a small guest claiming a huge
+     * chunk of resources in the HPT */
+    if (shift > (spapr_hpt_shift_for_ramsize(current_ram_size) + 1)) {
+        return H_RESOURCE;
+    }
+
+    if (pending) {
+        /* something already in progress */
+        if (pending->shift == shift) {
+            /* and it's suitable */
+            if (pending->complete) {
+                return pending->ret;
+            } else {
+                return H_LONG_BUSY_ORDER_100_MSEC;
+            }
+        }
+
+        /* not suitable, cancel and replace */
+        cancel_hpt_prepare(spapr);
+    }
+
+    if (!shift) {
+        /* nothing to do */
+        return H_SUCCESS;
+    }
+
+    /* start new prepare */
+
+    pending = g_new0(sPAPRPendingHPT, 1);
+    pending->shift = shift;
+    pending->ret = H_HARDWARE;
+
+    qemu_thread_create(&pending->thread, "sPAPR HPT prepare",
+                       hpt_prepare_thread, pending, QEMU_THREAD_DETACHED);
+
+    spapr->pending_hpt = pending;
+
+    /* In theory we could estimate the time more accurately based on
+     * the new size, but there's not much point */
+    return H_LONG_BUSY_ORDER_100_MSEC;
+}
+
+static uint64_t new_hpte_load0(void *htab, uint64_t pteg, int slot)
+{
+    uint8_t *addr = htab;
+
+    addr += pteg * HASH_PTEG_SIZE_64;
+    addr += slot * HASH_PTE_SIZE_64;
+    return  ldq_p(addr);
+}
+
+static void new_hpte_store(void *htab, uint64_t pteg, int slot,
+                           uint64_t pte0, uint64_t pte1)
+{
+    uint8_t *addr = htab;
+
+    addr += pteg * HASH_PTEG_SIZE_64;
+    addr += slot * HASH_PTE_SIZE_64;
+
+    stq_p(addr, pte0);
+    stq_p(addr + HASH_PTE_SIZE_64 / 2, pte1);
+}
+
+static int rehash_hpte(PowerPCCPU *cpu,
+                       const ppc_hash_pte64_t *hptes,
+                       void *old_hpt, uint64_t oldsize,
+                       void *new_hpt, uint64_t newsize,
+                       uint64_t pteg, int slot)
+{
+    uint64_t old_hash_mask = (oldsize >> 7) - 1;
+    uint64_t new_hash_mask = (newsize >> 7) - 1;
+    target_ulong pte0 = ppc_hash64_hpte0(cpu, hptes, slot);
+    target_ulong pte1;
+    uint64_t avpn;
+    unsigned base_pg_shift;
+    uint64_t hash, new_pteg, replace_pte0;
+
+    if (!(pte0 & HPTE64_V_VALID) || !(pte0 & HPTE64_V_BOLTED)) {
+        return H_SUCCESS;
+    }
+
+    pte1 = ppc_hash64_hpte1(cpu, hptes, slot);
+
+    base_pg_shift = ppc_hash64_hpte_page_shift_noslb(cpu, pte0, pte1);
+    assert(base_pg_shift); /* H_ENTER shouldn't allow a bad encoding */
+    avpn = HPTE64_V_AVPN_VAL(pte0) & ~(((1ULL << base_pg_shift) - 1) >> 23);
+
+    if (pte0 & HPTE64_V_SECONDARY) {
+        pteg = ~pteg;
+    }
+
+    if ((pte0 & HPTE64_V_SSIZE) == HPTE64_V_SSIZE_256M) {
+        uint64_t offset, vsid;
+
+        /* We only have 28 - 23 bits of offset in avpn */
+        offset = (avpn & 0x1f) << 23;
+        vsid = avpn >> 5;
+        /* We can find more bits from the pteg value */
+        if (base_pg_shift < 23) {
+            offset |= ((vsid ^ pteg) & old_hash_mask) << base_pg_shift;
+        }
+
+        hash = vsid ^ (offset >> base_pg_shift);
+    } else if ((pte0 & HPTE64_V_SSIZE) == HPTE64_V_SSIZE_1T) {
+        uint64_t offset, vsid;
+
+        /* We only have 40 - 23 bits of seg_off in avpn */
+        offset = (avpn & 0x1ffff) << 23;
+        vsid = avpn >> 17;
+        if (base_pg_shift < 23) {
+            offset |= ((vsid ^ (vsid << 25) ^ pteg) & old_hash_mask)
+                << base_pg_shift;
+        }
+
+        hash = vsid ^ (vsid << 25) ^ (offset >> base_pg_shift);
+    } else {
+        error_report("rehash_pte: Bad segment size in HPTE");
+        return H_HARDWARE;
+    }
+
+    new_pteg = hash & new_hash_mask;
+    if (pte0 & HPTE64_V_SECONDARY) {
+        assert(~pteg == (hash & old_hash_mask));
+        new_pteg = ~new_pteg;
+    } else {
+        assert(pteg == (hash & old_hash_mask));
+    }
+    assert((oldsize != newsize) || (pteg == new_pteg));
+    replace_pte0 = new_hpte_load0(new_hpt, new_pteg, slot);
+    /*
+     * Strictly speaking, we don't need all these tests, since we only
+     * ever rehash bolted HPTEs.  We might in future handle non-bolted
+     * HPTEs, though so make the logic correct for those cases as
+     * well.
+     */
+    if (replace_pte0 & HPTE64_V_VALID) {
+        assert(newsize < oldsize);
+        if (replace_pte0 & HPTE64_V_BOLTED) {
+            if (pte0 & HPTE64_V_BOLTED) {
+                /* Bolted collision, nothing we can do */
+                return H_PTEG_FULL;
+            } else {
+                /* Discard this hpte */
+                return H_SUCCESS;
+            }
+        }
+    }
+
+    new_hpte_store(new_hpt, new_pteg, slot, pte0, pte1);
+    return H_SUCCESS;
+}
+
+static int rehash_hpt(PowerPCCPU *cpu,
+                      void *old_hpt, uint64_t oldsize,
+                      void *new_hpt, uint64_t newsize)
+{
+    uint64_t n_ptegs = oldsize >> 7;
+    uint64_t pteg;
+    int slot;
+    int rc;
+
+    for (pteg = 0; pteg < n_ptegs; pteg++) {
+        hwaddr ptex = pteg * HPTES_PER_GROUP;
+        const ppc_hash_pte64_t *hptes
+            = ppc_hash64_map_hptes(cpu, ptex, HPTES_PER_GROUP);
+
+        if (!hptes) {
+            return H_HARDWARE;
+        }
+
+        for (slot = 0; slot < HPTES_PER_GROUP; slot++) {
+            rc = rehash_hpte(cpu, hptes, old_hpt, oldsize, new_hpt, newsize,
+                             pteg, slot);
+            if (rc != H_SUCCESS) {
+                ppc_hash64_unmap_hptes(cpu, hptes, ptex, HPTES_PER_GROUP);
+                return rc;
+            }
+        }
+        ppc_hash64_unmap_hptes(cpu, hptes, ptex, HPTES_PER_GROUP);
+    }
+
+    return H_SUCCESS;
 }
 
 static target_ulong h_resize_hpt_commit(PowerPCCPU *cpu,
@@ -377,13 +649,49 @@ static target_ulong h_resize_hpt_commit(PowerPCCPU *cpu,
 {
     target_ulong flags = args[0];
     target_ulong shift = args[1];
+    sPAPRPendingHPT *pending = spapr->pending_hpt;
+    int rc;
+    size_t newsize;
 
     if (spapr->resize_hpt == SPAPR_RESIZE_HPT_DISABLED) {
         return H_AUTHORITY;
     }
 
     trace_spapr_h_resize_hpt_commit(flags, shift);
-    return H_HARDWARE;
+
+    if (flags != 0) {
+        return H_PARAMETER;
+    }
+
+    if (!pending || (pending->shift != shift)) {
+        /* no matching prepare */
+        return H_CLOSED;
+    }
+
+    if (!pending->complete) {
+        /* prepare has not completed */
+        return H_BUSY;
+    }
+
+    /* Shouldn't have got past PREPARE without an HPT */
+    g_assert(spapr->htab_shift);
+
+    newsize = 1ULL << pending->shift;
+    rc = rehash_hpt(cpu, spapr->htab, HTAB_SIZE(spapr),
+                    pending->hpt, newsize);
+    if (rc == H_SUCCESS) {
+        qemu_vfree(spapr->htab);
+        spapr->htab = pending->hpt;
+        spapr->htab_shift = pending->shift;
+
+        pending->hpt = NULL; /* so it's not free()d */
+    }
+
+    /* Clean up */
+    spapr->pending_hpt = NULL;
+    free_pending_hpt(pending);
+
+    return rc;
 }
 
 static target_ulong h_set_sprg0(PowerPCCPU *cpu, sPAPRMachineState *spapr,