KVM: PPC: Move kvm->arch.slot_phys into memslot.arch

Now that we have an architecture-specific field in the kvm_memory_slot
structure, we can use it to store the array of page physical addresses
that we need for Book3S HV KVM on PPC970 processors.  This reduces the
size of struct kvm_arch for Book3S HV, and also reduces the size of
struct kvm_arch_memory_slot for other PPC KVM variants since the fields
in it are now only compiled in for Book3S HV.

This necessitates making the kvm_arch_create_memslot and
kvm_arch_free_memslot operations specific to each PPC KVM variant.
That in turn means that we now don't allocate the rmap arrays on
Book3S PR and Book E.

Since we now unpin pages and free the slot_phys array in
kvmppc_core_free_memslot, we no longer need to do it in
kvmppc_core_destroy_vm, since the generic code takes care to free
all the memslots when destroying a VM.

We now need the new memslot to be passed in to
kvmppc_core_prepare_memory_region, since we need to initialize its
arch.slot_phys member on Book3S HV.

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

1 files changed, 61 insertions, 43 deletions

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 48b0d4a73b9d..817837de7362 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1314,48 +1314,67 @@ static unsigned long slb_pgsize_encoding(unsigned long psize)
         return senc;
 }
 
-int kvmppc_core_prepare_memory_region(struct kvm *kvm,
-                                struct kvm_userspace_memory_region *mem)
+static void unpin_slot(struct kvm_memory_slot *memslot)
 {
-        unsigned long npages;
-        unsigned long *phys;
+        unsigned long *physp;
+        unsigned long j, npages, pfn;
+        struct page *page;
 
-        /* Allocate a slot_phys array */
-        phys = kvm->arch.slot_phys[mem->slot];
-        if (!kvm->arch.using_mmu_notifiers && !phys) {
-                npages = mem->memory_size >> PAGE_SHIFT;
-                phys = vzalloc(npages * sizeof(unsigned long));
-                if (!phys)
-                        return -ENOMEM;
-                kvm->arch.slot_phys[mem->slot] = phys;
-                kvm->arch.slot_npages[mem->slot] = npages;
+        physp = memslot->arch.slot_phys;
+        npages = memslot->npages;
+        if (!physp)
+                return;
+        for (j = 0; j < npages; j++) {
+                if (!(physp[j] & KVMPPC_GOT_PAGE))
+                        continue;
+                pfn = physp[j] >> PAGE_SHIFT;
+                page = pfn_to_page(pfn);
+                SetPageDirty(page);
+                put_page(page);
+        }
+}
+
+void kvmppc_core_free_memslot(struct kvm_memory_slot *free,
+                              struct kvm_memory_slot *dont)
+{
+        if (!dont || free->arch.rmap != dont->arch.rmap) {
+                vfree(free->arch.rmap);
+                free->arch.rmap = NULL;
         }
+        if (!dont || free->arch.slot_phys != dont->arch.slot_phys) {
+                unpin_slot(free);
+                vfree(free->arch.slot_phys);
+                free->arch.slot_phys = NULL;
+        }
+}
+
+int kvmppc_core_create_memslot(struct kvm_memory_slot *slot,
+                               unsigned long npages)
+{
+        slot->arch.rmap = vzalloc(npages * sizeof(*slot->arch.rmap));
+        if (!slot->arch.rmap)
+                return -ENOMEM;
+        slot->arch.slot_phys = NULL;
 
         return 0;
 }
 
-static void unpin_slot(struct kvm *kvm, int slot_id)
+int kvmppc_core_prepare_memory_region(struct kvm *kvm,
+                                      struct kvm_memory_slot *memslot,
+                                      struct kvm_userspace_memory_region *mem)
 {
-        unsigned long *physp;
-        unsigned long j, npages, pfn;
-        struct page *page;
+        unsigned long *phys;
 
-        physp = kvm->arch.slot_phys[slot_id];
-        npages = kvm->arch.slot_npages[slot_id];
-        if (physp) {
-                spin_lock(&kvm->arch.slot_phys_lock);
-                for (j = 0; j < npages; j++) {
-                        if (!(physp[j] & KVMPPC_GOT_PAGE))
-                                continue;
-                        pfn = physp[j] >> PAGE_SHIFT;
-                        page = pfn_to_page(pfn);
-                        SetPageDirty(page);
-                        put_page(page);
-                }
-                kvm->arch.slot_phys[slot_id] = NULL;
-                spin_unlock(&kvm->arch.slot_phys_lock);
-                vfree(physp);
+        /* Allocate a slot_phys array if needed */
+        phys = memslot->arch.slot_phys;
+        if (!kvm->arch.using_mmu_notifiers && !phys && memslot->npages) {
+                phys = vzalloc(memslot->npages * sizeof(unsigned long));
+                if (!phys)
+                        return -ENOMEM;
+                memslot->arch.slot_phys = phys;
         }
+
+        return 0;
 }
 
 void kvmppc_core_commit_memory_region(struct kvm *kvm,
@@ -1482,11 +1501,16 @@ static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu)
                 /* Initialize phys addrs of pages in RMO */
                 npages = ri->npages;
                 porder = __ilog2(npages);
-                physp = kvm->arch.slot_phys[memslot->id];
-                spin_lock(&kvm->arch.slot_phys_lock);
-                for (i = 0; i < npages; ++i)
-                        physp[i] = ((ri->base_pfn + i) << PAGE_SHIFT) + porder;
-                spin_unlock(&kvm->arch.slot_phys_lock);
+                physp = memslot->arch.slot_phys;
+                if (physp) {
+                        if (npages > memslot->npages)
+                                npages = memslot->npages;
+                        spin_lock(&kvm->arch.slot_phys_lock);
+                        for (i = 0; i < npages; ++i)
+                                physp[i] = ((ri->base_pfn + i) << PAGE_SHIFT) +
+                                        porder;
+                        spin_unlock(&kvm->arch.slot_phys_lock);
+                }
         }
 
         /* Order updates to kvm->arch.lpcr etc. vs. rma_setup_done */
@@ -1547,12 +1571,6 @@ int kvmppc_core_init_vm(struct kvm *kvm)
 
 void kvmppc_core_destroy_vm(struct kvm *kvm)
 {
-        unsigned long i;
-
-        if (!kvm->arch.using_mmu_notifiers)
-                for (i = 0; i < KVM_MEM_SLOTS_NUM; i++)
-                        unpin_slot(kvm, i);
-
         if (kvm->arch.rma) {
                 kvm_release_rma(kvm->arch.rma);
                 kvm->arch.rma = NULL;