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Diffstat (limited to 'arch/powerpc/kvm/book3s_64_mmu_hv.c')
-rw-r--r--arch/powerpc/kvm/book3s_64_mmu_hv.c116
1 files changed, 79 insertions, 37 deletions
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index fb25ebc0af0..80561074078 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -52,7 +52,7 @@ static void kvmppc_rmap_reset(struct kvm *kvm);
long kvmppc_alloc_hpt(struct kvm *kvm, u32 *htab_orderp)
{
- unsigned long hpt;
+ unsigned long hpt = 0;
struct revmap_entry *rev;
struct page *page = NULL;
long order = KVM_DEFAULT_HPT_ORDER;
@@ -64,22 +64,11 @@ long kvmppc_alloc_hpt(struct kvm *kvm, u32 *htab_orderp)
}
kvm->arch.hpt_cma_alloc = 0;
- /*
- * try first to allocate it from the kernel page allocator.
- * We keep the CMA reserved for failed allocation.
- */
- hpt = __get_free_pages(GFP_KERNEL | __GFP_ZERO | __GFP_REPEAT |
- __GFP_NOWARN, order - PAGE_SHIFT);
-
- /* Next try to allocate from the preallocated pool */
- if (!hpt) {
- VM_BUG_ON(order < KVM_CMA_CHUNK_ORDER);
- page = kvm_alloc_hpt(1 << (order - PAGE_SHIFT));
- if (page) {
- hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page));
- kvm->arch.hpt_cma_alloc = 1;
- } else
- --order;
+ VM_BUG_ON(order < KVM_CMA_CHUNK_ORDER);
+ page = kvm_alloc_hpt(1 << (order - PAGE_SHIFT));
+ if (page) {
+ hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page));
+ kvm->arch.hpt_cma_alloc = 1;
}
/* Lastly try successively smaller sizes from the page allocator */
@@ -596,6 +585,7 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
struct kvm *kvm = vcpu->kvm;
unsigned long *hptep, hpte[3], r;
unsigned long mmu_seq, psize, pte_size;
+ unsigned long gpa_base, gfn_base;
unsigned long gpa, gfn, hva, pfn;
struct kvm_memory_slot *memslot;
unsigned long *rmap;
@@ -634,7 +624,9 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
/* Translate the logical address and get the page */
psize = hpte_page_size(hpte[0], r);
- gpa = (r & HPTE_R_RPN & ~(psize - 1)) | (ea & (psize - 1));
+ gpa_base = r & HPTE_R_RPN & ~(psize - 1);
+ gfn_base = gpa_base >> PAGE_SHIFT;
+ gpa = gpa_base | (ea & (psize - 1));
gfn = gpa >> PAGE_SHIFT;
memslot = gfn_to_memslot(kvm, gfn);
@@ -646,6 +638,13 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
if (!kvm->arch.using_mmu_notifiers)
return -EFAULT; /* should never get here */
+ /*
+ * This should never happen, because of the slot_is_aligned()
+ * check in kvmppc_do_h_enter().
+ */
+ if (gfn_base < memslot->base_gfn)
+ return -EFAULT;
+
/* used to check for invalidations in progress */
mmu_seq = kvm->mmu_notifier_seq;
smp_rmb();
@@ -738,7 +737,8 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
goto out_unlock;
hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID;
- rmap = &memslot->arch.rmap[gfn - memslot->base_gfn];
+ /* Always put the HPTE in the rmap chain for the page base address */
+ rmap = &memslot->arch.rmap[gfn_base - memslot->base_gfn];
lock_rmap(rmap);
/* Check if we might have been invalidated; let the guest retry if so */
@@ -1060,22 +1060,33 @@ void kvm_set_spte_hva_hv(struct kvm *kvm, unsigned long hva, pte_t pte)
kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
}
-static int kvm_test_clear_dirty(struct kvm *kvm, unsigned long *rmapp)
+static int vcpus_running(struct kvm *kvm)
+{
+ return atomic_read(&kvm->arch.vcpus_running) != 0;
+}
+
+/*
+ * Returns the number of system pages that are dirty.
+ * This can be more than 1 if we find a huge-page HPTE.
+ */
+static int kvm_test_clear_dirty_npages(struct kvm *kvm, unsigned long *rmapp)
{
struct revmap_entry *rev = kvm->arch.revmap;
unsigned long head, i, j;
+ unsigned long n;
+ unsigned long v, r;
unsigned long *hptep;
- int ret = 0;
+ int npages_dirty = 0;
retry:
lock_rmap(rmapp);
if (*rmapp & KVMPPC_RMAP_CHANGED) {
*rmapp &= ~KVMPPC_RMAP_CHANGED;
- ret = 1;
+ npages_dirty = 1;
}
if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
unlock_rmap(rmapp);
- return ret;
+ return npages_dirty;
}
i = head = *rmapp & KVMPPC_RMAP_INDEX;
@@ -1083,7 +1094,22 @@ static int kvm_test_clear_dirty(struct kvm *kvm, unsigned long *rmapp)
hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4));
j = rev[i].forw;
- if (!(hptep[1] & HPTE_R_C))
+ /*
+ * Checking the C (changed) bit here is racy since there
+ * is no guarantee about when the hardware writes it back.
+ * If the HPTE is not writable then it is stable since the
+ * page can't be written to, and we would have done a tlbie
+ * (which forces the hardware to complete any writeback)
+ * when making the HPTE read-only.
+ * If vcpus are running then this call is racy anyway
+ * since the page could get dirtied subsequently, so we
+ * expect there to be a further call which would pick up
+ * any delayed C bit writeback.
+ * Otherwise we need to do the tlbie even if C==0 in
+ * order to pick up any delayed writeback of C.
+ */
+ if (!(hptep[1] & HPTE_R_C) &&
+ (!hpte_is_writable(hptep[1]) || vcpus_running(kvm)))
continue;
if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
@@ -1095,24 +1121,33 @@ static int kvm_test_clear_dirty(struct kvm *kvm, unsigned long *rmapp)
}
/* Now check and modify the HPTE */
- if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_C)) {
- /* need to make it temporarily absent to clear C */
- hptep[0] |= HPTE_V_ABSENT;
- kvmppc_invalidate_hpte(kvm, hptep, i);
- hptep[1] &= ~HPTE_R_C;
- eieio();
- hptep[0] = (hptep[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID;
+ if (!(hptep[0] & HPTE_V_VALID))
+ continue;
+
+ /* need to make it temporarily absent so C is stable */
+ hptep[0] |= HPTE_V_ABSENT;
+ kvmppc_invalidate_hpte(kvm, hptep, i);
+ v = hptep[0];
+ r = hptep[1];
+ if (r & HPTE_R_C) {
+ hptep[1] = r & ~HPTE_R_C;
if (!(rev[i].guest_rpte & HPTE_R_C)) {
rev[i].guest_rpte |= HPTE_R_C;
note_hpte_modification(kvm, &rev[i]);
}
- ret = 1;
+ n = hpte_page_size(v, r);
+ n = (n + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ if (n > npages_dirty)
+ npages_dirty = n;
+ eieio();
}
- hptep[0] &= ~HPTE_V_HVLOCK;
+ v &= ~(HPTE_V_ABSENT | HPTE_V_HVLOCK);
+ v |= HPTE_V_VALID;
+ hptep[0] = v;
} while ((i = j) != head);
unlock_rmap(rmapp);
- return ret;
+ return npages_dirty;
}
static void harvest_vpa_dirty(struct kvmppc_vpa *vpa,
@@ -1136,15 +1171,22 @@ static void harvest_vpa_dirty(struct kvmppc_vpa *vpa,
long kvmppc_hv_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot,
unsigned long *map)
{
- unsigned long i;
+ unsigned long i, j;
unsigned long *rmapp;
struct kvm_vcpu *vcpu;
preempt_disable();
rmapp = memslot->arch.rmap;
for (i = 0; i < memslot->npages; ++i) {
- if (kvm_test_clear_dirty(kvm, rmapp) && map)
- __set_bit_le(i, map);
+ int npages = kvm_test_clear_dirty_npages(kvm, rmapp);
+ /*
+ * Note that if npages > 0 then i must be a multiple of npages,
+ * since we always put huge-page HPTEs in the rmap chain
+ * corresponding to their page base address.
+ */
+ if (npages && map)
+ for (j = i; npages; ++j, --npages)
+ __set_bit_le(j, map);
++rmapp;
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-21 15:19:43 +0000