3 files changed, 64 insertions, 29 deletions

diff --git a/arch/powerpc/kvm/book3s_64_mmu.c b/arch/powerpc/kvm/book3s_64_mmu.c
index 29ebe2fd5867..a93d719edc90 100644
--- a/arch/powerpc/kvm/book3s_64_mmu.c
+++ b/arch/powerpc/kvm/book3s_64_mmu.c
@@ -235,6 +235,7 @@ static int kvmppc_mmu_book3s_64_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
                 gpte->may_read = true;
                 gpte->may_write = true;
                 gpte->page_size = MMU_PAGE_4K;
+                gpte->wimg = HPTE_R_M;
 
                 return 0;
         }
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index 966097232d21..b73dbc9e797d 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -65,11 +65,17 @@ struct kvm_resize_hpt {
         u32 order;
 
         /* These fields protected by kvm->lock */
+
+        /* Possible values and their usage:
+         *  <0     an error occurred during allocation,
+         *  -EBUSY allocation is in the progress,
+         *  0      allocation made successfuly.
+         */
         int error;
-        bool prepare_done;
 
-        /* Private to the work thread, until prepare_done is true,
-         * then protected by kvm->resize_hpt_sem */
+        /* Private to the work thread, until error != -EBUSY,
+         * then protected by kvm->lock.
+         */
         struct kvm_hpt_info hpt;
 };
 
@@ -159,8 +165,6 @@ long kvmppc_alloc_reset_hpt(struct kvm *kvm, int order)
                  * Reset all the reverse-mapping chains for all memslots
                  */
                 kvmppc_rmap_reset(kvm);
-                /* Ensure that each vcpu will flush its TLB on next entry. */
-                cpumask_setall(&kvm->arch.need_tlb_flush);
                 err = 0;
                 goto out;
         }
@@ -176,6 +180,10 @@ long kvmppc_alloc_reset_hpt(struct kvm *kvm, int order)
         kvmppc_set_hpt(kvm, &info);
 
 out:
+        if (err == 0)
+                /* Ensure that each vcpu will flush its TLB on next entry. */
+                cpumask_setall(&kvm->arch.need_tlb_flush);
+
         mutex_unlock(&kvm->lock);
         return err;
 }
@@ -1413,16 +1421,20 @@ static void resize_hpt_pivot(struct kvm_resize_hpt *resize)
 
 static void resize_hpt_release(struct kvm *kvm, struct kvm_resize_hpt *resize)
 {
-        BUG_ON(kvm->arch.resize_hpt != resize);
+        if (WARN_ON(!mutex_is_locked(&kvm->lock)))
+                return;
 
         if (!resize)
                 return;
 
-        if (resize->hpt.virt)
-                kvmppc_free_hpt(&resize->hpt);
+        if (resize->error != -EBUSY) {
+                if (resize->hpt.virt)
+                        kvmppc_free_hpt(&resize->hpt);
+                kfree(resize);
+        }
 
-        kvm->arch.resize_hpt = NULL;
-        kfree(resize);
+        if (kvm->arch.resize_hpt == resize)
+                kvm->arch.resize_hpt = NULL;
 }
 
 static void resize_hpt_prepare_work(struct work_struct *work)
@@ -1431,17 +1443,41 @@ static void resize_hpt_prepare_work(struct work_struct *work)
                                                      struct kvm_resize_hpt,
                                                      work);
         struct kvm *kvm = resize->kvm;
-        int err;
+        int err = 0;
 
-        resize_hpt_debug(resize, "resize_hpt_prepare_work(): order = %d\n",
-                         resize->order);
-
-        err = resize_hpt_allocate(resize);
+        if (WARN_ON(resize->error != -EBUSY))
+                return;
 
         mutex_lock(&kvm->lock);
 
+        /* Request is still current? */
+        if (kvm->arch.resize_hpt == resize) {
+                /* We may request large allocations here:
+                 * do not sleep with kvm->lock held for a while.
+                 */
+                mutex_unlock(&kvm->lock);
+
+                resize_hpt_debug(resize, "resize_hpt_prepare_work(): order = %d\n",
+                                 resize->order);
+
+                err = resize_hpt_allocate(resize);
+
+                /* We have strict assumption about -EBUSY
+                 * when preparing for HPT resize.
+                 */
+                if (WARN_ON(err == -EBUSY))
+                        err = -EINPROGRESS;
+
+                mutex_lock(&kvm->lock);
+                /* It is possible that kvm->arch.resize_hpt != resize
+                 * after we grab kvm->lock again.
+                 */
+        }
+
         resize->error = err;
-        resize->prepare_done = true;
+
+        if (kvm->arch.resize_hpt != resize)
+                resize_hpt_release(kvm, resize);
 
         mutex_unlock(&kvm->lock);
 }
@@ -1466,14 +1502,12 @@ long kvm_vm_ioctl_resize_hpt_prepare(struct kvm *kvm,
 
         if (resize) {
                 if (resize->order == shift) {
-                        /* Suitable resize in progress */
-                        if (resize->prepare_done) {
-                                ret = resize->error;
-                                if (ret != 0)
-                                        resize_hpt_release(kvm, resize);
-                        } else {
+                        /* Suitable resize in progress? */
+                        ret = resize->error;
+                        if (ret == -EBUSY)
                                 ret = 100; /* estimated time in ms */
-                        }
+                        else if (ret)
+                                resize_hpt_release(kvm, resize);
 
                         goto out;
                 }
@@ -1493,6 +1527,8 @@ long kvm_vm_ioctl_resize_hpt_prepare(struct kvm *kvm,
                 ret = -ENOMEM;
                 goto out;
         }
+
+        resize->error = -EBUSY;
         resize->order = shift;
         resize->kvm = kvm;
         INIT_WORK(&resize->work, resize_hpt_prepare_work);
@@ -1547,16 +1583,12 @@ long kvm_vm_ioctl_resize_hpt_commit(struct kvm *kvm,
         if (!resize || (resize->order != shift))
                 goto out;
 
-        ret = -EBUSY;
-        if (!resize->prepare_done)
-                goto out;
-
         ret = resize->error;
-        if (ret != 0)
+        if (ret)
                 goto out;
 
         ret = resize_hpt_rehash(resize);
-        if (ret != 0)
+        if (ret)
                 goto out;
 
         resize_hpt_pivot(resize);
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index d0dc8624198f..7deaeeb14b93 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -60,6 +60,7 @@ static void kvmppc_giveup_fac(struct kvm_vcpu *vcpu, ulong fac);
 #define MSR_USER32 MSR_USER
 #define MSR_USER64 MSR_USER
 #define HW_PAGE_SIZE PAGE_SIZE
+#define HPTE_R_M   _PAGE_COHERENT
 #endif
 
 static bool kvmppc_is_split_real(struct kvm_vcpu *vcpu)
@@ -557,6 +558,7 @@ int kvmppc_handle_pagefault(struct kvm_run *run, struct kvm_vcpu *vcpu,
                 pte.eaddr = eaddr;
                 pte.vpage = eaddr >> 12;
                 pte.page_size = MMU_PAGE_64K;
+                pte.wimg = HPTE_R_M;
         }
 
         switch (kvmppc_get_msr(vcpu) & (MSR_DR|MSR_IR)) {