KVM: PPC: Book3S HV: Rename hpte_setup_done to mmu_ready

This renames the kvm->arch.hpte_setup_done field to mmu_ready because
we will want to use it for radix guests too -- both for setting things
up before vcpu execution, and for excluding vcpus from executing while
MMU-related things get changed, such as in future switching the MMU
from radix to HPT mode or vice-versa.

This also moves the call to kvmppc_setup_partition_table() that was
done in kvmppc_hv_setup_htab_rma() for HPT guests, and the setting
of mmu_ready, into the caller in kvmppc_vcpu_run_hv().
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

arch/powerpc/include/asm/kvm_host.h

@@ -276,7 +276,7 @@ struct kvm_arch {
 	int tlbie_lock;
 	unsigned long lpcr;
 	unsigned long vrma_slb_v;
-	int hpte_setup_done;
+	int mmu_ready;
 	atomic_t vcpus_running;
 	u32 online_vcores;
 	atomic_t hpte_mod_interest;

arch/powerpc/kvm/book3s_64_mmu_hv.c

@@ -140,12 +140,12 @@ long kvmppc_alloc_reset_hpt(struct kvm *kvm, int order)
 		return -EINVAL;
 
 	mutex_lock(&kvm->lock);
-	if (kvm->arch.hpte_setup_done) {
-		kvm->arch.hpte_setup_done = 0;
-		/* order hpte_setup_done vs. vcpus_running */
+	if (kvm->arch.mmu_ready) {
+		kvm->arch.mmu_ready = 0;
+		/* order mmu_ready vs. vcpus_running */
 		smp_mb();
 		if (atomic_read(&kvm->arch.vcpus_running)) {
-			kvm->arch.hpte_setup_done = 1;
+			kvm->arch.mmu_ready = 1;
 			goto out;
 		}
 	}
@@ -1533,15 +1533,15 @@ long kvm_vm_ioctl_resize_hpt_commit(struct kvm *kvm,
 
 	/* This shouldn't be possible */
 	ret = -EIO;
-	if (WARN_ON(!kvm->arch.hpte_setup_done))
+	if (WARN_ON(!kvm->arch.mmu_ready))
 		goto out_no_hpt;
 
 	/* Stop VCPUs from running while we mess with the HPT */
-	kvm->arch.hpte_setup_done = 0;
+	kvm->arch.mmu_ready = 0;
 	smp_mb();
 
 	/* Boot all CPUs out of the guest so they re-read
-	 * hpte_setup_done */
+	 * mmu_ready */
 	on_each_cpu(resize_hpt_boot_vcpu, NULL, 1);
 
 	ret = -ENXIO;
@@ -1564,7 +1564,7 @@ long kvm_vm_ioctl_resize_hpt_commit(struct kvm *kvm,
 
 out:
 	/* Let VCPUs run again */
-	kvm->arch.hpte_setup_done = 1;
+	kvm->arch.mmu_ready = 1;
 	smp_mb();
 out_no_hpt:
 	resize_hpt_release(kvm, resize);
@@ -1802,7 +1802,7 @@ static ssize_t kvm_htab_write(struct file *file, const char __user *buf,
 	unsigned long tmp[2];
 	ssize_t nb;
 	long int err, ret;
-	int hpte_setup;
+	int mmu_ready;
 
 	if (!access_ok(VERIFY_READ, buf, count))
 		return -EFAULT;
@@ -1811,13 +1811,13 @@ static ssize_t kvm_htab_write(struct file *file, const char __user *buf,
 
 	/* lock out vcpus from running while we're doing this */
 	mutex_lock(&kvm->lock);
-	hpte_setup = kvm->arch.hpte_setup_done;
-	if (hpte_setup) {
-		kvm->arch.hpte_setup_done = 0;	/* temporarily */
-		/* order hpte_setup_done vs. vcpus_running */
+	mmu_ready = kvm->arch.mmu_ready;
+	if (mmu_ready) {
+		kvm->arch.mmu_ready = 0;	/* temporarily */
+		/* order mmu_ready vs. vcpus_running */
 		smp_mb();
 		if (atomic_read(&kvm->arch.vcpus_running)) {
-			kvm->arch.hpte_setup_done = 1;
+			kvm->arch.mmu_ready = 1;
 			mutex_unlock(&kvm->lock);
 			return -EBUSY;
 		}
@@ -1870,7 +1870,7 @@ static ssize_t kvm_htab_write(struct file *file, const char __user *buf,
 				       "r=%lx\n", ret, i, v, r);
 				goto out;
 			}
-			if (!hpte_setup && is_vrma_hpte(v)) {
+			if (!mmu_ready && is_vrma_hpte(v)) {
 				unsigned long psize = hpte_base_page_size(v, r);
 				unsigned long senc = slb_pgsize_encoding(psize);
 				unsigned long lpcr;
@@ -1879,7 +1879,7 @@ static ssize_t kvm_htab_write(struct file *file, const char __user *buf,
 					(VRMA_VSID << SLB_VSID_SHIFT_1T);
 				lpcr = senc << (LPCR_VRMASD_SH - 4);
 				kvmppc_update_lpcr(kvm, lpcr, LPCR_VRMASD);
-				hpte_setup = 1;
+				mmu_ready = 1;
 			}
 			++i;
 			hptp += 2;
@@ -1895,9 +1895,9 @@ static ssize_t kvm_htab_write(struct file *file, const char __user *buf,
 	}
 
  out:
-	/* Order HPTE updates vs. hpte_setup_done */
+	/* Order HPTE updates vs. mmu_ready */
 	smp_wmb();
-	kvm->arch.hpte_setup_done = hpte_setup;
+	kvm->arch.mmu_ready = mmu_ready;
 	mutex_unlock(&kvm->lock);
 
 	if (err)

arch/powerpc/kvm/book3s_hv.c

@@ -115,6 +115,7 @@ MODULE_PARM_DESC(h_ipi_redirect, "Redirect H_IPI wakeup to a free host core");
 
 static void kvmppc_end_cede(struct kvm_vcpu *vcpu);
 static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu);
+static void kvmppc_setup_partition_table(struct kvm *kvm);
 
 static inline struct kvm_vcpu *next_runnable_thread(struct kvmppc_vcore *vc,
 		int *ip)
@@ -3198,6 +3199,7 @@ static int kvmppc_vcpu_run_hv(struct kvm_run *run, struct kvm_vcpu *vcpu)
 	unsigned long ebb_regs[3] = {};	/* shut up GCC */
 	unsigned long user_tar = 0;
 	unsigned int user_vrsave;
+	struct kvm *kvm;
 
 	if (!vcpu->arch.sane) {
 		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
@@ -3235,13 +3237,25 @@ static int kvmppc_vcpu_run_hv(struct kvm_run *run, struct kvm_vcpu *vcpu)
 		return -EINTR;
 	}
 
-	atomic_inc(&vcpu->kvm->arch.vcpus_running);
-	/* Order vcpus_running vs. hpte_setup_done, see kvmppc_alloc_reset_hpt */
+	kvm = vcpu->kvm;
+	atomic_inc(&kvm->arch.vcpus_running);
+	/* Order vcpus_running vs. mmu_ready, see kvmppc_alloc_reset_hpt */
 	smp_mb();
 
-	/* On the first time here, set up HTAB and VRMA */
-	if (!kvm_is_radix(vcpu->kvm) && !vcpu->kvm->arch.hpte_setup_done) {
-		r = kvmppc_hv_setup_htab_rma(vcpu);
+	/* On the first time here, set up MMU if necessary */
+	if (!vcpu->kvm->arch.mmu_ready) {
+		mutex_lock(&kvm->lock);
+		r = 0;
+		if (!kvm->arch.mmu_ready) {
+			if (!kvm_is_radix(vcpu->kvm))
+				r = kvmppc_hv_setup_htab_rma(vcpu);
+			if (!r) {
+				if (cpu_has_feature(CPU_FTR_ARCH_300))
+					kvmppc_setup_partition_table(kvm);
+				kvm->arch.mmu_ready = 1;
+			}
+		}
+		mutex_unlock(&kvm->lock);
 		if (r)
 			goto out;
 	}
@@ -3530,6 +3544,10 @@ static void kvmppc_setup_partition_table(struct kvm *kvm)
 	mmu_partition_table_set_entry(kvm->arch.lpid, dw0, dw1);
 }
 
+/*
+ * Set up HPT (hashed page table) and RMA (real-mode area).
+ * Must be called with kvm->lock held.
+ */
 static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu)
 {
 	int err = 0;
@@ -3541,10 +3559,6 @@ static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu)
 	unsigned long psize, porder;
 	int srcu_idx;
 
-	mutex_lock(&kvm->lock);
-	if (kvm->arch.hpte_setup_done)
-		goto out;	/* another vcpu beat us to it */
-
 	/* Allocate hashed page table (if not done already) and reset it */
 	if (!kvm->arch.hpt.virt) {
 		int order = KVM_DEFAULT_HPT_ORDER;
@@ -3603,18 +3617,14 @@ static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu)
 		/* the -4 is to account for senc values starting at 0x10 */
 		lpcr = senc << (LPCR_VRMASD_SH - 4);
 		kvmppc_update_lpcr(kvm, lpcr, LPCR_VRMASD);
-	} else {
-		kvmppc_setup_partition_table(kvm);
 	}
 
-	/* Order updates to kvm->arch.lpcr etc. vs. hpte_setup_done */
+	/* Order updates to kvm->arch.lpcr etc. vs. mmu_ready */
 	smp_wmb();
-	kvm->arch.hpte_setup_done = 1;
 	err = 0;
  out_srcu:
 	srcu_read_unlock(&kvm->srcu, srcu_idx);
  out:
-	mutex_unlock(&kvm->lock);
 	return err;
 
  up_out:
@@ -3769,6 +3779,7 @@ static int kvmppc_core_init_vm_hv(struct kvm *kvm)
 	 */
 	if (radix_enabled()) {
 		kvm->arch.radix = 1;
+		kvm->arch.mmu_ready = 1;
 		lpcr &= ~LPCR_VPM1;
 		lpcr |= LPCR_UPRT | LPCR_GTSE | LPCR_HR;
 		ret = kvmppc_init_vm_radix(kvm);