1 files changed, 731 insertions, 0 deletions

diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
new file mode 100644
index 000000000..fc6bb9630
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_hv_builtin.c
@@ -0,0 +1,731 @@
+/*
+ * Copyright 2011 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/cpu.h>
+#include <linux/kvm_host.h>
+#include <linux/preempt.h>
+#include <linux/export.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/init.h>
+#include <linux/memblock.h>
+#include <linux/sizes.h>
+#include <linux/cma.h>
+#include <linux/bitops.h>
+
+#include <asm/asm-prototypes.h>
+#include <asm/cputable.h>
+#include <asm/kvm_ppc.h>
+#include <asm/kvm_book3s.h>
+#include <asm/archrandom.h>
+#include <asm/xics.h>
+#include <asm/xive.h>
+#include <asm/dbell.h>
+#include <asm/cputhreads.h>
+#include <asm/io.h>
+#include <asm/opal.h>
+#include <asm/smp.h>
+
+#define KVM_CMA_CHUNK_ORDER	18
+
+#include "book3s_xics.h"
+#include "book3s_xive.h"
+
+/*
+ * The XIVE module will populate these when it loads
+ */
+unsigned long (*__xive_vm_h_xirr)(struct kvm_vcpu *vcpu);
+unsigned long (*__xive_vm_h_ipoll)(struct kvm_vcpu *vcpu, unsigned long server);
+int (*__xive_vm_h_ipi)(struct kvm_vcpu *vcpu, unsigned long server,
+		       unsigned long mfrr);
+int (*__xive_vm_h_cppr)(struct kvm_vcpu *vcpu, unsigned long cppr);
+int (*__xive_vm_h_eoi)(struct kvm_vcpu *vcpu, unsigned long xirr);
+EXPORT_SYMBOL_GPL(__xive_vm_h_xirr);
+EXPORT_SYMBOL_GPL(__xive_vm_h_ipoll);
+EXPORT_SYMBOL_GPL(__xive_vm_h_ipi);
+EXPORT_SYMBOL_GPL(__xive_vm_h_cppr);
+EXPORT_SYMBOL_GPL(__xive_vm_h_eoi);
+
+/*
+ * Hash page table alignment on newer cpus(CPU_FTR_ARCH_206)
+ * should be power of 2.
+ */
+#define HPT_ALIGN_PAGES		((1 << 18) >> PAGE_SHIFT) /* 256k */
+/*
+ * By default we reserve 5% of memory for hash pagetable allocation.
+ */
+static unsigned long kvm_cma_resv_ratio = 5;
+
+static struct cma *kvm_cma;
+
+static int __init early_parse_kvm_cma_resv(char *p)
+{
+	pr_debug("%s(%s)\n", __func__, p);
+	if (!p)
+		return -EINVAL;
+	return kstrtoul(p, 0, &kvm_cma_resv_ratio);
+}
+early_param("kvm_cma_resv_ratio", early_parse_kvm_cma_resv);
+
+struct page *kvm_alloc_hpt_cma(unsigned long nr_pages)
+{
+	VM_BUG_ON(order_base_2(nr_pages) < KVM_CMA_CHUNK_ORDER - PAGE_SHIFT);
+
+	return cma_alloc(kvm_cma, nr_pages, order_base_2(HPT_ALIGN_PAGES),
+			 false);
+}
+EXPORT_SYMBOL_GPL(kvm_alloc_hpt_cma);
+
+void kvm_free_hpt_cma(struct page *page, unsigned long nr_pages)
+{
+	cma_release(kvm_cma, page, nr_pages);
+}
+EXPORT_SYMBOL_GPL(kvm_free_hpt_cma);
+
+/**
+ * kvm_cma_reserve() - reserve area for kvm hash pagetable
+ *
+ * This function reserves memory from early allocator. It should be
+ * called by arch specific code once the memblock allocator
+ * has been activated and all other subsystems have already allocated/reserved
+ * memory.
+ */
+void __init kvm_cma_reserve(void)
+{
+	unsigned long align_size;
+	struct memblock_region *reg;
+	phys_addr_t selected_size = 0;
+
+	/*
+	 * We need CMA reservation only when we are in HV mode
+	 */
+	if (!cpu_has_feature(CPU_FTR_HVMODE))
+		return;
+	/*
+	 * We cannot use memblock_phys_mem_size() here, because
+	 * memblock_analyze() has not been called yet.
+	 */
+	for_each_memblock(memory, reg)
+		selected_size += memblock_region_memory_end_pfn(reg) -
+				 memblock_region_memory_base_pfn(reg);
+
+	selected_size = (selected_size * kvm_cma_resv_ratio / 100) << PAGE_SHIFT;
+	if (selected_size) {
+		pr_debug("%s: reserving %ld MiB for global area\n", __func__,
+			 (unsigned long)selected_size / SZ_1M);
+		align_size = HPT_ALIGN_PAGES << PAGE_SHIFT;
+		cma_declare_contiguous(0, selected_size, 0, align_size,
+			KVM_CMA_CHUNK_ORDER - PAGE_SHIFT, false, "kvm_cma",
+			&kvm_cma);
+	}
+}
+
+/*
+ * Real-mode H_CONFER implementation.
+ * We check if we are the only vcpu out of this virtual core
+ * still running in the guest and not ceded.  If so, we pop up
+ * to the virtual-mode implementation; if not, just return to
+ * the guest.
+ */
+long int kvmppc_rm_h_confer(struct kvm_vcpu *vcpu, int target,
+			    unsigned int yield_count)
+{
+	struct kvmppc_vcore *vc = local_paca->kvm_hstate.kvm_vcore;
+	int ptid = local_paca->kvm_hstate.ptid;
+	int threads_running;
+	int threads_ceded;
+	int threads_conferring;
+	u64 stop = get_tb() + 10 * tb_ticks_per_usec;
+	int rv = H_SUCCESS; /* => don't yield */
+
+	set_bit(ptid, &vc->conferring_threads);
+	while ((get_tb() < stop) && !VCORE_IS_EXITING(vc)) {
+		threads_running = VCORE_ENTRY_MAP(vc);
+		threads_ceded = vc->napping_threads;
+		threads_conferring = vc->conferring_threads;
+		if ((threads_ceded | threads_conferring) == threads_running) {
+			rv = H_TOO_HARD; /* => do yield */
+			break;
+		}
+	}
+	clear_bit(ptid, &vc->conferring_threads);
+	return rv;
+}
+
+/*
+ * When running HV mode KVM we need to block certain operations while KVM VMs
+ * exist in the system. We use a counter of VMs to track this.
+ *
+ * One of the operations we need to block is onlining of secondaries, so we
+ * protect hv_vm_count with get/put_online_cpus().
+ */
+static atomic_t hv_vm_count;
+
+void kvm_hv_vm_activated(void)
+{
+	get_online_cpus();
+	atomic_inc(&hv_vm_count);
+	put_online_cpus();
+}
+EXPORT_SYMBOL_GPL(kvm_hv_vm_activated);
+
+void kvm_hv_vm_deactivated(void)
+{
+	get_online_cpus();
+	atomic_dec(&hv_vm_count);
+	put_online_cpus();
+}
+EXPORT_SYMBOL_GPL(kvm_hv_vm_deactivated);
+
+bool kvm_hv_mode_active(void)
+{
+	return atomic_read(&hv_vm_count) != 0;
+}
+
+extern int hcall_real_table[], hcall_real_table_end[];
+
+int kvmppc_hcall_impl_hv_realmode(unsigned long cmd)
+{
+	cmd /= 4;
+	if (cmd < hcall_real_table_end - hcall_real_table &&
+	    hcall_real_table[cmd])
+		return 1;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(kvmppc_hcall_impl_hv_realmode);
+
+int kvmppc_hwrng_present(void)
+{
+	return powernv_hwrng_present();
+}
+EXPORT_SYMBOL_GPL(kvmppc_hwrng_present);
+
+long kvmppc_h_random(struct kvm_vcpu *vcpu)
+{
+	int r;
+
+	/* Only need to do the expensive mfmsr() on radix */
+	if (kvm_is_radix(vcpu->kvm) && (mfmsr() & MSR_IR))
+		r = powernv_get_random_long(&vcpu->arch.regs.gpr[4]);
+	else
+		r = powernv_get_random_real_mode(&vcpu->arch.regs.gpr[4]);
+	if (r)
+		return H_SUCCESS;
+
+	return H_HARDWARE;
+}
+
+/*
+ * Send an interrupt or message to another CPU.
+ * The caller needs to include any barrier needed to order writes
+ * to memory vs. the IPI/message.
+ */
+void kvmhv_rm_send_ipi(int cpu)
+{
+	void __iomem *xics_phys;
+	unsigned long msg = PPC_DBELL_TYPE(PPC_DBELL_SERVER);
+
+	/* On POWER9 we can use msgsnd for any destination cpu. */
+	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
+		msg |= get_hard_smp_processor_id(cpu);
+		__asm__ __volatile__ (PPC_MSGSND(%0) : : "r" (msg));
+		return;
+	}
+
+	/* On POWER8 for IPIs to threads in the same core, use msgsnd. */
+	if (cpu_has_feature(CPU_FTR_ARCH_207S) &&
+	    cpu_first_thread_sibling(cpu) ==
+	    cpu_first_thread_sibling(raw_smp_processor_id())) {
+		msg |= cpu_thread_in_core(cpu);
+		__asm__ __volatile__ (PPC_MSGSND(%0) : : "r" (msg));
+		return;
+	}
+
+	/* We should never reach this */
+	if (WARN_ON_ONCE(xive_enabled()))
+	    return;
+
+	/* Else poke the target with an IPI */
+	xics_phys = paca_ptrs[cpu]->kvm_hstate.xics_phys;
+	if (xics_phys)
+		__raw_rm_writeb(IPI_PRIORITY, xics_phys + XICS_MFRR);
+	else
+		opal_int_set_mfrr(get_hard_smp_processor_id(cpu), IPI_PRIORITY);
+}
+
+/*
+ * The following functions are called from the assembly code
+ * in book3s_hv_rmhandlers.S.
+ */
+static void kvmhv_interrupt_vcore(struct kvmppc_vcore *vc, int active)
+{
+	int cpu = vc->pcpu;
+
+	/* Order setting of exit map vs. msgsnd/IPI */
+	smp_mb();
+	for (; active; active >>= 1, ++cpu)
+		if (active & 1)
+			kvmhv_rm_send_ipi(cpu);
+}
+
+void kvmhv_commence_exit(int trap)
+{
+	struct kvmppc_vcore *vc = local_paca->kvm_hstate.kvm_vcore;
+	int ptid = local_paca->kvm_hstate.ptid;
+	struct kvm_split_mode *sip = local_paca->kvm_hstate.kvm_split_mode;
+	int me, ee, i, t;
+	int cpu0;
+
+	/* Set our bit in the threads-exiting-guest map in the 0xff00
+	   bits of vcore->entry_exit_map */
+	me = 0x100 << ptid;
+	do {
+		ee = vc->entry_exit_map;
+	} while (cmpxchg(&vc->entry_exit_map, ee, ee | me) != ee);
+
+	/* Are we the first here? */
+	if ((ee >> 8) != 0)
+		return;
+
+	/*
+	 * Trigger the other threads in this vcore to exit the guest.
+	 * If this is a hypervisor decrementer interrupt then they
+	 * will be already on their way out of the guest.
+	 */
+	if (trap != BOOK3S_INTERRUPT_HV_DECREMENTER)
+		kvmhv_interrupt_vcore(vc, ee & ~(1 << ptid));
+
+	/*
+	 * If we are doing dynamic micro-threading, interrupt the other
+	 * subcores to pull them out of their guests too.
+	 */
+	if (!sip)
+		return;
+
+	for (i = 0; i < MAX_SUBCORES; ++i) {
+		vc = sip->vc[i];
+		if (!vc)
+			break;
+		do {
+			ee = vc->entry_exit_map;
+			/* Already asked to exit? */
+			if ((ee >> 8) != 0)
+				break;
+		} while (cmpxchg(&vc->entry_exit_map, ee,
+				 ee | VCORE_EXIT_REQ) != ee);
+		if ((ee >> 8) == 0)
+			kvmhv_interrupt_vcore(vc, ee);
+	}
+
+	/*
+	 * On POWER9 when running a HPT guest on a radix host (sip != NULL),
+	 * we have to interrupt inactive CPU threads to get them to
+	 * restore the host LPCR value.
+	 */
+	if (sip->lpcr_req) {
+		if (cmpxchg(&sip->do_restore, 0, 1) == 0) {
+			vc = local_paca->kvm_hstate.kvm_vcore;
+			cpu0 = vc->pcpu + ptid - local_paca->kvm_hstate.tid;
+			for (t = 1; t < threads_per_core; ++t) {
+				if (sip->napped[t])
+					kvmhv_rm_send_ipi(cpu0 + t);
+			}
+		}
+	}
+}
+
+struct kvmppc_host_rm_ops *kvmppc_host_rm_ops_hv;
+EXPORT_SYMBOL_GPL(kvmppc_host_rm_ops_hv);
+
+#ifdef CONFIG_KVM_XICS
+static struct kvmppc_irq_map *get_irqmap(struct kvmppc_passthru_irqmap *pimap,
+					 u32 xisr)
+{
+	int i;
+
+	/*
+	 * We access the mapped array here without a lock.  That
+	 * is safe because we never reduce the number of entries
+	 * in the array and we never change the v_hwirq field of
+	 * an entry once it is set.
+	 *
+	 * We have also carefully ordered the stores in the writer
+	 * and the loads here in the reader, so that if we find a matching
+	 * hwirq here, the associated GSI and irq_desc fields are valid.
+	 */
+	for (i = 0; i < pimap->n_mapped; i++)  {
+		if (xisr == pimap->mapped[i].r_hwirq) {
+			/*
+			 * Order subsequent reads in the caller to serialize
+			 * with the writer.
+			 */
+			smp_rmb();
+			return &pimap->mapped[i];
+		}
+	}
+	return NULL;
+}
+
+/*
+ * If we have an interrupt that's not an IPI, check if we have a
+ * passthrough adapter and if so, check if this external interrupt
+ * is for the adapter.
+ * We will attempt to deliver the IRQ directly to the target VCPU's
+ * ICP, the virtual ICP (based on affinity - the xive value in ICS).
+ *
+ * If the delivery fails or if this is not for a passthrough adapter,
+ * return to the host to handle this interrupt. We earlier
+ * saved a copy of the XIRR in the PACA, it will be picked up by
+ * the host ICP driver.
+ */
+static int kvmppc_check_passthru(u32 xisr, __be32 xirr, bool *again)
+{
+	struct kvmppc_passthru_irqmap *pimap;
+	struct kvmppc_irq_map *irq_map;
+	struct kvm_vcpu *vcpu;
+
+	vcpu = local_paca->kvm_hstate.kvm_vcpu;
+	if (!vcpu)
+		return 1;
+	pimap = kvmppc_get_passthru_irqmap(vcpu->kvm);
+	if (!pimap)
+		return 1;
+	irq_map = get_irqmap(pimap, xisr);
+	if (!irq_map)
+		return 1;
+
+	/* We're handling this interrupt, generic code doesn't need to */
+	local_paca->kvm_hstate.saved_xirr = 0;
+
+	return kvmppc_deliver_irq_passthru(vcpu, xirr, irq_map, pimap, again);
+}
+
+#else
+static inline int kvmppc_check_passthru(u32 xisr, __be32 xirr, bool *again)
+{
+	return 1;
+}
+#endif
+
+/*
+ * Determine what sort of external interrupt is pending (if any).
+ * Returns:
+ *	0 if no interrupt is pending
+ *	1 if an interrupt is pending that needs to be handled by the host
+ *	2 Passthrough that needs completion in the host
+ *	-1 if there was a guest wakeup IPI (which has now been cleared)
+ *	-2 if there is PCI passthrough external interrupt that was handled
+ */
+static long kvmppc_read_one_intr(bool *again);
+
+long kvmppc_read_intr(void)
+{
+	long ret = 0;
+	long rc;
+	bool again;
+
+	if (xive_enabled())
+		return 1;
+
+	do {
+		again = false;
+		rc = kvmppc_read_one_intr(&again);
+		if (rc && (ret == 0 || rc > ret))
+			ret = rc;
+	} while (again);
+	return ret;
+}
+
+static long kvmppc_read_one_intr(bool *again)
+{
+	void __iomem *xics_phys;
+	u32 h_xirr;
+	__be32 xirr;
+	u32 xisr;
+	u8 host_ipi;
+	int64_t rc;
+
+	if (xive_enabled())
+		return 1;
+
+	/* see if a host IPI is pending */
+	host_ipi = local_paca->kvm_hstate.host_ipi;
+	if (host_ipi)
+		return 1;
+
+	/* Now read the interrupt from the ICP */
+	xics_phys = local_paca->kvm_hstate.xics_phys;
+	rc = 0;
+	if (!xics_phys)
+		rc = opal_int_get_xirr(&xirr, false);
+	else
+		xirr = __raw_rm_readl(xics_phys + XICS_XIRR);
+	if (rc < 0)
+		return 1;
+
+	/*
+	 * Save XIRR for later. Since we get control in reverse endian
+	 * on LE systems, save it byte reversed and fetch it back in
+	 * host endian. Note that xirr is the value read from the
+	 * XIRR register, while h_xirr is the host endian version.
+	 */
+	h_xirr = be32_to_cpu(xirr);
+	local_paca->kvm_hstate.saved_xirr = h_xirr;
+	xisr = h_xirr & 0xffffff;
+	/*
+	 * Ensure that the store/load complete to guarantee all side
+	 * effects of loading from XIRR has completed
+	 */
+	smp_mb();
+
+	/* if nothing pending in the ICP */
+	if (!xisr)
+		return 0;
+
+	/* We found something in the ICP...
+	 *
+	 * If it is an IPI, clear the MFRR and EOI it.
+	 */
+	if (xisr == XICS_IPI) {
+		rc = 0;
+		if (xics_phys) {
+			__raw_rm_writeb(0xff, xics_phys + XICS_MFRR);
+			__raw_rm_writel(xirr, xics_phys + XICS_XIRR);
+		} else {
+			opal_int_set_mfrr(hard_smp_processor_id(), 0xff);
+			rc = opal_int_eoi(h_xirr);
+		}
+		/* If rc > 0, there is another interrupt pending */
+		*again = rc > 0;
+
+		/*
+		 * Need to ensure side effects of above stores
+		 * complete before proceeding.
+		 */
+		smp_mb();
+
+		/*
+		 * We need to re-check host IPI now in case it got set in the
+		 * meantime. If it's clear, we bounce the interrupt to the
+		 * guest
+		 */
+		host_ipi = local_paca->kvm_hstate.host_ipi;
+		if (unlikely(host_ipi != 0)) {
+			/* We raced with the host,
+			 * we need to resend that IPI, bummer
+			 */
+			if (xics_phys)
+				__raw_rm_writeb(IPI_PRIORITY,
+						xics_phys + XICS_MFRR);
+			else
+				opal_int_set_mfrr(hard_smp_processor_id(),
+						  IPI_PRIORITY);
+			/* Let side effects complete */
+			smp_mb();
+			return 1;
+		}
+
+		/* OK, it's an IPI for us */
+		local_paca->kvm_hstate.saved_xirr = 0;
+		return -1;
+	}
+
+	return kvmppc_check_passthru(xisr, xirr, again);
+}
+
+#ifdef CONFIG_KVM_XICS
+static inline bool is_rm(void)
+{
+	return !(mfmsr() & MSR_DR);
+}
+
+unsigned long kvmppc_rm_h_xirr(struct kvm_vcpu *vcpu)
+{
+	if (!kvmppc_xics_enabled(vcpu))
+		return H_TOO_HARD;
+	if (xive_enabled()) {
+		if (is_rm())
+			return xive_rm_h_xirr(vcpu);
+		if (unlikely(!__xive_vm_h_xirr))
+			return H_NOT_AVAILABLE;
+		return __xive_vm_h_xirr(vcpu);
+	} else
+		return xics_rm_h_xirr(vcpu);
+}
+
+unsigned long kvmppc_rm_h_xirr_x(struct kvm_vcpu *vcpu)
+{
+	if (!kvmppc_xics_enabled(vcpu))
+		return H_TOO_HARD;
+	vcpu->arch.regs.gpr[5] = get_tb();
+	if (xive_enabled()) {
+		if (is_rm())
+			return xive_rm_h_xirr(vcpu);
+		if (unlikely(!__xive_vm_h_xirr))
+			return H_NOT_AVAILABLE;
+		return __xive_vm_h_xirr(vcpu);
+	} else
+		return xics_rm_h_xirr(vcpu);
+}
+
+unsigned long kvmppc_rm_h_ipoll(struct kvm_vcpu *vcpu, unsigned long server)
+{
+	if (!kvmppc_xics_enabled(vcpu))
+		return H_TOO_HARD;
+	if (xive_enabled()) {
+		if (is_rm())
+			return xive_rm_h_ipoll(vcpu, server);
+		if (unlikely(!__xive_vm_h_ipoll))
+			return H_NOT_AVAILABLE;
+		return __xive_vm_h_ipoll(vcpu, server);
+	} else
+		return H_TOO_HARD;
+}
+
+int kvmppc_rm_h_ipi(struct kvm_vcpu *vcpu, unsigned long server,
+		    unsigned long mfrr)
+{
+	if (!kvmppc_xics_enabled(vcpu))
+		return H_TOO_HARD;
+	if (xive_enabled()) {
+		if (is_rm())
+			return xive_rm_h_ipi(vcpu, server, mfrr);
+		if (unlikely(!__xive_vm_h_ipi))
+			return H_NOT_AVAILABLE;
+		return __xive_vm_h_ipi(vcpu, server, mfrr);
+	} else
+		return xics_rm_h_ipi(vcpu, server, mfrr);
+}
+
+int kvmppc_rm_h_cppr(struct kvm_vcpu *vcpu, unsigned long cppr)
+{
+	if (!kvmppc_xics_enabled(vcpu))
+		return H_TOO_HARD;
+	if (xive_enabled()) {
+		if (is_rm())
+			return xive_rm_h_cppr(vcpu, cppr);
+		if (unlikely(!__xive_vm_h_cppr))
+			return H_NOT_AVAILABLE;
+		return __xive_vm_h_cppr(vcpu, cppr);
+	} else
+		return xics_rm_h_cppr(vcpu, cppr);
+}
+
+int kvmppc_rm_h_eoi(struct kvm_vcpu *vcpu, unsigned long xirr)
+{
+	if (!kvmppc_xics_enabled(vcpu))
+		return H_TOO_HARD;
+	if (xive_enabled()) {
+		if (is_rm())
+			return xive_rm_h_eoi(vcpu, xirr);
+		if (unlikely(!__xive_vm_h_eoi))
+			return H_NOT_AVAILABLE;
+		return __xive_vm_h_eoi(vcpu, xirr);
+	} else
+		return xics_rm_h_eoi(vcpu, xirr);
+}
+#endif /* CONFIG_KVM_XICS */
+
+void kvmppc_bad_interrupt(struct pt_regs *regs)
+{
+	/*
+	 * 100 could happen at any time, 200 can happen due to invalid real
+	 * address access for example (or any time due to a hardware problem).
+	 */
+	if (TRAP(regs) == 0x100) {
+		get_paca()->in_nmi++;
+		system_reset_exception(regs);
+		get_paca()->in_nmi--;
+	} else if (TRAP(regs) == 0x200) {
+		machine_check_exception(regs);
+	} else {
+		die("Bad interrupt in KVM entry/exit code", regs, SIGABRT);
+	}
+	panic("Bad KVM trap");
+}
+
+/*
+ * Functions used to switch LPCR HR and UPRT bits on all threads
+ * when entering and exiting HPT guests on a radix host.
+ */
+
+#define PHASE_REALMODE		1	/* in real mode */
+#define PHASE_SET_LPCR		2	/* have set LPCR */
+#define PHASE_OUT_OF_GUEST	4	/* have finished executing in guest */
+#define PHASE_RESET_LPCR	8	/* have reset LPCR to host value */
+
+#define ALL(p)		(((p) << 24) | ((p) << 16) | ((p) << 8) | (p))
+
+static void wait_for_sync(struct kvm_split_mode *sip, int phase)
+{
+	int thr = local_paca->kvm_hstate.tid;
+
+	sip->lpcr_sync.phase[thr] |= phase;
+	phase = ALL(phase);
+	while ((sip->lpcr_sync.allphases & phase) != phase) {
+		HMT_low();
+		barrier();
+	}
+	HMT_medium();
+}
+
+void kvmhv_p9_set_lpcr(struct kvm_split_mode *sip)
+{
+	unsigned long rb, set;
+
+	/* wait for every other thread to get to real mode */
+	wait_for_sync(sip, PHASE_REALMODE);
+
+	/* Set LPCR and LPIDR */
+	mtspr(SPRN_LPCR, sip->lpcr_req);
+	mtspr(SPRN_LPID, sip->lpidr_req);
+	isync();
+
+	/* Invalidate the TLB on thread 0 */
+	if (local_paca->kvm_hstate.tid == 0) {
+		sip->do_set = 0;
+		asm volatile("ptesync" : : : "memory");
+		for (set = 0; set < POWER9_TLB_SETS_RADIX; ++set) {
+			rb = TLBIEL_INVAL_SET_LPID +
+				(set << TLBIEL_INVAL_SET_SHIFT);
+			asm volatile(PPC_TLBIEL(%0, %1, 0, 0, 0) : :
+				     "r" (rb), "r" (0));
+		}
+		asm volatile("ptesync" : : : "memory");
+	}
+
+	/* indicate that we have done so and wait for others */
+	wait_for_sync(sip, PHASE_SET_LPCR);
+	/* order read of sip->lpcr_sync.allphases vs. sip->do_set */
+	smp_rmb();
+}
+
+/*
+ * Called when a thread that has been in the guest needs
+ * to reload the host LPCR value - but only on POWER9 when
+ * running a HPT guest on a radix host.
+ */
+void kvmhv_p9_restore_lpcr(struct kvm_split_mode *sip)
+{
+	/* we're out of the guest... */
+	wait_for_sync(sip, PHASE_OUT_OF_GUEST);
+
+	mtspr(SPRN_LPID, 0);
+	mtspr(SPRN_LPCR, sip->host_lpcr);
+	isync();
+
+	if (local_paca->kvm_hstate.tid == 0) {
+		sip->do_restore = 0;
+		smp_wmb();	/* order store of do_restore vs. phase */
+	}
+
+	wait_for_sync(sip, PHASE_RESET_LPCR);
+	smp_mb();
+	local_paca->kvm_hstate.kvm_split_mode = NULL;
+}