[mirror_ubuntu-bionic-kernel.git] / arch / powerpc / kvm / book3s_64_vio_hv.c

/*
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * Copyright 2010 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
 * Copyright 2011 David Gibson, IBM Corporation <dwg@au1.ibm.com>
 * Copyright 2016 Alexey Kardashevskiy, IBM Corporation <aik@au1.ibm.com>
 */

#include <linux/types.h>
#include <linux/string.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/highmem.h>
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/hugetlb.h>
#include <linux/list.h>

#include <asm/tlbflush.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
#include <asm/book3s/64/mmu-hash.h>
#include <asm/mmu_context.h>
#include <asm/hvcall.h>
#include <asm/synch.h>
#include <asm/ppc-opcode.h>
#include <asm/kvm_host.h>
#include <asm/udbg.h>
#include <asm/iommu.h>
#include <asm/tce.h>

#ifdef CONFIG_BUG

#define WARN_ON_ONCE_RM(condition)	({			\
	static bool __section(.data.unlikely) __warned;		\
	int __ret_warn_once = !!(condition);			\
								\
	if (unlikely(__ret_warn_once && !__warned)) {		\
		__warned = true;				\
		pr_err("WARN_ON_ONCE_RM: (%s) at %s:%u\n",	\
				__stringify(condition),		\
				__func__, __LINE__);		\
		dump_stack();					\
	}							\
	unlikely(__ret_warn_once);				\
})

#else

#define WARN_ON_ONCE_RM(condition) ({				\
	int __ret_warn_on = !!(condition);			\
	unlikely(__ret_warn_on);				\
})

#endif

#define TCES_PER_PAGE	(PAGE_SIZE / sizeof(u64))

/*
 * Finds a TCE table descriptor by LIOBN.
 *
 * WARNING: This will be called in real or virtual mode on HV KVM and virtual
 *          mode on PR KVM
 */
struct kvmppc_spapr_tce_table *kvmppc_find_table(struct kvm *kvm,
		unsigned long liobn)
{
	struct kvmppc_spapr_tce_table *stt;

	list_for_each_entry_lockless(stt, &kvm->arch.spapr_tce_tables, list)
		if (stt->liobn == liobn)
			return stt;

	return NULL;
}
EXPORT_SYMBOL_GPL(kvmppc_find_table);

/*
 * Validates TCE address.
 * At the moment flags and page mask are validated.
 * As the host kernel does not access those addresses (just puts them
 * to the table and user space is supposed to process them), we can skip
 * checking other things (such as TCE is a guest RAM address or the page
 * was actually allocated).
 *
 * WARNING: This will be called in real-mode on HV KVM and virtual
 *          mode on PR KVM
 */
long kvmppc_tce_validate(struct kvmppc_spapr_tce_table *stt, unsigned long tce)
{
	unsigned long gpa = tce & ~(TCE_PCI_READ | TCE_PCI_WRITE);
	enum dma_data_direction dir = iommu_tce_direction(tce);

	/* Allow userspace to poison TCE table */
	if (dir == DMA_NONE)
		return H_SUCCESS;

	if (iommu_tce_check_gpa(stt->page_shift, gpa))
		return H_PARAMETER;

	return H_SUCCESS;
}
EXPORT_SYMBOL_GPL(kvmppc_tce_validate);

/* Note on the use of page_address() in real mode,
 *
 * It is safe to use page_address() in real mode on ppc64 because
 * page_address() is always defined as lowmem_page_address()
 * which returns __va(PFN_PHYS(page_to_pfn(page))) which is arithmetic
 * operation and does not access page struct.
 *
 * Theoretically page_address() could be defined different
 * but either WANT_PAGE_VIRTUAL or HASHED_PAGE_VIRTUAL
 * would have to be enabled.
 * WANT_PAGE_VIRTUAL is never enabled on ppc32/ppc64,
 * HASHED_PAGE_VIRTUAL could be enabled for ppc32 only and only
 * if CONFIG_HIGHMEM is defined. As CONFIG_SPARSEMEM_VMEMMAP
 * is not expected to be enabled on ppc32, page_address()
 * is safe for ppc32 as well.
 *
 * WARNING: This will be called in real-mode on HV KVM and virtual
 *          mode on PR KVM
 */
static u64 *kvmppc_page_address(struct page *page)
{
#if defined(HASHED_PAGE_VIRTUAL) || defined(WANT_PAGE_VIRTUAL)
#error TODO: fix to avoid page_address() here
#endif
	return (u64 *) page_address(page);
}

/*
 * Handles TCE requests for emulated devices.
 * Puts guest TCE values to the table and expects user space to convert them.
 * Called in both real and virtual modes.
 * Cannot fail so kvmppc_tce_validate must be called before it.
 *
 * WARNING: This will be called in real-mode on HV KVM and virtual
 *          mode on PR KVM
 */
void kvmppc_tce_put(struct kvmppc_spapr_tce_table *stt,
		unsigned long idx, unsigned long tce)
{
	struct page *page;
	u64 *tbl;

	idx -= stt->offset;
	page = stt->pages[idx / TCES_PER_PAGE];
	tbl = kvmppc_page_address(page);

	tbl[idx % TCES_PER_PAGE] = tce;
}
EXPORT_SYMBOL_GPL(kvmppc_tce_put);

long kvmppc_gpa_to_ua(struct kvm *kvm, unsigned long gpa,
		unsigned long *ua, unsigned long **prmap)
{
	unsigned long gfn = gpa >> PAGE_SHIFT;
	struct kvm_memory_slot *memslot;

	memslot = search_memslots(kvm_memslots(kvm), gfn);
	if (!memslot)
		return -EINVAL;

	*ua = __gfn_to_hva_memslot(memslot, gfn) |
		(gpa & ~(PAGE_MASK | TCE_PCI_READ | TCE_PCI_WRITE));

#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
	if (prmap)
		*prmap = &memslot->arch.rmap[gfn - memslot->base_gfn];
#endif

	return 0;
}
EXPORT_SYMBOL_GPL(kvmppc_gpa_to_ua);

#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
static void kvmppc_rm_clear_tce(struct iommu_table *tbl, unsigned long entry)
{
	unsigned long hpa = 0;
	enum dma_data_direction dir = DMA_NONE;

	iommu_tce_xchg_rm(tbl, entry, &hpa, &dir);
}

static long kvmppc_rm_tce_iommu_mapped_dec(struct kvm *kvm,
		struct iommu_table *tbl, unsigned long entry)
{
	struct mm_iommu_table_group_mem_t *mem = NULL;
	const unsigned long pgsize = 1ULL << tbl->it_page_shift;
	unsigned long *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry);

	if (!pua)
		/* it_userspace allocation might be delayed */
		return H_TOO_HARD;

	pua = (void *) vmalloc_to_phys(pua);
	if (WARN_ON_ONCE_RM(!pua))
		return H_HARDWARE;

	mem = mm_iommu_lookup_rm(kvm->mm, *pua, pgsize);
	if (!mem)
		return H_TOO_HARD;

	mm_iommu_mapped_dec(mem);

	*pua = 0;

	return H_SUCCESS;
}

static long kvmppc_rm_tce_iommu_unmap(struct kvm *kvm,
		struct iommu_table *tbl, unsigned long entry)
{
	enum dma_data_direction dir = DMA_NONE;
	unsigned long hpa = 0;
	long ret;

	if (iommu_tce_xchg_rm(tbl, entry, &hpa, &dir))
		/*
		 * real mode xchg can fail if struct page crosses
		 * a page boundary
		 */
		return H_TOO_HARD;

	if (dir == DMA_NONE)
		return H_SUCCESS;

	ret = kvmppc_rm_tce_iommu_mapped_dec(kvm, tbl, entry);
	if (ret)
		iommu_tce_xchg_rm(tbl, entry, &hpa, &dir);

	return ret;
}

static long kvmppc_rm_tce_iommu_map(struct kvm *kvm, struct iommu_table *tbl,
		unsigned long entry, unsigned long ua,
		enum dma_data_direction dir)
{
	long ret;
	unsigned long hpa = 0;
	unsigned long *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry);
	struct mm_iommu_table_group_mem_t *mem;

	if (!pua)
		/* it_userspace allocation might be delayed */
		return H_TOO_HARD;

	mem = mm_iommu_lookup_rm(kvm->mm, ua, 1ULL << tbl->it_page_shift);
	if (!mem)
		return H_TOO_HARD;

	if (WARN_ON_ONCE_RM(mm_iommu_ua_to_hpa_rm(mem, ua, &hpa)))
		return H_HARDWARE;

	pua = (void *) vmalloc_to_phys(pua);
	if (WARN_ON_ONCE_RM(!pua))
		return H_HARDWARE;

	if (WARN_ON_ONCE_RM(mm_iommu_mapped_inc(mem)))
		return H_CLOSED;

	ret = iommu_tce_xchg_rm(tbl, entry, &hpa, &dir);
	if (ret) {
		mm_iommu_mapped_dec(mem);
		/*
		 * real mode xchg can fail if struct page crosses
		 * a page boundary
		 */
		return H_TOO_HARD;
	}

	if (dir != DMA_NONE)
		kvmppc_rm_tce_iommu_mapped_dec(kvm, tbl, entry);

	*pua = ua;

	return 0;
}

long kvmppc_rm_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
		unsigned long ioba, unsigned long tce)
{
	struct kvmppc_spapr_tce_table *stt;
	long ret;
	struct kvmppc_spapr_tce_iommu_table *stit;
	unsigned long entry, ua = 0;
	enum dma_data_direction dir;

	/* udbg_printf("H_PUT_TCE(): liobn=0x%lx ioba=0x%lx, tce=0x%lx\n", */
	/* 	    liobn, ioba, tce); */

	/* For radix, we might be in virtual mode, so punt */
	if (kvm_is_radix(vcpu->kvm))
		return H_TOO_HARD;

	stt = kvmppc_find_table(vcpu->kvm, liobn);
	if (!stt)
		return H_TOO_HARD;

	ret = kvmppc_ioba_validate(stt, ioba, 1);
	if (ret != H_SUCCESS)
		return ret;

	ret = kvmppc_tce_validate(stt, tce);
	if (ret != H_SUCCESS)
		return ret;

	dir = iommu_tce_direction(tce);
	if ((dir != DMA_NONE) && kvmppc_gpa_to_ua(vcpu->kvm,
			tce & ~(TCE_PCI_READ | TCE_PCI_WRITE), &ua, NULL))
		return H_PARAMETER;

	entry = ioba >> stt->page_shift;

	list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
		if (dir == DMA_NONE)
			ret = kvmppc_rm_tce_iommu_unmap(vcpu->kvm,
					stit->tbl, entry);
		else
			ret = kvmppc_rm_tce_iommu_map(vcpu->kvm,
					stit->tbl, entry, ua, dir);

		if (ret == H_SUCCESS)
			continue;

		if (ret == H_TOO_HARD)
			return ret;

		WARN_ON_ONCE_RM(1);
		kvmppc_rm_clear_tce(stit->tbl, entry);
	}

	kvmppc_tce_put(stt, entry, tce);

	return H_SUCCESS;
}

static long kvmppc_rm_ua_to_hpa(struct kvm_vcpu *vcpu,
		unsigned long ua, unsigned long *phpa)
{
	pte_t *ptep, pte;
	unsigned shift = 0;

	ptep = __find_linux_pte_or_hugepte(vcpu->arch.pgdir, ua, NULL, &shift);
	if (!ptep || !pte_present(*ptep))
		return -ENXIO;
	pte = *ptep;

	if (!shift)
		shift = PAGE_SHIFT;

	/* Avoid handling anything potentially complicated in realmode */
	if (shift > PAGE_SHIFT)
		return -EAGAIN;

	if (!pte_young(pte))
		return -EAGAIN;

	*phpa = (pte_pfn(pte) << PAGE_SHIFT) | (ua & ((1ULL << shift) - 1)) |
			(ua & ~PAGE_MASK);

	return 0;
}

long kvmppc_rm_h_put_tce_indirect(struct kvm_vcpu *vcpu,
		unsigned long liobn, unsigned long ioba,
		unsigned long tce_list,	unsigned long npages)
{
	struct kvmppc_spapr_tce_table *stt;
	long i, ret = H_SUCCESS;
	unsigned long tces, entry, ua = 0;
	unsigned long *rmap = NULL;
	bool prereg = false;
	struct kvmppc_spapr_tce_iommu_table *stit;

	/* For radix, we might be in virtual mode, so punt */
	if (kvm_is_radix(vcpu->kvm))
		return H_TOO_HARD;

	stt = kvmppc_find_table(vcpu->kvm, liobn);
	if (!stt)
		return H_TOO_HARD;

	entry = ioba >> stt->page_shift;
	/*
	 * The spec says that the maximum size of the list is 512 TCEs
	 * so the whole table addressed resides in 4K page
	 */
	if (npages > 512)
		return H_PARAMETER;

	if (tce_list & (SZ_4K - 1))
		return H_PARAMETER;

	ret = kvmppc_ioba_validate(stt, ioba, npages);
	if (ret != H_SUCCESS)
		return ret;

	if (mm_iommu_preregistered(vcpu->kvm->mm)) {
		/*
		 * We get here if guest memory was pre-registered which
		 * is normally VFIO case and gpa->hpa translation does not
		 * depend on hpt.
		 */
		struct mm_iommu_table_group_mem_t *mem;

		if (kvmppc_gpa_to_ua(vcpu->kvm, tce_list, &ua, NULL))
			return H_TOO_HARD;

		mem = mm_iommu_lookup_rm(vcpu->kvm->mm, ua, IOMMU_PAGE_SIZE_4K);
		if (mem)
			prereg = mm_iommu_ua_to_hpa_rm(mem, ua, &tces) == 0;
	}

	if (!prereg) {
		/*
		 * This is usually a case of a guest with emulated devices only
		 * when TCE list is not in preregistered memory.
		 * We do not require memory to be preregistered in this case
		 * so lock rmap and do __find_linux_pte_or_hugepte().
		 */
		if (kvmppc_gpa_to_ua(vcpu->kvm, tce_list, &ua, &rmap))
			return H_TOO_HARD;

		rmap = (void *) vmalloc_to_phys(rmap);
		if (WARN_ON_ONCE_RM(!rmap))
			return H_HARDWARE;

		/*
		 * Synchronize with the MMU notifier callbacks in
		 * book3s_64_mmu_hv.c (kvm_unmap_hva_hv etc.).
		 * While we have the rmap lock, code running on other CPUs
		 * cannot finish unmapping the host real page that backs
		 * this guest real page, so we are OK to access the host
		 * real page.
		 */
		lock_rmap(rmap);
		if (kvmppc_rm_ua_to_hpa(vcpu, ua, &tces)) {
			ret = H_TOO_HARD;
			goto unlock_exit;
		}
	}

	for (i = 0; i < npages; ++i) {
		unsigned long tce = be64_to_cpu(((u64 *)tces)[i]);

		ret = kvmppc_tce_validate(stt, tce);
		if (ret != H_SUCCESS)
			goto unlock_exit;

		ua = 0;
		if (kvmppc_gpa_to_ua(vcpu->kvm,
				tce & ~(TCE_PCI_READ | TCE_PCI_WRITE),
				&ua, NULL))
			return H_PARAMETER;

		list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
			ret = kvmppc_rm_tce_iommu_map(vcpu->kvm,
					stit->tbl, entry + i, ua,
					iommu_tce_direction(tce));

			if (ret == H_SUCCESS)
				continue;

			if (ret == H_TOO_HARD)
				goto unlock_exit;

			WARN_ON_ONCE_RM(1);
			kvmppc_rm_clear_tce(stit->tbl, entry);
		}

		kvmppc_tce_put(stt, entry + i, tce);
	}

unlock_exit:
	if (rmap)
		unlock_rmap(rmap);

	return ret;
}

long kvmppc_rm_h_stuff_tce(struct kvm_vcpu *vcpu,
		unsigned long liobn, unsigned long ioba,
		unsigned long tce_value, unsigned long npages)
{
	struct kvmppc_spapr_tce_table *stt;
	long i, ret;
	struct kvmppc_spapr_tce_iommu_table *stit;

	/* For radix, we might be in virtual mode, so punt */
	if (kvm_is_radix(vcpu->kvm))
		return H_TOO_HARD;

	stt = kvmppc_find_table(vcpu->kvm, liobn);
	if (!stt)
		return H_TOO_HARD;

	ret = kvmppc_ioba_validate(stt, ioba, npages);
	if (ret != H_SUCCESS)
		return ret;

	/* Check permission bits only to allow userspace poison TCE for debug */
	if (tce_value & (TCE_PCI_WRITE | TCE_PCI_READ))
		return H_PARAMETER;

	list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
		unsigned long entry = ioba >> stit->tbl->it_page_shift;

		for (i = 0; i < npages; ++i) {
			ret = kvmppc_rm_tce_iommu_unmap(vcpu->kvm,
					stit->tbl, entry + i);

			if (ret == H_SUCCESS)
				continue;

			if (ret == H_TOO_HARD)
				return ret;

			WARN_ON_ONCE_RM(1);
			kvmppc_rm_clear_tce(stit->tbl, entry);
		}
	}

	for (i = 0; i < npages; ++i, ioba += (1ULL << stt->page_shift))
		kvmppc_tce_put(stt, ioba >> stt->page_shift, tce_value);

	return H_SUCCESS;
}

/* This can be called in either virtual mode or real mode */
long kvmppc_h_get_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
		      unsigned long ioba)
{
	struct kvmppc_spapr_tce_table *stt;
	long ret;
	unsigned long idx;
	struct page *page;
	u64 *tbl;

	stt = kvmppc_find_table(vcpu->kvm, liobn);
	if (!stt)
		return H_TOO_HARD;

	ret = kvmppc_ioba_validate(stt, ioba, 1);
	if (ret != H_SUCCESS)
		return ret;

	idx = (ioba >> stt->page_shift) - stt->offset;
	page = stt->pages[idx / TCES_PER_PAGE];
	tbl = (u64 *)page_address(page);

	vcpu->arch.gpr[4] = tbl[idx % TCES_PER_PAGE];

	return H_SUCCESS;
}
EXPORT_SYMBOL_GPL(kvmppc_h_get_tce);

#endif /* KVM_BOOK3S_HV_POSSIBLE */
Commit	Line	Data
54738c09 DG	1	/*
	2	* This program is free software; you can redistribute it and/or modify
	3	* it under the terms of the GNU General Public License, version 2, as
	4	* published by the Free Software Foundation.
	5	*
	6	* This program is distributed in the hope that it will be useful,
	7	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	8	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	9	* GNU General Public License for more details.
	10	*
	11	* You should have received a copy of the GNU General Public License
	12	* along with this program; if not, write to the Free Software
	13	* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
	14	*
	15	* Copyright 2010 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
	16	* Copyright 2011 David Gibson, IBM Corporation <dwg@au1.ibm.com>
d3695aa4	17	* Copyright 2016 Alexey Kardashevskiy, IBM Corporation <aik@au1.ibm.com>
54738c09 DG	18	*/
	19
	20	#include <linux/types.h>
	21	#include <linux/string.h>
	22	#include <linux/kvm.h>
	23	#include <linux/kvm_host.h>
	24	#include <linux/highmem.h>
	25	#include <linux/gfp.h>
	26	#include <linux/slab.h>
	27	#include <linux/hugetlb.h>
	28	#include <linux/list.h>
	29
	30	#include <asm/tlbflush.h>
	31	#include <asm/kvm_ppc.h>
	32	#include <asm/kvm_book3s.h>
f64e8084	33	#include <asm/book3s/64/mmu-hash.h>
d3695aa4	34	#include <asm/mmu_context.h>
54738c09 DG	35	#include <asm/hvcall.h>
	36	#include <asm/synch.h>
	37	#include <asm/ppc-opcode.h>
	38	#include <asm/kvm_host.h>
	39	#include <asm/udbg.h>
fcbb2ce6	40	#include <asm/iommu.h>
5ee7af18	41	#include <asm/tce.h>
54738c09	42
121f80ba AK	43	#ifdef CONFIG_BUG
	44
	45	#define WARN_ON_ONCE_RM(condition) ({ \
	46	static bool __section(.data.unlikely) __warned; \
	47	int __ret_warn_once = !!(condition); \
	48	\
	49	if (unlikely(__ret_warn_once && !__warned)) { \
	50	__warned = true; \
	51	pr_err("WARN_ON_ONCE_RM: (%s) at %s:%u\n", \
	52	__stringify(condition), \
	53	__func__, __LINE__); \
	54	dump_stack(); \
	55	} \
	56	unlikely(__ret_warn_once); \
	57	})
	58
	59	#else
	60
	61	#define WARN_ON_ONCE_RM(condition) ({ \
	62	int __ret_warn_on = !!(condition); \
	63	unlikely(__ret_warn_on); \
	64	})
	65
	66	#endif
	67
54738c09 DG	68	#define TCES_PER_PAGE (PAGE_SIZE / sizeof(u64))
54738c09 DG	69
fcbb2ce6 AK	70	/*
	71	* Finds a TCE table descriptor by LIOBN.
	72	*
	73	* WARNING: This will be called in real or virtual mode on HV KVM and virtual
	74	* mode on PR KVM
	75	*/
503bfcbe	76	struct kvmppc_spapr_tce_table kvmppc_find_table(struct kvm kvm,
fcbb2ce6 AK	77	unsigned long liobn)
fcbb2ce6 AK	78	{
fcbb2ce6 AK	79	struct kvmppc_spapr_tce_table *stt;
fcbb2ce6 AK	80
366baf28	81	list_for_each_entry_lockless(stt, &kvm->arch.spapr_tce_tables, list)
fcbb2ce6 AK	82	if (stt->liobn == liobn)
	83	return stt;
	84
	85	return NULL;
	86	}
d3695aa4	87	EXPORT_SYMBOL_GPL(kvmppc_find_table);
fcbb2ce6	88
5ee7af18 AK	89	/*
	90	* Validates TCE address.
	91	* At the moment flags and page mask are validated.
	92	* As the host kernel does not access those addresses (just puts them
	93	* to the table and user space is supposed to process them), we can skip
	94	* checking other things (such as TCE is a guest RAM address or the page
	95	* was actually allocated).
	96	*
	97	* WARNING: This will be called in real-mode on HV KVM and virtual
	98	* mode on PR KVM
	99	*/
	100	long kvmppc_tce_validate(struct kvmppc_spapr_tce_table *stt, unsigned long tce)
	101	{
b1af23d8 AK	102	unsigned long gpa = tce & ~(TCE_PCI_READ \| TCE_PCI_WRITE);
	103	enum dma_data_direction dir = iommu_tce_direction(tce);
	104
	105	/* Allow userspace to poison TCE table */
	106	if (dir == DMA_NONE)
	107	return H_SUCCESS;
5ee7af18	108
b1af23d8	109	if (iommu_tce_check_gpa(stt->page_shift, gpa))
5ee7af18 AK	110	return H_PARAMETER;
	111
	112	return H_SUCCESS;
	113	}
	114	EXPORT_SYMBOL_GPL(kvmppc_tce_validate);
	115
	116	/* Note on the use of page_address() in real mode,
	117	*
	118	* It is safe to use page_address() in real mode on ppc64 because
	119	* page_address() is always defined as lowmem_page_address()
	120	* which returns __va(PFN_PHYS(page_to_pfn(page))) which is arithmetic
	121	* operation and does not access page struct.
	122	*
	123	* Theoretically page_address() could be defined different
	124	* but either WANT_PAGE_VIRTUAL or HASHED_PAGE_VIRTUAL
	125	* would have to be enabled.
	126	* WANT_PAGE_VIRTUAL is never enabled on ppc32/ppc64,
	127	* HASHED_PAGE_VIRTUAL could be enabled for ppc32 only and only
	128	* if CONFIG_HIGHMEM is defined. As CONFIG_SPARSEMEM_VMEMMAP
	129	* is not expected to be enabled on ppc32, page_address()
	130	* is safe for ppc32 as well.
	131	*
	132	* WARNING: This will be called in real-mode on HV KVM and virtual
	133	* mode on PR KVM
	134	*/
	135	static u64 kvmppc_page_address(struct page page)
	136	{
	137	#if defined(HASHED_PAGE_VIRTUAL) \|\| defined(WANT_PAGE_VIRTUAL)
	138	#error TODO: fix to avoid page_address() here
	139	#endif
	140	return (u64 *) page_address(page);
	141	}
	142
	143	/*
	144	* Handles TCE requests for emulated devices.
	145	* Puts guest TCE values to the table and expects user space to convert them.
	146	* Called in both real and virtual modes.
	147	* Cannot fail so kvmppc_tce_validate must be called before it.
	148	*
	149	* WARNING: This will be called in real-mode on HV KVM and virtual
	150	* mode on PR KVM
	151	*/
	152	void kvmppc_tce_put(struct kvmppc_spapr_tce_table *stt,
	153	unsigned long idx, unsigned long tce)
	154	{
	155	struct page *page;
	156	u64 *tbl;
	157
14f853f1	158	idx -= stt->offset;
5ee7af18 AK	159	page = stt->pages[idx / TCES_PER_PAGE];
	160	tbl = kvmppc_page_address(page);
	161
	162	tbl[idx % TCES_PER_PAGE] = tce;
	163	}
	164	EXPORT_SYMBOL_GPL(kvmppc_tce_put);
fcbb2ce6	165
d3695aa4 AK	166	long kvmppc_gpa_to_ua(struct kvm *kvm, unsigned long gpa,
	167	unsigned long ua, unsigned long *prmap)
	168	{
	169	unsigned long gfn = gpa >> PAGE_SHIFT;
	170	struct kvm_memory_slot *memslot;
	171
	172	memslot = search_memslots(kvm_memslots(kvm), gfn);
	173	if (!memslot)
	174	return -EINVAL;
	175
	176	*ua = __gfn_to_hva_memslot(memslot, gfn) \|
	177	(gpa & ~(PAGE_MASK \| TCE_PCI_READ \| TCE_PCI_WRITE));
	178
	179	#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
	180	if (prmap)
	181	*prmap = &memslot->arch.rmap[gfn - memslot->base_gfn];
	182	#endif
	183
	184	return 0;
	185	}
	186	EXPORT_SYMBOL_GPL(kvmppc_gpa_to_ua);
	187
	188	#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
121f80ba AK	189	static void kvmppc_rm_clear_tce(struct iommu_table *tbl, unsigned long entry)
	190	{
	191	unsigned long hpa = 0;
	192	enum dma_data_direction dir = DMA_NONE;
	193
	194	iommu_tce_xchg_rm(tbl, entry, &hpa, &dir);
	195	}
	196
	197	static long kvmppc_rm_tce_iommu_mapped_dec(struct kvm *kvm,
	198	struct iommu_table *tbl, unsigned long entry)
	199	{
	200	struct mm_iommu_table_group_mem_t *mem = NULL;
	201	const unsigned long pgsize = 1ULL << tbl->it_page_shift;
	202	unsigned long *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry);
	203
	204	if (!pua)
	205	/* it_userspace allocation might be delayed */
	206	return H_TOO_HARD;
	207
	208	pua = (void *) vmalloc_to_phys(pua);
	209	if (WARN_ON_ONCE_RM(!pua))
	210	return H_HARDWARE;
	211
	212	mem = mm_iommu_lookup_rm(kvm->mm, *pua, pgsize);
	213	if (!mem)
	214	return H_TOO_HARD;
	215
	216	mm_iommu_mapped_dec(mem);
	217
	218	*pua = 0;
	219
	220	return H_SUCCESS;
	221	}
	222
	223	static long kvmppc_rm_tce_iommu_unmap(struct kvm *kvm,
	224	struct iommu_table *tbl, unsigned long entry)
	225	{
	226	enum dma_data_direction dir = DMA_NONE;
	227	unsigned long hpa = 0;
	228	long ret;
	229
	230	if (iommu_tce_xchg_rm(tbl, entry, &hpa, &dir))
	231	/*
	232	* real mode xchg can fail if struct page crosses
	233	* a page boundary
	234	*/
	235	return H_TOO_HARD;
	236
	237	if (dir == DMA_NONE)
	238	return H_SUCCESS;
	239
	240	ret = kvmppc_rm_tce_iommu_mapped_dec(kvm, tbl, entry);
	241	if (ret)
	242	iommu_tce_xchg_rm(tbl, entry, &hpa, &dir);
	243
	244	return ret;
	245	}
	246
	247	static long kvmppc_rm_tce_iommu_map(struct kvm kvm, struct iommu_table tbl,
	248	unsigned long entry, unsigned long ua,
	249	enum dma_data_direction dir)
	250	{
	251	long ret;
	252	unsigned long hpa = 0;
253	unsigned long *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry);
254	struct mm_iommu_table_group_mem_t *mem;
255
256	if (!pua)
257	/* it_userspace allocation might be delayed */
258	return H_TOO_HARD;
259
260	mem = mm_iommu_lookup_rm(kvm->mm, ua, 1ULL << tbl->it_page_shift);
261	if (!mem)
262	return H_TOO_HARD;
263
264	if (WARN_ON_ONCE_RM(mm_iommu_ua_to_hpa_rm(mem, ua, &hpa)))
265	return H_HARDWARE;
266
267	pua = (void *) vmalloc_to_phys(pua);
268	if (WARN_ON_ONCE_RM(!pua))
269	return H_HARDWARE;
270
271	if (WARN_ON_ONCE_RM(mm_iommu_mapped_inc(mem)))
272	return H_CLOSED;
273
274	ret = iommu_tce_xchg_rm(tbl, entry, &hpa, &dir);
275	if (ret) {
276	mm_iommu_mapped_dec(mem);
277	/*
278	* real mode xchg can fail if struct page crosses
279	* a page boundary
280	*/
281	return H_TOO_HARD;
282	}
283
284	if (dir != DMA_NONE)
285	kvmppc_rm_tce_iommu_mapped_dec(kvm, tbl, entry);
286
287	*pua = ua;
288
289	return 0;
290	}
291
31217db7 AK	292	long kvmppc_rm_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
31217db7 AK	293	unsigned long ioba, unsigned long tce)
54738c09	294	{
503bfcbe	295	struct kvmppc_spapr_tce_table *stt;
fcbb2ce6	296	long ret;
121f80ba AK	297	struct kvmppc_spapr_tce_iommu_table *stit;
	298	unsigned long entry, ua = 0;
	299	enum dma_data_direction dir;
54738c09 DG	300
	301	/* udbg_printf("H_PUT_TCE(): liobn=0x%lx ioba=0x%lx, tce=0x%lx\n", */
	302	/* liobn, ioba, tce); */
	303
acde2572 PM	304	/* For radix, we might be in virtual mode, so punt */
	305	if (kvm_is_radix(vcpu->kvm))
	306	return H_TOO_HARD;
	307
503bfcbe	308	stt = kvmppc_find_table(vcpu->kvm, liobn);
fcbb2ce6 AK	309	if (!stt)
	310	return H_TOO_HARD;
	311
	312	ret = kvmppc_ioba_validate(stt, ioba, 1);
	313	if (ret != H_SUCCESS)
	314	return ret;
	315
5ee7af18 AK	316	ret = kvmppc_tce_validate(stt, tce);
	317	if (ret != H_SUCCESS)
	318	return ret;
fcbb2ce6	319
121f80ba AK	320	dir = iommu_tce_direction(tce);
	321	if ((dir != DMA_NONE) && kvmppc_gpa_to_ua(vcpu->kvm,
	322	tce & ~(TCE_PCI_READ \| TCE_PCI_WRITE), &ua, NULL))
	323	return H_PARAMETER;
	324
	325	entry = ioba >> stt->page_shift;
	326
	327	list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
	328	if (dir == DMA_NONE)
	329	ret = kvmppc_rm_tce_iommu_unmap(vcpu->kvm,
	330	stit->tbl, entry);
	331	else
	332	ret = kvmppc_rm_tce_iommu_map(vcpu->kvm,
	333	stit->tbl, entry, ua, dir);
	334
	335	if (ret == H_SUCCESS)
	336	continue;
	337
	338	if (ret == H_TOO_HARD)
	339	return ret;
	340
	341	WARN_ON_ONCE_RM(1);
	342	kvmppc_rm_clear_tce(stit->tbl, entry);
	343	}
	344
	345	kvmppc_tce_put(stt, entry, tce);
fcbb2ce6 AK	346
fcbb2ce6 AK	347	return H_SUCCESS;
54738c09	348	}
69e9fbb2	349
d3695aa4 AK	350	static long kvmppc_rm_ua_to_hpa(struct kvm_vcpu *vcpu,
	351	unsigned long ua, unsigned long *phpa)
	352	{
	353	pte_t *ptep, pte;
	354	unsigned shift = 0;
	355
	356	ptep = __find_linux_pte_or_hugepte(vcpu->arch.pgdir, ua, NULL, &shift);
	357	if (!ptep \|\| !pte_present(*ptep))
	358	return -ENXIO;
	359	pte = *ptep;
	360
	361	if (!shift)
	362	shift = PAGE_SHIFT;
	363
	364	/* Avoid handling anything potentially complicated in realmode */
	365	if (shift > PAGE_SHIFT)
	366	return -EAGAIN;
	367
	368	if (!pte_young(pte))
	369	return -EAGAIN;
	370
	371	*phpa = (pte_pfn(pte) << PAGE_SHIFT) \| (ua & ((1ULL << shift) - 1)) \|
	372	(ua & ~PAGE_MASK);
	373
	374	return 0;
	375	}
	376
	377	long kvmppc_rm_h_put_tce_indirect(struct kvm_vcpu *vcpu,
	378	unsigned long liobn, unsigned long ioba,
	379	unsigned long tce_list, unsigned long npages)
	380	{
	381	struct kvmppc_spapr_tce_table *stt;
	382	long i, ret = H_SUCCESS;
	383	unsigned long tces, entry, ua = 0;
	384	unsigned long *rmap = NULL;
da6f59e1	385	bool prereg = false;
121f80ba	386	struct kvmppc_spapr_tce_iommu_table *stit;
d3695aa4	387
acde2572 PM	388	/* For radix, we might be in virtual mode, so punt */
	389	if (kvm_is_radix(vcpu->kvm))
	390	return H_TOO_HARD;
	391
503bfcbe	392	stt = kvmppc_find_table(vcpu->kvm, liobn);
d3695aa4 AK	393	if (!stt)
	394	return H_TOO_HARD;
	395
fe26e527	396	entry = ioba >> stt->page_shift;
d3695aa4 AK	397	/*
	398	* The spec says that the maximum size of the list is 512 TCEs
	399	* so the whole table addressed resides in 4K page
	400	*/
	401	if (npages > 512)
	402	return H_PARAMETER;
	403
	404	if (tce_list & (SZ_4K - 1))
	405	return H_PARAMETER;
	406
	407	ret = kvmppc_ioba_validate(stt, ioba, npages);
	408	if (ret != H_SUCCESS)
	409	return ret;
	410
da6f59e1 AK	411	if (mm_iommu_preregistered(vcpu->kvm->mm)) {
	412	/*
	413	* We get here if guest memory was pre-registered which
	414	* is normally VFIO case and gpa->hpa translation does not
	415	* depend on hpt.
	416	*/
	417	struct mm_iommu_table_group_mem_t *mem;
d3695aa4	418
da6f59e1 AK	419	if (kvmppc_gpa_to_ua(vcpu->kvm, tce_list, &ua, NULL))
da6f59e1 AK	420	return H_TOO_HARD;
d3695aa4	421
da6f59e1 AK	422	mem = mm_iommu_lookup_rm(vcpu->kvm->mm, ua, IOMMU_PAGE_SIZE_4K);
	423	if (mem)
	424	prereg = mm_iommu_ua_to_hpa_rm(mem, ua, &tces) == 0;
	425	}
	426
	427	if (!prereg) {
	428	/*
	429	* This is usually a case of a guest with emulated devices only
	430	* when TCE list is not in preregistered memory.
	431	* We do not require memory to be preregistered in this case
	432	* so lock rmap and do __find_linux_pte_or_hugepte().
	433	*/
	434	if (kvmppc_gpa_to_ua(vcpu->kvm, tce_list, &ua, &rmap))
	435	return H_TOO_HARD;
	436
	437	rmap = (void *) vmalloc_to_phys(rmap);
121f80ba AK	438	if (WARN_ON_ONCE_RM(!rmap))
121f80ba AK	439	return H_HARDWARE;
da6f59e1 AK	440
	441	/*
	442	* Synchronize with the MMU notifier callbacks in
	443	* book3s_64_mmu_hv.c (kvm_unmap_hva_hv etc.).
	444	* While we have the rmap lock, code running on other CPUs
	445	* cannot finish unmapping the host real page that backs
	446	* this guest real page, so we are OK to access the host
	447	* real page.
	448	*/
	449	lock_rmap(rmap);
	450	if (kvmppc_rm_ua_to_hpa(vcpu, ua, &tces)) {
	451	ret = H_TOO_HARD;
	452	goto unlock_exit;
	453	}
d3695aa4 AK	454	}
	455
	456	for (i = 0; i < npages; ++i) {
	457	unsigned long tce = be64_to_cpu(((u64 *)tces)[i]);
	458
	459	ret = kvmppc_tce_validate(stt, tce);
	460	if (ret != H_SUCCESS)
	461	goto unlock_exit;
	462
121f80ba AK	463	ua = 0;
	464	if (kvmppc_gpa_to_ua(vcpu->kvm,
	465	tce & ~(TCE_PCI_READ \| TCE_PCI_WRITE),
	466	&ua, NULL))
	467	return H_PARAMETER;
	468
	469	list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
	470	ret = kvmppc_rm_tce_iommu_map(vcpu->kvm,
	471	stit->tbl, entry + i, ua,
	472	iommu_tce_direction(tce));
	473
	474	if (ret == H_SUCCESS)
	475	continue;
	476
	477	if (ret == H_TOO_HARD)
	478	goto unlock_exit;
	479
	480	WARN_ON_ONCE_RM(1);
	481	kvmppc_rm_clear_tce(stit->tbl, entry);
	482	}
	483
d3695aa4 AK	484	kvmppc_tce_put(stt, entry + i, tce);
	485	}
	486
	487	unlock_exit:
da6f59e1 AK	488	if (rmap)
da6f59e1 AK	489	unlock_rmap(rmap);
d3695aa4 AK	490
	491	return ret;
	492	}
	493
31217db7	494	long kvmppc_rm_h_stuff_tce(struct kvm_vcpu *vcpu,
d3695aa4 AK	495	unsigned long liobn, unsigned long ioba,
	496	unsigned long tce_value, unsigned long npages)
	497	{
	498	struct kvmppc_spapr_tce_table *stt;
	499	long i, ret;
121f80ba	500	struct kvmppc_spapr_tce_iommu_table *stit;
d3695aa4	501
acde2572 PM	502	/* For radix, we might be in virtual mode, so punt */
	503	if (kvm_is_radix(vcpu->kvm))
	504	return H_TOO_HARD;
	505
503bfcbe	506	stt = kvmppc_find_table(vcpu->kvm, liobn);
d3695aa4 AK	507	if (!stt)
	508	return H_TOO_HARD;
	509
	510	ret = kvmppc_ioba_validate(stt, ioba, npages);
	511	if (ret != H_SUCCESS)
	512	return ret;
	513
	514	/* Check permission bits only to allow userspace poison TCE for debug */
	515	if (tce_value & (TCE_PCI_WRITE \| TCE_PCI_READ))
	516	return H_PARAMETER;
	517
121f80ba AK	518	list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
	519	unsigned long entry = ioba >> stit->tbl->it_page_shift;
	520
	521	for (i = 0; i < npages; ++i) {
	522	ret = kvmppc_rm_tce_iommu_unmap(vcpu->kvm,
	523	stit->tbl, entry + i);
	524
	525	if (ret == H_SUCCESS)
	526	continue;
	527
	528	if (ret == H_TOO_HARD)
	529	return ret;
	530
	531	WARN_ON_ONCE_RM(1);
	532	kvmppc_rm_clear_tce(stit->tbl, entry);
	533	}
	534	}
	535
fe26e527 AK	536	for (i = 0; i < npages; ++i, ioba += (1ULL << stt->page_shift))
fe26e527 AK	537	kvmppc_tce_put(stt, ioba >> stt->page_shift, tce_value);
d3695aa4 AK	538
	539	return H_SUCCESS;
	540	}
d3695aa4	541
acde2572	542	/* This can be called in either virtual mode or real mode */
69e9fbb2 LD	543	long kvmppc_h_get_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
	544	unsigned long ioba)
	545	{
503bfcbe	546	struct kvmppc_spapr_tce_table *stt;
fcbb2ce6 AK	547	long ret;
	548	unsigned long idx;
	549	struct page *page;
	550	u64 *tbl;
69e9fbb2	551
503bfcbe	552	stt = kvmppc_find_table(vcpu->kvm, liobn);
fcbb2ce6 AK	553	if (!stt)
fcbb2ce6 AK	554	return H_TOO_HARD;
69e9fbb2	555
fcbb2ce6 AK	556	ret = kvmppc_ioba_validate(stt, ioba, 1);
	557	if (ret != H_SUCCESS)
	558	return ret;
69e9fbb2	559
14f853f1	560	idx = (ioba >> stt->page_shift) - stt->offset;
fcbb2ce6 AK	561	page = stt->pages[idx / TCES_PER_PAGE];
fcbb2ce6 AK	562	tbl = (u64 *)page_address(page);
69e9fbb2	563
fcbb2ce6	564	vcpu->arch.gpr[4] = tbl[idx % TCES_PER_PAGE];
69e9fbb2	565
fcbb2ce6	566	return H_SUCCESS;
69e9fbb2 LD	567	}
69e9fbb2 LD	568	EXPORT_SYMBOL_GPL(kvmppc_h_get_tce);
d3695aa4 AK	569
d3695aa4 AK	570	#endif /* KVM_BOOK3S_HV_POSSIBLE */