/*
* 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>
#include <asm/pte-walk.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;
/*
* Called in real mode with MSR_EE = 0. We are safe here.
* It is ok to do the lookup with arch.pgdir here, because
* we are doing this on secondary cpus and current task there
* is not the hypervisor. Also this is safe against THP in the
* host, because an IPI to primary thread will wait for the secondary
* to exit which will agains result in the below page table walk
* to finish.
*/
ptep = __find_linux_pte(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 */
