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authorLinus Torvalds <torvalds@linux-foundation.org>2015-04-26 13:23:15 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-26 13:23:15 -0700
commit63905bba5b0170492777b327ac5e2aaef64989d6 (patch)
treecb60404ffedfa7d842c1e34fa965de57715182a6 /arch/powerpc/kvm
parenteadf16a912b6bdf8bd476bde2f19fb41d06e0c3b (diff)
parent2e826695d87c2d213def07bc344ae97d88384f62 (diff)
downloadop-kernel-dev-63905bba5b0170492777b327ac5e2aaef64989d6.zip
op-kernel-dev-63905bba5b0170492777b327ac5e2aaef64989d6.tar.gz
Merge tag 'powerpc-4.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux
Pull powerpc fixes from Michael Ellerman: - fix for mm_dec_nr_pmds() from Scott. - fixes for oopses seen with KVM + THP from Aneesh. - build fixes from Aneesh & Shreyas. * tag 'powerpc-4.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: powerpc/mm: Fix build error with CONFIG_PPC_TRANSACTIONAL_MEM disabled powerpc/kvm: Fix ppc64_defconfig + PPC_POWERNV=n build error powerpc/mm/thp: Return pte address if we find trans_splitting. powerpc/mm/thp: Make page table walk safe against thp split/collapse KVM: PPC: Remove page table walk helpers KVM: PPC: Use READ_ONCE when dereferencing pte_t pointer powerpc/hugetlb: Call mm_dec_nr_pmds() in hugetlb_free_pmd_range()
Diffstat (limited to 'arch/powerpc/kvm')
-rw-r--r--arch/powerpc/kvm/Kconfig2
-rw-r--r--arch/powerpc/kvm/book3s_64_mmu_hv.c14
-rw-r--r--arch/powerpc/kvm/book3s_hv_rm_mmu.c86
-rw-r--r--arch/powerpc/kvm/e500_mmu_host.c32
4 files changed, 77 insertions, 57 deletions
diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig
index 2963e4d..3caec2c 100644
--- a/arch/powerpc/kvm/Kconfig
+++ b/arch/powerpc/kvm/Kconfig
@@ -75,7 +75,7 @@ config KVM_BOOK3S_64
config KVM_BOOK3S_64_HV
tristate "KVM support for POWER7 and PPC970 using hypervisor mode in host"
- depends on KVM_BOOK3S_64
+ depends on KVM_BOOK3S_64 && PPC_POWERNV
select KVM_BOOK3S_HV_POSSIBLE
select MMU_NOTIFIER
select CMA
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index d6fe308..1a4acf8 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -535,23 +535,21 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
}
/* if the guest wants write access, see if that is OK */
if (!writing && hpte_is_writable(r)) {
- unsigned int hugepage_shift;
pte_t *ptep, pte;
-
+ unsigned long flags;
/*
* We need to protect against page table destruction
- * while looking up and updating the pte.
+ * hugepage split and collapse.
*/
- rcu_read_lock_sched();
+ local_irq_save(flags);
ptep = find_linux_pte_or_hugepte(current->mm->pgd,
- hva, &hugepage_shift);
+ hva, NULL);
if (ptep) {
- pte = kvmppc_read_update_linux_pte(ptep, 1,
- hugepage_shift);
+ pte = kvmppc_read_update_linux_pte(ptep, 1);
if (pte_write(pte))
write_ok = 1;
}
- rcu_read_unlock_sched();
+ local_irq_restore(flags);
}
}
diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
index f6bf0b1..b027a89 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -26,11 +26,14 @@ static void *real_vmalloc_addr(void *x)
{
unsigned long addr = (unsigned long) x;
pte_t *p;
-
- p = find_linux_pte_or_hugepte(swapper_pg_dir, addr, NULL);
+ /*
+ * assume we don't have huge pages in vmalloc space...
+ * So don't worry about THP collapse/split. Called
+ * Only in realmode, hence won't need irq_save/restore.
+ */
+ p = __find_linux_pte_or_hugepte(swapper_pg_dir, addr, NULL);
if (!p || !pte_present(*p))
return NULL;
- /* assume we don't have huge pages in vmalloc space... */
addr = (pte_pfn(*p) << PAGE_SHIFT) | (addr & ~PAGE_MASK);
return __va(addr);
}
@@ -131,25 +134,6 @@ static void remove_revmap_chain(struct kvm *kvm, long pte_index,
unlock_rmap(rmap);
}
-static pte_t lookup_linux_pte_and_update(pgd_t *pgdir, unsigned long hva,
- int writing, unsigned long *pte_sizep)
-{
- pte_t *ptep;
- unsigned long ps = *pte_sizep;
- unsigned int hugepage_shift;
-
- ptep = find_linux_pte_or_hugepte(pgdir, hva, &hugepage_shift);
- if (!ptep)
- return __pte(0);
- if (hugepage_shift)
- *pte_sizep = 1ul << hugepage_shift;
- else
- *pte_sizep = PAGE_SIZE;
- if (ps > *pte_sizep)
- return __pte(0);
- return kvmppc_read_update_linux_pte(ptep, writing, hugepage_shift);
-}
-
long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags,
long pte_index, unsigned long pteh, unsigned long ptel,
pgd_t *pgdir, bool realmode, unsigned long *pte_idx_ret)
@@ -160,13 +144,13 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags,
struct revmap_entry *rev;
unsigned long g_ptel;
struct kvm_memory_slot *memslot;
- unsigned long pte_size;
+ unsigned hpage_shift;
unsigned long is_io;
unsigned long *rmap;
- pte_t pte;
+ pte_t *ptep;
unsigned int writing;
unsigned long mmu_seq;
- unsigned long rcbits;
+ unsigned long rcbits, irq_flags = 0;
psize = hpte_page_size(pteh, ptel);
if (!psize)
@@ -202,22 +186,46 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags,
/* Translate to host virtual address */
hva = __gfn_to_hva_memslot(memslot, gfn);
-
- /* Look up the Linux PTE for the backing page */
- pte_size = psize;
- pte = lookup_linux_pte_and_update(pgdir, hva, writing, &pte_size);
- if (pte_present(pte) && !pte_protnone(pte)) {
- if (writing && !pte_write(pte))
- /* make the actual HPTE be read-only */
- ptel = hpte_make_readonly(ptel);
- is_io = hpte_cache_bits(pte_val(pte));
- pa = pte_pfn(pte) << PAGE_SHIFT;
- pa |= hva & (pte_size - 1);
- pa |= gpa & ~PAGE_MASK;
+ /*
+ * If we had a page table table change after lookup, we would
+ * retry via mmu_notifier_retry.
+ */
+ if (realmode)
+ ptep = __find_linux_pte_or_hugepte(pgdir, hva, &hpage_shift);
+ else {
+ local_irq_save(irq_flags);
+ ptep = find_linux_pte_or_hugepte(pgdir, hva, &hpage_shift);
}
+ if (ptep) {
+ pte_t pte;
+ unsigned int host_pte_size;
- if (pte_size < psize)
- return H_PARAMETER;
+ if (hpage_shift)
+ host_pte_size = 1ul << hpage_shift;
+ else
+ host_pte_size = PAGE_SIZE;
+ /*
+ * We should always find the guest page size
+ * to <= host page size, if host is using hugepage
+ */
+ if (host_pte_size < psize) {
+ if (!realmode)
+ local_irq_restore(flags);
+ return H_PARAMETER;
+ }
+ pte = kvmppc_read_update_linux_pte(ptep, writing);
+ if (pte_present(pte) && !pte_protnone(pte)) {
+ if (writing && !pte_write(pte))
+ /* make the actual HPTE be read-only */
+ ptel = hpte_make_readonly(ptel);
+ is_io = hpte_cache_bits(pte_val(pte));
+ pa = pte_pfn(pte) << PAGE_SHIFT;
+ pa |= hva & (host_pte_size - 1);
+ pa |= gpa & ~PAGE_MASK;
+ }
+ }
+ if (!realmode)
+ local_irq_restore(irq_flags);
ptel &= ~(HPTE_R_PP0 - psize);
ptel |= pa;
diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c
index cc536d4..4d33e19 100644
--- a/arch/powerpc/kvm/e500_mmu_host.c
+++ b/arch/powerpc/kvm/e500_mmu_host.c
@@ -338,6 +338,7 @@ static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,
pte_t *ptep;
unsigned int wimg = 0;
pgd_t *pgdir;
+ unsigned long flags;
/* used to check for invalidations in progress */
mmu_seq = kvm->mmu_notifier_seq;
@@ -468,15 +469,28 @@ static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,
pgdir = vcpu_e500->vcpu.arch.pgdir;
- ptep = lookup_linux_ptep(pgdir, hva, &tsize_pages);
- if (pte_present(*ptep))
- wimg = (*ptep >> PTE_WIMGE_SHIFT) & MAS2_WIMGE_MASK;
- else {
- if (printk_ratelimit())
- pr_err("%s: pte not present: gfn %lx, pfn %lx\n",
- __func__, (long)gfn, pfn);
- ret = -EINVAL;
- goto out;
+ /*
+ * We are just looking at the wimg bits, so we don't
+ * care much about the trans splitting bit.
+ * We are holding kvm->mmu_lock so a notifier invalidate
+ * can't run hence pfn won't change.
+ */
+ local_irq_save(flags);
+ ptep = find_linux_pte_or_hugepte(pgdir, hva, NULL);
+ if (ptep) {
+ pte_t pte = READ_ONCE(*ptep);
+
+ if (pte_present(pte)) {
+ wimg = (pte_val(pte) >> PTE_WIMGE_SHIFT) &
+ MAS2_WIMGE_MASK;
+ local_irq_restore(flags);
+ } else {
+ local_irq_restore(flags);
+ pr_err_ratelimited("%s: pte not present: gfn %lx,pfn %lx\n",
+ __func__, (long)gfn, pfn);
+ ret = -EINVAL;
+ goto out;
+ }
}
kvmppc_e500_ref_setup(ref, gtlbe, pfn, wimg);
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