The radix fault handler will unmap a page table if it wants to install
a huge page there instead. It will just clear that page table entry,
free the page, and flush the pwc.
Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
---
arch/powerpc/kvm/book3s_64_mmu_radix.c | 147 +++++++++++++++++--------
1 file changed, 100 insertions(+), 47 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
index ad6675a9485a..da507b41fdd3 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -236,6 +236,104 @@ static void kvmppc_unmap_pte(struct kvm *kvm, pte_t *pte,
}
}
+/*
+ * kvmppc_free_p?d are used to free existing page tables, and recursively
+ * descend and clear and free children.
+ * Callers are responsible for flushing the PWC.
+ */
+static void kvmppc_unmap_free_pte(struct kvm *kvm, pte_t *pte, bool full)
+{
+ if (full) {
+ memset(pte, 0, sizeof(long) << PTE_INDEX_SIZE);
+ } else {
+ pte_t *p = pte;
+ unsigned long it;
+
+ for (it = 0; it < PTRS_PER_PTE; ++it, ++p) {
+ if (pte_val(*p) == 0)
+ continue;
+ kvmppc_unmap_pte(kvm, p,
+ pte_pfn(*p) << PAGE_SHIFT,
+ PAGE_SHIFT);
+ }
+ }
+
+ kvmppc_pte_free(pte);
+}
+
+static void kvmppc_unmap_free_pmd(struct kvm *kvm, pmd_t *pmd, bool full)
+{
+ unsigned long im;
+ pmd_t *p = pmd;
+
+ for (im = 0; im < PTRS_PER_PMD; ++im, ++p) {
+ if (!pmd_present(*p))
+ continue;
+ if (pmd_is_leaf(*p)) {
+ if (full)
+ pmd_clear(p);
+ else
+ kvmppc_unmap_pte(kvm, (pte_t *)p,
+ pte_pfn(*(pte_t *)p) << PAGE_SHIFT,
+ PMD_SHIFT);
+ } else {
+ pte_t *pte;
+
+ pte = pte_offset_map(p, 0);
+ kvmppc_unmap_free_pte(kvm, pte, full);
+ pmd_clear(p);
+ }
+ }
+ pmd_free(kvm->mm, pmd);
+}
+
+static void kvmppc_unmap_free_pud(struct kvm *kvm, pud_t *pud, bool full)
+{
+ unsigned long iu;
+ pud_t *p = pud;
+
+ for (iu = 0; iu < PTRS_PER_PUD; ++iu, ++p) {
+ if (!pud_present(*p))
+ continue;
+ if (pud_huge(*p)) {
+ if (full)
+ pud_clear(p);
+ else
+ kvmppc_unmap_pte(kvm, (pte_t *)p,
+ pte_pfn(*(pte_t *)p) << PAGE_SHIFT,
+ PUD_SHIFT);
+ } else {
+ pmd_t *pmd;
+
+ pmd = pmd_offset(p, 0);
+ kvmppc_unmap_free_pmd(kvm, pmd, full);
+ pud_clear(p);
+ }
+ }
+ pud_free(kvm->mm, pud);
+}
+
+void kvmppc_free_radix(struct kvm *kvm)
+{
+ unsigned long ig;
+ pgd_t *pgd;
+
+ if (!kvm->arch.pgtable)
+ return;
+ pgd = kvm->arch.pgtable;
+ for (ig = 0; ig < PTRS_PER_PGD; ++ig, ++pgd) {
+ pud_t *pud;
+
+ if (!pgd_present(*pgd))
+ continue;
+ pud = pud_offset(pgd, 0);
+ kvmppc_unmap_free_pud(kvm, pud, true);
+ pgd_clear(pgd);
+ }
+ pgd_free(kvm->mm, kvm->arch.pgtable);
+ kvm->arch.pgtable = NULL;
+}
+
static int kvmppc_create_pte(struct kvm *kvm, pte_t pte, unsigned long gpa,
unsigned int level, unsigned long mmu_seq)
{
@@ -303,7 +401,7 @@ static int kvmppc_create_pte(struct kvm *kvm, pte_t pte, unsigned long gpa,
* install a large page, so remove and free the page
* table page. new_pmd will be NULL since level == 2.
*/
- new_pmd = pmd_offset(pud, 0);
+ kvmppc_unmap_free_pmd(kvm, pmd_offset(pud, 0), false);
pud_clear(pud);
kvmppc_radix_flush_pwc(kvm, gpa);
}
@@ -344,7 +442,7 @@ static int kvmppc_create_pte(struct kvm *kvm, pte_t pte, unsigned long gpa,
* install a large page, so remove and free the page
* table page. new_ptep will be NULL since level == 1.
*/
- new_ptep = pte_offset_kernel(pmd, 0);
+ kvmppc_unmap_free_pte(kvm, pte_offset_kernel(pmd, 0), false);
pmd_clear(pmd);
kvmppc_radix_flush_pwc(kvm, gpa);
}
@@ -723,51 +821,6 @@ int kvmppc_init_vm_radix(struct kvm *kvm)
return 0;
}
-void kvmppc_free_radix(struct kvm *kvm)
-{
- unsigned long ig, iu, im;
- pte_t *pte;
- pmd_t *pmd;
- pud_t *pud;
- pgd_t *pgd;
-
- if (!kvm->arch.pgtable)
- return;
- pgd = kvm->arch.pgtable;
- for (ig = 0; ig < PTRS_PER_PGD; ++ig, ++pgd) {
- if (!pgd_present(*pgd))
- continue;
- pud = pud_offset(pgd, 0);
- for (iu = 0; iu < PTRS_PER_PUD; ++iu, ++pud) {
- if (!pud_present(*pud))
- continue;
- if (pud_huge(*pud)) {
- pud_clear(pud);
- continue;
- }
- pmd = pmd_offset(pud, 0);
- for (im = 0; im < PTRS_PER_PMD; ++im, ++pmd) {
- if (pmd_is_leaf(*pmd)) {
- pmd_clear(pmd);
- continue;
- }
- if (!pmd_present(*pmd))
- continue;
- pte = pte_offset_map(pmd, 0);
- memset(pte, 0, sizeof(long) << PTE_INDEX_SIZE);
- kvmppc_pte_free(pte);
- pmd_clear(pmd);
- }
- pmd_free(kvm->mm, pmd_offset(pud, 0));
- pud_clear(pud);
- }
- pud_free(kvm->mm, pud_offset(pgd, 0));
- pgd_clear(pgd);
- }
- pgd_free(kvm->mm, kvm->arch.pgtable);
- kvm->arch.pgtable = NULL;
-}
-
static void pte_ctor(void *addr)
{
memset(addr, 0, PTE_TABLE_SIZE);
--
2.17.0
--
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