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-rw-r--r--arch/arm/include/asm/kvm_mmu.h10
-rw-r--r--arch/arm/kvm/mmu.c67
2 files changed, 53 insertions, 24 deletions
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index bf0fe99e8ca9..c57c41dc7e87 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -162,16 +162,14 @@ static inline bool kvm_page_empty(void *ptr)
#define KVM_PREALLOC_LEVEL 0
-static inline int kvm_prealloc_hwpgd(struct kvm *kvm, pgd_t *pgd)
+static inline void *kvm_get_hwpgd(struct kvm *kvm)
{
- return 0;
+ return kvm->arch.pgd;
}
-static inline void kvm_free_hwpgd(struct kvm *kvm) { }
-
-static inline void *kvm_get_hwpgd(struct kvm *kvm)
+static inline unsigned int kvm_get_hwpgd_size(void)
{
- return kvm->arch.pgd;
+ return PTRS_PER_S2_PGD * sizeof(pgd_t);
}
struct kvm;
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 3e6859bc3e11..a48a73c6b866 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -632,6 +632,20 @@ int create_hyp_io_mappings(void *from, void *to, phys_addr_t phys_addr)
__phys_to_pfn(phys_addr), PAGE_HYP_DEVICE);
}
+/* Free the HW pgd, one page at a time */
+static void kvm_free_hwpgd(void *hwpgd)
+{
+ free_pages_exact(hwpgd, kvm_get_hwpgd_size());
+}
+
+/* Allocate the HW PGD, making sure that each page gets its own refcount */
+static void *kvm_alloc_hwpgd(void)
+{
+ unsigned int size = kvm_get_hwpgd_size();
+
+ return alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
+}
+
/**
* kvm_alloc_stage2_pgd - allocate level-1 table for stage-2 translation.
* @kvm: The KVM struct pointer for the VM.
@@ -645,15 +659,31 @@ int create_hyp_io_mappings(void *from, void *to, phys_addr_t phys_addr)
*/
int kvm_alloc_stage2_pgd(struct kvm *kvm)
{
- int ret;
pgd_t *pgd;
+ void *hwpgd;
if (kvm->arch.pgd != NULL) {
kvm_err("kvm_arch already initialized?\n");
return -EINVAL;
}
+ hwpgd = kvm_alloc_hwpgd();
+ if (!hwpgd)
+ return -ENOMEM;
+
+ /* When the kernel uses more levels of page tables than the
+ * guest, we allocate a fake PGD and pre-populate it to point
+ * to the next-level page table, which will be the real
+ * initial page table pointed to by the VTTBR.
+ *
+ * When KVM_PREALLOC_LEVEL==2, we allocate a single page for
+ * the PMD and the kernel will use folded pud.
+ * When KVM_PREALLOC_LEVEL==1, we allocate 2 consecutive PUD
+ * pages.
+ */
if (KVM_PREALLOC_LEVEL > 0) {
+ int i;
+
/*
* Allocate fake pgd for the page table manipulation macros to
* work. This is not used by the hardware and we have no
@@ -661,30 +691,32 @@ int kvm_alloc_stage2_pgd(struct kvm *kvm)
*/
pgd = (pgd_t *)kmalloc(PTRS_PER_S2_PGD * sizeof(pgd_t),
GFP_KERNEL | __GFP_ZERO);
+
+ if (!pgd) {
+ kvm_free_hwpgd(hwpgd);
+ return -ENOMEM;
+ }
+
+ /* Plug the HW PGD into the fake one. */
+ for (i = 0; i < PTRS_PER_S2_PGD; i++) {
+ if (KVM_PREALLOC_LEVEL == 1)
+ pgd_populate(NULL, pgd + i,
+ (pud_t *)hwpgd + i * PTRS_PER_PUD);
+ else if (KVM_PREALLOC_LEVEL == 2)
+ pud_populate(NULL, pud_offset(pgd, 0) + i,
+ (pmd_t *)hwpgd + i * PTRS_PER_PMD);
+ }
} else {
/*
* Allocate actual first-level Stage-2 page table used by the
* hardware for Stage-2 page table walks.
*/
- pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, S2_PGD_ORDER);
+ pgd = (pgd_t *)hwpgd;
}
- if (!pgd)
- return -ENOMEM;
-
- ret = kvm_prealloc_hwpgd(kvm, pgd);
- if (ret)
- goto out_err;
-
kvm_clean_pgd(pgd);
kvm->arch.pgd = pgd;
return 0;
-out_err:
- if (KVM_PREALLOC_LEVEL > 0)
- kfree(pgd);
- else
- free_pages((unsigned long)pgd, S2_PGD_ORDER);
- return ret;
}
/**
@@ -785,11 +817,10 @@ void kvm_free_stage2_pgd(struct kvm *kvm)
return;
unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE);
- kvm_free_hwpgd(kvm);
+ kvm_free_hwpgd(kvm_get_hwpgd(kvm));
if (KVM_PREALLOC_LEVEL > 0)
kfree(kvm->arch.pgd);
- else
- free_pages((unsigned long)kvm->arch.pgd, S2_PGD_ORDER);
+
kvm->arch.pgd = NULL;
}