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-rw-r--r--arch/arm64/include/asm/kvm_mmu.h64
-rw-r--r--arch/arm64/include/asm/stage2_pgtable-nopmd.h42
-rw-r--r--arch/arm64/include/asm/stage2_pgtable-nopud.h39
-rw-r--r--arch/arm64/include/asm/stage2_pgtable.h122
4 files changed, 172 insertions, 95 deletions
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index a3c0d05311ef..e3fee0acd1a2 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -45,18 +45,6 @@
*/
#define TRAMPOLINE_VA (HYP_PAGE_OFFSET_MASK & PAGE_MASK)
-/*
- * KVM_MMU_CACHE_MIN_PAGES is the number of stage2 page table translation
- * levels in addition to the PGD and potentially the PUD which are
- * pre-allocated (we pre-allocate the fake PGD and the PUD when the Stage-2
- * tables use one level of tables less than the kernel.
- */
-#ifdef CONFIG_ARM64_64K_PAGES
-#define KVM_MMU_CACHE_MIN_PAGES 1
-#else
-#define KVM_MMU_CACHE_MIN_PAGES 2
-#endif
-
#ifdef __ASSEMBLY__
#include <asm/alternative.h>
@@ -155,69 +143,21 @@ static inline bool kvm_s2pmd_readonly(pmd_t *pmd)
static inline void *kvm_get_hwpgd(struct kvm *kvm)
{
- pgd_t *pgd = kvm->arch.pgd;
- pud_t *pud;
-
- if (KVM_PREALLOC_LEVEL == 0)
- return pgd;
-
- pud = pud_offset(pgd, 0);
- if (KVM_PREALLOC_LEVEL == 1)
- return pud;
-
- BUG_ON(KVM_PREALLOC_LEVEL != 2);
- return pmd_offset(pud, 0);
+ return kvm->arch.pgd;
}
static inline unsigned int kvm_get_hwpgd_size(void)
{
- if (KVM_PREALLOC_LEVEL > 0)
- return PTRS_PER_S2_PGD * PAGE_SIZE;
return PTRS_PER_S2_PGD * sizeof(pgd_t);
}
-/*
- * Allocate fake pgd for the host kernel page table macros to work.
- * This is not used by the hardware and we have no alignment
- * requirement for this allocation.
- */
static inline pgd_t *kvm_setup_fake_pgd(pgd_t *hwpgd)
{
- int i;
- pgd_t *pgd;
-
- if (!KVM_PREALLOC_LEVEL)
- return hwpgd;
-
- /*
- * 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.
- */
-
- pgd = kmalloc(PTRS_PER_S2_PGD * sizeof(pgd_t),
- GFP_KERNEL | __GFP_ZERO);
- if (!pgd)
- return ERR_PTR(-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);
- }
-
- return pgd;
+ return hwpgd;
}
static inline void kvm_free_fake_pgd(pgd_t *pgd)
{
- if (KVM_PREALLOC_LEVEL > 0)
- kfree(pgd);
}
static inline bool kvm_page_empty(void *ptr)
{
diff --git a/arch/arm64/include/asm/stage2_pgtable-nopmd.h b/arch/arm64/include/asm/stage2_pgtable-nopmd.h
new file mode 100644
index 000000000000..2656a0fd05a6
--- /dev/null
+++ b/arch/arm64/include/asm/stage2_pgtable-nopmd.h
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2016 - ARM Ltd
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __ARM64_S2_PGTABLE_NOPMD_H_
+#define __ARM64_S2_PGTABLE_NOPMD_H_
+
+#include <asm/stage2_pgtable-nopud.h>
+
+#define __S2_PGTABLE_PMD_FOLDED
+
+#define S2_PMD_SHIFT S2_PUD_SHIFT
+#define S2_PTRS_PER_PMD 1
+#define S2_PMD_SIZE (1UL << S2_PMD_SHIFT)
+#define S2_PMD_MASK (~(S2_PMD_SIZE-1))
+
+#define stage2_pud_none(pud) (0)
+#define stage2_pud_present(pud) (1)
+#define stage2_pud_clear(pud) do { } while (0)
+#define stage2_pud_populate(pud, pmd) do { } while (0)
+#define stage2_pmd_offset(pud, address) ((pmd_t *)(pud))
+
+#define stage2_pmd_free(pmd) do { } while (0)
+
+#define stage2_pmd_addr_end(addr, end) (end)
+
+#define stage2_pud_huge(pud) (0)
+#define stage2_pmd_table_empty(pmdp) (0)
+
+#endif
diff --git a/arch/arm64/include/asm/stage2_pgtable-nopud.h b/arch/arm64/include/asm/stage2_pgtable-nopud.h
new file mode 100644
index 000000000000..5ee87b54ebf3
--- /dev/null
+++ b/arch/arm64/include/asm/stage2_pgtable-nopud.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2016 - ARM Ltd
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __ARM64_S2_PGTABLE_NOPUD_H_
+#define __ARM64_S2_PGTABLE_NOPUD_H_
+
+#define __S2_PGTABLE_PUD_FOLDED
+
+#define S2_PUD_SHIFT S2_PGDIR_SHIFT
+#define S2_PTRS_PER_PUD 1
+#define S2_PUD_SIZE (_AC(1, UL) << S2_PUD_SHIFT)
+#define S2_PUD_MASK (~(S2_PUD_SIZE-1))
+
+#define stage2_pgd_none(pgd) (0)
+#define stage2_pgd_present(pgd) (1)
+#define stage2_pgd_clear(pgd) do { } while (0)
+#define stage2_pgd_populate(pgd, pud) do { } while (0)
+
+#define stage2_pud_offset(pgd, address) ((pud_t *)(pgd))
+
+#define stage2_pud_free(x) do { } while (0)
+
+#define stage2_pud_addr_end(addr, end) (end)
+#define stage2_pud_table_empty(pmdp) (0)
+
+#endif
diff --git a/arch/arm64/include/asm/stage2_pgtable.h b/arch/arm64/include/asm/stage2_pgtable.h
index 0ec218fe83c5..8b68099348e5 100644
--- a/arch/arm64/include/asm/stage2_pgtable.h
+++ b/arch/arm64/include/asm/stage2_pgtable.h
@@ -22,32 +22,61 @@
#include <asm/pgtable.h>
/*
- * In the case where PGDIR_SHIFT is larger than KVM_PHYS_SHIFT, we can address
- * the entire IPA input range with a single pgd entry, and we would only need
- * one pgd entry. Note that in this case, the pgd is actually not used by
- * the MMU for Stage-2 translations, but is merely a fake pgd used as a data
- * structure for the kernel pgtable macros to work.
+ * The hardware supports concatenation of up to 16 tables at stage2 entry level
+ * and we use the feature whenever possible.
+ *
+ * Now, the minimum number of bits resolved at any level is (PAGE_SHIFT - 3).
+ * On arm64, the smallest PAGE_SIZE supported is 4k, which means
+ * (PAGE_SHIFT - 3) > 4 holds for all page sizes.
+ * This implies, the total number of page table levels at stage2 expected
+ * by the hardware is actually the number of levels required for (KVM_PHYS_SHIFT - 4)
+ * in normal translations(e.g, stage1), since we cannot have another level in
+ * the range (KVM_PHYS_SHIFT, KVM_PHYS_SHIFT - 4).
*/
-#if PGDIR_SHIFT > KVM_PHYS_SHIFT
-#define PTRS_PER_S2_PGD_SHIFT 0
-#else
-#define PTRS_PER_S2_PGD_SHIFT (KVM_PHYS_SHIFT - PGDIR_SHIFT)
-#endif
-#define PTRS_PER_S2_PGD (1 << PTRS_PER_S2_PGD_SHIFT)
+#define STAGE2_PGTABLE_LEVELS ARM64_HW_PGTABLE_LEVELS(KVM_PHYS_SHIFT - 4)
/*
- * If we are concatenating first level stage-2 page tables, we would have less
- * than or equal to 16 pointers in the fake PGD, because that's what the
- * architecture allows. In this case, (4 - CONFIG_PGTABLE_LEVELS)
- * represents the first level for the host, and we add 1 to go to the next
- * level (which uses contatenation) for the stage-2 tables.
+ * With all the supported VA_BITs and 40bit guest IPA, the following condition
+ * is always true:
+ *
+ * STAGE2_PGTABLE_LEVELS <= CONFIG_PGTABLE_LEVELS
+ *
+ * We base our stage-2 page table walker helpers on this assumption and
+ * fall back to using the host version of the helper wherever possible.
+ * i.e, if a particular level is not folded (e.g, PUD) at stage2, we fall back
+ * to using the host version, since it is guaranteed it is not folded at host.
+ *
+ * If the condition breaks in the future, we can rearrange the host level
+ * definitions and reuse them for stage2. Till then...
*/
-#if PTRS_PER_S2_PGD <= 16
-#define KVM_PREALLOC_LEVEL (4 - CONFIG_PGTABLE_LEVELS + 1)
-#else
-#define KVM_PREALLOC_LEVEL (0)
+#if STAGE2_PGTABLE_LEVELS > CONFIG_PGTABLE_LEVELS
+#error "Unsupported combination of guest IPA and host VA_BITS."
#endif
+/* S2_PGDIR_SHIFT is the size mapped by top-level stage2 entry */
+#define S2_PGDIR_SHIFT ARM64_HW_PGTABLE_LEVEL_SHIFT(4 - STAGE2_PGTABLE_LEVELS)
+#define S2_PGDIR_SIZE (_AC(1, UL) << S2_PGDIR_SHIFT)
+#define S2_PGDIR_MASK (~(S2_PGDIR_SIZE - 1))
+
+/*
+ * The number of PTRS across all concatenated stage2 tables given by the
+ * number of bits resolved at the initial level.
+ */
+#define PTRS_PER_S2_PGD (1 << (KVM_PHYS_SHIFT - S2_PGDIR_SHIFT))
+
+/*
+ * KVM_MMU_CACHE_MIN_PAGES is the number of stage2 page table translation
+ * levels in addition to the PGD.
+ */
+#define KVM_MMU_CACHE_MIN_PAGES (STAGE2_PGTABLE_LEVELS - 1)
+
+
+#if STAGE2_PGTABLE_LEVELS > 3
+
+#define S2_PUD_SHIFT ARM64_HW_PGTABLE_LEVEL_SHIFT(1)
+#define S2_PUD_SIZE (_AC(1, UL) << S2_PUD_SHIFT)
+#define S2_PUD_MASK (~(S2_PUD_SIZE - 1))
+
#define stage2_pgd_none(pgd) pgd_none(pgd)
#define stage2_pgd_clear(pgd) pgd_clear(pgd)
#define stage2_pgd_present(pgd) pgd_present(pgd)
@@ -55,6 +84,24 @@
#define stage2_pud_offset(pgd, address) pud_offset(pgd, address)
#define stage2_pud_free(pud) pud_free(NULL, pud)
+#define stage2_pud_table_empty(pudp) kvm_page_empty(pudp)
+
+static inline phys_addr_t stage2_pud_addr_end(phys_addr_t addr, phys_addr_t end)
+{
+ phys_addr_t boundary = (addr + S2_PUD_SIZE) & S2_PUD_MASK;
+
+ return (boundary - 1 < end - 1) ? boundary : end;
+}
+
+#endif /* STAGE2_PGTABLE_LEVELS > 3 */
+
+
+#if STAGE2_PGTABLE_LEVELS > 2
+
+#define S2_PMD_SHIFT ARM64_HW_PGTABLE_LEVEL_SHIFT(2)
+#define S2_PMD_SIZE (_AC(1, UL) << S2_PMD_SHIFT)
+#define S2_PMD_MASK (~(S2_PMD_SIZE - 1))
+
#define stage2_pud_none(pud) pud_none(pud)
#define stage2_pud_clear(pud) pud_clear(pud)
#define stage2_pud_present(pud) pud_present(pud)
@@ -63,24 +110,33 @@
#define stage2_pmd_free(pmd) pmd_free(NULL, pmd)
#define stage2_pud_huge(pud) pud_huge(pud)
+#define stage2_pmd_table_empty(pmdp) kvm_page_empty(pmdp)
+
+static inline phys_addr_t stage2_pmd_addr_end(phys_addr_t addr, phys_addr_t end)
+{
+ phys_addr_t boundary = (addr + S2_PMD_SIZE) & S2_PMD_MASK;
-#define stage2_pgd_addr_end(address, end) pgd_addr_end(address, end)
-#define stage2_pud_addr_end(address, end) pud_addr_end(address, end)
-#define stage2_pmd_addr_end(address, end) pmd_addr_end(address, end)
+ return (boundary - 1 < end - 1) ? boundary : end;
+}
+
+#endif /* STAGE2_PGTABLE_LEVELS > 2 */
#define stage2_pte_table_empty(ptep) kvm_page_empty(ptep)
-#ifdef __PGTABLE_PMD_FOLDED
-#define stage2_pmd_table_empty(pmdp) (0)
-#else
-#define stage2_pmd_table_empty(pmdp) ((KVM_PREALLOC_LEVEL < 2) && kvm_page_empty(pmdp))
-#endif
-#ifdef __PGTABLE_PUD_FOLDED
-#define stage2_pud_table_empty(pudp) (0)
-#else
-#define stage2_pud_table_empty(pudp) ((KVM_PREALLOC_LEVEL < 1) && kvm_page_empty(pudp))
+#if STAGE2_PGTABLE_LEVELS == 2
+#include <asm/stage2_pgtable-nopmd.h>
+#elif STAGE2_PGTABLE_LEVELS == 3
+#include <asm/stage2_pgtable-nopud.h>
#endif
-#define stage2_pgd_index(addr) (((addr) >> PGDIR_SHIFT) & (PTRS_PER_S2_PGD - 1))
+
+#define stage2_pgd_index(addr) (((addr) >> S2_PGDIR_SHIFT) & (PTRS_PER_S2_PGD - 1))
+
+static inline phys_addr_t stage2_pgd_addr_end(phys_addr_t addr, phys_addr_t end)
+{
+ phys_addr_t boundary = (addr + S2_PGDIR_SIZE) & S2_PGDIR_MASK;
+
+ return (boundary - 1 < end - 1) ? boundary : end;
+}
#endif /* __ARM64_S2_PGTABLE_H_ */