2023-04-21 16:57:35

by Vipin Sharma

[permalink] [raw]
Subject: [PATCH 8/9] KMV: arm64: Allow stage2_apply_range_sched() to pass page table walker flags

Allow stage2_apply_range_sched() to pass enum kvm_pgtable_walk_flags{}
to stage 2 walkers. Pass 0 as the flag to make this change no-op

This capability will be used in future commits to enable clear-dirty-log
operation under MMU read lock.

Current users of stage2_apply_range_*() API run under assumption of
holding MMU write lock. Stage2 page table walkers then run under the
same assumption. In future commits when clear-dirty-log operation under
MMU read lock is added then there needs to be a way to pass this shared
intent to page table walkers.

No functional changes intended.

Signed-off-by: Vipin Sharma <[email protected]>
---
arch/arm64/include/asm/kvm_pgtable.h | 12 +++++++++---
arch/arm64/kvm/hyp/nvhe/mem_protect.c | 4 ++--
arch/arm64/kvm/hyp/pgtable.c | 16 ++++++++++------
arch/arm64/kvm/mmu.c | 26 ++++++++++++++++----------
4 files changed, 37 insertions(+), 21 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
index 4cd62506c198..79a452d78e08 100644
--- a/arch/arm64/include/asm/kvm_pgtable.h
+++ b/arch/arm64/include/asm/kvm_pgtable.h
@@ -508,6 +508,7 @@ int kvm_pgtable_stage2_set_owner(struct kvm_pgtable *pgt, u64 addr, u64 size,
* @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*().
* @addr: Intermediate physical address from which to remove the mapping.
* @size: Size of the mapping.
+ * @flags: Page-table walker flags.
*
* The offset of @addr within a page is ignored and @size is rounded-up to
* the next page boundary.
@@ -520,7 +521,8 @@ int kvm_pgtable_stage2_set_owner(struct kvm_pgtable *pgt, u64 addr, u64 size,
*
* Return: 0 on success, negative error code on failure.
*/
-int kvm_pgtable_stage2_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size);
+int kvm_pgtable_stage2_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size,
+ enum kvm_pgtable_walk_flags flags);

/**
* kvm_pgtable_stage2_wrprotect() - Write-protect guest stage-2 address range
@@ -528,6 +530,7 @@ int kvm_pgtable_stage2_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size);
* @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*().
* @addr: Intermediate physical address from which to write-protect,
* @size: Size of the range.
+ * @flags: Page-table walker flags.
*
* The offset of @addr within a page is ignored and @size is rounded-up to
* the next page boundary.
@@ -538,7 +541,8 @@ int kvm_pgtable_stage2_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size);
*
* Return: 0 on success, negative error code on failure.
*/
-int kvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size);
+int kvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size,
+ enum kvm_pgtable_walk_flags flags);

/**
* kvm_pgtable_stage2_mkyoung() - Set the access flag in a page-table entry.
@@ -610,13 +614,15 @@ bool kvm_pgtable_stage2_is_young(struct kvm_pgtable *pgt, u64 addr);
* @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*().
* @addr: Intermediate physical address from which to flush.
* @size: Size of the range.
+ * @flags: Page-table walker flags.
*
* The offset of @addr within a page is ignored and @size is rounded-up to
* the next page boundary.
*
* Return: 0 on success, negative error code on failure.
*/
-int kvm_pgtable_stage2_flush(struct kvm_pgtable *pgt, u64 addr, u64 size);
+int kvm_pgtable_stage2_flush(struct kvm_pgtable *pgt, u64 addr, u64 size,
+ enum kvm_pgtable_walk_flags flags);

/**
* kvm_pgtable_walk() - Walk a page-table.
diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index 552653fa18be..bac3c2c31cbe 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -326,11 +326,11 @@ static int host_stage2_unmap_dev_all(void)
/* Unmap all non-memory regions to recycle the pages */
for (i = 0; i < hyp_memblock_nr; i++, addr = reg->base + reg->size) {
reg = &hyp_memory[i];
- ret = kvm_pgtable_stage2_unmap(pgt, addr, reg->base - addr);
+ ret = kvm_pgtable_stage2_unmap(pgt, addr, reg->base - addr, 0);
if (ret)
return ret;
}
- return kvm_pgtable_stage2_unmap(pgt, addr, BIT(pgt->ia_bits) - addr);
+ return kvm_pgtable_stage2_unmap(pgt, addr, BIT(pgt->ia_bits) - addr, 0);
}

struct kvm_mem_range {
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index 3d61bd3e591d..3a585e1fba11 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -1024,12 +1024,14 @@ static int stage2_unmap_walker(const struct kvm_pgtable_visit_ctx *ctx,
return 0;
}

-int kvm_pgtable_stage2_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size)
+int kvm_pgtable_stage2_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size,
+ enum kvm_pgtable_walk_flags flags)
{
struct kvm_pgtable_walker walker = {
.cb = stage2_unmap_walker,
.arg = pgt,
- .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST,
+ .flags = flags | KVM_PGTABLE_WALK_LEAF |
+ KVM_PGTABLE_WALK_TABLE_POST,
};

return kvm_pgtable_walk(pgt, addr, size, &walker);
@@ -1108,11 +1110,12 @@ static int stage2_update_leaf_attrs(struct kvm_pgtable *pgt, u64 addr,
return 0;
}

-int kvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size)
+int kvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size,
+ enum kvm_pgtable_walk_flags flags)
{
return stage2_update_leaf_attrs(pgt, addr, size, 0,
KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W,
- NULL, NULL, 0);
+ NULL, NULL, flags);
}

kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr)
@@ -1193,11 +1196,12 @@ static int stage2_flush_walker(const struct kvm_pgtable_visit_ctx *ctx,
return 0;
}

-int kvm_pgtable_stage2_flush(struct kvm_pgtable *pgt, u64 addr, u64 size)
+int kvm_pgtable_stage2_flush(struct kvm_pgtable *pgt, u64 addr, u64 size,
+ enum kvm_pgtable_walk_flags flags)
{
struct kvm_pgtable_walker walker = {
.cb = stage2_flush_walker,
- .flags = KVM_PGTABLE_WALK_LEAF,
+ .flags = flags | KVM_PGTABLE_WALK_LEAF,
.arg = pgt,
};

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index dc1c9059604e..e0189cdda43d 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -48,7 +48,9 @@ static phys_addr_t stage2_range_addr_end(phys_addr_t addr, phys_addr_t end)
*/
static int stage2_apply_range(struct kvm_s2_mmu *mmu, phys_addr_t addr,
phys_addr_t end,
- int (*fn)(struct kvm_pgtable *, u64, u64),
+ enum kvm_pgtable_walk_flags flags,
+ int (*fn)(struct kvm_pgtable *, u64, u64,
+ enum kvm_pgtable_walk_flags),
bool resched)
{
struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu);
@@ -61,7 +63,7 @@ static int stage2_apply_range(struct kvm_s2_mmu *mmu, phys_addr_t addr,
return -EINVAL;

next = stage2_range_addr_end(addr, end);
- ret = fn(pgt, addr, next - addr);
+ ret = fn(pgt, addr, next - addr, flags);
if (ret)
break;

@@ -72,8 +74,8 @@ static int stage2_apply_range(struct kvm_s2_mmu *mmu, phys_addr_t addr,
return ret;
}

-#define stage2_apply_range_resched(mmu, addr, end, fn) \
- stage2_apply_range(mmu, addr, end, fn, true)
+#define stage2_apply_range_resched(mmu, addr, end, flags, fn) \
+ stage2_apply_range(mmu, addr, end, flags, fn, true)

static bool memslot_is_logging(struct kvm_memory_slot *memslot)
{
@@ -236,7 +238,7 @@ static void __unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64

lockdep_assert_held_write(&kvm->mmu_lock);
WARN_ON(size & ~PAGE_MASK);
- WARN_ON(stage2_apply_range(mmu, start, end, kvm_pgtable_stage2_unmap,
+ WARN_ON(stage2_apply_range(mmu, start, end, 0, kvm_pgtable_stage2_unmap,
may_block));
}

@@ -251,7 +253,8 @@ static void stage2_flush_memslot(struct kvm *kvm,
phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
phys_addr_t end = addr + PAGE_SIZE * memslot->npages;

- stage2_apply_range_resched(&kvm->arch.mmu, addr, end, kvm_pgtable_stage2_flush);
+ stage2_apply_range_resched(&kvm->arch.mmu, addr, end, 0,
+ kvm_pgtable_stage2_flush);
}

/**
@@ -932,10 +935,13 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
* @mmu: The KVM stage-2 MMU pointer
* @addr: Start address of range
* @end: End address of range
+ * @flags: Page-table walker flags.
*/
-static void stage2_wp_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end)
+static void stage2_wp_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end,
+ enum kvm_pgtable_walk_flags flags)
{
- stage2_apply_range_resched(mmu, addr, end, kvm_pgtable_stage2_wrprotect);
+ stage2_apply_range_resched(mmu, addr, end, flags,
+ kvm_pgtable_stage2_wrprotect);
}

/**
@@ -964,7 +970,7 @@ static void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot)
end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT;

write_lock(&kvm->mmu_lock);
- stage2_wp_range(&kvm->arch.mmu, start, end);
+ stage2_wp_range(&kvm->arch.mmu, start, end, 0);
write_unlock(&kvm->mmu_lock);
kvm_flush_remote_tlbs(kvm);
}
@@ -988,7 +994,7 @@ static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm,
phys_addr_t start = (base_gfn + __ffs(mask)) << PAGE_SHIFT;
phys_addr_t end = (base_gfn + __fls(mask) + 1) << PAGE_SHIFT;

- stage2_wp_range(&kvm->arch.mmu, start, end);
+ stage2_wp_range(&kvm->arch.mmu, start, end, 0);
}

/*
--
2.40.0.634.g4ca3ef3211-goog