| Message ID | 20210809152448.1810400-5-qperret@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Track shared pages at EL2 in protected mode | expand |
On Mon, 9 Aug 2021 at 16:25, Quentin Perret <qperret@google.com> wrote: > > From: Marc Zyngier <maz@kernel.org> > > It is becoming a common need to fetch the PTE for a given address > together with its level. Add such a helper. > > Signed-off-by: Marc Zyngier <maz@kernel.org> > Signed-off-by: Quentin Perret <qperret@google.com> > --- > arch/arm64/include/asm/kvm_pgtable.h | 19 ++++++++++++++ > arch/arm64/kvm/hyp/pgtable.c | 39 ++++++++++++++++++++++++++++ > 2 files changed, 58 insertions(+) > > diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h > index f004c0115d89..082b9d65f40b 100644 > --- a/arch/arm64/include/asm/kvm_pgtable.h > +++ b/arch/arm64/include/asm/kvm_pgtable.h > @@ -432,6 +432,25 @@ int kvm_pgtable_stage2_flush(struct kvm_pgtable *pgt, u64 addr, u64 size); > int kvm_pgtable_walk(struct kvm_pgtable *pgt, u64 addr, u64 size, > struct kvm_pgtable_walker *walker); > > +/** > + * kvm_pgtable_get_leaf() - Walk a page-table and retrieve the leaf entry > + * with its level. > + * @pgt: Page-table structure initialised by kvm_pgtable_*_init(). > + * @addr: Input address for the start of the walk. > + * @ptep: Pointer to storage for the retrieved PTE. > + * @level: Pointer to storage for the level of the retrieved PTE. > + * > + * The offset of @addr within a page is ignored. > + * > + * The walker will walk the page-table entries corresponding to the input > + * address specified, retrieving the leaf corresponding to this address. > + * Invalid entries are treated as leaf entries. > + * > + * Return: 0 on success, negative error code on failure. > + */ > +int kvm_pgtable_get_leaf(struct kvm_pgtable *pgt, u64 addr, > + kvm_pte_t *ptep, u32 *level); > + > /** > * kvm_pgtable_stage2_find_range() - Find a range of Intermediate Physical > * Addresses with compatible permission > diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c > index 05321f4165e3..78f36bd5df6c 100644 > --- a/arch/arm64/kvm/hyp/pgtable.c > +++ b/arch/arm64/kvm/hyp/pgtable.c > @@ -326,6 +326,45 @@ int kvm_pgtable_walk(struct kvm_pgtable *pgt, u64 addr, u64 size, > return _kvm_pgtable_walk(&walk_data); > } > > +struct leaf_walk_data { > + kvm_pte_t pte; > + u32 level; > +}; > + > +static int leaf_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, > + enum kvm_pgtable_walk_flags flag, void * const arg) > +{ > + struct leaf_walk_data *data = arg; > + > + data->pte = *ptep; > + data->level = level; > + > + return 0; > +} > + > +int kvm_pgtable_get_leaf(struct kvm_pgtable *pgt, u64 addr, > + kvm_pte_t *ptep, u32 *level) > +{ > + struct leaf_walk_data data; > + struct kvm_pgtable_walker walker = { > + .cb = leaf_walker, > + .flags = KVM_PGTABLE_WALK_LEAF, > + .arg = &data, > + }; > + int ret; > + > + ret = kvm_pgtable_walk(pgt, ALIGN_DOWN(addr, PAGE_SIZE), > + PAGE_SIZE, &walker); > + if (!ret) { > + if (ptep) > + *ptep = data.pte; > + if (level) > + *level = data.level; > + } > + > + return ret; > +} > + > struct hyp_map_data { > u64 phys; > kvm_pte_t attr; > -- > 2.32.0.605.g8dce9f2422-goog > Reviewed-by: Andrew Walbran <qwandor@google.com>
diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index f004c0115d89..082b9d65f40b 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -432,6 +432,25 @@ int kvm_pgtable_stage2_flush(struct kvm_pgtable *pgt, u64 addr, u64 size); int kvm_pgtable_walk(struct kvm_pgtable *pgt, u64 addr, u64 size, struct kvm_pgtable_walker *walker); +/** + * kvm_pgtable_get_leaf() - Walk a page-table and retrieve the leaf entry + * with its level. + * @pgt: Page-table structure initialised by kvm_pgtable_*_init(). + * @addr: Input address for the start of the walk. + * @ptep: Pointer to storage for the retrieved PTE. + * @level: Pointer to storage for the level of the retrieved PTE. + * + * The offset of @addr within a page is ignored. + * + * The walker will walk the page-table entries corresponding to the input + * address specified, retrieving the leaf corresponding to this address. + * Invalid entries are treated as leaf entries. + * + * Return: 0 on success, negative error code on failure. + */ +int kvm_pgtable_get_leaf(struct kvm_pgtable *pgt, u64 addr, + kvm_pte_t *ptep, u32 *level); + /** * kvm_pgtable_stage2_find_range() - Find a range of Intermediate Physical * Addresses with compatible permission diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index 05321f4165e3..78f36bd5df6c 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -326,6 +326,45 @@ int kvm_pgtable_walk(struct kvm_pgtable *pgt, u64 addr, u64 size, return _kvm_pgtable_walk(&walk_data); } +struct leaf_walk_data { + kvm_pte_t pte; + u32 level; +}; + +static int leaf_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, + enum kvm_pgtable_walk_flags flag, void * const arg) +{ + struct leaf_walk_data *data = arg; + + data->pte = *ptep; + data->level = level; + + return 0; +} + +int kvm_pgtable_get_leaf(struct kvm_pgtable *pgt, u64 addr, + kvm_pte_t *ptep, u32 *level) +{ + struct leaf_walk_data data; + struct kvm_pgtable_walker walker = { + .cb = leaf_walker, + .flags = KVM_PGTABLE_WALK_LEAF, + .arg = &data, + }; + int ret; + + ret = kvm_pgtable_walk(pgt, ALIGN_DOWN(addr, PAGE_SIZE), + PAGE_SIZE, &walker); + if (!ret) { + if (ptep) + *ptep = data.pte; + if (level) + *level = data.level; + } + + return ret; +} + struct hyp_map_data { u64 phys; kvm_pte_t attr;