| Message ID | 20221107215644.1895162-5-oliver.upton@linux.dev (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: arm64: Parallel stage-2 fault handling | expand |
On Mon, Nov 7, 2022 at 1:57 PM Oliver Upton <oliver.upton@linux.dev> wrote: > > In order to tear down page tables from outside the context of > kvm_pgtable (such as an RCU callback), stop passing a pointer through > kvm_pgtable_walk_data. > > No functional change intended. > > Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Reviewed-by: Ben Gardon <bgardon@google.com> > --- > arch/arm64/kvm/hyp/pgtable.c | 18 +++++------------- > 1 file changed, 5 insertions(+), 13 deletions(-) > > diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c > index db25e81a9890..93989b750a26 100644 > --- a/arch/arm64/kvm/hyp/pgtable.c > +++ b/arch/arm64/kvm/hyp/pgtable.c > @@ -50,7 +50,6 @@ > #define KVM_MAX_OWNER_ID 1 > > struct kvm_pgtable_walk_data { > - struct kvm_pgtable *pgt; > struct kvm_pgtable_walker *walker; > > u64 addr; > @@ -88,7 +87,7 @@ static u32 kvm_pgtable_idx(struct kvm_pgtable_walk_data *data, u32 level) > return (data->addr >> shift) & mask; > } > > -static u32 __kvm_pgd_page_idx(struct kvm_pgtable *pgt, u64 addr) > +static u32 kvm_pgd_page_idx(struct kvm_pgtable *pgt, u64 addr) > { > u64 shift = kvm_granule_shift(pgt->start_level - 1); /* May underflow */ > u64 mask = BIT(pgt->ia_bits) - 1; > @@ -96,11 +95,6 @@ static u32 __kvm_pgd_page_idx(struct kvm_pgtable *pgt, u64 addr) > return (addr & mask) >> shift; > } > > -static u32 kvm_pgd_page_idx(struct kvm_pgtable_walk_data *data) > -{ > - return __kvm_pgd_page_idx(data->pgt, data->addr); > -} > - > static u32 kvm_pgd_pages(u32 ia_bits, u32 start_level) > { > struct kvm_pgtable pgt = { > @@ -108,7 +102,7 @@ static u32 kvm_pgd_pages(u32 ia_bits, u32 start_level) > .start_level = start_level, > }; > > - return __kvm_pgd_page_idx(&pgt, -1ULL) + 1; > + return kvm_pgd_page_idx(&pgt, -1ULL) + 1; > } > > static bool kvm_pte_table(kvm_pte_t pte, u32 level) > @@ -255,11 +249,10 @@ static int __kvm_pgtable_walk(struct kvm_pgtable_walk_data *data, > return ret; > } > > -static int _kvm_pgtable_walk(struct kvm_pgtable_walk_data *data) > +static int _kvm_pgtable_walk(struct kvm_pgtable *pgt, struct kvm_pgtable_walk_data *data) > { > u32 idx; > int ret = 0; > - struct kvm_pgtable *pgt = data->pgt; > u64 limit = BIT(pgt->ia_bits); > > if (data->addr > limit || data->end > limit) > @@ -268,7 +261,7 @@ static int _kvm_pgtable_walk(struct kvm_pgtable_walk_data *data) > if (!pgt->pgd) > return -EINVAL; > > - for (idx = kvm_pgd_page_idx(data); data->addr < data->end; ++idx) { > + for (idx = kvm_pgd_page_idx(pgt, data->addr); data->addr < data->end; ++idx) { > kvm_pte_t *ptep = &pgt->pgd[idx * PTRS_PER_PTE]; > > ret = __kvm_pgtable_walk(data, pgt->mm_ops, ptep, pgt->start_level); > @@ -283,13 +276,12 @@ int kvm_pgtable_walk(struct kvm_pgtable *pgt, u64 addr, u64 size, > struct kvm_pgtable_walker *walker) > { > struct kvm_pgtable_walk_data walk_data = { > - .pgt = pgt, > .addr = ALIGN_DOWN(addr, PAGE_SIZE), > .end = PAGE_ALIGN(walk_data.addr + size), > .walker = walker, > }; > > - return _kvm_pgtable_walk(&walk_data); > + return _kvm_pgtable_walk(pgt, &walk_data); > } > > struct leaf_walk_data { > -- > 2.38.1.431.g37b22c650d-goog >
Hi Oliver, On 11/8/22 5:56 AM, Oliver Upton wrote: > In order to tear down page tables from outside the context of > kvm_pgtable (such as an RCU callback), stop passing a pointer through > kvm_pgtable_walk_data. > > No functional change intended. > > Signed-off-by: Oliver Upton <oliver.upton@linux.dev> > --- > arch/arm64/kvm/hyp/pgtable.c | 18 +++++------------- > 1 file changed, 5 insertions(+), 13 deletions(-) > Reviewed-by: Gavin Shan <gshan@redhat.com> > diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c > index db25e81a9890..93989b750a26 100644 > --- a/arch/arm64/kvm/hyp/pgtable.c > +++ b/arch/arm64/kvm/hyp/pgtable.c > @@ -50,7 +50,6 @@ > #define KVM_MAX_OWNER_ID 1 > > struct kvm_pgtable_walk_data { > - struct kvm_pgtable *pgt; > struct kvm_pgtable_walker *walker; > > u64 addr; Ok. Here is the answer why data->pgt->mm_ops isn't reachable in the walker and visitor, and @mm_ops needs to be passed down. > @@ -88,7 +87,7 @@ static u32 kvm_pgtable_idx(struct kvm_pgtable_walk_data *data, u32 level) > return (data->addr >> shift) & mask; > } > > -static u32 __kvm_pgd_page_idx(struct kvm_pgtable *pgt, u64 addr) > +static u32 kvm_pgd_page_idx(struct kvm_pgtable *pgt, u64 addr) > { > u64 shift = kvm_granule_shift(pgt->start_level - 1); /* May underflow */ > u64 mask = BIT(pgt->ia_bits) - 1; > @@ -96,11 +95,6 @@ static u32 __kvm_pgd_page_idx(struct kvm_pgtable *pgt, u64 addr) > return (addr & mask) >> shift; > } > > -static u32 kvm_pgd_page_idx(struct kvm_pgtable_walk_data *data) > -{ > - return __kvm_pgd_page_idx(data->pgt, data->addr); > -} > - > static u32 kvm_pgd_pages(u32 ia_bits, u32 start_level) > { > struct kvm_pgtable pgt = { > @@ -108,7 +102,7 @@ static u32 kvm_pgd_pages(u32 ia_bits, u32 start_level) > .start_level = start_level, > }; > > - return __kvm_pgd_page_idx(&pgt, -1ULL) + 1; > + return kvm_pgd_page_idx(&pgt, -1ULL) + 1; > } > > static bool kvm_pte_table(kvm_pte_t pte, u32 level) > @@ -255,11 +249,10 @@ static int __kvm_pgtable_walk(struct kvm_pgtable_walk_data *data, > return ret; > } > > -static int _kvm_pgtable_walk(struct kvm_pgtable_walk_data *data) > +static int _kvm_pgtable_walk(struct kvm_pgtable *pgt, struct kvm_pgtable_walk_data *data) > { > u32 idx; > int ret = 0; > - struct kvm_pgtable *pgt = data->pgt; > u64 limit = BIT(pgt->ia_bits); > > if (data->addr > limit || data->end > limit) > @@ -268,7 +261,7 @@ static int _kvm_pgtable_walk(struct kvm_pgtable_walk_data *data) > if (!pgt->pgd) > return -EINVAL; > > - for (idx = kvm_pgd_page_idx(data); data->addr < data->end; ++idx) { > + for (idx = kvm_pgd_page_idx(pgt, data->addr); data->addr < data->end; ++idx) { > kvm_pte_t *ptep = &pgt->pgd[idx * PTRS_PER_PTE]; > > ret = __kvm_pgtable_walk(data, pgt->mm_ops, ptep, pgt->start_level); > @@ -283,13 +276,12 @@ int kvm_pgtable_walk(struct kvm_pgtable *pgt, u64 addr, u64 size, > struct kvm_pgtable_walker *walker) > { > struct kvm_pgtable_walk_data walk_data = { > - .pgt = pgt, > .addr = ALIGN_DOWN(addr, PAGE_SIZE), > .end = PAGE_ALIGN(walk_data.addr + size), > .walker = walker, > }; > > - return _kvm_pgtable_walk(&walk_data); > + return _kvm_pgtable_walk(pgt, &walk_data); > } > > struct leaf_walk_data { > Thanks, Gavin
On Thu, Nov 10, 2022 at 01:30:08PM +0800, Gavin Shan wrote: > Hi Oliver, > > On 11/8/22 5:56 AM, Oliver Upton wrote: > > In order to tear down page tables from outside the context of > > kvm_pgtable (such as an RCU callback), stop passing a pointer through > > kvm_pgtable_walk_data. > > > > No functional change intended. > > > > Signed-off-by: Oliver Upton <oliver.upton@linux.dev> > > --- > > arch/arm64/kvm/hyp/pgtable.c | 18 +++++------------- > > 1 file changed, 5 insertions(+), 13 deletions(-) > > > > Reviewed-by: Gavin Shan <gshan@redhat.com> Appreciated :) > > diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c > > index db25e81a9890..93989b750a26 100644 > > --- a/arch/arm64/kvm/hyp/pgtable.c > > +++ b/arch/arm64/kvm/hyp/pgtable.c > > @@ -50,7 +50,6 @@ > > #define KVM_MAX_OWNER_ID 1 > > struct kvm_pgtable_walk_data { > > - struct kvm_pgtable *pgt; > > struct kvm_pgtable_walker *walker; > > u64 addr; > > Ok. Here is the answer why data->pgt->mm_ops isn't reachable in the walker > and visitor, and @mm_ops needs to be passed down. Yup, the reason for unhitching all of this from kvm_pgtable is explained in the cover letter as well: Patches 1-4 clean up the context associated with a page table walk / PTE visit. This is helpful for: - Extending the context passed through for a visit - Building page table walkers that operate outside of a kvm_pgtable context (e.g. RCU callback) -- Thanks, Oliver
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index db25e81a9890..93989b750a26 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -50,7 +50,6 @@ #define KVM_MAX_OWNER_ID 1 struct kvm_pgtable_walk_data { - struct kvm_pgtable *pgt; struct kvm_pgtable_walker *walker; u64 addr; @@ -88,7 +87,7 @@ static u32 kvm_pgtable_idx(struct kvm_pgtable_walk_data *data, u32 level) return (data->addr >> shift) & mask; } -static u32 __kvm_pgd_page_idx(struct kvm_pgtable *pgt, u64 addr) +static u32 kvm_pgd_page_idx(struct kvm_pgtable *pgt, u64 addr) { u64 shift = kvm_granule_shift(pgt->start_level - 1); /* May underflow */ u64 mask = BIT(pgt->ia_bits) - 1; @@ -96,11 +95,6 @@ static u32 __kvm_pgd_page_idx(struct kvm_pgtable *pgt, u64 addr) return (addr & mask) >> shift; } -static u32 kvm_pgd_page_idx(struct kvm_pgtable_walk_data *data) -{ - return __kvm_pgd_page_idx(data->pgt, data->addr); -} - static u32 kvm_pgd_pages(u32 ia_bits, u32 start_level) { struct kvm_pgtable pgt = { @@ -108,7 +102,7 @@ static u32 kvm_pgd_pages(u32 ia_bits, u32 start_level) .start_level = start_level, }; - return __kvm_pgd_page_idx(&pgt, -1ULL) + 1; + return kvm_pgd_page_idx(&pgt, -1ULL) + 1; } static bool kvm_pte_table(kvm_pte_t pte, u32 level) @@ -255,11 +249,10 @@ static int __kvm_pgtable_walk(struct kvm_pgtable_walk_data *data, return ret; } -static int _kvm_pgtable_walk(struct kvm_pgtable_walk_data *data) +static int _kvm_pgtable_walk(struct kvm_pgtable *pgt, struct kvm_pgtable_walk_data *data) { u32 idx; int ret = 0; - struct kvm_pgtable *pgt = data->pgt; u64 limit = BIT(pgt->ia_bits); if (data->addr > limit || data->end > limit) @@ -268,7 +261,7 @@ static int _kvm_pgtable_walk(struct kvm_pgtable_walk_data *data) if (!pgt->pgd) return -EINVAL; - for (idx = kvm_pgd_page_idx(data); data->addr < data->end; ++idx) { + for (idx = kvm_pgd_page_idx(pgt, data->addr); data->addr < data->end; ++idx) { kvm_pte_t *ptep = &pgt->pgd[idx * PTRS_PER_PTE]; ret = __kvm_pgtable_walk(data, pgt->mm_ops, ptep, pgt->start_level); @@ -283,13 +276,12 @@ int kvm_pgtable_walk(struct kvm_pgtable *pgt, u64 addr, u64 size, struct kvm_pgtable_walker *walker) { struct kvm_pgtable_walk_data walk_data = { - .pgt = pgt, .addr = ALIGN_DOWN(addr, PAGE_SIZE), .end = PAGE_ALIGN(walk_data.addr + size), .walker = walker, }; - return _kvm_pgtable_walk(&walk_data); + return _kvm_pgtable_walk(pgt, &walk_data); } struct leaf_walk_data {
In order to tear down page tables from outside the context of kvm_pgtable (such as an RCU callback), stop passing a pointer through kvm_pgtable_walk_data. No functional change intended. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> --- arch/arm64/kvm/hyp/pgtable.c | 18 +++++------------- 1 file changed, 5 insertions(+), 13 deletions(-)