| Message ID | 20241004152804.72508-3-steven.price@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: Support for Arm CCA in KVM | expand |
On 10/5/24 1:27 AM, Steven Price wrote: > From: Suzuki K Poulose <suzuki.poulose@arm.com> > > Keep track of the number of pages allocated for the top level PGD, > rather than computing it every time (though we need it only twice now). > This will be used later by Arm CCA KVM changes. > > Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> > Signed-off-by: Steven Price <steven.price@arm.com> > --- > arch/arm64/include/asm/kvm_pgtable.h | 2 ++ > arch/arm64/kvm/hyp/pgtable.c | 5 +++-- > 2 files changed, 5 insertions(+), 2 deletions(-) > If we really want to have the number of pages for the top level PGDs, the existing helpers kvm_pgtable_stage2_pgd_size() for the same purpose needs to replaced by (struct kvm_pgtable::pgd_pages << PAGE_SHIFT) and then removed. The alternative would be just to use kvm_pgtable_stage2_pgd_size() instead of introducing struct kvm_pgtable::pgd_pages, which will be used in the slow paths where realm is created or destroyed. > diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h > index 03f4c3d7839c..25b512756200 100644 > --- a/arch/arm64/include/asm/kvm_pgtable.h > +++ b/arch/arm64/include/asm/kvm_pgtable.h > @@ -404,6 +404,7 @@ static inline bool kvm_pgtable_walk_lock_held(void) > * struct kvm_pgtable - KVM page-table. > * @ia_bits: Maximum input address size, in bits. > * @start_level: Level at which the page-table walk starts. > + * @pgd_pages: Number of pages in the entry level of the page-table. > * @pgd: Pointer to the first top-level entry of the page-table. > * @mm_ops: Memory management callbacks. > * @mmu: Stage-2 KVM MMU struct. Unused for stage-1 page-tables. > @@ -414,6 +415,7 @@ static inline bool kvm_pgtable_walk_lock_held(void) > struct kvm_pgtable { > u32 ia_bits; > s8 start_level; > + u8 pgd_pages; > kvm_pteref_t pgd; > struct kvm_pgtable_mm_ops *mm_ops; > > diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c > index b11bcebac908..9e1be28c3dc9 100644 > --- a/arch/arm64/kvm/hyp/pgtable.c > +++ b/arch/arm64/kvm/hyp/pgtable.c > @@ -1534,7 +1534,8 @@ int __kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_s2_mmu *mmu, > u32 sl0 = FIELD_GET(VTCR_EL2_SL0_MASK, vtcr); > s8 start_level = VTCR_EL2_TGRAN_SL0_BASE - sl0; > > - pgd_sz = kvm_pgd_pages(ia_bits, start_level) * PAGE_SIZE; > + pgt->pgd_pages = kvm_pgd_pages(ia_bits, start_level); > + pgd_sz = pgt->pgd_pages * PAGE_SIZE; > pgt->pgd = (kvm_pteref_t)mm_ops->zalloc_pages_exact(pgd_sz); > if (!pgt->pgd) > return -ENOMEM; > @@ -1586,7 +1587,7 @@ void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt) > }; > > WARN_ON(kvm_pgtable_walk(pgt, 0, BIT(pgt->ia_bits), &walker)); > - pgd_sz = kvm_pgd_pages(pgt->ia_bits, pgt->start_level) * PAGE_SIZE; > + pgd_sz = pgt->pgd_pages * PAGE_SIZE; > pgt->mm_ops->free_pages_exact(kvm_dereference_pteref(&walker, pgt->pgd), pgd_sz); > pgt->pgd = NULL; > } Thanks, Gavin
On 23/10/2024 05:03, Gavin Shan wrote: > On 10/5/24 1:27 AM, Steven Price wrote: >> From: Suzuki K Poulose <suzuki.poulose@arm.com> >> >> Keep track of the number of pages allocated for the top level PGD, >> rather than computing it every time (though we need it only twice now). >> This will be used later by Arm CCA KVM changes. >> >> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> >> Signed-off-by: Steven Price <steven.price@arm.com> >> --- >> arch/arm64/include/asm/kvm_pgtable.h | 2 ++ >> arch/arm64/kvm/hyp/pgtable.c | 5 +++-- >> 2 files changed, 5 insertions(+), 2 deletions(-) >> > > If we really want to have the number of pages for the top level PGDs, > the existing helpers kvm_pgtable_stage2_pgd_size() for the same purpose > needs to replaced by (struct kvm_pgtable::pgd_pages << PAGE_SHIFT) and > then removed. > > The alternative would be just to use kvm_pgtable_stage2_pgd_size() > instead of > introducing struct kvm_pgtable::pgd_pages, which will be used in the slow > paths where realm is created or destroyed. I think just dropping this patch and using kvm_pgtable_stage2_pgd_size() in the slow paths makes sense. I think originally there had been some issue with the value being hard to obtain in the relevant path, but I can't see any problem now. Thanks, Steve >> diff --git a/arch/arm64/include/asm/kvm_pgtable.h >> b/arch/arm64/include/asm/kvm_pgtable.h >> index 03f4c3d7839c..25b512756200 100644 >> --- a/arch/arm64/include/asm/kvm_pgtable.h >> +++ b/arch/arm64/include/asm/kvm_pgtable.h >> @@ -404,6 +404,7 @@ static inline bool kvm_pgtable_walk_lock_held(void) >> * struct kvm_pgtable - KVM page-table. >> * @ia_bits: Maximum input address size, in bits. >> * @start_level: Level at which the page-table walk starts. >> + * @pgd_pages: Number of pages in the entry level of the >> page-table. >> * @pgd: Pointer to the first top-level entry of the page-table. >> * @mm_ops: Memory management callbacks. >> * @mmu: Stage-2 KVM MMU struct. Unused for stage-1 page-tables. >> @@ -414,6 +415,7 @@ static inline bool kvm_pgtable_walk_lock_held(void) >> struct kvm_pgtable { >> u32 ia_bits; >> s8 start_level; >> + u8 pgd_pages; >> kvm_pteref_t pgd; >> struct kvm_pgtable_mm_ops *mm_ops; >> diff --git a/arch/arm64/kvm/hyp/pgtable.c >> b/arch/arm64/kvm/hyp/pgtable.c >> index b11bcebac908..9e1be28c3dc9 100644 >> --- a/arch/arm64/kvm/hyp/pgtable.c >> +++ b/arch/arm64/kvm/hyp/pgtable.c >> @@ -1534,7 +1534,8 @@ int __kvm_pgtable_stage2_init(struct kvm_pgtable >> *pgt, struct kvm_s2_mmu *mmu, >> u32 sl0 = FIELD_GET(VTCR_EL2_SL0_MASK, vtcr); >> s8 start_level = VTCR_EL2_TGRAN_SL0_BASE - sl0; >> - pgd_sz = kvm_pgd_pages(ia_bits, start_level) * PAGE_SIZE; >> + pgt->pgd_pages = kvm_pgd_pages(ia_bits, start_level); >> + pgd_sz = pgt->pgd_pages * PAGE_SIZE; >> pgt->pgd = (kvm_pteref_t)mm_ops->zalloc_pages_exact(pgd_sz); >> if (!pgt->pgd) >> return -ENOMEM; >> @@ -1586,7 +1587,7 @@ void kvm_pgtable_stage2_destroy(struct >> kvm_pgtable *pgt) >> }; >> WARN_ON(kvm_pgtable_walk(pgt, 0, BIT(pgt->ia_bits), &walker)); >> - pgd_sz = kvm_pgd_pages(pgt->ia_bits, pgt->start_level) * PAGE_SIZE; >> + pgd_sz = pgt->pgd_pages * PAGE_SIZE; >> pgt->mm_ops->free_pages_exact(kvm_dereference_pteref(&walker, >> pgt->pgd), pgd_sz); >> pgt->pgd = NULL; >> } > > Thanks, > Gavin >
diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index 03f4c3d7839c..25b512756200 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -404,6 +404,7 @@ static inline bool kvm_pgtable_walk_lock_held(void) * struct kvm_pgtable - KVM page-table. * @ia_bits: Maximum input address size, in bits. * @start_level: Level at which the page-table walk starts. + * @pgd_pages: Number of pages in the entry level of the page-table. * @pgd: Pointer to the first top-level entry of the page-table. * @mm_ops: Memory management callbacks. * @mmu: Stage-2 KVM MMU struct. Unused for stage-1 page-tables. @@ -414,6 +415,7 @@ static inline bool kvm_pgtable_walk_lock_held(void) struct kvm_pgtable { u32 ia_bits; s8 start_level; + u8 pgd_pages; kvm_pteref_t pgd; struct kvm_pgtable_mm_ops *mm_ops; diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index b11bcebac908..9e1be28c3dc9 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -1534,7 +1534,8 @@ int __kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_s2_mmu *mmu, u32 sl0 = FIELD_GET(VTCR_EL2_SL0_MASK, vtcr); s8 start_level = VTCR_EL2_TGRAN_SL0_BASE - sl0; - pgd_sz = kvm_pgd_pages(ia_bits, start_level) * PAGE_SIZE; + pgt->pgd_pages = kvm_pgd_pages(ia_bits, start_level); + pgd_sz = pgt->pgd_pages * PAGE_SIZE; pgt->pgd = (kvm_pteref_t)mm_ops->zalloc_pages_exact(pgd_sz); if (!pgt->pgd) return -ENOMEM; @@ -1586,7 +1587,7 @@ void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt) }; WARN_ON(kvm_pgtable_walk(pgt, 0, BIT(pgt->ia_bits), &walker)); - pgd_sz = kvm_pgd_pages(pgt->ia_bits, pgt->start_level) * PAGE_SIZE; + pgd_sz = pgt->pgd_pages * PAGE_SIZE; pgt->mm_ops->free_pages_exact(kvm_dereference_pteref(&walker, pgt->pgd), pgd_sz); pgt->pgd = NULL; }