Re: [PATCH] KVM: ARM: Remove pgtable page standard functions from stage-2 page tables
From: Suzuki K Poulose <suzuki.poulose@arm.com>
Date: 2019-03-12 10:37:17
Also in:
linux-mm
Hi Anshuman, On 12/03/2019 02:19, Anshuman Khandual wrote:
quoted hunk ↗ jump to hunk
ARM64 standard pgtable functions are going to use pgtable_page_[ctor|dtor] or pgtable_pmd_page_[ctor|dtor] constructs. At present KVM guest stage-2 PUD|PMD|PTE level page tabe pages are allocated with __get_free_page() via mmu_memory_cache_alloc() but released with standard pud|pmd_free() or pte_free_kernel(). These will fail once they start calling into pgtable_ [pmd]_page_dtor() for pages which never originally went through respective constructor functions. Hence convert all stage-2 page table page release functions to call buddy directly while freeing pages. Signed-off-by: Anshuman Khandual <redacted> --- arch/arm/include/asm/stage2_pgtable.h | 4 ++-- arch/arm64/include/asm/stage2_pgtable.h | 4 ++-- virt/kvm/arm/mmu.c | 2 +- 3 files changed, 5 insertions(+), 5 deletions(-)diff --git a/arch/arm/include/asm/stage2_pgtable.h b/arch/arm/include/asm/stage2_pgtable.h index de2089501b8b..417a3be00718 100644 --- a/arch/arm/include/asm/stage2_pgtable.h +++ b/arch/arm/include/asm/stage2_pgtable.h@@ -32,14 +32,14 @@ #define stage2_pgd_present(kvm, pgd) pgd_present(pgd) #define stage2_pgd_populate(kvm, pgd, pud) pgd_populate(NULL, pgd, pud) #define stage2_pud_offset(kvm, pgd, address) pud_offset(pgd, address) -#define stage2_pud_free(kvm, pud) pud_free(NULL, pud) +#define stage2_pud_free(kvm, pud) free_page((unsigned long)pud)
That must be a NOP, as we don't have pud on arm32 (we have 3 level table). The pud_* helpers here all fallback to the generic no-pud helpers.
quoted hunk ↗ jump to hunk
#define stage2_pud_none(kvm, pud) pud_none(pud) #define stage2_pud_clear(kvm, pud) pud_clear(pud) #define stage2_pud_present(kvm, pud) pud_present(pud) #define stage2_pud_populate(kvm, pud, pmd) pud_populate(NULL, pud, pmd) #define stage2_pmd_offset(kvm, pud, address) pmd_offset(pud, address) -#define stage2_pmd_free(kvm, pmd) pmd_free(NULL, pmd) +#define stage2_pmd_free(kvm, pmd) free_page((unsigned long)pmd) #define stage2_pud_huge(kvm, pud) pud_huge(pud)diff --git a/arch/arm64/include/asm/stage2_pgtable.h b/arch/arm64/include/asm/stage2_pgtable.h index 5412fa40825e..915809e4ac32 100644 --- a/arch/arm64/include/asm/stage2_pgtable.h +++ b/arch/arm64/include/asm/stage2_pgtable.h@@ -119,7 +119,7 @@ static inline pud_t *stage2_pud_offset(struct kvm *kvm, static inline void stage2_pud_free(struct kvm *kvm, pud_t *pud) { if (kvm_stage2_has_pud(kvm)) - pud_free(NULL, pud); + free_page((unsigned long)pud); } static inline bool stage2_pud_table_empty(struct kvm *kvm, pud_t *pudp)@@ -192,7 +192,7 @@ static inline pmd_t *stage2_pmd_offset(struct kvm *kvm, static inline void stage2_pmd_free(struct kvm *kvm, pmd_t *pmd) { if (kvm_stage2_has_pmd(kvm)) - pmd_free(NULL, pmd); + free_page((unsigned long)pmd); } static inline bool stage2_pud_huge(struct kvm *kvm, pud_t pud)diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index e9d28a7ca673..00bd79a2f0b1 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c@@ -191,7 +191,7 @@ static void clear_stage2_pmd_entry(struct kvm *kvm, pmd_t *pmd, phys_addr_t addr VM_BUG_ON(pmd_thp_or_huge(*pmd)); pmd_clear(pmd); kvm_tlb_flush_vmid_ipa(kvm, addr); - pte_free_kernel(NULL, pte_table); + __free_page(virt_to_page(pte_table)); put_page(virt_to_page(pmd)); }
With that fixed, Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel