| Message ID | 1442331684-28818-13-git-send-email-suzuki.poulose@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 15/09/15 16:41, Suzuki K. Poulose wrote: > From: "Suzuki K. Poulose" <suzuki.poulose@arm.com> > > Rearrange the code for fake pgd handling, which is applicable > to only ARM64. The intention is to keep the common code cleaner, > unaware of the underlying hacks. > > Cc: kvmarm@lists.cs.columbia.edu > Cc: christoffer.dall@linaro.org > Cc: Marc.Zyngier@arm.com > Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> > --- > arch/arm/include/asm/kvm_mmu.h | 7 ++++++ > arch/arm/kvm/mmu.c | 44 +++++--------------------------------- > arch/arm64/include/asm/kvm_mmu.h | 43 +++++++++++++++++++++++++++++++++++++ > 3 files changed, 55 insertions(+), 39 deletions(-) > > diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h > index 405aa18..1c9aa8a 100644 > --- a/arch/arm/include/asm/kvm_mmu.h > +++ b/arch/arm/include/asm/kvm_mmu.h > @@ -173,6 +173,13 @@ static inline unsigned int kvm_get_hwpgd_size(void) > return PTRS_PER_S2_PGD * sizeof(pgd_t); > } > > +static inline pgd_t *kvm_setup_fake_pgd(pgd_t *pgd) > +{ > + return pgd; > +} > + > +static inline void kvm_free_fake_pgd(pgd_t *pgd) {} > + > struct kvm; > > #define kvm_flush_dcache_to_poc(a,l) __cpuc_flush_dcache_area((a), (l)) > diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c > index 7b42012..b210622 100644 > --- a/arch/arm/kvm/mmu.c > +++ b/arch/arm/kvm/mmu.c > @@ -677,43 +677,11 @@ int kvm_alloc_stage2_pgd(struct kvm *kvm) > * guest, we allocate a fake PGD and pre-populate it to point > * to the next-level page table, which will be the real > * initial page table pointed to by the VTTBR. > - * > - * When KVM_PREALLOC_LEVEL==2, we allocate a single page for > - * the PMD and the kernel will use folded pud. > - * When KVM_PREALLOC_LEVEL==1, we allocate 2 consecutive PUD > - * pages. > */ > - if (KVM_PREALLOC_LEVEL > 0) { > - int i; > - > - /* > - * Allocate fake pgd for the page table manipulation macros to > - * work. This is not used by the hardware and we have no > - * alignment requirement for this allocation. > - */ > - pgd = kmalloc(PTRS_PER_S2_PGD * sizeof(pgd_t), > - GFP_KERNEL | __GFP_ZERO); > - > - if (!pgd) { > - kvm_free_hwpgd(hwpgd); > - return -ENOMEM; > - } > - > - /* Plug the HW PGD into the fake one. */ > - for (i = 0; i < PTRS_PER_S2_PGD; i++) { > - if (KVM_PREALLOC_LEVEL == 1) > - pgd_populate(NULL, pgd + i, > - (pud_t *)hwpgd + i * PTRS_PER_PUD); > - else if (KVM_PREALLOC_LEVEL == 2) > - pud_populate(NULL, pud_offset(pgd, 0) + i, > - (pmd_t *)hwpgd + i * PTRS_PER_PMD); > - } > - } else { > - /* > - * Allocate actual first-level Stage-2 page table used by the > - * hardware for Stage-2 page table walks. > - */ > - pgd = (pgd_t *)hwpgd; > + pgd = kvm_setup_fake_pgd(hwpgd); > + if (IS_ERR(pgd)) { > + kvm_free_hwpgd(hwpgd); > + return PTR_ERR(pgd); > } > > kvm_clean_pgd(pgd); > @@ -820,9 +788,7 @@ void kvm_free_stage2_pgd(struct kvm *kvm) > > unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE); > kvm_free_hwpgd(kvm_get_hwpgd(kvm)); > - if (KVM_PREALLOC_LEVEL > 0) > - kfree(kvm->arch.pgd); > - > + kvm_free_fake_pgd(kvm->arch.pgd); > kvm->arch.pgd = NULL; > } > > diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h > index 6150567..2567fe8 100644 > --- a/arch/arm64/include/asm/kvm_mmu.h > +++ b/arch/arm64/include/asm/kvm_mmu.h > @@ -198,6 +198,49 @@ static inline unsigned int kvm_get_hwpgd_size(void) > return PTRS_PER_S2_PGD * sizeof(pgd_t); > } > > +/* > + * Allocate fake pgd for the page table manipulation macros to > + * work. This is not used by the hardware and we have no > + * alignment requirement for this allocation. > + */ > +static inline pgd_t* kvm_setup_fake_pgd(pgd_t *hwpgd) > +{ > + int i; > + pgd_t *pgd; > + > + if (!KVM_PREALLOC_LEVEL) > + return hwpgd; > + /* > + * When KVM_PREALLOC_LEVEL==2, we allocate a single page for > + * the PMD and the kernel will use folded pud. > + * When KVM_PREALLOC_LEVEL==1, we allocate 2 consecutive PUD > + * pages. > + */ > + pgd = kmalloc(PTRS_PER_S2_PGD * sizeof(pgd_t), > + GFP_KERNEL | __GFP_ZERO); > + > + if (!pgd) > + return ERR_PTR(-ENOMEM); > + > + /* Plug the HW PGD into the fake one. */ > + for (i = 0; i < PTRS_PER_S2_PGD; i++) { > + if (KVM_PREALLOC_LEVEL == 1) > + pgd_populate(NULL, pgd + i, > + (pud_t *)hwpgd + i * PTRS_PER_PUD); > + else if (KVM_PREALLOC_LEVEL == 2) > + pud_populate(NULL, pud_offset(pgd, 0) + i, > + (pmd_t *)hwpgd + i * PTRS_PER_PMD); > + } > + > + return pgd; > +} > + > +static inline void kvm_free_fake_pgd(pgd_t *pgd) > +{ > + if (KVM_PREALLOC_LEVEL > 0) > + kfree(pgd); > +} > + > static inline bool kvm_page_empty(void *ptr) > { > struct page *ptr_page = virt_to_page(ptr); > Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> M.
On Wed, Oct 07, 2015 at 11:23:52AM +0100, Marc Zyngier wrote: > On 15/09/15 16:41, Suzuki K. Poulose wrote: > > From: "Suzuki K. Poulose" <suzuki.poulose@arm.com> > > > > Rearrange the code for fake pgd handling, which is applicable > > to only ARM64. The intention is to keep the common code cleaner, > > unaware of the underlying hacks. > > > > Cc: kvmarm@lists.cs.columbia.edu > > Cc: christoffer.dall@linaro.org > > Cc: Marc.Zyngier@arm.com > > Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> > > --- > > arch/arm/include/asm/kvm_mmu.h | 7 ++++++ > > arch/arm/kvm/mmu.c | 44 +++++--------------------------------- > > arch/arm64/include/asm/kvm_mmu.h | 43 +++++++++++++++++++++++++++++++++++++ > > 3 files changed, 55 insertions(+), 39 deletions(-) > > > > diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h > > index 405aa18..1c9aa8a 100644 > > --- a/arch/arm/include/asm/kvm_mmu.h > > +++ b/arch/arm/include/asm/kvm_mmu.h > > @@ -173,6 +173,13 @@ static inline unsigned int kvm_get_hwpgd_size(void) > > return PTRS_PER_S2_PGD * sizeof(pgd_t); > > } > > > > +static inline pgd_t *kvm_setup_fake_pgd(pgd_t *pgd) > > +{ > > + return pgd; > > +} > > + > > +static inline void kvm_free_fake_pgd(pgd_t *pgd) {} > > + > > struct kvm; > > > > #define kvm_flush_dcache_to_poc(a,l) __cpuc_flush_dcache_area((a), (l)) > > diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c > > index 7b42012..b210622 100644 > > --- a/arch/arm/kvm/mmu.c > > +++ b/arch/arm/kvm/mmu.c > > @@ -677,43 +677,11 @@ int kvm_alloc_stage2_pgd(struct kvm *kvm) > > * guest, we allocate a fake PGD and pre-populate it to point > > * to the next-level page table, which will be the real > > * initial page table pointed to by the VTTBR. > > - * > > - * When KVM_PREALLOC_LEVEL==2, we allocate a single page for > > - * the PMD and the kernel will use folded pud. > > - * When KVM_PREALLOC_LEVEL==1, we allocate 2 consecutive PUD > > - * pages. > > */ > > - if (KVM_PREALLOC_LEVEL > 0) { > > - int i; > > - > > - /* > > - * Allocate fake pgd for the page table manipulation macros to > > - * work. This is not used by the hardware and we have no > > - * alignment requirement for this allocation. > > - */ > > - pgd = kmalloc(PTRS_PER_S2_PGD * sizeof(pgd_t), > > - GFP_KERNEL | __GFP_ZERO); > > - > > - if (!pgd) { > > - kvm_free_hwpgd(hwpgd); > > - return -ENOMEM; > > - } > > - > > - /* Plug the HW PGD into the fake one. */ > > - for (i = 0; i < PTRS_PER_S2_PGD; i++) { > > - if (KVM_PREALLOC_LEVEL == 1) > > - pgd_populate(NULL, pgd + i, > > - (pud_t *)hwpgd + i * PTRS_PER_PUD); > > - else if (KVM_PREALLOC_LEVEL == 2) > > - pud_populate(NULL, pud_offset(pgd, 0) + i, > > - (pmd_t *)hwpgd + i * PTRS_PER_PMD); > > - } > > - } else { > > - /* > > - * Allocate actual first-level Stage-2 page table used by the > > - * hardware for Stage-2 page table walks. > > - */ > > - pgd = (pgd_t *)hwpgd; > > + pgd = kvm_setup_fake_pgd(hwpgd); > > + if (IS_ERR(pgd)) { > > + kvm_free_hwpgd(hwpgd); > > + return PTR_ERR(pgd); > > } > > > > kvm_clean_pgd(pgd); > > @@ -820,9 +788,7 @@ void kvm_free_stage2_pgd(struct kvm *kvm) > > > > unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE); > > kvm_free_hwpgd(kvm_get_hwpgd(kvm)); > > - if (KVM_PREALLOC_LEVEL > 0) > > - kfree(kvm->arch.pgd); > > - > > + kvm_free_fake_pgd(kvm->arch.pgd); > > kvm->arch.pgd = NULL; > > } > > > > diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h > > index 6150567..2567fe8 100644 > > --- a/arch/arm64/include/asm/kvm_mmu.h > > +++ b/arch/arm64/include/asm/kvm_mmu.h > > @@ -198,6 +198,49 @@ static inline unsigned int kvm_get_hwpgd_size(void) > > return PTRS_PER_S2_PGD * sizeof(pgd_t); > > } > > > > +/* > > + * Allocate fake pgd for the page table manipulation macros to > > + * work. This is not used by the hardware and we have no > > + * alignment requirement for this allocation. > > + */ > > +static inline pgd_t* kvm_setup_fake_pgd(pgd_t *hwpgd) > > +{ > > + int i; > > + pgd_t *pgd; > > + > > + if (!KVM_PREALLOC_LEVEL) > > + return hwpgd; > > + /* > > + * When KVM_PREALLOC_LEVEL==2, we allocate a single page for > > + * the PMD and the kernel will use folded pud. > > + * When KVM_PREALLOC_LEVEL==1, we allocate 2 consecutive PUD > > + * pages. > > + */ > > + pgd = kmalloc(PTRS_PER_S2_PGD * sizeof(pgd_t), > > + GFP_KERNEL | __GFP_ZERO); > > + > > + if (!pgd) > > + return ERR_PTR(-ENOMEM); > > + > > + /* Plug the HW PGD into the fake one. */ > > + for (i = 0; i < PTRS_PER_S2_PGD; i++) { > > + if (KVM_PREALLOC_LEVEL == 1) > > + pgd_populate(NULL, pgd + i, > > + (pud_t *)hwpgd + i * PTRS_PER_PUD); > > + else if (KVM_PREALLOC_LEVEL == 2) > > + pud_populate(NULL, pud_offset(pgd, 0) + i, > > + (pmd_t *)hwpgd + i * PTRS_PER_PMD); > > + } > > + > > + return pgd; > > +} > > + > > +static inline void kvm_free_fake_pgd(pgd_t *pgd) > > +{ > > + if (KVM_PREALLOC_LEVEL > 0) > > + kfree(pgd); > > +} > > + > > static inline bool kvm_page_empty(void *ptr) > > { > > struct page *ptr_page = virt_to_page(ptr); > > > > Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> I see we like moving this code around: a987370 (arm64: KVM: Fix stage-2 PGD allocation to have per-page refcounting, 2015-03-10) But I think the end result from this patch looks nice and it seems correct to me: Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Thanks, -Christoffer -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index 405aa18..1c9aa8a 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -173,6 +173,13 @@ static inline unsigned int kvm_get_hwpgd_size(void) return PTRS_PER_S2_PGD * sizeof(pgd_t); } +static inline pgd_t *kvm_setup_fake_pgd(pgd_t *pgd) +{ + return pgd; +} + +static inline void kvm_free_fake_pgd(pgd_t *pgd) {} + struct kvm; #define kvm_flush_dcache_to_poc(a,l) __cpuc_flush_dcache_area((a), (l)) diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 7b42012..b210622 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -677,43 +677,11 @@ int kvm_alloc_stage2_pgd(struct kvm *kvm) * guest, we allocate a fake PGD and pre-populate it to point * to the next-level page table, which will be the real * initial page table pointed to by the VTTBR. - * - * When KVM_PREALLOC_LEVEL==2, we allocate a single page for - * the PMD and the kernel will use folded pud. - * When KVM_PREALLOC_LEVEL==1, we allocate 2 consecutive PUD - * pages. */ - if (KVM_PREALLOC_LEVEL > 0) { - int i; - - /* - * Allocate fake pgd for the page table manipulation macros to - * work. This is not used by the hardware and we have no - * alignment requirement for this allocation. - */ - pgd = kmalloc(PTRS_PER_S2_PGD * sizeof(pgd_t), - GFP_KERNEL | __GFP_ZERO); - - if (!pgd) { - kvm_free_hwpgd(hwpgd); - return -ENOMEM; - } - - /* Plug the HW PGD into the fake one. */ - for (i = 0; i < PTRS_PER_S2_PGD; i++) { - if (KVM_PREALLOC_LEVEL == 1) - pgd_populate(NULL, pgd + i, - (pud_t *)hwpgd + i * PTRS_PER_PUD); - else if (KVM_PREALLOC_LEVEL == 2) - pud_populate(NULL, pud_offset(pgd, 0) + i, - (pmd_t *)hwpgd + i * PTRS_PER_PMD); - } - } else { - /* - * Allocate actual first-level Stage-2 page table used by the - * hardware for Stage-2 page table walks. - */ - pgd = (pgd_t *)hwpgd; + pgd = kvm_setup_fake_pgd(hwpgd); + if (IS_ERR(pgd)) { + kvm_free_hwpgd(hwpgd); + return PTR_ERR(pgd); } kvm_clean_pgd(pgd); @@ -820,9 +788,7 @@ void kvm_free_stage2_pgd(struct kvm *kvm) unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE); kvm_free_hwpgd(kvm_get_hwpgd(kvm)); - if (KVM_PREALLOC_LEVEL > 0) - kfree(kvm->arch.pgd); - + kvm_free_fake_pgd(kvm->arch.pgd); kvm->arch.pgd = NULL; } diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 6150567..2567fe8 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -198,6 +198,49 @@ static inline unsigned int kvm_get_hwpgd_size(void) return PTRS_PER_S2_PGD * sizeof(pgd_t); } +/* + * Allocate fake pgd for the page table manipulation macros to + * work. This is not used by the hardware and we have no + * alignment requirement for this allocation. + */ +static inline pgd_t* kvm_setup_fake_pgd(pgd_t *hwpgd) +{ + int i; + pgd_t *pgd; + + if (!KVM_PREALLOC_LEVEL) + return hwpgd; + /* + * When KVM_PREALLOC_LEVEL==2, we allocate a single page for + * the PMD and the kernel will use folded pud. + * When KVM_PREALLOC_LEVEL==1, we allocate 2 consecutive PUD + * pages. + */ + pgd = kmalloc(PTRS_PER_S2_PGD * sizeof(pgd_t), + GFP_KERNEL | __GFP_ZERO); + + if (!pgd) + return ERR_PTR(-ENOMEM); + + /* Plug the HW PGD into the fake one. */ + for (i = 0; i < PTRS_PER_S2_PGD; i++) { + if (KVM_PREALLOC_LEVEL == 1) + pgd_populate(NULL, pgd + i, + (pud_t *)hwpgd + i * PTRS_PER_PUD); + else if (KVM_PREALLOC_LEVEL == 2) + pud_populate(NULL, pud_offset(pgd, 0) + i, + (pmd_t *)hwpgd + i * PTRS_PER_PMD); + } + + return pgd; +} + +static inline void kvm_free_fake_pgd(pgd_t *pgd) +{ + if (KVM_PREALLOC_LEVEL > 0) + kfree(pgd); +} + static inline bool kvm_page_empty(void *ptr) { struct page *ptr_page = virt_to_page(ptr);