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[188.178.240.98]) by mx.google.com with ESMTPSA id lq20sm18482387lbb.24.2014.05.28.07.23.02 for (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 28 May 2014 07:23:03 -0700 (PDT) From: Christoffer Dall To: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Subject: [PATCH v2] arm/arm64: KVM: Fix and refactor unmap_range Date: Wed, 28 May 2014 16:22:56 +0200 Message-Id: <1401286977-59260-1-git-send-email-christoffer.dall@linaro.org> X-Mailer: git-send-email 1.8.5.2 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140528_072327_342075_1A58A147 X-CRM114-Status: GOOD ( 16.23 ) X-Spam-Score: -0.7 (/) X-Spam-Report: SpamAssassin version 3.3.2 on bombadil.infradead.org summary: Content analysis details: (-0.7 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [209.85.215.50 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record Cc: Marc Zyngier , Steve Capper , Christoffer Dall , Jungseok Lee , Mario Smarduch X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: , List-Help: , List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org X-Removed-Original-Auth: Dkim didn't pass. X-Original-Sender: christoffer.dall@linaro.org X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of patch+caf_=patchwork-forward=linaro.org@linaro.org designates 209.85.220.181 as permitted sender) smtp.mail=patch+caf_=patchwork-forward=linaro.org@linaro.org Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org X-Google-Group-Id: 836684582541 unmap_range() was utterly broken, to quote Marc, and broke in all sorts of situations. It was also quite complicated to follow and didn't follow the usual scheme of having a separate iterating function for each level of page tables. Address this by refactoring the code and introduce a pgd_clear() function. Acked-by: Marc Zyngier Signed-off-by: Christoffer Dall Reviewed-by: Jungseok Lee Reviewed-by: Mario Smarduch --- Changes since v2: - Don't define custom __unused but reuse __maybe_unused arch/arm/include/asm/kvm_mmu.h | 12 ++++ arch/arm/kvm/mmu.c | 122 ++++++++++++++++++++++----------------- arch/arm64/include/asm/kvm_mmu.h | 15 +++++ 3 files changed, 95 insertions(+), 54 deletions(-) diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index 5c7aa3c..5cc0b0f 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -127,6 +127,18 @@ static inline void kvm_set_s2pmd_writable(pmd_t *pmd) (__boundary - 1 < (end) - 1)? __boundary: (end); \ }) +static inline bool kvm_page_empty(void *ptr) +{ + struct page *ptr_page = virt_to_page(ptr); + return page_count(ptr_page) == 1; +} + + +#define kvm_pte_table_empty(ptep) kvm_page_empty(ptep) +#define kvm_pmd_table_empty(pmdp) kvm_page_empty(pmdp) +#define kvm_pud_table_empty(pudp) (0) + + 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 16f8049..6ee6e06 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -90,10 +90,13 @@ static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc) return p; } -static bool page_empty(void *ptr) +static void clear_pgd_entry(struct kvm *kvm, pgd_t *pgd, phys_addr_t addr) { - struct page *ptr_page = virt_to_page(ptr); - return page_count(ptr_page) == 1; + pud_t *pud_table __maybe_unused = pud_offset(pgd, 0); + pgd_clear(pgd); + kvm_tlb_flush_vmid_ipa(kvm, addr); + pud_free(NULL, pud_table); + put_page(virt_to_page(pgd)); } static void clear_pud_entry(struct kvm *kvm, pud_t *pud, phys_addr_t addr) @@ -124,70 +127,81 @@ static void clear_pmd_entry(struct kvm *kvm, pmd_t *pmd, phys_addr_t addr) put_page(virt_to_page(pmd)); } -static void clear_pte_entry(struct kvm *kvm, pte_t *pte, phys_addr_t addr) +static void unmap_ptes(struct kvm *kvm, pmd_t *pmd, + unsigned long long addr, unsigned long long end) { - if (pte_present(*pte)) { - kvm_set_pte(pte, __pte(0)); - put_page(virt_to_page(pte)); - kvm_tlb_flush_vmid_ipa(kvm, addr); - } + pte_t *pte, *start_pte; + unsigned long long start_addr = addr; + + start_pte = pte = pte_offset_kernel(pmd, addr); + do { + if (!pte_none(*pte)) { + kvm_set_pte(pte, __pte(0)); + put_page(virt_to_page(pte)); + kvm_tlb_flush_vmid_ipa(kvm, addr); + } + } while (pte++, addr += PAGE_SIZE, addr != end); + + if (kvm_pte_table_empty(start_pte)) + clear_pmd_entry(kvm, pmd, start_addr); } -static void unmap_range(struct kvm *kvm, pgd_t *pgdp, - unsigned long long start, u64 size) +static void unmap_pmds(struct kvm *kvm, pud_t *pud, + unsigned long long addr, unsigned long long end) { - pgd_t *pgd; - pud_t *pud; - pmd_t *pmd; - pte_t *pte; - unsigned long long addr = start, end = start + size; - u64 next; - - while (addr < end) { - pgd = pgdp + pgd_index(addr); - pud = pud_offset(pgd, addr); - pte = NULL; - if (pud_none(*pud)) { - addr = kvm_pud_addr_end(addr, end); - continue; - } + unsigned long long next, start_addr = addr; + pmd_t *pmd, *start_pmd; - if (pud_huge(*pud)) { - /* - * If we are dealing with a huge pud, just clear it and - * move on. - */ - clear_pud_entry(kvm, pud, addr); - addr = kvm_pud_addr_end(addr, end); - continue; + start_pmd = pmd = pmd_offset(pud, addr); + do { + next = kvm_pmd_addr_end(addr, end); + if (!pmd_none(*pmd)) { + if (kvm_pmd_huge(*pmd)) + clear_pmd_entry(kvm, pmd, addr); + else + unmap_ptes(kvm, pmd, addr, next); } + } while (pmd++, addr = next, addr != end); - pmd = pmd_offset(pud, addr); - if (pmd_none(*pmd)) { - addr = kvm_pmd_addr_end(addr, end); - continue; - } + if (kvm_pmd_table_empty(start_pmd)) + clear_pud_entry(kvm, pud, start_addr); +} - if (!kvm_pmd_huge(*pmd)) { - pte = pte_offset_kernel(pmd, addr); - clear_pte_entry(kvm, pte, addr); - next = addr + PAGE_SIZE; - } +static void unmap_puds(struct kvm *kvm, pgd_t *pgd, + unsigned long long addr, unsigned long long end) +{ + unsigned long long next, start_addr = addr; + pud_t *pud, *start_pud; - /* - * If the pmd entry is to be cleared, walk back up the ladder - */ - if (kvm_pmd_huge(*pmd) || (pte && page_empty(pte))) { - clear_pmd_entry(kvm, pmd, addr); - next = kvm_pmd_addr_end(addr, end); - if (page_empty(pmd) && !page_empty(pud)) { + start_pud = pud = pud_offset(pgd, addr); + do { + next = kvm_pud_addr_end(addr, end); + if (!pud_none(*pud)) { + if (pud_huge(*pid)) { clear_pud_entry(kvm, pud, addr); - next = kvm_pud_addr_end(addr, end); + } else { + unmap_pmds(kvm, pud, addr, next); } } + } while (pud++, addr = next, addr != end); - addr = next; - } + if (kvm_pud_table_empty(start_pud)) + clear_pgd_entry(kvm, pgd, start_addr); +} + + +static void unmap_range(struct kvm *kvm, pgd_t *pgdp, + unsigned long long start, u64 size) +{ + pgd_t *pgd; + unsigned long long addr = start, end = start + size; + unsigned long long next; + + pgd = pgdp + pgd_index(addr); + do { + next = kvm_pgd_addr_end(addr, end); + unmap_puds(kvm, pgd, addr, next); + } while (pgd++, addr = next, addr != end); } static void stage2_flush_ptes(struct kvm *kvm, pmd_t *pmd, diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 7d29847..8e138c7 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -125,6 +125,21 @@ static inline void kvm_set_s2pmd_writable(pmd_t *pmd) #define kvm_pud_addr_end(addr, end) pud_addr_end(addr, end) #define kvm_pmd_addr_end(addr, end) pmd_addr_end(addr, end) +static inline bool kvm_page_empty(void *ptr) +{ + struct page *ptr_page = virt_to_page(ptr); + return page_count(ptr_page) == 1; +} + +#define kvm_pte_table_empty(ptep) kvm_page_empty(ptep) +#ifndef CONFIG_ARM64_64K_PAGES +#define kvm_pmd_table_empty(pmdp) kvm_page_empty(pmdp) +#else +#define kvm_pmd_table_empty(pmdp) (0) +#endif +#define kvm_pud_table_empty(pudp) (0) + + struct kvm; #define kvm_flush_dcache_to_poc(a,l) __flush_dcache_area((a), (l))