From d4cb9df5d1f79950b34e78ec5d1b1b59d6e9c7b7 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 14 May 2013 12:11:34 +0100 Subject: [PATCH] ARM: KVM: be more thorough when invalidating TLBs The KVM/ARM MMU code doesn't take care of invalidating TLBs before freeing a {pte,pmd} table. This could cause problems if the page is reallocated and then speculated into by another CPU. Reported-by: Catalin Marinas Signed-off-by: Marc Zyngier Acked-by: Catalin Marinas Signed-off-by: Christoffer Dall --- arch/arm/kvm/mmu.c | 41 ++++++++++++++++++++++++++--------------- 1 file changed, 26 insertions(+), 15 deletions(-) diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 965706578f13..84ba67b982c0 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -43,7 +43,14 @@ static phys_addr_t hyp_idmap_vector; static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa) { - kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, kvm, ipa); + /* + * This function also gets called when dealing with HYP page + * tables. As HYP doesn't have an associated struct kvm (and + * the HYP page tables are fairly static), we don't do + * anything there. + */ + if (kvm) + kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, kvm, ipa); } static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache, @@ -78,18 +85,20 @@ static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc) return p; } -static void clear_pud_entry(pud_t *pud) +static void clear_pud_entry(struct kvm *kvm, pud_t *pud, phys_addr_t addr) { pmd_t *pmd_table = pmd_offset(pud, 0); pud_clear(pud); + kvm_tlb_flush_vmid_ipa(kvm, addr); pmd_free(NULL, pmd_table); put_page(virt_to_page(pud)); } -static void clear_pmd_entry(pmd_t *pmd) +static void clear_pmd_entry(struct kvm *kvm, pmd_t *pmd, phys_addr_t addr) { pte_t *pte_table = pte_offset_kernel(pmd, 0); pmd_clear(pmd); + kvm_tlb_flush_vmid_ipa(kvm, addr); pte_free_kernel(NULL, pte_table); put_page(virt_to_page(pmd)); } @@ -100,11 +109,12 @@ static bool pmd_empty(pmd_t *pmd) return page_count(pmd_page) == 1; } -static void clear_pte_entry(pte_t *pte) +static void clear_pte_entry(struct kvm *kvm, pte_t *pte, phys_addr_t addr) { if (pte_present(*pte)) { kvm_set_pte(pte, __pte(0)); put_page(virt_to_page(pte)); + kvm_tlb_flush_vmid_ipa(kvm, addr); } } @@ -114,7 +124,8 @@ static bool pte_empty(pte_t *pte) return page_count(pte_page) == 1; } -static void unmap_range(pgd_t *pgdp, unsigned long long start, u64 size) +static void unmap_range(struct kvm *kvm, pgd_t *pgdp, + unsigned long long start, u64 size) { pgd_t *pgd; pud_t *pud; @@ -138,15 +149,15 @@ static void unmap_range(pgd_t *pgdp, unsigned long long start, u64 size) } pte = pte_offset_kernel(pmd, addr); - clear_pte_entry(pte); + clear_pte_entry(kvm, pte, addr); range = PAGE_SIZE; /* If we emptied the pte, walk back up the ladder */ if (pte_empty(pte)) { - clear_pmd_entry(pmd); + clear_pmd_entry(kvm, pmd, addr); range = PMD_SIZE; if (pmd_empty(pmd)) { - clear_pud_entry(pud); + clear_pud_entry(kvm, pud, addr); range = PUD_SIZE; } } @@ -165,14 +176,14 @@ void free_boot_hyp_pgd(void) mutex_lock(&kvm_hyp_pgd_mutex); if (boot_hyp_pgd) { - unmap_range(boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE); - unmap_range(boot_hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE); + unmap_range(NULL, boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE); + unmap_range(NULL, boot_hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE); kfree(boot_hyp_pgd); boot_hyp_pgd = NULL; } if (hyp_pgd) - unmap_range(hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE); + unmap_range(NULL, hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE); kfree(init_bounce_page); init_bounce_page = NULL; @@ -200,9 +211,10 @@ void free_hyp_pgds(void) if (hyp_pgd) { for (addr = PAGE_OFFSET; virt_addr_valid(addr); addr += PGDIR_SIZE) - unmap_range(hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE); + unmap_range(NULL, hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE); for (addr = VMALLOC_START; is_vmalloc_addr((void*)addr); addr += PGDIR_SIZE) - unmap_range(hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE); + unmap_range(NULL, hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE); + kfree(hyp_pgd); hyp_pgd = NULL; } @@ -393,7 +405,7 @@ int kvm_alloc_stage2_pgd(struct kvm *kvm) */ static void unmap_stage2_range(struct kvm *kvm, phys_addr_t start, u64 size) { - unmap_range(kvm->arch.pgd, start, size); + unmap_range(kvm, kvm->arch.pgd, start, size); } /** @@ -675,7 +687,6 @@ static void handle_hva_to_gpa(struct kvm *kvm, static void kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, void *data) { unmap_stage2_range(kvm, gpa, PAGE_SIZE); - kvm_tlb_flush_vmid_ipa(kvm, gpa); } int kvm_unmap_hva(struct kvm *kvm, unsigned long hva) -- 2.20.1