From 6da64fdb8c0c683016b70c96200057347aa8fbb0 Mon Sep 17 00:00:00 2001 From: Thomas Meyer Date: Tue, 8 Nov 2011 20:32:19 +0100 Subject: KVM: Use kmemdup rather than duplicating its implementation Use kmemdup rather than duplicating its implementation The semantic patch that makes this change is available in scripts/coccinelle/api/memdup.cocci. More information about semantic patching is available at http://coccinelle.lip6.fr/ Signed-off-by: Thomas Meyer Signed-off-by: Marcelo Tosatti --- virt/kvm/kvm_main.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) (limited to 'virt/kvm/kvm_main.c') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index d9cfb782cb81..4c5b9a239674 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -775,10 +775,10 @@ skip_lpage: if (!npages) { r = -ENOMEM; - slots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL); + slots = kmemdup(kvm->memslots, sizeof(struct kvm_memslots), + GFP_KERNEL); if (!slots) goto out_free; - memcpy(slots, kvm->memslots, sizeof(struct kvm_memslots)); if (mem->slot >= slots->nmemslots) slots->nmemslots = mem->slot + 1; slots->generation++; @@ -810,10 +810,10 @@ skip_lpage: } r = -ENOMEM; - slots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL); + slots = kmemdup(kvm->memslots, sizeof(struct kvm_memslots), + GFP_KERNEL); if (!slots) goto out_free; - memcpy(slots, kvm->memslots, sizeof(struct kvm_memslots)); if (mem->slot >= slots->nmemslots) slots->nmemslots = mem->slot + 1; slots->generation++; @@ -2520,10 +2520,9 @@ int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, if (bus->dev_count > NR_IOBUS_DEVS-1) return -ENOSPC; - new_bus = kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL); + new_bus = kmemdup(bus, sizeof(struct kvm_io_bus), GFP_KERNEL); if (!new_bus) return -ENOMEM; - memcpy(new_bus, bus, sizeof(struct kvm_io_bus)); kvm_io_bus_insert_dev(new_bus, dev, addr, len); rcu_assign_pointer(kvm->buses[bus_idx], new_bus); synchronize_srcu_expedited(&kvm->srcu); -- cgit v1.2.3 From 7850ac5420803996e2960d15b924021f28e0dffc Mon Sep 17 00:00:00 2001 From: Takuya Yoshikawa Date: Mon, 14 Nov 2011 18:23:34 +0900 Subject: KVM: Count the number of dirty pages for dirty logging Needed for the next patch which uses this number to decide how to write protect a slot. Signed-off-by: Takuya Yoshikawa Signed-off-by: Avi Kivity --- virt/kvm/kvm_main.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'virt/kvm/kvm_main.c') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 4c5b9a239674..af5c988cafcc 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -625,6 +625,7 @@ static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot) return -ENOMEM; memslot->dirty_bitmap_head = memslot->dirty_bitmap; + memslot->nr_dirty_pages = 0; return 0; } #endif /* !CONFIG_S390 */ @@ -1491,7 +1492,8 @@ void mark_page_dirty_in_slot(struct kvm *kvm, struct kvm_memory_slot *memslot, if (memslot && memslot->dirty_bitmap) { unsigned long rel_gfn = gfn - memslot->base_gfn; - __set_bit_le(rel_gfn, memslot->dirty_bitmap); + if (!__test_and_set_bit_le(rel_gfn, memslot->dirty_bitmap)) + memslot->nr_dirty_pages++; } } -- cgit v1.2.3 From 93a5cef07d686a0341d056b0f930a762c7174a13 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Thu, 24 Nov 2011 17:37:48 +0800 Subject: KVM: introduce KVM_MEM_SLOTS_NUM macro Introduce KVM_MEM_SLOTS_NUM macro to instead of KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS Signed-off-by: Xiao Guangrong Signed-off-by: Avi Kivity --- virt/kvm/kvm_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'virt/kvm/kvm_main.c') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index af5c988cafcc..9ad94c9996e7 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -663,7 +663,7 @@ int __kvm_set_memory_region(struct kvm *kvm, (void __user *)(unsigned long)mem->userspace_addr, mem->memory_size))) goto out; - if (mem->slot >= KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS) + if (mem->slot >= KVM_MEM_SLOTS_NUM) goto out; if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr) goto out; -- cgit v1.2.3 From be593d6286075801bba6d60fa466a39c24cc7616 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Thu, 24 Nov 2011 17:38:24 +0800 Subject: KVM: introduce update_memslots function Introduce update_memslots to update slot which will be update to kvm->memslots Signed-off-by: Xiao Guangrong Signed-off-by: Avi Kivity --- virt/kvm/kvm_main.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) (limited to 'virt/kvm/kvm_main.c') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 9ad94c9996e7..b5ed7770ced3 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -630,6 +630,19 @@ static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot) } #endif /* !CONFIG_S390 */ +void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new) +{ + if (new) { + int id = new->id; + + slots->memslots[id] = *new; + if (id >= slots->nmemslots) + slots->nmemslots = id + 1; + } + + slots->generation++; +} + /* * Allocate some memory and give it an address in the guest physical address * space. @@ -780,10 +793,8 @@ skip_lpage: GFP_KERNEL); if (!slots) goto out_free; - if (mem->slot >= slots->nmemslots) - slots->nmemslots = mem->slot + 1; - slots->generation++; slots->memslots[mem->slot].flags |= KVM_MEMSLOT_INVALID; + update_memslots(slots, NULL); old_memslots = kvm->memslots; rcu_assign_pointer(kvm->memslots, slots); @@ -815,9 +826,6 @@ skip_lpage: GFP_KERNEL); if (!slots) goto out_free; - if (mem->slot >= slots->nmemslots) - slots->nmemslots = mem->slot + 1; - slots->generation++; /* actual memory is freed via old in kvm_free_physmem_slot below */ if (!npages) { @@ -827,7 +835,7 @@ skip_lpage: new.lpage_info[i] = NULL; } - slots->memslots[mem->slot] = new; + update_memslots(slots, &new); old_memslots = kvm->memslots; rcu_assign_pointer(kvm->memslots, slots); synchronize_srcu_expedited(&kvm->srcu); -- cgit v1.2.3 From be6ba0f0962a39091c52eb9167ddea201fe80716 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Thu, 24 Nov 2011 17:39:18 +0800 Subject: KVM: introduce kvm_for_each_memslot macro Introduce kvm_for_each_memslot to walk all valid memslot Signed-off-by: Xiao Guangrong Signed-off-by: Avi Kivity --- virt/kvm/kvm_main.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) (limited to 'virt/kvm/kvm_main.c') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index b5ed7770ced3..4c2900c5d81d 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -547,11 +547,11 @@ static void kvm_free_physmem_slot(struct kvm_memory_slot *free, void kvm_free_physmem(struct kvm *kvm) { - int i; struct kvm_memslots *slots = kvm->memslots; + struct kvm_memory_slot *memslot; - for (i = 0; i < slots->nmemslots; ++i) - kvm_free_physmem_slot(&slots->memslots[i], NULL); + kvm_for_each_memslot(memslot, slots) + kvm_free_physmem_slot(memslot, NULL); kfree(kvm->memslots); } @@ -975,15 +975,13 @@ EXPORT_SYMBOL_GPL(kvm_is_error_hva); static struct kvm_memory_slot *__gfn_to_memslot(struct kvm_memslots *slots, gfn_t gfn) { - int i; - - for (i = 0; i < slots->nmemslots; ++i) { - struct kvm_memory_slot *memslot = &slots->memslots[i]; + struct kvm_memory_slot *memslot; + kvm_for_each_memslot(memslot, slots) if (gfn >= memslot->base_gfn && gfn < memslot->base_gfn + memslot->npages) return memslot; - } + return NULL; } -- cgit v1.2.3 From 28a37544fb0223eb9805d2567b88f7360edec52a Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Thu, 24 Nov 2011 19:04:35 +0800 Subject: KVM: introduce id_to_memslot function Introduce id_to_memslot to get memslot by slot id Signed-off-by: Xiao Guangrong Signed-off-by: Avi Kivity --- virt/kvm/kvm_main.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'virt/kvm/kvm_main.c') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 4c2900c5d81d..7b6084999424 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -634,8 +634,9 @@ void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new) { if (new) { int id = new->id; + struct kvm_memory_slot *old = id_to_memslot(slots, id); - slots->memslots[id] = *new; + *old = *new; if (id >= slots->nmemslots) slots->nmemslots = id + 1; } @@ -681,7 +682,7 @@ int __kvm_set_memory_region(struct kvm *kvm, if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr) goto out; - memslot = &kvm->memslots->memslots[mem->slot]; + memslot = id_to_memslot(kvm->memslots, mem->slot); base_gfn = mem->guest_phys_addr >> PAGE_SHIFT; npages = mem->memory_size >> PAGE_SHIFT; @@ -788,12 +789,16 @@ skip_lpage: #endif /* not defined CONFIG_S390 */ if (!npages) { + struct kvm_memory_slot *slot; + r = -ENOMEM; slots = kmemdup(kvm->memslots, sizeof(struct kvm_memslots), GFP_KERNEL); if (!slots) goto out_free; - slots->memslots[mem->slot].flags |= KVM_MEMSLOT_INVALID; + slot = id_to_memslot(slots, mem->slot); + slot->flags |= KVM_MEMSLOT_INVALID; + update_memslots(slots, NULL); old_memslots = kvm->memslots; @@ -897,7 +902,7 @@ int kvm_get_dirty_log(struct kvm *kvm, if (log->slot >= KVM_MEMORY_SLOTS) goto out; - memslot = &kvm->memslots->memslots[log->slot]; + memslot = id_to_memslot(kvm->memslots, log->slot); r = -ENOENT; if (!memslot->dirty_bitmap) goto out; -- cgit v1.2.3 From bf3e05bc1e2781d5d8d3ddb2d8bf2d6ec207e5cb Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Thu, 24 Nov 2011 17:40:57 +0800 Subject: KVM: sort memslots by its size and use line search Sort memslots base on its size and use line search to find it, so that the larger memslots have better fit The idea is from Avi Signed-off-by: Xiao Guangrong Signed-off-by: Avi Kivity --- virt/kvm/kvm_main.c | 79 ++++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 57 insertions(+), 22 deletions(-) (limited to 'virt/kvm/kvm_main.c') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 7b6084999424..6e8eb15dd30b 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -440,6 +440,15 @@ static int kvm_init_mmu_notifier(struct kvm *kvm) #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */ +static void kvm_init_memslots_id(struct kvm *kvm) +{ + int i; + struct kvm_memslots *slots = kvm->memslots; + + for (i = 0; i < KVM_MEM_SLOTS_NUM; i++) + slots->memslots[i].id = i; +} + static struct kvm *kvm_create_vm(void) { int r, i; @@ -465,6 +474,7 @@ static struct kvm *kvm_create_vm(void) kvm->memslots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL); if (!kvm->memslots) goto out_err_nosrcu; + kvm_init_memslots_id(kvm); if (init_srcu_struct(&kvm->srcu)) goto out_err_nosrcu; for (i = 0; i < KVM_NR_BUSES; i++) { @@ -630,15 +640,54 @@ static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot) } #endif /* !CONFIG_S390 */ +static struct kvm_memory_slot * +search_memslots(struct kvm_memslots *slots, gfn_t gfn) +{ + struct kvm_memory_slot *memslot; + + kvm_for_each_memslot(memslot, slots) + if (gfn >= memslot->base_gfn && + gfn < memslot->base_gfn + memslot->npages) + return memslot; + + return NULL; +} + +static int cmp_memslot(const void *slot1, const void *slot2) +{ + struct kvm_memory_slot *s1, *s2; + + s1 = (struct kvm_memory_slot *)slot1; + s2 = (struct kvm_memory_slot *)slot2; + + if (s1->npages < s2->npages) + return 1; + if (s1->npages > s2->npages) + return -1; + + return 0; +} + +/* + * Sort the memslots base on its size, so the larger slots + * will get better fit. + */ +static void sort_memslots(struct kvm_memslots *slots) +{ + sort(slots->memslots, KVM_MEM_SLOTS_NUM, + sizeof(struct kvm_memory_slot), cmp_memslot, NULL); +} + void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new) { if (new) { int id = new->id; struct kvm_memory_slot *old = id_to_memslot(slots, id); + unsigned long npages = old->npages; *old = *new; - if (id >= slots->nmemslots) - slots->nmemslots = id + 1; + if (new->npages != npages) + sort_memslots(slots); } slots->generation++; @@ -980,14 +1029,7 @@ EXPORT_SYMBOL_GPL(kvm_is_error_hva); static struct kvm_memory_slot *__gfn_to_memslot(struct kvm_memslots *slots, gfn_t gfn) { - struct kvm_memory_slot *memslot; - - kvm_for_each_memslot(memslot, slots) - if (gfn >= memslot->base_gfn - && gfn < memslot->base_gfn + memslot->npages) - return memslot; - - return NULL; + return search_memslots(slots, gfn); } struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn) @@ -998,20 +1040,13 @@ EXPORT_SYMBOL_GPL(gfn_to_memslot); int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn) { - int i; - struct kvm_memslots *slots = kvm_memslots(kvm); - - for (i = 0; i < KVM_MEMORY_SLOTS; ++i) { - struct kvm_memory_slot *memslot = &slots->memslots[i]; + struct kvm_memory_slot *memslot = gfn_to_memslot(kvm, gfn); - if (memslot->flags & KVM_MEMSLOT_INVALID) - continue; + if (!memslot || memslot->id >= KVM_MEMORY_SLOTS || + memslot->flags & KVM_MEMSLOT_INVALID) + return 0; - if (gfn >= memslot->base_gfn - && gfn < memslot->base_gfn + memslot->npages) - return 1; - } - return 0; + return 1; } EXPORT_SYMBOL_GPL(kvm_is_visible_gfn); -- cgit v1.2.3 From f85e2cb5dbaf905e9470d3fe099b31619da431fc Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Thu, 24 Nov 2011 17:41:54 +0800 Subject: KVM: introduce a table to map slot id to index in memslots array The operation of getting dirty log is frequent when framebuffer-based displays are used(for example, Xwindow), so, we introduce a mapping table to speed up id_to_memslot() Signed-off-by: Xiao Guangrong Signed-off-by: Avi Kivity --- virt/kvm/kvm_main.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'virt/kvm/kvm_main.c') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 6e8eb15dd30b..e289486edc6d 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -446,7 +446,7 @@ static void kvm_init_memslots_id(struct kvm *kvm) struct kvm_memslots *slots = kvm->memslots; for (i = 0; i < KVM_MEM_SLOTS_NUM; i++) - slots->memslots[i].id = i; + slots->id_to_index[i] = slots->memslots[i].id = i; } static struct kvm *kvm_create_vm(void) @@ -674,8 +674,13 @@ static int cmp_memslot(const void *slot1, const void *slot2) */ static void sort_memslots(struct kvm_memslots *slots) { + int i; + sort(slots->memslots, KVM_MEM_SLOTS_NUM, sizeof(struct kvm_memory_slot), cmp_memslot, NULL); + + for (i = 0; i < KVM_MEM_SLOTS_NUM; i++) + slots->id_to_index[slots->memslots[i].id] = i; } void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new) -- cgit v1.2.3 From cdfca7b346e6dbab1ba33260c28ccb8333485a5b Mon Sep 17 00:00:00 2001 From: Sasha Levin Date: Sun, 4 Dec 2011 19:36:28 +0200 Subject: KVM: Use kmemdup() instead of kmalloc/memcpy Switch to kmemdup() in two places to shorten the code and avoid possible bugs. Signed-off-by: Sasha Levin Signed-off-by: Avi Kivity --- virt/kvm/kvm_main.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'virt/kvm/kvm_main.c') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index e289486edc6d..a6e612fced73 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2591,13 +2591,12 @@ int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, int i, r; struct kvm_io_bus *new_bus, *bus; - new_bus = kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL); + bus = kvm->buses[bus_idx]; + + new_bus = kmemdup(bus, sizeof(*bus), GFP_KERNEL); if (!new_bus) return -ENOMEM; - bus = kvm->buses[bus_idx]; - memcpy(new_bus, bus, sizeof(struct kvm_io_bus)); - r = -ENOENT; for (i = 0; i < new_bus->dev_count; i++) if (new_bus->range[i].dev == dev) { -- cgit v1.2.3 From ff5c2c0316ff0e3e2dba3ca14167d994453df093 Mon Sep 17 00:00:00 2001 From: Sasha Levin Date: Sun, 4 Dec 2011 19:36:29 +0200 Subject: KVM: Use memdup_user instead of kmalloc/copy_from_user Switch to using memdup_user when possible. This makes code more smaller and compact, and prevents errors. Signed-off-by: Sasha Levin Signed-off-by: Avi Kivity --- virt/kvm/kvm_main.c | 29 ++++++++++++----------------- 1 file changed, 12 insertions(+), 17 deletions(-) (limited to 'virt/kvm/kvm_main.c') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index a6e612fced73..d8bac0751666 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1821,12 +1821,11 @@ out_free1: struct kvm_regs *kvm_regs; r = -ENOMEM; - kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL); - if (!kvm_regs) + kvm_regs = memdup_user(argp, sizeof(*kvm_regs)); + if (IS_ERR(kvm_regs)) { + r = PTR_ERR(kvm_regs); goto out; - r = -EFAULT; - if (copy_from_user(kvm_regs, argp, sizeof(struct kvm_regs))) - goto out_free2; + } r = kvm_arch_vcpu_ioctl_set_regs(vcpu, kvm_regs); if (r) goto out_free2; @@ -1850,13 +1849,11 @@ out_free2: break; } case KVM_SET_SREGS: { - kvm_sregs = kmalloc(sizeof(struct kvm_sregs), GFP_KERNEL); - r = -ENOMEM; - if (!kvm_sregs) - goto out; - r = -EFAULT; - if (copy_from_user(kvm_sregs, argp, sizeof(struct kvm_sregs))) + kvm_sregs = memdup_user(argp, sizeof(*kvm_sregs)); + if (IS_ERR(kvm_sregs)) { + r = PTR_ERR(kvm_sregs); goto out; + } r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, kvm_sregs); if (r) goto out; @@ -1952,13 +1949,11 @@ out_free2: break; } case KVM_SET_FPU: { - fpu = kmalloc(sizeof(struct kvm_fpu), GFP_KERNEL); - r = -ENOMEM; - if (!fpu) - goto out; - r = -EFAULT; - if (copy_from_user(fpu, argp, sizeof(struct kvm_fpu))) + fpu = memdup_user(argp, sizeof(*fpu)); + if (IS_ERR(fpu)) { + r = PTR_ERR(fpu); goto out; + } r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, fpu); if (r) goto out; -- cgit v1.2.3 From d546cb406ea0d83e2d39ec14221957a24f88a622 Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Thu, 15 Dec 2011 12:38:40 +0200 Subject: KVM: drop bsp_vcpu pointer from kvm struct Drop bsp_vcpu pointer from kvm struct since its only use is incorrect anyway. Signed-off-by: Gleb Natapov Signed-off-by: Marcelo Tosatti --- virt/kvm/kvm_main.c | 4 ---- 1 file changed, 4 deletions(-) (limited to 'virt/kvm/kvm_main.c') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index d8bac0751666..0835c4b90d2f 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1743,10 +1743,6 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id) smp_wmb(); atomic_inc(&kvm->online_vcpus); -#ifdef CONFIG_KVM_APIC_ARCHITECTURE - if (kvm->bsp_vcpu_id == id) - kvm->bsp_vcpu = vcpu; -#endif mutex_unlock(&kvm->lock); return r; -- cgit v1.2.3 From 4f69b6805c4f818cf7f4126978cc4a54c489119f Mon Sep 17 00:00:00 2001 From: Hamo Date: Thu, 15 Dec 2011 14:23:16 +0800 Subject: KVM: ensure that debugfs entries have been created by checking the return value from kvm_init_debug, we can ensure that the entries under debugfs for KVM have been created correctly. Signed-off-by: Yang Bai Signed-off-by: Marcelo Tosatti --- virt/kvm/kvm_main.c | 26 +++++++++++++++++++++++--- 1 file changed, 23 insertions(+), 3 deletions(-) (limited to 'virt/kvm/kvm_main.c') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 0835c4b90d2f..7287bf5d1c9e 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2654,15 +2654,29 @@ static const struct file_operations *stat_fops[] = { [KVM_STAT_VM] = &vm_stat_fops, }; -static void kvm_init_debug(void) +static int kvm_init_debug(void) { + int r = -EFAULT; struct kvm_stats_debugfs_item *p; kvm_debugfs_dir = debugfs_create_dir("kvm", NULL); - for (p = debugfs_entries; p->name; ++p) + if (kvm_debugfs_dir == NULL) + goto out; + + for (p = debugfs_entries; p->name; ++p) { p->dentry = debugfs_create_file(p->name, 0444, kvm_debugfs_dir, (void *)(long)p->offset, stat_fops[p->kind]); + if (p->dentry == NULL) + goto out_dir; + } + + return 0; + +out_dir: + debugfs_remove_recursive(kvm_debugfs_dir); +out: + return r; } static void kvm_exit_debug(void) @@ -2806,10 +2820,16 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align, kvm_preempt_ops.sched_in = kvm_sched_in; kvm_preempt_ops.sched_out = kvm_sched_out; - kvm_init_debug(); + r = kvm_init_debug(); + if (r) { + printk(KERN_ERR "kvm: create debugfs files failed\n"); + goto out_undebugfs; + } return 0; +out_undebugfs: + unregister_syscore_ops(&kvm_syscore_ops); out_unreg: kvm_async_pf_deinit(); out_free: -- cgit v1.2.3 From 50e92b3c971129c96a5fffb51dd42691e2ee4004 Mon Sep 17 00:00:00 2001 From: Takuya Yoshikawa Date: Wed, 4 Jan 2012 15:06:43 +0900 Subject: KVM: Fix __set_bit() race in mark_page_dirty() during dirty logging It is possible that the __set_bit() in mark_page_dirty() is called simultaneously on the same region of memory, which may result in only one bit being set, because some callers do not take mmu_lock before mark_page_dirty(). This problem is hard to produce because when we reach mark_page_dirty() beginning from, e.g., tdp_page_fault(), mmu_lock is being held during __direct_map(): making kvm-unit-tests' dirty log api test write to two pages concurrently was not useful for this reason. So we have confirmed that there can actually be race condition by checking if some callers really reach there without holding mmu_lock using spin_is_locked(): probably they were from kvm_write_guest_page(). To fix this race, this patch changes the bit operation to the atomic version: note that nr_dirty_pages also suffers from the race but we do not need exactly correct numbers for now. Signed-off-by: Takuya Yoshikawa Signed-off-by: Marcelo Tosatti --- virt/kvm/kvm_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'virt/kvm/kvm_main.c') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 7287bf5d1c9e..a91f980077d8 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1543,7 +1543,7 @@ void mark_page_dirty_in_slot(struct kvm *kvm, struct kvm_memory_slot *memslot, if (memslot && memslot->dirty_bitmap) { unsigned long rel_gfn = gfn - memslot->base_gfn; - if (!__test_and_set_bit_le(rel_gfn, memslot->dirty_bitmap)) + if (!test_and_set_bit_le(rel_gfn, memslot->dirty_bitmap)) memslot->nr_dirty_pages++; } } -- cgit v1.2.3