Add support for generic implementation of dirty log read function. For now both x86_64 and ARMv7 share generic dirty log read. Other architectures call their architecture specific functions. Signed-off-by: Mario Smarduch <m.smarduch@xxxxxxxxxxx> --- arch/arm/include/asm/kvm_host.h | 2 + arch/arm/kvm/Kconfig | 1 + arch/arm/kvm/arm.c | 2 +- arch/arm64/include/asm/kvm_host.h | 2 + arch/arm64/kvm/Kconfig | 1 + arch/ia64/include/asm/kvm_host.h | 1 + arch/ia64/kvm/Kconfig | 1 + arch/ia64/kvm/kvm-ia64.c | 2 +- arch/mips/include/asm/kvm_host.h | 1 + arch/mips/kvm/Kconfig | 1 + arch/mips/kvm/mips.c | 2 +- arch/powerpc/include/asm/kvm_host.h | 2 + arch/powerpc/kvm/Kconfig | 1 + arch/powerpc/kvm/book3s.c | 2 +- arch/powerpc/kvm/booke.c | 2 +- arch/s390/include/asm/kvm_host.h | 2 + arch/s390/kvm/Kconfig | 1 + arch/s390/kvm/kvm-s390.c | 2 +- arch/x86/kvm/x86.c | 86 ----------------------------------- include/linux/kvm_host.h | 2 + virt/kvm/Kconfig | 3 ++ virt/kvm/kvm_main.c | 90 +++++++++++++++++++++++++++++++++++++ 22 files changed, 117 insertions(+), 92 deletions(-) diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 193ceaf..8fc078d 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -231,4 +231,6 @@ int kvm_perf_teardown(void); u64 kvm_arm_timer_get_reg(struct kvm_vcpu *, u64 regid); int kvm_arm_timer_set_reg(struct kvm_vcpu *, u64 regid, u64 value); +int kvm_arch_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log); + #endif /* __ARM_KVM_HOST_H__ */ diff --git a/arch/arm/kvm/Kconfig b/arch/arm/kvm/Kconfig index 4be5bb1..cd9bb1c 100644 --- a/arch/arm/kvm/Kconfig +++ b/arch/arm/kvm/Kconfig @@ -23,6 +23,7 @@ config KVM select HAVE_KVM_CPU_RELAX_INTERCEPT select KVM_MMIO select KVM_ARM_HOST + select HAVE_KVM_ARCH_DIRTY_LOG depends on ARM_VIRT_EXT && ARM_LPAE && !CPU_BIG_ENDIAN ---help--- Support hosting virtualized guest machines. You will also diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 3c82b37..c52b2bd 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -774,7 +774,7 @@ long kvm_arch_vcpu_ioctl(struct file *filp, } } -int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log) +int kvm_arch_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log) { return -EINVAL; } diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 92242ce..b4a280b 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -200,4 +200,6 @@ static inline void __cpu_init_hyp_mode(phys_addr_t boot_pgd_ptr, hyp_stack_ptr, vector_ptr); } +int kvm_arch_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log); + #endif /* __ARM64_KVM_HOST_H__ */ diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig index 8ba85e9..40a8d19 100644 --- a/arch/arm64/kvm/Kconfig +++ b/arch/arm64/kvm/Kconfig @@ -26,6 +26,7 @@ config KVM select KVM_ARM_HOST select KVM_ARM_VGIC select KVM_ARM_TIMER + select HAVE_KVM_ARCH_DIRTY_LOG ---help--- Support hosting virtualized guest machines. diff --git a/arch/ia64/include/asm/kvm_host.h b/arch/ia64/include/asm/kvm_host.h index db95f57..d79f520 100644 --- a/arch/ia64/include/asm/kvm_host.h +++ b/arch/ia64/include/asm/kvm_host.h @@ -594,6 +594,7 @@ void kvm_sal_emul(struct kvm_vcpu *vcpu); #define __KVM_HAVE_ARCH_VM_ALLOC 1 struct kvm *kvm_arch_alloc_vm(void); void kvm_arch_free_vm(struct kvm *kvm); +int kvm_arch_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log); #endif /* __ASSEMBLY__*/ diff --git a/arch/ia64/kvm/Kconfig b/arch/ia64/kvm/Kconfig index 990b864..217f10a 100644 --- a/arch/ia64/kvm/Kconfig +++ b/arch/ia64/kvm/Kconfig @@ -28,6 +28,7 @@ config KVM select HAVE_KVM_IRQ_ROUTING select KVM_APIC_ARCHITECTURE select KVM_MMIO + select HAVE_KVM_ARCH_DIRTY_LOG ---help--- Support hosting fully virtualized guest machines using hardware virtualization extensions. You will need a fairly recent diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c index 6a4309b..3166df5 100644 --- a/arch/ia64/kvm/kvm-ia64.c +++ b/arch/ia64/kvm/kvm-ia64.c @@ -1812,7 +1812,7 @@ static void kvm_ia64_sync_dirty_log(struct kvm *kvm, spin_unlock(&kvm->arch.dirty_log_lock); } -int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, +int kvm_arch_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log) { int r; diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h index 7a3fc67..e2cd1ea 100644 --- a/arch/mips/include/asm/kvm_host.h +++ b/arch/mips/include/asm/kvm_host.h @@ -767,5 +767,6 @@ extern int kvm_mips_trans_mtc0(uint32_t inst, uint32_t *opc, extern void kvm_mips_dump_stats(struct kvm_vcpu *vcpu); extern unsigned long kvm_mips_get_ramsize(struct kvm *kvm); +int kvm_arch_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log); #endif /* __MIPS_KVM_HOST_H__ */ diff --git a/arch/mips/kvm/Kconfig b/arch/mips/kvm/Kconfig index 30e334e..b57f49e 100644 --- a/arch/mips/kvm/Kconfig +++ b/arch/mips/kvm/Kconfig @@ -20,6 +20,7 @@ config KVM select PREEMPT_NOTIFIERS select ANON_INODES select KVM_MMIO + select HAVE_KVM_ARCH_DIRTY_LOG ---help--- Support for hosting Guest kernels. Currently supported on MIPS32 processors. diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c index d687c6e..885fdfe 100644 --- a/arch/mips/kvm/mips.c +++ b/arch/mips/kvm/mips.c @@ -791,7 +791,7 @@ out: } /* Get (and clear) the dirty memory log for a memory slot. */ -int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log) +int kvm_arch_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log) { struct kvm_memory_slot *memslot; unsigned long ga, ga_end; diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index bb66d8b..df092d2 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -683,4 +683,6 @@ struct kvm_vcpu_arch { #define __KVM_HAVE_ARCH_WQP #define __KVM_HAVE_CREATE_DEVICE +int kvm_arch_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log); + #endif /* __POWERPC_KVM_HOST_H__ */ diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig index d6a53b9..4f28a82 100644 --- a/arch/powerpc/kvm/Kconfig +++ b/arch/powerpc/kvm/Kconfig @@ -21,6 +21,7 @@ config KVM select PREEMPT_NOTIFIERS select ANON_INODES select HAVE_KVM_EVENTFD + select HAVE_KVM_ARCH_DIRTY_LOG config KVM_BOOK3S_HANDLER bool diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c index c254c27..304faa1 100644 --- a/arch/powerpc/kvm/book3s.c +++ b/arch/powerpc/kvm/book3s.c @@ -815,7 +815,7 @@ int kvmppc_core_check_requests(struct kvm_vcpu *vcpu) return vcpu->kvm->arch.kvm_ops->check_requests(vcpu); } -int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log) +int kvm_arch_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log) { return kvm->arch.kvm_ops->get_dirty_log(kvm, log); } diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index ab62109..50dd33d 100644 --- a/arch/powerpc/kvm/booke.c +++ b/arch/powerpc/kvm/booke.c @@ -1624,7 +1624,7 @@ int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu, return r; } -int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log) +int kvm_arch_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log) { return -ENOTSUPP; } diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index 4181d7b..2f54644 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -432,6 +432,7 @@ static inline bool kvm_is_error_hva(unsigned long addr) } #define ASYNC_PF_PER_VCPU 64 +struct kvm; struct kvm_vcpu; struct kvm_async_pf; struct kvm_arch_async_pf { @@ -451,4 +452,5 @@ void kvm_arch_async_page_present(struct kvm_vcpu *vcpu, extern int sie64a(struct kvm_s390_sie_block *, u64 *); extern char sie_exit; +int kvm_arch_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log); #endif diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig index 10d529a..6306bb6 100644 --- a/arch/s390/kvm/Kconfig +++ b/arch/s390/kvm/Kconfig @@ -27,6 +27,7 @@ config KVM select KVM_ASYNC_PF_SYNC select HAVE_KVM_IRQCHIP select HAVE_KVM_IRQ_ROUTING + select HAVE_KVM_ARCH_DIRTY_LOG ---help--- Support hosting paravirtualized guest machines using the SIE virtualization capability on the mainframe. This should work diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 2f3e14f..7712cf6 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -208,7 +208,7 @@ static void kvm_s390_sync_dirty_log(struct kvm *kvm, /* * Get (and clear) the dirty memory log for a memory slot. */ -int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, +int kvm_arch_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log) { int r; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 5a8691b..652bd28 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3577,92 +3577,6 @@ static int kvm_vm_ioctl_reinject(struct kvm *kvm, return 0; } -/** - * kvm_vm_ioctl_get_dirty_log - get and clear the log of dirty pages in a slot - * @kvm: kvm instance - * @log: slot id and address to which we copy the log - * - * We need to keep it in mind that VCPU threads can write to the bitmap - * concurrently. So, to avoid losing data, we keep the following order for - * each bit: - * - * 1. Take a snapshot of the bit and clear it if needed. - * 2. Write protect the corresponding page. - * 3. Flush TLB's if needed. - * 4. Copy the snapshot to the userspace. - * - * Between 2 and 3, the guest may write to the page using the remaining TLB - * entry. This is not a problem because the page will be reported dirty at - * step 4 using the snapshot taken before and step 3 ensures that successive - * writes will be logged for the next call. - */ -int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log) -{ - int r; - struct kvm_memory_slot *memslot; - unsigned long n, i; - unsigned long *dirty_bitmap; - unsigned long *dirty_bitmap_buffer; - bool is_dirty = false; - - mutex_lock(&kvm->slots_lock); - - r = -EINVAL; - if (log->slot >= KVM_USER_MEM_SLOTS) - goto out; - - memslot = id_to_memslot(kvm->memslots, log->slot); - - dirty_bitmap = memslot->dirty_bitmap; - r = -ENOENT; - if (!dirty_bitmap) - goto out; - - n = kvm_dirty_bitmap_bytes(memslot); - - dirty_bitmap_buffer = dirty_bitmap + n / sizeof(long); - memset(dirty_bitmap_buffer, 0, n); - - spin_lock(&kvm->mmu_lock); - - for (i = 0; i < n / sizeof(long); i++) { - unsigned long mask; - gfn_t offset; - - if (!dirty_bitmap[i]) - continue; - - is_dirty = true; - - mask = xchg(&dirty_bitmap[i], 0); - dirty_bitmap_buffer[i] = mask; - - offset = i * BITS_PER_LONG; - kvm_mmu_write_protect_pt_masked(kvm, memslot, offset, mask); - } - - spin_unlock(&kvm->mmu_lock); - - /* See the comments in kvm_mmu_slot_remove_write_access(). */ - lockdep_assert_held(&kvm->slots_lock); - - /* - * All the TLBs can be flushed out of mmu lock, see the comments in - * kvm_mmu_slot_remove_write_access(). - */ - if (is_dirty) - kvm_flush_remote_tlbs(kvm); - - r = -EFAULT; - if (copy_to_user(log->dirty_bitmap, dirty_bitmap_buffer, n)) - goto out; - - r = 0; -out: - mutex_unlock(&kvm->slots_lock); - return r; -} - int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_event, bool line_status) { diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index ec4e3bd..9a3c734 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -608,6 +608,8 @@ int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log, int *is_dirty); int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log); +void kvm_mmu_write_protect_pt_masked(struct kvm *kvm, + struct kvm_memory_slot *slot, gfn_t gfn_offset, unsigned long mask); int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level, bool line_status); diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig index f1efaa5..975733f 100644 --- a/virt/kvm/Kconfig +++ b/virt/kvm/Kconfig @@ -37,3 +37,6 @@ config KVM_VFIO config HAVE_KVM_ARCH_TLB_FLUSH_ALL bool + +config HAVE_KVM_ARCH_DIRTY_LOG + bool diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index d0a24f5..1c27344 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -442,6 +442,96 @@ static int kvm_init_mmu_notifier(struct kvm *kvm) #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */ +/** + * kvm_vm_ioctl_get_dirty_log - get and clear the log of dirty pages in a slot + * @kvm: kvm instance + * @log: slot id and address to which we copy the log + * + * We need to keep it in mind that VCPU threads can write to the bitmap + * concurrently. So, to avoid losing data, we keep the following order for + * each bit: + * + * 1. Take a snapshot of the bit and clear it if needed. + * 2. Write protect the corresponding page. + * 3. Flush TLB's if needed. + * 4. Copy the snapshot to the userspace. + * + * Between 2 and 3, the guest may write to the page using the remaining TLB + * entry. This is not a problem because the page will be reported dirty at + * step 4 using the snapshot taken before and step 3 ensures that successive + * writes will be logged for the next call. + */ +int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log) +{ +#ifdef CONFIG_HAVE_KVM_ARCH_DIRTY_LOG + return kvm_arch_vm_ioctl_get_dirty_log(kvm, log); +#else + int r; + struct kvm_memory_slot *memslot; + unsigned long n, i; + unsigned long *dirty_bitmap; + unsigned long *dirty_bitmap_buffer; + bool is_dirty = false; + + mutex_lock(&kvm->slots_lock); + + r = -EINVAL; + if (log->slot >= KVM_USER_MEM_SLOTS) + goto out; + + memslot = id_to_memslot(kvm->memslots, log->slot); + + dirty_bitmap = memslot->dirty_bitmap; + r = -ENOENT; + if (!dirty_bitmap) + goto out; + + n = kvm_dirty_bitmap_bytes(memslot); + + dirty_bitmap_buffer = dirty_bitmap + n / sizeof(long); + memset(dirty_bitmap_buffer, 0, n); + + spin_lock(&kvm->mmu_lock); + + for (i = 0; i < n / sizeof(long); i++) { + unsigned long mask; + gfn_t offset; + + if (!dirty_bitmap[i]) + continue; + + is_dirty = true; + + mask = xchg(&dirty_bitmap[i], 0); + dirty_bitmap_buffer[i] = mask; + + offset = i * BITS_PER_LONG; + kvm_mmu_write_protect_pt_masked(kvm, memslot, offset, mask); + } + + spin_unlock(&kvm->mmu_lock); + + /* See the comments in kvm_mmu_slot_remove_write_access(). */ + lockdep_assert_held(&kvm->slots_lock); + + /* + * All the TLBs can be flushed out of mmu lock, see the comments in + * kvm_mmu_slot_remove_write_access(). + */ + if (is_dirty) + kvm_flush_remote_tlbs(kvm); + + r = -EFAULT; + if (copy_to_user(log->dirty_bitmap, dirty_bitmap_buffer, n)) + goto out; + + r = 0; +out: + mutex_unlock(&kvm->slots_lock); + return r; +#endif +} + static void kvm_init_memslots_id(struct kvm *kvm) { int i; -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html