diff options
author | Paolo Bonzini <pbonzini@redhat.com> | 2015-01-23 13:39:51 +0100 |
---|---|---|
committer | Paolo Bonzini <pbonzini@redhat.com> | 2015-01-23 13:39:51 +0100 |
commit | 1c6007d59a20762052cc92c0a2889ff11030d23a (patch) | |
tree | 40bd72fe4e4d38a811312e5ae35bafd04c995d40 /arch/x86/kvm | |
parent | c6156df9d32141e5f1abb43078c56f2e5a0cb294 (diff) | |
parent | 4b990589952f0e30aa860184ac6c76219a74632e (diff) |
Merge tag 'kvm-arm-for-3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-next
KVM/ARM changes for v3.20 including GICv3 emulation, dirty page logging, added
trace symbols, and adding an explicit VGIC init device control IOCTL.
Conflicts:
arch/arm64/include/asm/kvm_arm.h
arch/arm64/kvm/handle_exit.c
Diffstat (limited to 'arch/x86/kvm')
-rw-r--r-- | arch/x86/kvm/Kconfig | 1 | ||||
-rw-r--r-- | arch/x86/kvm/mmu.c | 4 | ||||
-rw-r--r-- | arch/x86/kvm/x86.c | 72 |
3 files changed, 16 insertions, 61 deletions
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig index f9d16ff56c6b..d07359466d5d 100644 --- a/arch/x86/kvm/Kconfig +++ b/arch/x86/kvm/Kconfig @@ -39,6 +39,7 @@ config KVM select PERF_EVENTS select HAVE_KVM_MSI select HAVE_KVM_CPU_RELAX_INTERCEPT + select KVM_GENERIC_DIRTYLOG_READ_PROTECT select KVM_VFIO ---help--- Support hosting fully virtualized guest machines using hardware diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 97898abe8386..0ed9f795e4f0 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1216,7 +1216,7 @@ static bool __rmap_write_protect(struct kvm *kvm, unsigned long *rmapp, } /** - * kvm_mmu_write_protect_pt_masked - write protect selected PT level pages + * kvm_arch_mmu_write_protect_pt_masked - write protect selected PT level pages * @kvm: kvm instance * @slot: slot to protect * @gfn_offset: start of the BITS_PER_LONG pages we care about @@ -1225,7 +1225,7 @@ static bool __rmap_write_protect(struct kvm *kvm, unsigned long *rmapp, * Used when we do not need to care about huge page mappings: e.g. during dirty * logging we do not have any such mappings. */ -void kvm_mmu_write_protect_pt_masked(struct kvm *kvm, +void kvm_arch_mmu_write_protect_pt_masked(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn_offset, unsigned long mask) { diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 917672f8034a..d2bbb2d86610 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3759,83 +3759,37 @@ static int kvm_vm_ioctl_reinject(struct kvm *kvm, * @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: + * Steps 1-4 below provide general overview of dirty page logging. See + * kvm_get_dirty_log_protect() function description for additional details. + * + * We call kvm_get_dirty_log_protect() to handle steps 1-3, upon return we + * always flush the TLB (step 4) even if previous step failed and the dirty + * bitmap may be corrupt. Regardless of previous outcome the KVM logging API + * does not preclude user space subsequent dirty log read. Flushing TLB ensures + * writes will be marked dirty for next log read. * * 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. + * 3. Copy the snapshot to the userspace. + * 4. Flush TLB's if needed. */ 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; + int r; 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); + r = kvm_get_dirty_log_protect(kvm, log, &is_dirty); /* * All the TLBs can be flushed out of mmu lock, see the comments in * kvm_mmu_slot_remove_write_access(). */ + lockdep_assert_held(&kvm->slots_lock); 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; } |