Message ID | 20181205053628.3210-2-jglisse@redhat.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | mmu notifier contextual informations | expand |
On Wed 05-12-18 00:36:26, jglisse@redhat.com wrote: > diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c > index 5119ff846769..5f6665ae3ee2 100644 > --- a/mm/mmu_notifier.c > +++ b/mm/mmu_notifier.c > @@ -178,14 +178,20 @@ int __mmu_notifier_invalidate_range_start(struct mm_struct *mm, > unsigned long start, unsigned long end, > bool blockable) > { > + struct mmu_notifier_range _range, *range = &_range; Why these games with two variables? > struct mmu_notifier *mn; > int ret = 0; > int id; > > + range->blockable = blockable; > + range->start = start; > + range->end = end; > + range->mm = mm; > + Use your init function for this? > id = srcu_read_lock(&srcu); > hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) { > if (mn->ops->invalidate_range_start) { > - int _ret = mn->ops->invalidate_range_start(mn, mm, start, end, blockable); > + int _ret = mn->ops->invalidate_range_start(mn, range); > if (_ret) { > pr_info("%pS callback failed with %d in %sblockable context.\n", > mn->ops->invalidate_range_start, _ret, > @@ -205,9 +211,20 @@ void __mmu_notifier_invalidate_range_end(struct mm_struct *mm, > unsigned long end, > bool only_end) > { > + struct mmu_notifier_range _range, *range = &_range; > struct mmu_notifier *mn; > int id; > > + /* > + * The end call back will never be call if the start refused to go > + * through because of blockable was false so here assume that we > + * can block. > + */ > + range->blockable = true; > + range->start = start; > + range->end = end; > + range->mm = mm; > + The same as above. Otherwise the patch looks good to me. Honza
On Wed, Dec 05, 2018 at 05:35:20PM +0100, Jan Kara wrote: > On Wed 05-12-18 00:36:26, jglisse@redhat.com wrote: > > diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c > > index 5119ff846769..5f6665ae3ee2 100644 > > --- a/mm/mmu_notifier.c > > +++ b/mm/mmu_notifier.c > > @@ -178,14 +178,20 @@ int __mmu_notifier_invalidate_range_start(struct mm_struct *mm, > > unsigned long start, unsigned long end, > > bool blockable) > > { > > + struct mmu_notifier_range _range, *range = &_range; > > Why these games with two variables? This is a temporary step i dediced to do the convertion in 2 steps, first i convert the callback to use the structure so that people having mmu notifier callback only have to review this patch and do not get distracted by the second step which update all the mm call site that trigger invalidation. In the final result this code disappear. I did it that way to make the thing more reviewable. Sorry if that is a bit confusing. > > > struct mmu_notifier *mn; > > int ret = 0; > > int id; > > > > + range->blockable = blockable; > > + range->start = start; > > + range->end = end; > > + range->mm = mm; > > + > > Use your init function for this? This get remove in the next patch, i can respawn with the init function but this is a temporary step like explain above. > > > id = srcu_read_lock(&srcu); > > hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) { > > if (mn->ops->invalidate_range_start) { > > - int _ret = mn->ops->invalidate_range_start(mn, mm, start, end, blockable); > > + int _ret = mn->ops->invalidate_range_start(mn, range); > > if (_ret) { > > pr_info("%pS callback failed with %d in %sblockable context.\n", > > mn->ops->invalidate_range_start, _ret, > > @@ -205,9 +211,20 @@ void __mmu_notifier_invalidate_range_end(struct mm_struct *mm, > > unsigned long end, > > bool only_end) > > { > > + struct mmu_notifier_range _range, *range = &_range; > > struct mmu_notifier *mn; > > int id; > > > > + /* > > + * The end call back will never be call if the start refused to go > > + * through because of blockable was false so here assume that we > > + * can block. > > + */ > > + range->blockable = true; > > + range->start = start; > > + range->end = end; > > + range->mm = mm; > > + > > The same as above. > > Otherwise the patch looks good to me. Thank you for reviewing. Cheers, Jérôme
On Wed 05-12-18 11:40:52, Jerome Glisse wrote: > On Wed, Dec 05, 2018 at 05:35:20PM +0100, Jan Kara wrote: > > On Wed 05-12-18 00:36:26, jglisse@redhat.com wrote: > > > diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c > > > index 5119ff846769..5f6665ae3ee2 100644 > > > --- a/mm/mmu_notifier.c > > > +++ b/mm/mmu_notifier.c > > > @@ -178,14 +178,20 @@ int __mmu_notifier_invalidate_range_start(struct mm_struct *mm, > > > unsigned long start, unsigned long end, > > > bool blockable) > > > { > > > + struct mmu_notifier_range _range, *range = &_range; > > > > Why these games with two variables? > > This is a temporary step i dediced to do the convertion in 2 steps, > first i convert the callback to use the structure so that people > having mmu notifier callback only have to review this patch and do > not get distracted by the second step which update all the mm call > site that trigger invalidation. > > In the final result this code disappear. I did it that way to make > the thing more reviewable. Sorry if that is a bit confusing. Aha, right. Thanks for clarification. You can add: Acked-by: Jan Kara <jack@suse.cz> Honza
The amdgpu part looks good to me. A minor nit-pick in mmu_notifier.c (inline). Either way, the series is Acked-by: Felix Kuehling <Felix.Kuehling@amd.com> On 2018-12-05 12:36 a.m., jglisse@redhat.com wrote: > From: Jérôme Glisse <jglisse@redhat.com> > > To avoid having to change many callback definition everytime we want > to add a parameter use a structure to group all parameters for the > mmu_notifier invalidate_range_start/end callback. No functional changes > with this patch. > > Signed-off-by: Jérôme Glisse <jglisse@redhat.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Matthew Wilcox <mawilcox@microsoft.com> > Cc: Ross Zwisler <zwisler@kernel.org> > Cc: Jan Kara <jack@suse.cz> > Cc: Dan Williams <dan.j.williams@intel.com> > Cc: Paolo Bonzini <pbonzini@redhat.com> > Cc: Radim Krčmář <rkrcmar@redhat.com> > Cc: Michal Hocko <mhocko@kernel.org> > Cc: Christian Koenig <christian.koenig@amd.com> > Cc: Felix Kuehling <felix.kuehling@amd.com> > Cc: Ralph Campbell <rcampbell@nvidia.com> > Cc: John Hubbard <jhubbard@nvidia.com> > Cc: kvm@vger.kernel.org > Cc: dri-devel@lists.freedesktop.org > Cc: linux-rdma@vger.kernel.org > Cc: linux-fsdevel@vger.kernel.org > --- > drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c | 43 +++++++++++-------------- > drivers/gpu/drm/i915/i915_gem_userptr.c | 14 ++++---- > drivers/gpu/drm/radeon/radeon_mn.c | 16 ++++----- > drivers/infiniband/core/umem_odp.c | 20 +++++------- > drivers/infiniband/hw/hfi1/mmu_rb.c | 13 +++----- > drivers/misc/mic/scif/scif_dma.c | 11 ++----- > drivers/misc/sgi-gru/grutlbpurge.c | 14 ++++---- > drivers/xen/gntdev.c | 12 +++---- > include/linux/mmu_notifier.h | 14 +++++--- > mm/hmm.c | 23 ++++++------- > mm/mmu_notifier.c | 21 ++++++++++-- > virt/kvm/kvm_main.c | 14 +++----- > 12 files changed, 102 insertions(+), 113 deletions(-) > [snip] > diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c > index 5119ff846769..5f6665ae3ee2 100644 > --- a/mm/mmu_notifier.c > +++ b/mm/mmu_notifier.c > @@ -178,14 +178,20 @@ int __mmu_notifier_invalidate_range_start(struct mm_struct *mm, > unsigned long start, unsigned long end, > bool blockable) > { > + struct mmu_notifier_range _range, *range = &_range; I'm not sure why you need to access _range indirectly through a pointer. See below. > struct mmu_notifier *mn; > int ret = 0; > int id; > > + range->blockable = blockable; > + range->start = start; > + range->end = end; > + range->mm = mm; This could just assign _range.blockable, _range.start, etc. without the indirection. Or you could even use an initializer instead: struct mmu_notifier_range range = { .blockable = blockable, .start = start, ... }; > + > id = srcu_read_lock(&srcu); > hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) { > if (mn->ops->invalidate_range_start) { > - int _ret = mn->ops->invalidate_range_start(mn, mm, start, end, blockable); > + int _ret = mn->ops->invalidate_range_start(mn, range); This could just use &_range without the indirection. Same in ..._invalidate_range_end below. Regards, Felix > if (_ret) { > pr_info("%pS callback failed with %d in %sblockable context.\n", > mn->ops->invalidate_range_start, _ret, > @@ -205,9 +211,20 @@ void __mmu_notifier_invalidate_range_end(struct mm_struct *mm, > unsigned long end, > bool only_end) > { > + struct mmu_notifier_range _range, *range = &_range; > struct mmu_notifier *mn; > int id; > > + /* > + * The end call back will never be call if the start refused to go > + * through because of blockable was false so here assume that we > + * can block. > + */ > + range->blockable = true; > + range->start = start; > + range->end = end; > + range->mm = mm; > + > id = srcu_read_lock(&srcu); > hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) { > /* > @@ -226,7 +243,7 @@ void __mmu_notifier_invalidate_range_end(struct mm_struct *mm, > if (!only_end && mn->ops->invalidate_range) > mn->ops->invalidate_range(mn, mm, start, end); > if (mn->ops->invalidate_range_end) > - mn->ops->invalidate_range_end(mn, mm, start, end); > + mn->ops->invalidate_range_end(mn, range); > } > srcu_read_unlock(&srcu, id); > } > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 2679e476b6c3..f829f63f2b16 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -360,10 +360,7 @@ static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn, > } > > static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn, > - struct mm_struct *mm, > - unsigned long start, > - unsigned long end, > - bool blockable) > + const struct mmu_notifier_range *range) > { > struct kvm *kvm = mmu_notifier_to_kvm(mn); > int need_tlb_flush = 0, idx; > @@ -377,7 +374,7 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn, > * count is also read inside the mmu_lock critical section. > */ > kvm->mmu_notifier_count++; > - need_tlb_flush = kvm_unmap_hva_range(kvm, start, end); > + need_tlb_flush = kvm_unmap_hva_range(kvm, range->start, range->end); > need_tlb_flush |= kvm->tlbs_dirty; > /* we've to flush the tlb before the pages can be freed */ > if (need_tlb_flush) > @@ -385,7 +382,8 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn, > > spin_unlock(&kvm->mmu_lock); > > - ret = kvm_arch_mmu_notifier_invalidate_range(kvm, start, end, blockable); > + ret = kvm_arch_mmu_notifier_invalidate_range(kvm, range->start, > + range->end, range->blockable); > > srcu_read_unlock(&kvm->srcu, idx); > > @@ -393,9 +391,7 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn, > } > > static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn, > - struct mm_struct *mm, > - unsigned long start, > - unsigned long end) > + const struct mmu_notifier_range *range) > { > struct kvm *kvm = mmu_notifier_to_kvm(mn); >
On Wed, Dec 05, 2018 at 09:42:45PM +0000, Kuehling, Felix wrote: > The amdgpu part looks good to me. > > A minor nit-pick in mmu_notifier.c (inline). > > Either way, the series is Acked-by: Felix Kuehling <Felix.Kuehling@amd.com> > > On 2018-12-05 12:36 a.m., jglisse@redhat.com wrote: > > From: Jérôme Glisse <jglisse@redhat.com> > > > > To avoid having to change many callback definition everytime we want > > to add a parameter use a structure to group all parameters for the > > mmu_notifier invalidate_range_start/end callback. No functional changes > > with this patch. > > > > Signed-off-by: Jérôme Glisse <jglisse@redhat.com> > > Cc: Andrew Morton <akpm@linux-foundation.org> > > Cc: Matthew Wilcox <mawilcox@microsoft.com> > > Cc: Ross Zwisler <zwisler@kernel.org> > > Cc: Jan Kara <jack@suse.cz> > > Cc: Dan Williams <dan.j.williams@intel.com> > > Cc: Paolo Bonzini <pbonzini@redhat.com> > > Cc: Radim Krčmář <rkrcmar@redhat.com> > > Cc: Michal Hocko <mhocko@kernel.org> > > Cc: Christian Koenig <christian.koenig@amd.com> > > Cc: Felix Kuehling <felix.kuehling@amd.com> > > Cc: Ralph Campbell <rcampbell@nvidia.com> > > Cc: John Hubbard <jhubbard@nvidia.com> > > Cc: kvm@vger.kernel.org > > Cc: dri-devel@lists.freedesktop.org > > Cc: linux-rdma@vger.kernel.org > > Cc: linux-fsdevel@vger.kernel.org > > --- > > drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c | 43 +++++++++++-------------- > > drivers/gpu/drm/i915/i915_gem_userptr.c | 14 ++++---- > > drivers/gpu/drm/radeon/radeon_mn.c | 16 ++++----- > > drivers/infiniband/core/umem_odp.c | 20 +++++------- > > drivers/infiniband/hw/hfi1/mmu_rb.c | 13 +++----- > > drivers/misc/mic/scif/scif_dma.c | 11 ++----- > > drivers/misc/sgi-gru/grutlbpurge.c | 14 ++++---- > > drivers/xen/gntdev.c | 12 +++---- > > include/linux/mmu_notifier.h | 14 +++++--- > > mm/hmm.c | 23 ++++++------- > > mm/mmu_notifier.c | 21 ++++++++++-- > > virt/kvm/kvm_main.c | 14 +++----- > > 12 files changed, 102 insertions(+), 113 deletions(-) > > > [snip] > > diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c > > index 5119ff846769..5f6665ae3ee2 100644 > > --- a/mm/mmu_notifier.c > > +++ b/mm/mmu_notifier.c > > @@ -178,14 +178,20 @@ int __mmu_notifier_invalidate_range_start(struct mm_struct *mm, > > unsigned long start, unsigned long end, > > bool blockable) > > { > > + struct mmu_notifier_range _range, *range = &_range; > > I'm not sure why you need to access _range indirectly through a pointer. > See below. > > > > struct mmu_notifier *mn; > > int ret = 0; > > int id; > > > > + range->blockable = blockable; > > + range->start = start; > > + range->end = end; > > + range->mm = mm; > > This could just assign _range.blockable, _range.start, etc. without the > indirection. Or you could even use an initializer instead: > > struct mmu_notifier_range range = { > .blockable = blockable, > .start = start, > ... > }; > > > > + > > id = srcu_read_lock(&srcu); > > hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) { > > if (mn->ops->invalidate_range_start) { > > - int _ret = mn->ops->invalidate_range_start(mn, mm, start, end, blockable); > > + int _ret = mn->ops->invalidate_range_start(mn, range); > > This could just use &_range without the indirection. > > Same in ..._invalidate_range_end below. So explaination is that this is a temporary step all this code is remove in the second patch. It was done this way in this patch to minimize the diff within the next patch. I did this because i wanted to do the convertion in 2 steps the first step i convert all the listener of mmu notifier and in the second step i convert all the call site that trigger a mmu notifer. I did that to help people reviewing only the part they care about. Apparently it end up confusing people more than it helped :) Do people have strong feeling about getting this code that is deleted in the second patch fix in the first patch anyway ? I can respin if so but i don't see much value in formating code that is deleted in the serie. Thank you for reviewing Cheers, Jérôme
On 2018-12-05 6:04 p.m., Jerome Glisse wrote: > On Wed, Dec 05, 2018 at 09:42:45PM +0000, Kuehling, Felix wrote: >> The amdgpu part looks good to me. >> >> A minor nit-pick in mmu_notifier.c (inline). >> >> Either way, the series is Acked-by: Felix Kuehling <Felix.Kuehling@amd.com> >> >> On 2018-12-05 12:36 a.m., jglisse@redhat.com wrote: >>> From: Jérôme Glisse <jglisse@redhat.com> >>> >>> To avoid having to change many callback definition everytime we want >>> to add a parameter use a structure to group all parameters for the >>> mmu_notifier invalidate_range_start/end callback. No functional changes >>> with this patch. >>> >>> Signed-off-by: Jérôme Glisse <jglisse@redhat.com> >>> Cc: Andrew Morton <akpm@linux-foundation.org> >>> Cc: Matthew Wilcox <mawilcox@microsoft.com> >>> Cc: Ross Zwisler <zwisler@kernel.org> >>> Cc: Jan Kara <jack@suse.cz> >>> Cc: Dan Williams <dan.j.williams@intel.com> >>> Cc: Paolo Bonzini <pbonzini@redhat.com> >>> Cc: Radim Krčmář <rkrcmar@redhat.com> >>> Cc: Michal Hocko <mhocko@kernel.org> >>> Cc: Christian Koenig <christian.koenig@amd.com> >>> Cc: Felix Kuehling <felix.kuehling@amd.com> >>> Cc: Ralph Campbell <rcampbell@nvidia.com> >>> Cc: John Hubbard <jhubbard@nvidia.com> >>> Cc: kvm@vger.kernel.org >>> Cc: dri-devel@lists.freedesktop.org >>> Cc: linux-rdma@vger.kernel.org >>> Cc: linux-fsdevel@vger.kernel.org >>> --- >>> drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c | 43 +++++++++++-------------- >>> drivers/gpu/drm/i915/i915_gem_userptr.c | 14 ++++---- >>> drivers/gpu/drm/radeon/radeon_mn.c | 16 ++++----- >>> drivers/infiniband/core/umem_odp.c | 20 +++++------- >>> drivers/infiniband/hw/hfi1/mmu_rb.c | 13 +++----- >>> drivers/misc/mic/scif/scif_dma.c | 11 ++----- >>> drivers/misc/sgi-gru/grutlbpurge.c | 14 ++++---- >>> drivers/xen/gntdev.c | 12 +++---- >>> include/linux/mmu_notifier.h | 14 +++++--- >>> mm/hmm.c | 23 ++++++------- >>> mm/mmu_notifier.c | 21 ++++++++++-- >>> virt/kvm/kvm_main.c | 14 +++----- >>> 12 files changed, 102 insertions(+), 113 deletions(-) >>> >> [snip] >>> diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c >>> index 5119ff846769..5f6665ae3ee2 100644 >>> --- a/mm/mmu_notifier.c >>> +++ b/mm/mmu_notifier.c >>> @@ -178,14 +178,20 @@ int __mmu_notifier_invalidate_range_start(struct mm_struct *mm, >>> unsigned long start, unsigned long end, >>> bool blockable) >>> { >>> + struct mmu_notifier_range _range, *range = &_range; >> I'm not sure why you need to access _range indirectly through a pointer. >> See below. >> >> >>> struct mmu_notifier *mn; >>> int ret = 0; >>> int id; >>> >>> + range->blockable = blockable; >>> + range->start = start; >>> + range->end = end; >>> + range->mm = mm; >> This could just assign _range.blockable, _range.start, etc. without the >> indirection. Or you could even use an initializer instead: >> >> struct mmu_notifier_range range = { >> .blockable = blockable, >> .start = start, >> ... >> }; >> >> >>> + >>> id = srcu_read_lock(&srcu); >>> hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) { >>> if (mn->ops->invalidate_range_start) { >>> - int _ret = mn->ops->invalidate_range_start(mn, mm, start, end, blockable); >>> + int _ret = mn->ops->invalidate_range_start(mn, range); >> This could just use &_range without the indirection. >> >> Same in ..._invalidate_range_end below. > So explaination is that this is a temporary step all this code is > remove in the second patch. It was done this way in this patch to > minimize the diff within the next patch. I was actually looking for that because I suspected that this would make more sense in the context of the other patches. But then I missed the mmu_notifier.c change in patch 2 in the noise of all the other mm changes. Never mind. > I did this because i wanted to do the convertion in 2 steps the > first step i convert all the listener of mmu notifier and in the > second step i convert all the call site that trigger a mmu notifer. That part makes sense and I appreciate that it keeps the patches reasonably separate for different audiences. Thanks, Felix > I did that to help people reviewing only the part they care about. > > Apparently it end up confusing people more than it helped :) > > Do people have strong feeling about getting this code that is > deleted in the second patch fix in the first patch anyway ? > > I can respin if so but i don't see much value in formating code > that is deleted in the serie. > > Thank you for reviewing > > Cheers, > Jérôme
On Wed, Dec 05, 2018 at 12:36:26AM -0500, jglisse@redhat.com wrote: > From: Jérôme Glisse <jglisse@redhat.com> > > To avoid having to change many callback definition everytime we want > to add a parameter use a structure to group all parameters for the > mmu_notifier invalidate_range_start/end callback. No functional changes > with this patch. > > Signed-off-by: Jérôme Glisse <jglisse@redhat.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Matthew Wilcox <mawilcox@microsoft.com> > Cc: Ross Zwisler <zwisler@kernel.org> > Cc: Jan Kara <jack@suse.cz> > Cc: Dan Williams <dan.j.williams@intel.com> > Cc: Paolo Bonzini <pbonzini@redhat.com> > Cc: Radim Krčmář <rkrcmar@redhat.com> > Cc: Michal Hocko <mhocko@kernel.org> > Cc: Christian Koenig <christian.koenig@amd.com> > Cc: Felix Kuehling <felix.kuehling@amd.com> > Cc: Ralph Campbell <rcampbell@nvidia.com> > Cc: John Hubbard <jhubbard@nvidia.com> > Cc: kvm@vger.kernel.org > Cc: dri-devel@lists.freedesktop.org > Cc: linux-rdma@vger.kernel.org > Cc: linux-fsdevel@vger.kernel.org > --- > drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c | 43 +++++++++++-------------- > drivers/gpu/drm/i915/i915_gem_userptr.c | 14 ++++---- > drivers/gpu/drm/radeon/radeon_mn.c | 16 ++++----- > drivers/infiniband/core/umem_odp.c | 20 +++++------- > drivers/infiniband/hw/hfi1/mmu_rb.c | 13 +++----- > drivers/misc/mic/scif/scif_dma.c | 11 ++----- > drivers/misc/sgi-gru/grutlbpurge.c | 14 ++++---- > drivers/xen/gntdev.c | 12 +++---- > include/linux/mmu_notifier.h | 14 +++++--- > mm/hmm.c | 23 ++++++------- > mm/mmu_notifier.c | 21 ++++++++++-- > virt/kvm/kvm_main.c | 14 +++----- > 12 files changed, 102 insertions(+), 113 deletions(-) The changes to drivers/infiniband look mechanical and fine to me. It even looks like this avoids merge conflicts with the other changes to these files :) For infiniband: Acked-by: Jason Gunthorpe <jgg@mellanox.com> I assume this will go through the mm tree? Jason
On Thu, Dec 06, 2018 at 08:30:27PM -0700, Jason Gunthorpe wrote: > On Wed, Dec 05, 2018 at 12:36:26AM -0500, jglisse@redhat.com wrote: > > From: Jérôme Glisse <jglisse@redhat.com> > > > > To avoid having to change many callback definition everytime we want > > to add a parameter use a structure to group all parameters for the > > mmu_notifier invalidate_range_start/end callback. No functional changes > > with this patch. > > > > Signed-off-by: Jérôme Glisse <jglisse@redhat.com> > > Cc: Andrew Morton <akpm@linux-foundation.org> > > Cc: Matthew Wilcox <mawilcox@microsoft.com> > > Cc: Ross Zwisler <zwisler@kernel.org> > > Cc: Jan Kara <jack@suse.cz> > > Cc: Dan Williams <dan.j.williams@intel.com> > > Cc: Paolo Bonzini <pbonzini@redhat.com> > > Cc: Radim Krčmář <rkrcmar@redhat.com> > > Cc: Michal Hocko <mhocko@kernel.org> > > Cc: Christian Koenig <christian.koenig@amd.com> > > Cc: Felix Kuehling <felix.kuehling@amd.com> > > Cc: Ralph Campbell <rcampbell@nvidia.com> > > Cc: John Hubbard <jhubbard@nvidia.com> > > Cc: kvm@vger.kernel.org > > Cc: dri-devel@lists.freedesktop.org > > Cc: linux-rdma@vger.kernel.org > > Cc: linux-fsdevel@vger.kernel.org > > --- > > drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c | 43 +++++++++++-------------- > > drivers/gpu/drm/i915/i915_gem_userptr.c | 14 ++++---- > > drivers/gpu/drm/radeon/radeon_mn.c | 16 ++++----- > > drivers/infiniband/core/umem_odp.c | 20 +++++------- > > drivers/infiniband/hw/hfi1/mmu_rb.c | 13 +++----- > > drivers/misc/mic/scif/scif_dma.c | 11 ++----- > > drivers/misc/sgi-gru/grutlbpurge.c | 14 ++++---- > > drivers/xen/gntdev.c | 12 +++---- > > include/linux/mmu_notifier.h | 14 +++++--- > > mm/hmm.c | 23 ++++++------- > > mm/mmu_notifier.c | 21 ++++++++++-- > > virt/kvm/kvm_main.c | 14 +++----- > > 12 files changed, 102 insertions(+), 113 deletions(-) > > The changes to drivers/infiniband look mechanical and fine to me. > > It even looks like this avoids merge conflicts with the other changes > to these files :) > > For infiniband: > > Acked-by: Jason Gunthorpe <jgg@mellanox.com> > > I assume this will go through the mm tree? Yes this is my exceptation as in the ends it touch more mm stuff than anything else. Andrew already added v1 to its patchset. Cheers, Jérôme
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c index e55508b39496..5bc7e59a05a1 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c @@ -246,36 +246,34 @@ static void amdgpu_mn_invalidate_node(struct amdgpu_mn_node *node, * potentially dirty. */ static int amdgpu_mn_invalidate_range_start_gfx(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long start, - unsigned long end, - bool blockable) + const struct mmu_notifier_range *range) { struct amdgpu_mn *amn = container_of(mn, struct amdgpu_mn, mn); struct interval_tree_node *it; + unsigned long end; /* notification is exclusive, but interval is inclusive */ - end -= 1; + end = range->end - 1; /* TODO we should be able to split locking for interval tree and * amdgpu_mn_invalidate_node */ - if (amdgpu_mn_read_lock(amn, blockable)) + if (amdgpu_mn_read_lock(amn, range->blockable)) return -EAGAIN; - it = interval_tree_iter_first(&amn->objects, start, end); + it = interval_tree_iter_first(&amn->objects, range->start, end); while (it) { struct amdgpu_mn_node *node; - if (!blockable) { + if (!range->blockable) { amdgpu_mn_read_unlock(amn); return -EAGAIN; } node = container_of(it, struct amdgpu_mn_node, it); - it = interval_tree_iter_next(it, start, end); + it = interval_tree_iter_next(it, range->start, end); - amdgpu_mn_invalidate_node(node, start, end); + amdgpu_mn_invalidate_node(node, range->start, end); } return 0; @@ -294,39 +292,38 @@ static int amdgpu_mn_invalidate_range_start_gfx(struct mmu_notifier *mn, * are restorted in amdgpu_mn_invalidate_range_end_hsa. */ static int amdgpu_mn_invalidate_range_start_hsa(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long start, - unsigned long end, - bool blockable) + const struct mmu_notifier_range *range) { struct amdgpu_mn *amn = container_of(mn, struct amdgpu_mn, mn); struct interval_tree_node *it; + unsigned long end; /* notification is exclusive, but interval is inclusive */ - end -= 1; + end = range->end - 1; - if (amdgpu_mn_read_lock(amn, blockable)) + if (amdgpu_mn_read_lock(amn, range->blockable)) return -EAGAIN; - it = interval_tree_iter_first(&amn->objects, start, end); + it = interval_tree_iter_first(&amn->objects, range->start, end); while (it) { struct amdgpu_mn_node *node; struct amdgpu_bo *bo; - if (!blockable) { + if (!range->blockable) { amdgpu_mn_read_unlock(amn); return -EAGAIN; } node = container_of(it, struct amdgpu_mn_node, it); - it = interval_tree_iter_next(it, start, end); + it = interval_tree_iter_next(it, range->start, end); list_for_each_entry(bo, &node->bos, mn_list) { struct kgd_mem *mem = bo->kfd_bo; if (amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, - start, end)) - amdgpu_amdkfd_evict_userptr(mem, mm); + range->start, + end)) + amdgpu_amdkfd_evict_userptr(mem, range->mm); } } @@ -344,9 +341,7 @@ static int amdgpu_mn_invalidate_range_start_hsa(struct mmu_notifier *mn, * Release the lock again to allow new command submissions. */ static void amdgpu_mn_invalidate_range_end(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long start, - unsigned long end) + const struct mmu_notifier_range *range) { struct amdgpu_mn *amn = container_of(mn, struct amdgpu_mn, mn); diff --git a/drivers/gpu/drm/i915/i915_gem_userptr.c b/drivers/gpu/drm/i915/i915_gem_userptr.c index 2c9b284036d1..3df77020aada 100644 --- a/drivers/gpu/drm/i915/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/i915_gem_userptr.c @@ -113,27 +113,25 @@ static void del_object(struct i915_mmu_object *mo) } static int i915_gem_userptr_mn_invalidate_range_start(struct mmu_notifier *_mn, - struct mm_struct *mm, - unsigned long start, - unsigned long end, - bool blockable) + const struct mmu_notifier_range *range) { struct i915_mmu_notifier *mn = container_of(_mn, struct i915_mmu_notifier, mn); struct i915_mmu_object *mo; struct interval_tree_node *it; LIST_HEAD(cancelled); + unsigned long end; if (RB_EMPTY_ROOT(&mn->objects.rb_root)) return 0; /* interval ranges are inclusive, but invalidate range is exclusive */ - end--; + end = range->end - 1; spin_lock(&mn->lock); - it = interval_tree_iter_first(&mn->objects, start, end); + it = interval_tree_iter_first(&mn->objects, range->start, end); while (it) { - if (!blockable) { + if (!range->blockable) { spin_unlock(&mn->lock); return -EAGAIN; } @@ -151,7 +149,7 @@ static int i915_gem_userptr_mn_invalidate_range_start(struct mmu_notifier *_mn, queue_work(mn->wq, &mo->work); list_add(&mo->link, &cancelled); - it = interval_tree_iter_next(it, start, end); + it = interval_tree_iter_next(it, range->start, end); } list_for_each_entry(mo, &cancelled, link) del_object(mo); diff --git a/drivers/gpu/drm/radeon/radeon_mn.c b/drivers/gpu/drm/radeon/radeon_mn.c index f8b35df44c60..b3019505065a 100644 --- a/drivers/gpu/drm/radeon/radeon_mn.c +++ b/drivers/gpu/drm/radeon/radeon_mn.c @@ -119,40 +119,38 @@ static void radeon_mn_release(struct mmu_notifier *mn, * unmap them by move them into system domain again. */ static int radeon_mn_invalidate_range_start(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long start, - unsigned long end, - bool blockable) + const struct mmu_notifier_range *range) { struct radeon_mn *rmn = container_of(mn, struct radeon_mn, mn); struct ttm_operation_ctx ctx = { false, false }; struct interval_tree_node *it; + unsigned long end; int ret = 0; /* notification is exclusive, but interval is inclusive */ - end -= 1; + end = range->end - 1; /* TODO we should be able to split locking for interval tree and * the tear down. */ - if (blockable) + if (range->blockable) mutex_lock(&rmn->lock); else if (!mutex_trylock(&rmn->lock)) return -EAGAIN; - it = interval_tree_iter_first(&rmn->objects, start, end); + it = interval_tree_iter_first(&rmn->objects, range->start, end); while (it) { struct radeon_mn_node *node; struct radeon_bo *bo; long r; - if (!blockable) { + if (!range->blockable) { ret = -EAGAIN; goto out_unlock; } node = container_of(it, struct radeon_mn_node, it); - it = interval_tree_iter_next(it, start, end); + it = interval_tree_iter_next(it, range->start, end); list_for_each_entry(bo, &node->bos, mn_list) { diff --git a/drivers/infiniband/core/umem_odp.c b/drivers/infiniband/core/umem_odp.c index 676c1fd1119d..25db6ff68c70 100644 --- a/drivers/infiniband/core/umem_odp.c +++ b/drivers/infiniband/core/umem_odp.c @@ -146,15 +146,12 @@ static int invalidate_range_start_trampoline(struct ib_umem_odp *item, } static int ib_umem_notifier_invalidate_range_start(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long start, - unsigned long end, - bool blockable) + const struct mmu_notifier_range *range) { struct ib_ucontext_per_mm *per_mm = container_of(mn, struct ib_ucontext_per_mm, mn); - if (blockable) + if (range->blockable) down_read(&per_mm->umem_rwsem); else if (!down_read_trylock(&per_mm->umem_rwsem)) return -EAGAIN; @@ -169,9 +166,10 @@ static int ib_umem_notifier_invalidate_range_start(struct mmu_notifier *mn, return 0; } - return rbt_ib_umem_for_each_in_range(&per_mm->umem_tree, start, end, + return rbt_ib_umem_for_each_in_range(&per_mm->umem_tree, range->start, + range->end, invalidate_range_start_trampoline, - blockable, NULL); + range->blockable, NULL); } static int invalidate_range_end_trampoline(struct ib_umem_odp *item, u64 start, @@ -182,9 +180,7 @@ static int invalidate_range_end_trampoline(struct ib_umem_odp *item, u64 start, } static void ib_umem_notifier_invalidate_range_end(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long start, - unsigned long end) + const struct mmu_notifier_range *range) { struct ib_ucontext_per_mm *per_mm = container_of(mn, struct ib_ucontext_per_mm, mn); @@ -192,8 +188,8 @@ static void ib_umem_notifier_invalidate_range_end(struct mmu_notifier *mn, if (unlikely(!per_mm->active)) return; - rbt_ib_umem_for_each_in_range(&per_mm->umem_tree, start, - end, + rbt_ib_umem_for_each_in_range(&per_mm->umem_tree, range->start, + range->end, invalidate_range_end_trampoline, true, NULL); up_read(&per_mm->umem_rwsem); } diff --git a/drivers/infiniband/hw/hfi1/mmu_rb.c b/drivers/infiniband/hw/hfi1/mmu_rb.c index 475b769e120c..14d2a90964c3 100644 --- a/drivers/infiniband/hw/hfi1/mmu_rb.c +++ b/drivers/infiniband/hw/hfi1/mmu_rb.c @@ -68,8 +68,7 @@ struct mmu_rb_handler { static unsigned long mmu_node_start(struct mmu_rb_node *); static unsigned long mmu_node_last(struct mmu_rb_node *); static int mmu_notifier_range_start(struct mmu_notifier *, - struct mm_struct *, - unsigned long, unsigned long, bool); + const struct mmu_notifier_range *); static struct mmu_rb_node *__mmu_rb_search(struct mmu_rb_handler *, unsigned long, unsigned long); static void do_remove(struct mmu_rb_handler *handler, @@ -284,10 +283,7 @@ void hfi1_mmu_rb_remove(struct mmu_rb_handler *handler, } static int mmu_notifier_range_start(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long start, - unsigned long end, - bool blockable) + const struct mmu_notifier_range *range) { struct mmu_rb_handler *handler = container_of(mn, struct mmu_rb_handler, mn); @@ -297,10 +293,11 @@ static int mmu_notifier_range_start(struct mmu_notifier *mn, bool added = false; spin_lock_irqsave(&handler->lock, flags); - for (node = __mmu_int_rb_iter_first(root, start, end - 1); + for (node = __mmu_int_rb_iter_first(root, range->start, range->end-1); node; node = ptr) { /* Guard against node removal. */ - ptr = __mmu_int_rb_iter_next(node, start, end - 1); + ptr = __mmu_int_rb_iter_next(node, range->start, + range->end - 1); trace_hfi1_mmu_mem_invalidate(node->addr, node->len); if (handler->ops->invalidate(handler->ops_arg, node)) { __mmu_int_rb_remove(node, root); diff --git a/drivers/misc/mic/scif/scif_dma.c b/drivers/misc/mic/scif/scif_dma.c index 18b8ed57c4ac..e0d97044d0e9 100644 --- a/drivers/misc/mic/scif/scif_dma.c +++ b/drivers/misc/mic/scif/scif_dma.c @@ -201,23 +201,18 @@ static void scif_mmu_notifier_release(struct mmu_notifier *mn, } static int scif_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long start, - unsigned long end, - bool blockable) + const struct mmu_notifier_range *range) { struct scif_mmu_notif *mmn; mmn = container_of(mn, struct scif_mmu_notif, ep_mmu_notifier); - scif_rma_destroy_tcw(mmn, start, end - start); + scif_rma_destroy_tcw(mmn, range->start, range->end - range->start); return 0; } static void scif_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long start, - unsigned long end) + const struct mmu_notifier_range *range) { /* * Nothing to do here, everything needed was done in diff --git a/drivers/misc/sgi-gru/grutlbpurge.c b/drivers/misc/sgi-gru/grutlbpurge.c index 03b49d52092e..ca2032afe035 100644 --- a/drivers/misc/sgi-gru/grutlbpurge.c +++ b/drivers/misc/sgi-gru/grutlbpurge.c @@ -220,9 +220,7 @@ void gru_flush_all_tlb(struct gru_state *gru) * MMUOPS notifier callout functions */ static int gru_invalidate_range_start(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long start, unsigned long end, - bool blockable) + const struct mmu_notifier_range *range) { struct gru_mm_struct *gms = container_of(mn, struct gru_mm_struct, ms_notifier); @@ -230,15 +228,14 @@ static int gru_invalidate_range_start(struct mmu_notifier *mn, STAT(mmu_invalidate_range); atomic_inc(&gms->ms_range_active); gru_dbg(grudev, "gms %p, start 0x%lx, end 0x%lx, act %d\n", gms, - start, end, atomic_read(&gms->ms_range_active)); - gru_flush_tlb_range(gms, start, end - start); + range->start, range->end, atomic_read(&gms->ms_range_active)); + gru_flush_tlb_range(gms, range->start, range->end - range->start); return 0; } static void gru_invalidate_range_end(struct mmu_notifier *mn, - struct mm_struct *mm, unsigned long start, - unsigned long end) + const struct mmu_notifier_range *range) { struct gru_mm_struct *gms = container_of(mn, struct gru_mm_struct, ms_notifier); @@ -247,7 +244,8 @@ static void gru_invalidate_range_end(struct mmu_notifier *mn, (void)atomic_dec_and_test(&gms->ms_range_active); wake_up_all(&gms->ms_wait_queue); - gru_dbg(grudev, "gms %p, start 0x%lx, end 0x%lx\n", gms, start, end); + gru_dbg(grudev, "gms %p, start 0x%lx, end 0x%lx\n", + gms, range->start, range->end); } static void gru_release(struct mmu_notifier *mn, struct mm_struct *mm) diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index b0b02a501167..5efc5eee9544 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -520,26 +520,26 @@ static int unmap_if_in_range(struct gntdev_grant_map *map, } static int mn_invl_range_start(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long start, unsigned long end, - bool blockable) + const struct mmu_notifier_range *range) { struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); struct gntdev_grant_map *map; int ret = 0; - if (blockable) + if (range->blockable) mutex_lock(&priv->lock); else if (!mutex_trylock(&priv->lock)) return -EAGAIN; list_for_each_entry(map, &priv->maps, next) { - ret = unmap_if_in_range(map, start, end, blockable); + ret = unmap_if_in_range(map, range->start, range->end, + range->blockable); if (ret) goto out_unlock; } list_for_each_entry(map, &priv->freeable_maps, next) { - ret = unmap_if_in_range(map, start, end, blockable); + ret = unmap_if_in_range(map, range->start, range->end, + range->blockable); if (ret) goto out_unlock; } diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index 9893a6432adf..368f0c1a049d 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -25,6 +25,13 @@ struct mmu_notifier_mm { spinlock_t lock; }; +struct mmu_notifier_range { + struct mm_struct *mm; + unsigned long start; + unsigned long end; + bool blockable; +}; + struct mmu_notifier_ops { /* * Called either by mmu_notifier_unregister or when the mm is @@ -146,12 +153,9 @@ struct mmu_notifier_ops { * */ int (*invalidate_range_start)(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long start, unsigned long end, - bool blockable); + const struct mmu_notifier_range *range); void (*invalidate_range_end)(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long start, unsigned long end); + const struct mmu_notifier_range *range); /* * invalidate_range() is either called between diff --git a/mm/hmm.c b/mm/hmm.c index 90c34f3d1243..1965f2caf5eb 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -189,35 +189,30 @@ static void hmm_release(struct mmu_notifier *mn, struct mm_struct *mm) } static int hmm_invalidate_range_start(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long start, - unsigned long end, - bool blockable) + const struct mmu_notifier_range *range) { struct hmm_update update; - struct hmm *hmm = mm->hmm; + struct hmm *hmm = range->mm->hmm; VM_BUG_ON(!hmm); - update.start = start; - update.end = end; + update.start = range->start; + update.end = range->end; update.event = HMM_UPDATE_INVALIDATE; - update.blockable = blockable; + update.blockable = range->blockable; return hmm_invalidate_range(hmm, true, &update); } static void hmm_invalidate_range_end(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long start, - unsigned long end) + const struct mmu_notifier_range *range) { struct hmm_update update; - struct hmm *hmm = mm->hmm; + struct hmm *hmm = range->mm->hmm; VM_BUG_ON(!hmm); - update.start = start; - update.end = end; + update.start = range->start; + update.end = range->end; update.event = HMM_UPDATE_INVALIDATE; update.blockable = true; hmm_invalidate_range(hmm, false, &update); diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c index 5119ff846769..5f6665ae3ee2 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -178,14 +178,20 @@ int __mmu_notifier_invalidate_range_start(struct mm_struct *mm, unsigned long start, unsigned long end, bool blockable) { + struct mmu_notifier_range _range, *range = &_range; struct mmu_notifier *mn; int ret = 0; int id; + range->blockable = blockable; + range->start = start; + range->end = end; + range->mm = mm; + id = srcu_read_lock(&srcu); hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) { if (mn->ops->invalidate_range_start) { - int _ret = mn->ops->invalidate_range_start(mn, mm, start, end, blockable); + int _ret = mn->ops->invalidate_range_start(mn, range); if (_ret) { pr_info("%pS callback failed with %d in %sblockable context.\n", mn->ops->invalidate_range_start, _ret, @@ -205,9 +211,20 @@ void __mmu_notifier_invalidate_range_end(struct mm_struct *mm, unsigned long end, bool only_end) { + struct mmu_notifier_range _range, *range = &_range; struct mmu_notifier *mn; int id; + /* + * The end call back will never be call if the start refused to go + * through because of blockable was false so here assume that we + * can block. + */ + range->blockable = true; + range->start = start; + range->end = end; + range->mm = mm; + id = srcu_read_lock(&srcu); hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) { /* @@ -226,7 +243,7 @@ void __mmu_notifier_invalidate_range_end(struct mm_struct *mm, if (!only_end && mn->ops->invalidate_range) mn->ops->invalidate_range(mn, mm, start, end); if (mn->ops->invalidate_range_end) - mn->ops->invalidate_range_end(mn, mm, start, end); + mn->ops->invalidate_range_end(mn, range); } srcu_read_unlock(&srcu, id); } diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 2679e476b6c3..f829f63f2b16 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -360,10 +360,7 @@ static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn, } static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long start, - unsigned long end, - bool blockable) + const struct mmu_notifier_range *range) { struct kvm *kvm = mmu_notifier_to_kvm(mn); int need_tlb_flush = 0, idx; @@ -377,7 +374,7 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn, * count is also read inside the mmu_lock critical section. */ kvm->mmu_notifier_count++; - need_tlb_flush = kvm_unmap_hva_range(kvm, start, end); + need_tlb_flush = kvm_unmap_hva_range(kvm, range->start, range->end); need_tlb_flush |= kvm->tlbs_dirty; /* we've to flush the tlb before the pages can be freed */ if (need_tlb_flush) @@ -385,7 +382,8 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn, spin_unlock(&kvm->mmu_lock); - ret = kvm_arch_mmu_notifier_invalidate_range(kvm, start, end, blockable); + ret = kvm_arch_mmu_notifier_invalidate_range(kvm, range->start, + range->end, range->blockable); srcu_read_unlock(&kvm->srcu, idx); @@ -393,9 +391,7 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn, } static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long start, - unsigned long end) + const struct mmu_notifier_range *range) { struct kvm *kvm = mmu_notifier_to_kvm(mn);