| Message ID | 20200309214424.330363-3-peterx@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: Dirty ring interface | expand |
On Mon, Mar 09, 2020 at 05:44:12PM -0400, Peter Xu wrote: > Cache the address space ID just like the slot ID. It will be used in > order to fill in the dirty ring entries. > > Suggested-by: Paolo Bonzini <pbonzini@redhat.com> > Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com> > Signed-off-by: Peter Xu <peterx@redhat.com> > --- > include/linux/kvm_host.h | 1 + > virt/kvm/kvm_main.c | 2 ++ > 2 files changed, 3 insertions(+) > > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > index bcb9b2ac0791..afa0e9034881 100644 > --- a/include/linux/kvm_host.h > +++ b/include/linux/kvm_host.h > @@ -346,6 +346,7 @@ struct kvm_memory_slot { > unsigned long userspace_addr; > u32 flags; > short id; > + u8 as_id; My vote is to store this as a u16 and remove the BUILD_BUG_ON. Using a u8 doesn't save any memory since the compiler will pad out the struct. > }; > > static inline unsigned long kvm_dirty_bitmap_bytes(struct kvm_memory_slot *memslot) > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 70f03ce0e5c1..e6484dabfc59 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -1036,6 +1036,8 @@ int __kvm_set_memory_region(struct kvm *kvm, > > new = old = *slot; > > + BUILD_BUG_ON(U8_MAX < KVM_ADDRESS_SPACE_NUM); > + new.as_id = as_id; > new.id = id; > new.base_gfn = base_gfn; > new.npages = npages; > -- > 2.24.1 >
On Tue, Mar 10, 2020 at 07:48:59AM -0700, Sean Christopherson wrote: > On Mon, Mar 09, 2020 at 05:44:12PM -0400, Peter Xu wrote: > > Cache the address space ID just like the slot ID. It will be used in > > order to fill in the dirty ring entries. > > > > Suggested-by: Paolo Bonzini <pbonzini@redhat.com> > > Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com> > > Signed-off-by: Peter Xu <peterx@redhat.com> > > --- > > include/linux/kvm_host.h | 1 + > > virt/kvm/kvm_main.c | 2 ++ > > 2 files changed, 3 insertions(+) > > > > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > > index bcb9b2ac0791..afa0e9034881 100644 > > --- a/include/linux/kvm_host.h > > +++ b/include/linux/kvm_host.h > > @@ -346,6 +346,7 @@ struct kvm_memory_slot { > > unsigned long userspace_addr; > > u32 flags; > > short id; > > + u8 as_id; > > My vote is to store this as a u16 and remove the BUILD_BUG_ON. Using a u8 > doesn't save any memory since the compiler will pad out the struct. Sure. Indeed that BUILD_BUG_ON does not help much in this case. Thanks, > > > }; > > > > static inline unsigned long kvm_dirty_bitmap_bytes(struct kvm_memory_slot *memslot) > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > > index 70f03ce0e5c1..e6484dabfc59 100644 > > --- a/virt/kvm/kvm_main.c > > +++ b/virt/kvm/kvm_main.c > > @@ -1036,6 +1036,8 @@ int __kvm_set_memory_region(struct kvm *kvm, > > > > new = old = *slot; > > > > + BUILD_BUG_ON(U8_MAX < KVM_ADDRESS_SPACE_NUM); > > + new.as_id = as_id; > > new.id = id; > > new.base_gfn = base_gfn; > > new.npages = npages; > > -- > > 2.24.1 > > >
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index bcb9b2ac0791..afa0e9034881 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -346,6 +346,7 @@ struct kvm_memory_slot { unsigned long userspace_addr; u32 flags; short id; + u8 as_id; }; static inline unsigned long kvm_dirty_bitmap_bytes(struct kvm_memory_slot *memslot) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 70f03ce0e5c1..e6484dabfc59 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1036,6 +1036,8 @@ int __kvm_set_memory_region(struct kvm *kvm, new = old = *slot; + BUILD_BUG_ON(U8_MAX < KVM_ADDRESS_SPACE_NUM); + new.as_id = as_id; new.id = id; new.base_gfn = base_gfn; new.npages = npages;
Cache the address space ID just like the slot ID. It will be used in order to fill in the dirty ring entries. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Peter Xu <peterx@redhat.com> --- include/linux/kvm_host.h | 1 + virt/kvm/kvm_main.c | 2 ++ 2 files changed, 3 insertions(+)