diff mbox series

[RFC,v12,01/33] KVM: Tweak kvm_hva_range and hva_handler_t to allow reusing for gfn ranges

Message ID 20230914015531.1419405-2-seanjc@google.com (mailing list archive)
State New
Headers show
Series KVM: guest_memfd() and per-page attributes | expand

Commit Message

Sean Christopherson Sept. 14, 2023, 1:54 a.m. UTC 
Rework and rename "struct kvm_hva_range" into "kvm_mmu_notifier_range" so
that the structure can be used to handle notifications that operate on gfn
context, i.e. that aren't tied to a host virtual address.

Practically speaking, this is a nop for 64-bit kernels as the only
meaningful change is to store start+end as u64s instead of unsigned longs.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 virt/kvm/kvm_main.c | 34 +++++++++++++++++++---------------
 1 file changed, 19 insertions(+), 15 deletions(-)

Comments

Xiaoyao Li Sept. 15, 2023, 6:47 a.m. UTC | #1 
On 9/14/2023 9:54 AM, Sean Christopherson wrote:
> Rework and rename "struct kvm_hva_range" into "kvm_mmu_notifier_range" so
> that the structure can be used to handle notifications that operate on gfn
> context, i.e. that aren't tied to a host virtual address.
> 
> Practically speaking, this is a nop for 64-bit kernels as the only
> meaningful change is to store start+end as u64s instead of unsigned longs.
> 
> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
>   virt/kvm/kvm_main.c | 34 +++++++++++++++++++---------------
>   1 file changed, 19 insertions(+), 15 deletions(-)
> 
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 486800a7024b..0524933856d4 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -541,18 +541,22 @@ static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn)
>   	return container_of(mn, struct kvm, mmu_notifier);
>   }
>   
> -typedef bool (*hva_handler_t)(struct kvm *kvm, struct kvm_gfn_range *range);
> +typedef bool (*gfn_handler_t)(struct kvm *kvm, struct kvm_gfn_range *range);

Is it worth mentioning the rename of it as well in changelog?

Anyway,

Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Sean Christopherson Sept. 15, 2023, 9:05 p.m. UTC | #2 
On Fri, Sep 15, 2023, Xiaoyao Li wrote:
> On 9/14/2023 9:54 AM, Sean Christopherson wrote:
> > Rework and rename "struct kvm_hva_range" into "kvm_mmu_notifier_range" so
> > that the structure can be used to handle notifications that operate on gfn
> > context, i.e. that aren't tied to a host virtual address.
> > 
> > Practically speaking, this is a nop for 64-bit kernels as the only
> > meaningful change is to store start+end as u64s instead of unsigned longs.
> > 
> > Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
> > Signed-off-by: Sean Christopherson <seanjc@google.com>
> > ---
> >   virt/kvm/kvm_main.c | 34 +++++++++++++++++++---------------
> >   1 file changed, 19 insertions(+), 15 deletions(-)
> > 
> > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> > index 486800a7024b..0524933856d4 100644
> > --- a/virt/kvm/kvm_main.c
> > +++ b/virt/kvm/kvm_main.c
> > @@ -541,18 +541,22 @@ static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn)
> >   	return container_of(mn, struct kvm, mmu_notifier);
> >   }
> > -typedef bool (*hva_handler_t)(struct kvm *kvm, struct kvm_gfn_range *range);
> > +typedef bool (*gfn_handler_t)(struct kvm *kvm, struct kvm_gfn_range *range);
> 
> Is it worth mentioning the rename of it as well in changelog?

Meh, I suppose.  At some point, we do have to assume a certain level of code
literacy though :-)
diff mbox series

Patch

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 486800a7024b..0524933856d4 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -541,18 +541,22 @@  static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn)
 	return container_of(mn, struct kvm, mmu_notifier);
 }
 
-typedef bool (*hva_handler_t)(struct kvm *kvm, struct kvm_gfn_range *range);
+typedef bool (*gfn_handler_t)(struct kvm *kvm, struct kvm_gfn_range *range);
 
 typedef void (*on_lock_fn_t)(struct kvm *kvm, unsigned long start,
 			     unsigned long end);
 
 typedef void (*on_unlock_fn_t)(struct kvm *kvm);
 
-struct kvm_hva_range {
-	unsigned long start;
-	unsigned long end;
+struct kvm_mmu_notifier_range {
+	/*
+	 * 64-bit addresses, as KVM notifiers can operate on host virtual
+	 * addresses (unsigned long) and guest physical addresses (64-bit).
+	 */
+	u64 start;
+	u64 end;
 	union kvm_mmu_notifier_arg arg;
-	hva_handler_t handler;
+	gfn_handler_t handler;
 	on_lock_fn_t on_lock;
 	on_unlock_fn_t on_unlock;
 	bool flush_on_ret;
@@ -581,7 +585,7 @@  static const union kvm_mmu_notifier_arg KVM_MMU_NOTIFIER_NO_ARG;
 	     node = interval_tree_iter_next(node, start, last))	     \
 
 static __always_inline int __kvm_handle_hva_range(struct kvm *kvm,
-						  const struct kvm_hva_range *range)
+						  const struct kvm_mmu_notifier_range *range)
 {
 	bool ret = false, locked = false;
 	struct kvm_gfn_range gfn_range;
@@ -608,9 +612,9 @@  static __always_inline int __kvm_handle_hva_range(struct kvm *kvm,
 			unsigned long hva_start, hva_end;
 
 			slot = container_of(node, struct kvm_memory_slot, hva_node[slots->node_idx]);
-			hva_start = max(range->start, slot->userspace_addr);
-			hva_end = min(range->end, slot->userspace_addr +
-						  (slot->npages << PAGE_SHIFT));
+			hva_start = max_t(unsigned long, range->start, slot->userspace_addr);
+			hva_end = min_t(unsigned long, range->end,
+					slot->userspace_addr + (slot->npages << PAGE_SHIFT));
 
 			/*
 			 * To optimize for the likely case where the address
@@ -660,10 +664,10 @@  static __always_inline int kvm_handle_hva_range(struct mmu_notifier *mn,
 						unsigned long start,
 						unsigned long end,
 						union kvm_mmu_notifier_arg arg,
-						hva_handler_t handler)
+						gfn_handler_t handler)
 {
 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
-	const struct kvm_hva_range range = {
+	const struct kvm_mmu_notifier_range range = {
 		.start		= start,
 		.end		= end,
 		.arg		= arg,
@@ -680,10 +684,10 @@  static __always_inline int kvm_handle_hva_range(struct mmu_notifier *mn,
 static __always_inline int kvm_handle_hva_range_no_flush(struct mmu_notifier *mn,
 							 unsigned long start,
 							 unsigned long end,
-							 hva_handler_t handler)
+							 gfn_handler_t handler)
 {
 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
-	const struct kvm_hva_range range = {
+	const struct kvm_mmu_notifier_range range = {
 		.start		= start,
 		.end		= end,
 		.handler	= handler,
@@ -771,7 +775,7 @@  static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
 					const struct mmu_notifier_range *range)
 {
 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
-	const struct kvm_hva_range hva_range = {
+	const struct kvm_mmu_notifier_range hva_range = {
 		.start		= range->start,
 		.end		= range->end,
 		.handler	= kvm_unmap_gfn_range,
@@ -835,7 +839,7 @@  static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
 					const struct mmu_notifier_range *range)
 {
 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
-	const struct kvm_hva_range hva_range = {
+	const struct kvm_mmu_notifier_range hva_range = {
 		.start		= range->start,
 		.end		= range->end,
 		.handler	= (void *)kvm_null_fn,