KVM: Use gfn_to_pfn_cache's immutable "kvm" in kvm_gpc_refresh()

Make kvm_gpc_refresh() use kvm instance cached in gfn_to_pfn_cache.

No functional change intended.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
[sean: leave kvm_gpc_unmap() as-is]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>

arch/x86/kvm/x86.c

@@ -3039,7 +3039,7 @@ static void kvm_setup_guest_pvclock(struct kvm_vcpu *v,
 			      offset + sizeof(*guest_hv_clock))) {
 		read_unlock_irqrestore(&gpc->lock, flags);
 
-		if (kvm_gpc_refresh(v->kvm, gpc, gpc->gpa,
+		if (kvm_gpc_refresh(gpc, gpc->gpa,
 				    offset + sizeof(*guest_hv_clock)))
 			return;
 

arch/x86/kvm/xen.c

@@ -279,7 +279,7 @@ static void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, bool atomic)
 		if (atomic)
 			return;
 
-		if (kvm_gpc_refresh(v->kvm, gpc1, gpc1->gpa, user_len1))
+		if (kvm_gpc_refresh(gpc1, gpc1->gpa, user_len1))
 			return;
 
 		read_lock_irqsave(&gpc1->lock, flags);
@@ -491,8 +491,7 @@ void kvm_xen_inject_pending_events(struct kvm_vcpu *v)
 	while (!kvm_gpc_check(gpc, gpc->gpa, sizeof(struct vcpu_info))) {
 		read_unlock_irqrestore(&gpc->lock, flags);
 
-		if (kvm_gpc_refresh(v->kvm, gpc, gpc->gpa,
-				    sizeof(struct vcpu_info)))
+		if (kvm_gpc_refresh(gpc, gpc->gpa, sizeof(struct vcpu_info)))
 			return;
 
 		read_lock_irqsave(&gpc->lock, flags);
@@ -566,8 +565,7 @@ int __kvm_xen_has_interrupt(struct kvm_vcpu *v)
 		if (in_atomic() || !task_is_running(current))
 			return 1;
 
-		if (kvm_gpc_refresh(v->kvm, gpc, gpc->gpa,
-				    sizeof(struct vcpu_info))) {
+		if (kvm_gpc_refresh(gpc, gpc->gpa, sizeof(struct vcpu_info))) {
 			/*
 			 * If this failed, userspace has screwed up the
 			 * vcpu_info mapping. No interrupts for you.
@@ -1710,7 +1708,7 @@ static int kvm_xen_set_evtchn(struct kvm_xen_evtchn *xe, struct kvm *kvm)
 			break;
 
 		idx = srcu_read_lock(&kvm->srcu);
-		rc = kvm_gpc_refresh(kvm, gpc, gpc->gpa, PAGE_SIZE);
+		rc = kvm_gpc_refresh(gpc, gpc->gpa, PAGE_SIZE);
 		srcu_read_unlock(&kvm->srcu, idx);
 	} while(!rc);
 

include/linux/kvm_host.h

@@ -1317,23 +1317,21 @@ bool kvm_gpc_check(struct gfn_to_pfn_cache *gpc, gpa_t gpa, unsigned long len);
 /**
  * kvm_gpc_refresh - update a previously initialized cache.
  *
- * @kvm:	   pointer to kvm instance.
  * @gpc:	   struct gfn_to_pfn_cache object.
  * @gpa:	   updated guest physical address to map.
  * @len:	   sanity check; the range being access must fit a single page.
- *
+
  * @return:	   0 for success.
  *		   -EINVAL for a mapping which would cross a page boundary.
- *                 -EFAULT for an untranslatable guest physical address.
+ *		   -EFAULT for an untranslatable guest physical address.
  *
  * This will attempt to refresh a gfn_to_pfn_cache. Note that a successful
- * returm from this function does not mean the page can be immediately
+ * return from this function does not mean the page can be immediately
  * accessed because it may have raced with an invalidation. Callers must
  * still lock and check the cache status, as this function does not return
  * with the lock still held to permit access.
  */
-int kvm_gpc_refresh(struct kvm *kvm, struct gfn_to_pfn_cache *gpc, gpa_t gpa,
-		    unsigned long len);
+int kvm_gpc_refresh(struct gfn_to_pfn_cache *gpc, gpa_t gpa, unsigned long len);
 
 /**
  * kvm_gpc_unmap - temporarily unmap a gfn_to_pfn_cache.

virt/kvm/pfncache.c

@@ -237,10 +237,9 @@ static kvm_pfn_t hva_to_pfn_retry(struct gfn_to_pfn_cache *gpc)
 	return -EFAULT;
 }
 
-int kvm_gpc_refresh(struct kvm *kvm, struct gfn_to_pfn_cache *gpc, gpa_t gpa,
-		    unsigned long len)
+int kvm_gpc_refresh(struct gfn_to_pfn_cache *gpc, gpa_t gpa, unsigned long len)
 {
-	struct kvm_memslots *slots = kvm_memslots(kvm);
+	struct kvm_memslots *slots = kvm_memslots(gpc->kvm);
 	unsigned long page_offset = gpa & ~PAGE_MASK;
 	bool unmap_old = false;
 	unsigned long old_uhva;
@@ -399,7 +398,7 @@ int kvm_gpc_activate(struct gfn_to_pfn_cache *gpc, gpa_t gpa, unsigned long len)
 		gpc->active = true;
 		write_unlock_irq(&gpc->lock);
 	}
-	return kvm_gpc_refresh(kvm, gpc, gpa, len);
+	return kvm_gpc_refresh(gpc, gpa, len);
 }
 EXPORT_SYMBOL_GPL(kvm_gpc_activate);