KVM: x86/mmu: Remove need for a vcpu from mmu_try_to_unsync_pages

The vCPU argument to mmu_try_to_unsync_pages is now only used to get a
pointer to the associated struct kvm, so pass in the kvm pointer from
the beginning to remove the need for a vCPU when calling the function.
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20211115234603.2908381-7-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/mmu/mmu.c

@@ -2565,10 +2565,10 @@ static int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
 	return r;
 }
 
-static void kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
+static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp)
 {
 	trace_kvm_mmu_unsync_page(sp);
-	++vcpu->kvm->stat.mmu_unsync;
+	++kvm->stat.mmu_unsync;
 	sp->unsync = 1;
 
 	kvm_mmu_mark_parents_unsync(sp);
@@ -2580,7 +2580,7 @@ static void kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
  * were marked unsync (or if there is no shadow page), -EPERM if the SPTE must
  * be write-protected.
  */
-int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot,
+int mmu_try_to_unsync_pages(struct kvm *kvm, struct kvm_memory_slot *slot,
 			    gfn_t gfn, bool can_unsync, bool prefetch)
 {
 	struct kvm_mmu_page *sp;
@@ -2591,7 +2591,7 @@ int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot,
 	 * track machinery is used to write-protect upper-level shadow pages,
 	 * i.e. this guards the role.level == 4K assertion below!
 	 */
-	if (kvm_slot_page_track_is_active(vcpu->kvm, slot, gfn, KVM_PAGE_TRACK_WRITE))
+	if (kvm_slot_page_track_is_active(kvm, slot, gfn, KVM_PAGE_TRACK_WRITE))
 		return -EPERM;
 
 	/*
@@ -2600,7 +2600,7 @@ int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot,
 	 * that case, KVM must complete emulation of the guest TLB flush before
 	 * allowing shadow pages to become unsync (writable by the guest).
 	 */
-	for_each_gfn_indirect_valid_sp(vcpu->kvm, sp, gfn) {
+	for_each_gfn_indirect_valid_sp(kvm, sp, gfn) {
 		if (!can_unsync)
 			return -EPERM;
 
@@ -2619,7 +2619,7 @@ int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot,
 		 */
 		if (!locked) {
 			locked = true;
-			spin_lock(&vcpu->kvm->arch.mmu_unsync_pages_lock);
+			spin_lock(&kvm->arch.mmu_unsync_pages_lock);
 
 			/*
 			 * Recheck after taking the spinlock, a different vCPU
@@ -2634,10 +2634,10 @@ int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot,
 		}
 
 		WARN_ON(sp->role.level != PG_LEVEL_4K);
-		kvm_unsync_page(vcpu, sp);
+		kvm_unsync_page(kvm, sp);
 	}
 	if (locked)
-		spin_unlock(&vcpu->kvm->arch.mmu_unsync_pages_lock);
+		spin_unlock(&kvm->arch.mmu_unsync_pages_lock);
 
 	/*
 	 * We need to ensure that the marking of unsync pages is visible

arch/x86/kvm/mmu/mmu_internal.h

@@ -117,7 +117,7 @@ static inline bool kvm_mmu_page_ad_need_write_protect(struct kvm_mmu_page *sp)
 	return kvm_x86_ops.cpu_dirty_log_size && sp->role.guest_mode;
 }
 
-int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot,
+int mmu_try_to_unsync_pages(struct kvm *kvm, struct kvm_memory_slot *slot,
 			    gfn_t gfn, bool can_unsync, bool prefetch);
 
 void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn);

arch/x86/kvm/mmu/spte.c

@@ -161,7 +161,7 @@ bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
 		 * e.g. it's write-tracked (upper-level SPs) or has one or more
 		 * shadow pages and unsync'ing pages is not allowed.
 		 */
-		if (mmu_try_to_unsync_pages(vcpu, slot, gfn, can_unsync, prefetch)) {
+		if (mmu_try_to_unsync_pages(vcpu->kvm, slot, gfn, can_unsync, prefetch)) {
 			pgprintk("%s: found shadow page for %llx, marking ro\n",
 				 __func__, gfn);
 			wrprot = true;