[RFC PATCH 3/4] KVM: plumb MMU_NOTIFIER_RANGE_PERM_UPGRADE into kvm_gfn_range

["Carlos López" <clopez@suse.de>]

Propagate the permission upgrade flag from the mmu_notifier range into
struct kvm_gfn_range, so the unmap handler can react accordingly. The
value is not consumed yet, so no functional change.

Signed-off-by: Carlos López <clopez@suse.de>
---
 include/linux/kvm_host.h | 1 +
 virt/kvm/kvm_main.c      | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index e7fc94e2910a..aa109818cede 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -274,6 +274,7 @@ struct kvm_gfn_range {
 	enum kvm_gfn_range_filter attr_filter;
 	bool may_block;
 	bool lockless;
+	bool perm_upgrade;
 };
 bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range);
 bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index cf4cb586f140..0d0073615fa8 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -532,6 +532,7 @@ struct kvm_mmu_notifier_range {
 	bool flush_on_ret;
 	bool may_block;
 	bool lockless;
+	bool perm_upgrade;
 };
 
 /*
@@ -613,6 +614,7 @@ static __always_inline kvm_mn_ret_t kvm_handle_hva_range(struct kvm *kvm,
 			 */
 			gfn_range.arg = range->arg;
 			gfn_range.may_block = range->may_block;
+			gfn_range.perm_upgrade = range->perm_upgrade;
 			/*
 			 * HVA-based notifications aren't relevant to private
 			 * mappings as they don't have a userspace mapping.
@@ -738,6 +740,7 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
 		.on_lock	= kvm_mmu_invalidate_start,
 		.flush_on_ret	= true,
 		.may_block	= mmu_notifier_range_blockable(range),
+		.perm_upgrade = !!(range->flags & MMU_NOTIFIER_RANGE_PERM_UPGRADE),
 	};
 
 	trace_kvm_unmap_hva_range(range->start, range->end);
@@ -2552,6 +2555,7 @@ static __always_inline void kvm_handle_gfn_range(struct kvm *kvm,
 
 	gfn_range.arg = range->arg;
 	gfn_range.may_block = range->may_block;
+	gfn_range.perm_upgrade = range->perm_upgrade;
 
 	/*
 	 * If/when KVM supports more attributes beyond private .vs shared, this
-- 
2.51.0