Merge tag 'kvm-x86-fixes-6.11-rcN' of https://github.com/kvm-x86/linux into kvm-master

KVM x86 fixes for 6.11

 - Fixup missed comments from the REMOVED_SPTE=>FROZEN_SPTE rename.

 - Ensure a root is successfully loaded when pre-faulting SPTEs.

 - Grab kvm->srcu when handling KVM_SET_VCPU_EVENTS to guard against accessing
   memslots if toggling SMM happens to force a VM-Exit.

 - Emulate MSR_{FS,GS}_BASE on SVM even though interception is always disabled,
   so that KVM does the right thing if KVM's emulator encounters {RD,WR}MSR.

 - Explicitly clear BUS_LOCK_DETECT from KVM's caps on AMD, as KVM doesn't yet
   virtualize BUS_LOCK_DETECT on AMD.

 - Cleanup the help message for CONFIG_KVM_AMD_SEV, and call out that KVM now
   supports SEV-SNP too.

1 files changed, 37 insertions, 2 deletions

diff --git a/fs/inode.c b/fs/inode.c
index 86670941884b..10c4619faeef 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -488,6 +488,39 @@ static void inode_lru_list_del(struct inode *inode)
 		this_cpu_dec(nr_unused);
 }
 
+static void inode_pin_lru_isolating(struct inode *inode)
+{
+	lockdep_assert_held(&inode->i_lock);
+	WARN_ON(inode->i_state & (I_LRU_ISOLATING | I_FREEING | I_WILL_FREE));
+	inode->i_state |= I_LRU_ISOLATING;
+}
+
+static void inode_unpin_lru_isolating(struct inode *inode)
+{
+	spin_lock(&inode->i_lock);
+	WARN_ON(!(inode->i_state & I_LRU_ISOLATING));
+	inode->i_state &= ~I_LRU_ISOLATING;
+	smp_mb();
+	wake_up_bit(&inode->i_state, __I_LRU_ISOLATING);
+	spin_unlock(&inode->i_lock);
+}
+
+static void inode_wait_for_lru_isolating(struct inode *inode)
+{
+	spin_lock(&inode->i_lock);
+	if (inode->i_state & I_LRU_ISOLATING) {
+		DEFINE_WAIT_BIT(wq, &inode->i_state, __I_LRU_ISOLATING);
+		wait_queue_head_t *wqh;
+
+		wqh = bit_waitqueue(&inode->i_state, __I_LRU_ISOLATING);
+		spin_unlock(&inode->i_lock);
+		__wait_on_bit(wqh, &wq, bit_wait, TASK_UNINTERRUPTIBLE);
+		spin_lock(&inode->i_lock);
+		WARN_ON(inode->i_state & I_LRU_ISOLATING);
+	}
+	spin_unlock(&inode->i_lock);
+}
+
 /**
  * inode_sb_list_add - add inode to the superblock list of inodes
  * @inode: inode to add
@@ -657,6 +690,8 @@ static void evict(struct inode *inode)
 
 	inode_sb_list_del(inode);
 
+	inode_wait_for_lru_isolating(inode);
+
 	/*
 	 * Wait for flusher thread to be done with the inode so that filesystem
 	 * does not start destroying it while writeback is still running. Since
@@ -855,7 +890,7 @@ static enum lru_status inode_lru_isolate(struct list_head *item,
 	 * be under pressure before the cache inside the highmem zone.
 	 */
 	if (inode_has_buffers(inode) || !mapping_empty(&inode->i_data)) {
-		__iget(inode);
+		inode_pin_lru_isolating(inode);
 		spin_unlock(&inode->i_lock);
 		spin_unlock(lru_lock);
 		if (remove_inode_buffers(inode)) {
@@ -867,7 +902,7 @@ static enum lru_status inode_lru_isolate(struct list_head *item,
 				__count_vm_events(PGINODESTEAL, reap);
 			mm_account_reclaimed_pages(reap);
 		}
-		iput(inode);
+		inode_unpin_lru_isolating(inode);
 		spin_lock(lru_lock);
 		return LRU_RETRY;
 	}