[GIT PULL] x86 fixes

[Ingo Molnar <mingo@kernel.org>]

Linus,

Please pull the latest x86/urgent Git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-urgent-2026-07-11

for you to fetch changes up to 4c2509f3b79756679a02bea649c6a7501b58f52c:

Misc x86 fixes:

 - Fix resctrl resource leak (Tony Luck)

 - Fix resctrl umount race (Tony Luck)

 - Fix resctrl double-free (Reinette Chatre)

 - Fix x86 VGA display fallback logic during bootup on
   certain multi-GPU systems (Mario Limonciello)

 - Re-add a WBINVD call to the SNP bootstrap path to
   fix an SNP regression (Tycho Andersen)

 Thanks,

	Ingo

------------------>
Mario Limonciello (1):
      x86/video: Only fall back to vga_default_device() without screen info

Reinette Chatre (1):
      fs/resctrl: Fix double-add of pseudo-locked region's RMID to free list

Tony Luck (2):
      fs/resctrl: Free mon_data structures on rdt_get_tree() failure
      fs/resctrl: Fix use-after-free during unmount

Tycho Andersen (AMD) (1):
      x86/virt/sev: Revert "Drop WBINVD before setting MSR_AMD64_SYSCFG_SNP_EN"


 arch/x86/video/video-common.c | 23 ++++++++++++++---------
 arch/x86/virt/svm/sev.c       |  2 ++
 fs/resctrl/rdtgroup.c         | 33 ++++++++++++++++++++++++++-------
 3 files changed, 42 insertions(+), 16 deletions(-)

diff --git a/arch/x86/video/video-common.c b/arch/x86/video/video-common.c
index 152789f00fcd..8ed82fff7638 100644
--- a/arch/x86/video/video-common.c
+++ b/arch/x86/video/video-common.c
@@ -43,21 +43,26 @@ bool video_is_primary_device(struct device *dev)
 	if (!pci_is_display(pdev))
 		return false;
 
-	if (pdev == vga_default_device())
-		return true;
-
 #ifdef CONFIG_SCREEN_INFO
 	numres = screen_info_resources(si, res, ARRAY_SIZE(res));
-	for (i = 0; i < numres; ++i) {
-		if (!(res[i].flags & IORESOURCE_MEM))
-			continue;
+	if (numres > 0) {
+		for (i = 0; i < numres; ++i) {
+			if (!(res[i].flags & IORESOURCE_MEM))
+				continue;
+
+			if (pci_find_resource(pdev, &res[i]))
+				return true;
+		}
 
-		if (pci_find_resource(pdev, &res[i]))
-			return true;
+		return false;
 	}
 #endif
 
-	return false;
+	/*
+	 * No framebuffer was set up by the firmware/bootloader, so fall back
+	 * to the default VGA device.
+	 */
+	return pdev == vga_default_device();
 }
 EXPORT_SYMBOL(video_is_primary_device);
 
diff --git a/arch/x86/virt/svm/sev.c b/arch/x86/virt/svm/sev.c
index 8bcdce98f6dc..cff285d8ad8e 100644
--- a/arch/x86/virt/svm/sev.c
+++ b/arch/x86/virt/svm/sev.c
@@ -536,6 +536,8 @@ int snp_prepare(void)
 		goto unlock;
 	}
 
+	wbinvd_on_all_cpus();
+
 	/*
 	 * MtrrFixDramModEn is not shared between threads on a core,
 	 * therefore it must be set on all CPUs prior to enabling SNP.
diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
index af2cbab14497..cc9966ff6cdf 100644
--- a/fs/resctrl/rdtgroup.c
+++ b/fs/resctrl/rdtgroup.c
@@ -74,6 +74,8 @@ static int rdtgroup_setup_root(struct rdt_fs_context *ctx);
 
 static void rdtgroup_destroy_root(void);
 
+static void mon_put_kn_priv(void);
+
 struct dentry *debugfs_resctrl;
 
 /*
@@ -585,14 +587,20 @@ static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of,
  *
  * On resource group creation via a mkdir, an extra kernfs_node reference is
  * taken to ensure that the rdtgroup structure remains accessible for the
- * rdtgroup_kn_unlock() calls where it is removed.
+ * rdtgroup_kn_unlock() calls where it is removed. The default group is
+ * statically allocated: it does not have an extra reference but will have
+ * RDT_DELETED set on unmount to support safe access to its associated files
+ * via rdtgroup_kn_lock_live/rdtgroup_kn_unlock().
  *
- * Drop the extra reference here, then free the rdtgroup structure.
+ * For all but the default group: drop the extra reference, then free the
+ * rdtgroup structure.
  *
  * Return: void
  */
 static void rdtgroup_remove(struct rdtgroup *rdtgrp)
 {
+	if (rdtgrp == &rdtgroup_default)
+		return;
 	kernfs_put(rdtgrp->kn);
 	kfree(rdtgrp);
 }
@@ -2812,6 +2820,12 @@ static int rdt_get_tree(struct fs_context *fc)
 		goto out;
 	}
 
+	/* Avoid races from pending operations from a previous mount */
+	if (atomic_read(&rdtgroup_default.waitcount) != 0) {
+		ret = -EBUSY;
+		goto out;
+	}
+
 	ret = setup_rmid_lru_list();
 	if (ret)
 		goto out;
@@ -2893,6 +2907,7 @@ static int rdt_get_tree(struct fs_context *fc)
 		kernfs_remove(kn_mondata);
 out_mongrp:
 	if (resctrl_arch_mon_capable()) {
+		mon_put_kn_priv();
 		rdtgroup_unassign_cntrs(&rdtgroup_default);
 		kernfs_remove(kn_mongrp);
 	}
@@ -3069,10 +3084,6 @@ static void rmdir_all_sub(void)
 		if (rdtgrp == &rdtgroup_default)
 			continue;
 
-		if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
-		    rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)
-			rdtgroup_pseudo_lock_remove(rdtgrp);
-
 		/*
 		 * Give any CPUs back to the default group. We cannot copy
 		 * cpu_online_mask because a CPU might have executed the
@@ -3083,7 +3094,13 @@ static void rmdir_all_sub(void)
 
 		rdtgroup_unassign_cntrs(rdtgrp);
 
-		free_rmid(rdtgrp->closid, rdtgrp->mon.rmid);
+		if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
+		    rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
+			rdtgroup_pseudo_lock_remove(rdtgrp);
+		} else {
+			/* Pseudo-locked group's RMID is freed during setup. */
+			free_rmid(rdtgrp->closid, rdtgrp->mon.rmid);
+		}
 
 		kernfs_remove(rdtgrp->kn);
 		list_del(&rdtgrp->rdtgroup_list);
@@ -3174,6 +3191,7 @@ static void resctrl_fs_teardown(void)
 	mon_put_kn_priv();
 	rdt_pseudo_lock_release();
 	rdtgroup_default.mode = RDT_MODE_SHAREABLE;
+	rdtgroup_default.flags = RDT_DELETED;
 	closid_exit();
 	schemata_list_destroy();
 	rdtgroup_destroy_root();
@@ -4274,6 +4292,7 @@ static int rdtgroup_setup_root(struct rdt_fs_context *ctx)
 
 	ctx->kfc.root = rdt_root;
 	rdtgroup_default.kn = kernfs_root_to_node(rdt_root);
+	rdtgroup_default.flags = 0;
 
 	return 0;
 }