Merge tag 'x86_urgent_for_v6.0-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Dave Hansen:

 - A performance fix for recent large AMD systems that avoids an ancient
   cpu idle hardware workaround

 - A new Intel model number. Folks like these upstream as soon as
   possible so that each developer doing feature development doesn't
   need to carry their own #define

 - SGX fixes for a userspace crash and a rare kernel warning

* tag 'x86_urgent_for_v6.0-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ACPI: processor idle: Practically limit "Dummy wait" workaround to old Intel systems
  x86/sgx: Handle VA page allocation failure for EAUG on PF.
  x86/sgx: Do not fail on incomplete sanitization on premature stop of ksgxd
  x86/cpu: Add CPU model numbers for Meteor Lake

arch/x86/include/asm/intel-family.h

@@ -115,6 +115,9 @@
 #define INTEL_FAM6_RAPTORLAKE_P		0xBA
 #define INTEL_FAM6_RAPTORLAKE_S		0xBF
 
+#define INTEL_FAM6_METEORLAKE		0xAC
+#define INTEL_FAM6_METEORLAKE_L		0xAA
+
 /* "Small Core" Processors (Atom) */
 
 #define INTEL_FAM6_ATOM_BONNELL		0x1C /* Diamondville, Pineview */

arch/x86/kernel/cpu/sgx/encl.c

@@ -344,8 +344,11 @@ static vm_fault_t sgx_encl_eaug_page(struct vm_area_struct *vma,
 	}
 
 	va_page = sgx_encl_grow(encl, false);
-	if (IS_ERR(va_page))
+	if (IS_ERR(va_page)) {
+		if (PTR_ERR(va_page) == -EBUSY)
+			vmret = VM_FAULT_NOPAGE;
 		goto err_out_epc;
+	}
 
 	if (va_page)
 		list_add(&va_page->list, &encl->va_pages);

arch/x86/kernel/cpu/sgx/main.c

@@ -49,9 +49,13 @@ static LIST_HEAD(sgx_dirty_page_list);
  * Reset post-kexec EPC pages to the uninitialized state. The pages are removed
  * from the input list, and made available for the page allocator. SECS pages
  * prepending their children in the input list are left intact.
+ *
+ * Return 0 when sanitization was successful or kthread was stopped, and the
+ * number of unsanitized pages otherwise.
  */
-static void __sgx_sanitize_pages(struct list_head *dirty_page_list)
+static unsigned long __sgx_sanitize_pages(struct list_head *dirty_page_list)
 {
+	unsigned long left_dirty = 0;
 	struct sgx_epc_page *page;
 	LIST_HEAD(dirty);
 	int ret;
@@ -59,7 +63,7 @@ static void __sgx_sanitize_pages(struct list_head *dirty_page_list)
 	/* dirty_page_list is thread-local, no need for a lock: */
 	while (!list_empty(dirty_page_list)) {
 		if (kthread_should_stop())
-			return;
+			return 0;
 
 		page = list_first_entry(dirty_page_list, struct sgx_epc_page, list);
 
@@ -92,12 +96,14 @@ static void __sgx_sanitize_pages(struct list_head *dirty_page_list)
 		} else {
 			/* The page is not yet clean - move to the dirty list. */
 			list_move_tail(&page->list, &dirty);
+			left_dirty++;
 		}
 
 		cond_resched();
 	}
 
 	list_splice(&dirty, dirty_page_list);
+	return left_dirty;
 }
 
 static bool sgx_reclaimer_age(struct sgx_epc_page *epc_page)
@@ -395,10 +401,7 @@ static int ksgxd(void *p)
 	 * required for SECS pages, whose child pages blocked EREMOVE.
 	 */
 	__sgx_sanitize_pages(&sgx_dirty_page_list);
-	__sgx_sanitize_pages(&sgx_dirty_page_list);
-
-	/* sanity check: */
-	WARN_ON(!list_empty(&sgx_dirty_page_list));
+	WARN_ON(__sgx_sanitize_pages(&sgx_dirty_page_list));
 
 	while (!kthread_should_stop()) {
 		if (try_to_freeze())

drivers/acpi/processor_idle.c

@@ -531,10 +531,27 @@ static void wait_for_freeze(void)
 	/* No delay is needed if we are in guest */
 	if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
 		return;
+	/*
+	 * Modern (>=Nehalem) Intel systems use ACPI via intel_idle,
+	 * not this code.  Assume that any Intel systems using this
+	 * are ancient and may need the dummy wait.  This also assumes
+	 * that the motivating chipset issue was Intel-only.
+	 */
+	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
+		return;
 #endif
-	/* Dummy wait op - must do something useless after P_LVL2 read
-	   because chipsets cannot guarantee that STPCLK# signal
-	   gets asserted in time to freeze execution properly. */
+	/*
+	 * Dummy wait op - must do something useless after P_LVL2 read
+	 * because chipsets cannot guarantee that STPCLK# signal gets
+	 * asserted in time to freeze execution properly
+	 *
+	 * This workaround has been in place since the original ACPI
+	 * implementation was merged, circa 2002.
+	 *
+	 * If a profile is pointing to this instruction, please first
+	 * consider moving your system to a more modern idle
+	 * mechanism.
+	 */
 	inl(acpi_gbl_FADT.xpm_timer_block.address);
 }