svn commit: r333125 - in head/sys/x86: acpica include

[Konstantin Belousov]

Author: kib
Date: Mon Apr 30 20:18:32 2018
New Revision: 333125
URL: https://svnweb.freebsd.org/changeset/base/333125

Log:
  Turn off IBRS on suspend.
  
  Resume starts CPU from the init state, which clears any loaded
  microcode updates.  As result, IBRS MSRs are no longer available,
  until the microcode is reloaded.
  
  I have to forcibly clear cpu_stdext_feature3, which assumes that CPUID
  leaf 7 reg %ebx does not report anything except Meltdown/Spectre bugs
  bits.  If future CPUs add new bits there, hw_ibrs_recalculate() and
  identify_cpu1()/identify_cpu2() need to be adjusted for that.
  
  Submitted and tested by:	Michael Danilov <mike.d.ft402 at gmail.com>
  PR:	227866
  Sponsored by:	The FreeBSD Foundation
  MFC after:	1 week
  Differential revision:	https://reviews.freebsd.org/D15236

Modified:
  head/sys/x86/acpica/acpi_wakeup.c
  head/sys/x86/include/x86_var.h

Modified: head/sys/x86/acpica/acpi_wakeup.c
==============================================================================
--- head/sys/x86/acpica/acpi_wakeup.c	Mon Apr 30 19:37:32 2018	(r333124)
+++ head/sys/x86/acpica/acpi_wakeup.c	Mon Apr 30 20:18:32 2018	(r333125)
@@ -209,6 +209,10 @@ acpi_sleep_machdep(struct acpi_softc *sc, int state)
 {
 	ACPI_STATUS	status;
 	struct pcb	*pcb;
+#ifdef __amd64__
+	struct pcpu *pc;
+	int i;
+#endif
 
 	if (sc->acpi_wakeaddr == 0ul)
 		return (-1);	/* couldn't alloc wake memory */
@@ -236,6 +240,14 @@ acpi_sleep_machdep(struct acpi_softc *sc, int state)
 		if (!CPU_EMPTY(&suspcpus) && suspend_cpus(suspcpus) == 0) {
 			device_printf(sc->acpi_dev, "Failed to suspend APs\n");
 			return (0);	/* couldn't sleep */
+		}
+#endif
+#ifdef __amd64__
+		hw_ibrs_active = 0;
+		cpu_stdext_feature3 = 0;
+		CPU_FOREACH(i) {
+			pc = pcpu_find(i);
+			pc->pc_ibpb_set = 0;
 		}
 #endif
 

Modified: head/sys/x86/include/x86_var.h
==============================================================================
--- head/sys/x86/include/x86_var.h	Mon Apr 30 19:37:32 2018	(r333124)
+++ head/sys/x86/include/x86_var.h	Mon Apr 30 20:18:32 2018	(r333125)
@@ -83,7 +83,8 @@ extern	int	_ugssel;
 extern	int	use_xsave;
 extern	uint64_t xsave_mask;
 extern	u_int	max_apic_id;
-extern int	pti;
+extern	int	pti;
+extern	int	hw_ibrs_active;
 
 struct	pcb;
 struct	thread;