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authorJuergen Gross <jgross@suse.com>2022-09-26 13:16:56 +0200
committerJuergen Gross <jgross@suse.com>2022-10-11 10:51:05 +0200
commit3fac3734c43a2e21fefeb72124d8bd31dff3956f (patch)
treed500099e8e4eb012db4510dfaf17da126f3156df /Documentation/admin-guide
parenta1886b915e81439ba045b1431f3319d37ac1b906 (diff)
downloadlinux-3fac3734c43a2e21fefeb72124d8bd31dff3956f.tar.gz
xen/pv: support selecting safe/unsafe msr accesses
Instead of always doing the safe variants for reading and writing MSRs
in Xen PV guests, make the behavior controllable via Kconfig option
and a boot parameter.

The default will be the current behavior, which is to always use the
safe variant.

Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'Documentation/admin-guide')
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt6
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 426fa892d311..1bda9cf18fae 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -6836,6 +6836,12 @@
 			Crash from Xen panic notifier, without executing late
 			panic() code such as dumping handler.
 
+	xen_msr_safe=	[X86,XEN]
+			Format: <bool>
+			Select whether to always use non-faulting (safe) MSR
+			access functions when running as Xen PV guest. The
+			default value is controlled by CONFIG_XEN_PV_MSR_SAFE.
+
 	xen_nopvspin	[X86,XEN]
 			Disables the qspinlock slowpath using Xen PV optimizations.
 			This parameter is obsoleted by "nopvspin" parameter, which