From 3fac3734c43a2e21fefeb72124d8bd31dff3956f Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Mon, 26 Sep 2022 13:16:56 +0200 Subject: 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 --- Documentation/admin-guide/kernel-parameters.txt | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'Documentation') 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: + 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 -- cgit v1.2.3-70-g09d2