From: Konrad Rzeszutek Wilk <[email protected]> Very very partial backport from aa8c6248f8c75 where there is a check to see if this is an Xen PV guest - and if so disable it.
The reason is that the PV ABI would require a major overhaul to be Meltdown resistent. Instead there are mitigations (PV in HVM) which are far more suitable. Signed-off-by: Konrad Rzeszutek Wilk <[email protected]> --- arch/x86/mm/kaiser.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/mm/kaiser.c b/arch/x86/mm/kaiser.c index 50783ad4861d..05fb616c9e2a 100644 --- a/arch/x86/mm/kaiser.c +++ b/arch/x86/mm/kaiser.c @@ -10,6 +10,7 @@ #include <linux/mm.h> #include <linux/uaccess.h> #include <linux/ftrace.h> +#include <xen/xen.h> #include <asm/kaiser.h> #include <asm/tlbflush.h> /* to verify its kaiser declarations */ @@ -264,6 +265,9 @@ void __init kaiser_check_boottime_disable(void) char arg[5]; int ret; + if (xen_pv_domain()) + goto disable; + ret = cmdline_find_option(boot_command_line, "pti", arg, sizeof(arg)); if (ret > 0) { if (!strncmp(arg, "on", 2)) -- 2.16.2
