From 0ccf96d6eee2affd66ebde69247397542a03185b Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Wed, 30 May 2018 13:09:56 +0200 Subject: [PATCH 91/93] x86/amd: revert commit 944e0fc51a89c9827b9 Revert commit 944e0fc51a89c9827b98813d65dc083274777c7f ("x86/amd: don't set X86_BUG_SYSRET_SS_ATTRS when running under Xen") as it is lacking a prerequisite patch and is making things worse. Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/amd.c | 5 ++--- arch/x86/xen/enlighten.c | 4 +++- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 4c2be99..cd0abf8 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -857,9 +857,8 @@ static void init_amd(struct cpuinfo_x86 *c) if (cpu_has(c, X86_FEATURE_3DNOW) || cpu_has(c, X86_FEATURE_LM)) set_cpu_cap(c, X86_FEATURE_3DNOWPREFETCH); - /* AMD CPUs don't reset SS attributes on SYSRET, Xen does. */ - if (!cpu_has(c, X86_FEATURE_XENPV)) - set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS); + /* AMD CPUs don't reset SS attributes on SYSRET */ + set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS); } #ifdef CONFIG_X86_32 diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index af79764..c926db0 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1971,8 +1971,10 @@ EXPORT_SYMBOL_GPL(xen_hvm_need_lapic); static void xen_set_cpu_features(struct cpuinfo_x86 *c) { - if (xen_pv_domain()) + if (xen_pv_domain()) { + clear_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS); set_cpu_cap(c, X86_FEATURE_XENPV); + } } static void xen_pin_vcpu(int cpu) -- 2.7.4