Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

[linux.git] / arch / x86 / xen / enlighten_pv.c

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index a732bc2b9dfcd860f832e64c344d60fef59ea4c9..f33eef4ebd12b55645365732135638855ef313cd 100644 (file)
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -142,9 +142,7 @@ static void __init xen_banner(void)
        struct xen_extraversion extra;
        HYPERVISOR_xen_version(XENVER_extraversion, &extra);
 
-       pr_info("Booting paravirtualized kernel %son %s\n",
-               xen_feature(XENFEAT_auto_translated_physmap) ?
-                       "with PVH extensions " : "", pv_info.name);
+       pr_info("Booting paravirtualized kernel on %s\n", pv_info.name);
        printk(KERN_INFO "Xen version: %d.%d%s%s\n",
               version >> 16, version & 0xffff, extra.extraversion,
               xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
@@ -277,31 +275,19 @@ static bool __init xen_check_mwait(void)
 
 static bool __init xen_check_xsave(void)
 {
-       unsigned int err, eax, edx;
+       unsigned int cx, xsave_mask;
 
-       /*
-        * Xen 4.0 and older accidentally leaked the host XSAVE flag into guest
-        * view, despite not being able to support guests using the
-        * functionality. Probe for the actual availability of XSAVE by seeing
-        * whether xgetbv executes successfully or raises #UD.
-        */
-       asm volatile("1: .byte 0x0f,0x01,0xd0\n\t" /* xgetbv */
-                    "xor %[err], %[err]\n"
-                    "2:\n\t"
-                    ".pushsection .fixup,\"ax\"\n\t"
-                    "3: movl $1,%[err]\n\t"
-                    "jmp 2b\n\t"
-                    ".popsection\n\t"
-                    _ASM_EXTABLE(1b, 3b)
-                    : [err] "=r" (err), "=a" (eax), "=d" (edx)
-                    : "c" (0));
-
-       return err == 0;
+       cx = cpuid_ecx(1);
+
+       xsave_mask = (1 << (X86_FEATURE_XSAVE % 32)) |
+                    (1 << (X86_FEATURE_OSXSAVE % 32));
+
+       /* Xen will set CR4.OSXSAVE if supported and not disabled by force */
+       return (cx & xsave_mask) == xsave_mask;
 }
 
 static void __init xen_init_capabilities(void)
 {
-       setup_clear_cpu_cap(X86_BUG_SYSRET_SS_ATTRS);
        setup_force_cpu_cap(X86_FEATURE_XENPV);
        setup_clear_cpu_cap(X86_FEATURE_DCA);
        setup_clear_cpu_cap(X86_FEATURE_APERFMPERF);
@@ -317,10 +303,7 @@ static void __init xen_init_capabilities(void)
        else
                setup_clear_cpu_cap(X86_FEATURE_MWAIT);
 
-       if (xen_check_xsave()) {
-               setup_force_cpu_cap(X86_FEATURE_XSAVE);
-               setup_force_cpu_cap(X86_FEATURE_OSXSAVE);
-       } else {
+       if (!xen_check_xsave()) {
                setup_clear_cpu_cap(X86_FEATURE_XSAVE);
                setup_clear_cpu_cap(X86_FEATURE_OSXSAVE);
        }
@@ -972,15 +955,10 @@ static void xen_write_msr(unsigned int msr, unsigned low, unsigned high)
 
 void xen_setup_shared_info(void)
 {
-       if (!xen_feature(XENFEAT_auto_translated_physmap)) {
-               set_fixmap(FIX_PARAVIRT_BOOTMAP,
-                          xen_start_info->shared_info);
+       set_fixmap(FIX_PARAVIRT_BOOTMAP, xen_start_info->shared_info);
 
-               HYPERVISOR_shared_info =
-                       (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
-       } else
-               HYPERVISOR_shared_info =
-                       (struct shared_info *)__va(xen_start_info->shared_info);
+       HYPERVISOR_shared_info =
+               (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
 
 #ifndef CONFIG_SMP
        /* In UP this is as good a place as any to set up shared info */
@@ -988,6 +966,13 @@ void xen_setup_shared_info(void)
 #endif
 
        xen_setup_mfn_list_list();
+
+       /*
+        * Now that shared info is set up we can start using routines that
+        * point to pvclock area.
+        */
+       if (system_state == SYSTEM_BOOTING)
+               xen_init_time_ops();
 }
 
 /* This is called once we have the cpu_possible_mask */
@@ -1286,8 +1271,6 @@ asmlinkage __visible void __init xen_start_kernel(void)
        x86_init.oem.arch_setup = xen_arch_setup;
        x86_init.oem.banner = xen_banner;
 
-       xen_init_time_ops();
-
        /*
         * Set up some pagetable state before starting to set any ptes.
         */