xen: use hypercall rather than clts
Xen will trap and emulate clts, but its better to use a hypercall.
Also, xenner doesn't handle clts.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index a05b772..446f4cd 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -607,6 +607,30 @@
xen_mc_issue(PARAVIRT_LAZY_MMU);
}
+static void xen_clts(void)
+{
+ struct multicall_space mcs;
+
+ mcs = xen_mc_entry(0);
+
+ MULTI_fpu_taskswitch(mcs.mc, 0);
+
+ xen_mc_issue(PARAVIRT_LAZY_CPU);
+}
+
+static void xen_write_cr0(unsigned long cr0)
+{
+ struct multicall_space mcs;
+
+ /* Only pay attention to cr0.TS; everything else is
+ ignored. */
+ mcs = xen_mc_entry(0);
+
+ MULTI_fpu_taskswitch(mcs.mc, (cr0 & X86_CR0_TS) != 0);
+
+ xen_mc_issue(PARAVIRT_LAZY_CPU);
+}
+
static void xen_write_cr2(unsigned long cr2)
{
x86_read_percpu(xen_vcpu)->arch.cr2 = cr2;
@@ -978,10 +1002,10 @@
.set_debugreg = xen_set_debugreg,
.get_debugreg = xen_get_debugreg,
- .clts = native_clts,
+ .clts = xen_clts,
.read_cr0 = native_read_cr0,
- .write_cr0 = native_write_cr0,
+ .write_cr0 = xen_write_cr0,
.read_cr4 = native_read_cr4,
.read_cr4_safe = native_read_cr4_safe,
diff --git a/include/asm-x86/xen/hypercall.h b/include/asm-x86/xen/hypercall.h
index c2ccd99..897ff79 100644
--- a/include/asm-x86/xen/hypercall.h
+++ b/include/asm-x86/xen/hypercall.h
@@ -315,6 +315,13 @@
}
static inline void
+MULTI_fpu_taskswitch(struct multicall_entry *mcl, int set)
+{
+ mcl->op = __HYPERVISOR_fpu_taskswitch;
+ mcl->args[0] = set;
+}
+
+static inline void
MULTI_update_va_mapping(struct multicall_entry *mcl, unsigned long va,
pte_t new_val, unsigned long flags)
{