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-rw-r--r--arch/x86/kernel/entry_32.S3
-rw-r--r--arch/x86/kernel/entry_64.S3
-rw-r--r--arch/x86/xen/enlighten.c20
3 files changed, 25 insertions, 1 deletions
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 000d4199b03e..31e2d5bf3e38 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -982,6 +982,9 @@ ENTRY(xen_hypervisor_callback)
ENTRY(xen_do_upcall)
1: mov %esp, %eax
call xen_evtchn_do_upcall
+#ifndef CONFIG_PREEMPT
+ call xen_maybe_preempt_hcall
+#endif
jmp ret_from_intr
CFI_ENDPROC
ENDPROC(xen_hypervisor_callback)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index db13655c3a2a..10074ad9ebf8 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1208,6 +1208,9 @@ ENTRY(xen_do_hypervisor_callback) # do_hypervisor_callback(struct *pt_regs)
popq %rsp
CFI_DEF_CFA_REGISTER rsp
decl PER_CPU_VAR(irq_count)
+#ifndef CONFIG_PREEMPT
+ call xen_maybe_preempt_hcall
+#endif
jmp error_exit
CFI_ENDPROC
END(xen_do_hypervisor_callback)
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index bd8b8459c3d0..5240f563076d 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1070,6 +1070,23 @@ static inline void xen_write_cr8(unsigned long val)
BUG_ON(val);
}
#endif
+
+static u64 xen_read_msr_safe(unsigned int msr, int *err)
+{
+ u64 val;
+
+ val = native_read_msr_safe(msr, err);
+ switch (msr) {
+ case MSR_IA32_APICBASE:
+#ifdef CONFIG_X86_X2APIC
+ if (!(cpuid_ecx(1) & (1 << (X86_FEATURE_X2APIC & 31))))
+#endif
+ val &= ~X2APIC_ENABLE;
+ break;
+ }
+ return val;
+}
+
static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
{
int ret;
@@ -1240,7 +1257,7 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = {
.wbinvd = native_wbinvd,
- .read_msr = native_read_msr_safe,
+ .read_msr = xen_read_msr_safe,
.write_msr = xen_write_msr_safe,
.read_tsc = native_read_tsc,
@@ -1741,6 +1758,7 @@ asmlinkage __visible void __init xen_start_kernel(void)
#ifdef CONFIG_X86_32
i386_start_kernel();
#else
+ cr4_init_shadow(); /* 32b kernel does this in i386_start_kernel() */
x86_64_start_reservations((char *)__pa_symbol(&boot_params));
#endif
}