x86/HVM: move per-vendor function tables into .init.data

hvm_enable() copies the table contents rather than storing the pointer,
so there's no need to keep these tables post-boot.

Also constify the return values of the per-vendor initialization
functions, making clear that once the per-vendor initialization is
complete, the vendor specific tables won't get modified anymore.

Finally, in hvm_enable(), use the returned pointer for all read
accesses as being more efficient than global variable accesses. Writes
of course still need to go to the global variable.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index 6866cd080b..51187a932a 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -1502,7 +1502,7 @@ static void vmx_sync_pir_to_irr(struct vcpu *v)
         vlapic_set_vector(i, &vlapic->regs->data[APIC_IRR]);
 }
 
-static struct hvm_function_table __read_mostly vmx_function_table = {
+static struct hvm_function_table __initdata vmx_function_table = {
     .name                 = "VMX",
     .cpu_up_prepare       = vmx_cpu_up_prepare,
     .cpu_dead             = vmx_cpu_dead,
@@ -1557,7 +1557,7 @@ static struct hvm_function_table __read_mostly vmx_function_table = {
     .nhvm_hap_walk_L1_p2m = nvmx_hap_walk_L1_p2m,
 };
 
-struct hvm_function_table * __init start_vmx(void)
+const struct hvm_function_table * __init start_vmx(void)
 {
     set_in_cr4(X86_CR4_VMXE);