KVM: nVMX: Allocate and configure VM{READ,WRITE} bitmaps iff enable_shadow_vmcs
...and make enable_shadow_vmcs depend on nested. Aside from the obvious
memory savings, this will allow moving the relevant code out of vmx.c in
the future, e.g. to a nested specific file.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 3ec47b7..49c5b15 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -4862,6 +4862,9 @@ static void init_vmcs_shadow_fields(void)
{
int i, j;
+ memset(vmx_vmread_bitmap, 0xff, PAGE_SIZE);
+ memset(vmx_vmwrite_bitmap, 0xff, PAGE_SIZE);
+
for (i = j = 0; i < max_shadow_read_only_fields; i++) {
u16 field = shadow_read_only_fields[i];
if (vmcs_field_width(field) == VMCS_FIELD_WIDTH_U64 &&
@@ -7904,19 +7907,8 @@ static __init int hardware_setup(void)
for (i = 0; i < ARRAY_SIZE(vmx_msr_index); ++i)
kvm_define_shared_msr(i, vmx_msr_index[i]);
- for (i = 0; i < VMX_BITMAP_NR; i++) {
- vmx_bitmap[i] = (unsigned long *)__get_free_page(GFP_KERNEL);
- if (!vmx_bitmap[i])
- goto out;
- }
-
- memset(vmx_vmread_bitmap, 0xff, PAGE_SIZE);
- memset(vmx_vmwrite_bitmap, 0xff, PAGE_SIZE);
-
- if (setup_vmcs_config(&vmcs_config) < 0) {
- r = -EIO;
- goto out;
- }
+ if (setup_vmcs_config(&vmcs_config) < 0)
+ return -EIO;
if (boot_cpu_has(X86_FEATURE_NX))
kvm_enable_efer_bits(EFER_NX);
@@ -8027,10 +8019,18 @@ static __init int hardware_setup(void)
kvm_x86_ops->cancel_hv_timer = NULL;
}
- if (!cpu_has_vmx_shadow_vmcs())
+ if (!cpu_has_vmx_shadow_vmcs() || !nested)
enable_shadow_vmcs = 0;
- if (enable_shadow_vmcs)
+ if (enable_shadow_vmcs) {
+ for (i = 0; i < VMX_BITMAP_NR; i++) {
+ vmx_bitmap[i] = (unsigned long *)
+ __get_free_page(GFP_KERNEL);
+ if (!vmx_bitmap[i])
+ goto out;
+ }
+
init_vmcs_shadow_fields();
+ }
kvm_set_posted_intr_wakeup_handler(wakeup_handler);
nested_vmx_setup_ctls_msrs(&vmcs_config.nested, enable_apicv);
@@ -8043,9 +8043,10 @@ static __init int hardware_setup(void)
return 0;
out:
- for (i = 0; i < VMX_BITMAP_NR; i++)
- free_page((unsigned long)vmx_bitmap[i]);
-
+ if (enable_shadow_vmcs) {
+ for (i = 0; i < VMX_BITMAP_NR; i++)
+ free_page((unsigned long)vmx_bitmap[i]);
+ }
return r;
}
@@ -8053,8 +8054,10 @@ static __exit void hardware_unsetup(void)
{
int i;
- for (i = 0; i < VMX_BITMAP_NR; i++)
- free_page((unsigned long)vmx_bitmap[i]);
+ if (enable_shadow_vmcs) {
+ for (i = 0; i < VMX_BITMAP_NR; i++)
+ free_page((unsigned long)vmx_bitmap[i]);
+ }
free_kvm_area();
}