[PATCH] KVM: nVMX: Don't return error on nested bitmap memory allocation failure

Bandan Das
2015-04-28T19:55:43Z

If get_free_page() fails for nested bitmap area, it's evident that
we are gonna get screwed anyway but returning failure because we failed
allocating memory for a nested structure seems like an unnecessary big
hammer. Also, save the call for later; after we are done with other
non-nested allocations.

Signed-off-by: Bandan Das <bsd@redhat.com>
---
arch/x86/kvm/vmx.c | 29 +++++++++++++++--------------
1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index f7b6168..200bc5c 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6039,20 +6039,22 @@ static __init int hardware_setup(void)
if (!vmx_msr_bitmap_longmode_x2apic)
goto out4;

- if (nested) {
- vmx_msr_bitmap_nested =
- (unsigned long *)__get_free_page(GFP_KERNEL);
- if (!vmx_msr_bitmap_nested)
- goto out5;
- }
-
vmx_vmread_bitmap = (unsigned long *)__get_free_page(GFP_KERNEL);
if (!vmx_vmread_bitmap)
- goto out6;
+ goto out5;

vmx_vmwrite_bitmap = (unsigned long *)__get_free_page(GFP_KERNEL);
if (!vmx_vmwrite_bitmap)
- goto out7;
+ goto out6;
+
+ if (nested) {
+ vmx_msr_bitmap_nested =
+ (unsigned long *)__get_free_page(GFP_KERNEL);
+ if (!vmx_msr_bitmap_nested) {
+ printk(KERN_WARNING
+ "vmx: Failed getting memory for nested bitmap\n");
+ nested = 0;
+ }

memset(vmx_vmread_bitmap, 0xff, PAGE_SIZE);
memset(vmx_vmwrite_bitmap, 0xff, PAGE_SIZE);
@@ -6073,7 +6075,7 @@ static __init int hardware_setup(void)

if (setup_vmcs_config(&vmcs_config) < 0) {
r = -EIO;
- goto out8;
+ goto out7;
}

if (boot_cpu_has(X86_FEATURE_NX))
@@ -6190,13 +6192,12 @@ static __init int hardware_setup(void)

return alloc_kvm_area();

-out8:
- free_page((unsigned long)vmx_vmwrite_bitmap);
out7:
- free_page((unsigned long)vmx_vmread_bitmap);
-out6:
if (nested)
free_page((unsigned long)vmx_msr_bitmap_nested);
+ free_page((unsigned long)vmx_vmwrite_bitmap);
+out6:
+ free_page((unsigned long)vmx_vmread_bitmap);
out5:
free_page((unsigned long)vmx_msr_bitmap_longmode_x2apic);
out4:
--
2.1.0