kvm: vmx: Stop wasting a page for guest_msrs
We will never need more guest_msrs than there are indices in
vmx_msr_index. Thus, at present, the guest_msrs array will not exceed
168 bytes.
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index d175429..e7ea332 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6674,7 +6674,6 @@
free_vpid(vmx->vpid);
nested_vmx_free_vcpu(vcpu);
free_loaded_vmcs(vmx->loaded_vmcs);
- kfree(vmx->guest_msrs);
kvm_vcpu_uninit(vcpu);
kmem_cache_free(x86_fpu_cache, vmx->vcpu.arch.user_fpu);
kmem_cache_free(x86_fpu_cache, vmx->vcpu.arch.guest_fpu);
@@ -6731,12 +6730,7 @@
goto uninit_vcpu;
}
- vmx->guest_msrs = kmalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);
- BUILD_BUG_ON(ARRAY_SIZE(vmx_msr_index) * sizeof(vmx->guest_msrs[0])
- > PAGE_SIZE);
-
- if (!vmx->guest_msrs)
- goto free_pml;
+ BUILD_BUG_ON(ARRAY_SIZE(vmx_msr_index) != NR_SHARED_MSRS);
for (i = 0; i < ARRAY_SIZE(vmx_msr_index); ++i) {
u32 index = vmx_msr_index[i];
@@ -6768,7 +6762,7 @@
err = alloc_loaded_vmcs(&vmx->vmcs01);
if (err < 0)
- goto free_msrs;
+ goto free_pml;
msr_bitmap = vmx->vmcs01.msr_bitmap;
vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_TSC, MSR_TYPE_R);
@@ -6830,8 +6824,6 @@
free_vmcs:
free_loaded_vmcs(vmx->loaded_vmcs);
-free_msrs:
- kfree(vmx->guest_msrs);
free_pml:
vmx_destroy_pml_buffer(vmx);
uninit_vcpu:
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 7c1b978..a4f7f73 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -22,6 +22,12 @@
#define X2APIC_MSR(r) (APIC_BASE_MSR + ((r) >> 4))
+#ifdef CONFIG_X86_64
+#define NR_SHARED_MSRS 7
+#else
+#define NR_SHARED_MSRS 4
+#endif
+
#define NR_LOADSTORE_MSRS 8
struct vmx_msrs {
@@ -206,7 +212,7 @@
u32 idt_vectoring_info;
ulong rflags;
- struct shared_msr_entry *guest_msrs;
+ struct shared_msr_entry guest_msrs[NR_SHARED_MSRS];
int nmsrs;
int save_nmsrs;
bool guest_msrs_ready;
