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authorJim Mattson <jmattson@google.com>2019-12-03 16:24:42 -0800
committerPaolo Bonzini <pbonzini@redhat.com>2019-12-04 12:23:27 +0100
commit7d73710d9ca2564f29d291d0b3badc09efdf25e9 (patch)
tree3faff2296cb15f547fd961b4c468bdda0924771a
parent433f4ba1904100da65a311033f17a9bf586b287e (diff)
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>
-rw-r--r--arch/x86/kvm/vmx/vmx.c12
-rw-r--r--arch/x86/kvm/vmx/vmx.h8
2 files changed, 9 insertions, 11 deletions
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index d175429c91b0..e7ea332ad1e8 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6674,7 +6674,6 @@ static void vmx_free_vcpu(struct kvm_vcpu *vcpu)
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 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
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 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
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 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
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 7c1b978b2df4..a4f7f737c5d4 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -22,6 +22,12 @@ extern u32 get_umwait_control_msr(void);
#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 @@ struct vcpu_vmx {
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;