No need to use MAX_POSSIBLE_PASSTHROUGH_MSRS in the definition of array
vmx_possible_passthrough_msrs, as the macro name indicates the _possible_
maximum size of passthrough MSRs.
Use ARRAY_SIZE instead of MAX_POSSIBLE_PASSTHROUGH_MSRS when the size of
the array is needed and add a BUILD_BUG_ON to make sure the actual array
size does not exceed the possible maximum size of passthrough MSRs.
Signed-off-by: Xin Li (Intel) <xin@xxxxxxxxx>
Tested-by: Shan Kang <shan.kang@xxxxxxxxx>
---
arch/x86/kvm/vmx/vmx.c | 8 +++++---
arch/x86/kvm/vmx/vmx.h | 2 +-
2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 9acc9661fdb2..28cf89c97bda 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -167,7 +167,7 @@ module_param(allow_smaller_maxphyaddr, bool, S_IRUGO);
* List of MSRs that can be directly passed to the guest.
* In addition to these x2apic, PT and LBR MSRs are handled specially.
*/
-static u32 vmx_possible_passthrough_msrs[MAX_POSSIBLE_PASSTHROUGH_MSRS] = {
+static u32 vmx_possible_passthrough_msrs[] = {
MSR_IA32_SPEC_CTRL,
MSR_IA32_PRED_CMD,
MSR_IA32_FLUSH_CMD,
@@ -4182,6 +4182,8 @@ void vmx_msr_filter_changed(struct kvm_vcpu *vcpu)
if (!cpu_has_vmx_msr_bitmap())
return;
+ BUILD_BUG_ON(ARRAY_SIZE(vmx_possible_passthrough_msrs) > MAX_POSSIBLE_PASSTHROUGH_MSRS);
+
/*
* Redo intercept permissions for MSRs that KVM is passing through to
* the guest. Disabling interception will check the new MSR filter and
@@ -7626,8 +7628,8 @@ int vmx_vcpu_create(struct kvm_vcpu *vcpu)
}
/* The MSR bitmap starts with all ones */
- bitmap_fill(vmx->shadow_msr_intercept.read, MAX_POSSIBLE_PASSTHROUGH_MSRS);
- bitmap_fill(vmx->shadow_msr_intercept.write, MAX_POSSIBLE_PASSTHROUGH_MSRS);
+ bitmap_fill(vmx->shadow_msr_intercept.read, ARRAY_SIZE(vmx_possible_passthrough_msrs));
+ bitmap_fill(vmx->shadow_msr_intercept.write, ARRAY_SIZE(vmx_possible_passthrough_msrs));
vmx_disable_intercept_for_msr(vcpu, MSR_IA32_TSC, MSR_TYPE_R);
#ifdef CONFIG_X86_64
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index e0d76d2460ef..e7409f8f28b1 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -356,7 +356,7 @@ struct vcpu_vmx {
struct lbr_desc lbr_desc;
/* Save desired MSR intercept (read: pass-through) state */
-#define MAX_POSSIBLE_PASSTHROUGH_MSRS 16
+#define MAX_POSSIBLE_PASSTHROUGH_MSRS 64
struct {
DECLARE_BITMAP(read, MAX_POSSIBLE_PASSTHROUGH_MSRS);
DECLARE_BITMAP(write, MAX_POSSIBLE_PASSTHROUGH_MSRS);
--
2.46.2
