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* [PATCH v2] KVM: X86: Fix initialization of MSR lists(msrs_to_save[], emulated_msrs[] and msr_based_features[])
@ 2019-11-06  6:35 Chenyi Qiang
  2019-11-11  5:10 ` cqiang
  2019-11-11 13:30 ` Paolo Bonzini
  0 siblings, 2 replies; 3+ messages in thread
From: Chenyi Qiang @ 2019-11-06  6:35 UTC (permalink / raw)
  To: Paolo Bonzini, Radim Krčmář,
	Sean Christopherson, Vitaly Kuznetsov, Jim Mattson, Joerg Roedel
  Cc: Xiaoyao Li, kvm, linux-kernel, stable

The three MSR lists(msrs_to_save[], emulated_msrs[] and
msr_based_features[]) are global arrays of kvm.ko, which are
adjusted (copy supported MSRs forward to override the unsupported MSRs)
when insmod kvm-{intel,amd}.ko, but it doesn't reset these three arrays
to their initial value when rmmod kvm-{intel,amd}.ko. Thus, at the next
installation, kvm-{intel,amd}.ko will do operations on the modified
arrays with some MSRs lost and some MSRs duplicated.

So define three constant arrays to hold the initial MSR lists and
initialize msrs_to_save[], emulated_msrs[] and msr_based_features[]
based on the constant arrays.

Cc: stable@vger.kernel.org
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
---
Changes in v2:
 - define initial MSR lists with static const.
 - change the dynamic allocation of supported MSR lists to static allocation.

 arch/x86/kvm/x86.c | 51 +++++++++++++++++++++++++---------------------
 1 file changed, 28 insertions(+), 23 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 89621025577a..0b4b6db5b13f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1138,13 +1138,15 @@ EXPORT_SYMBOL_GPL(kvm_rdpmc);
  * List of msr numbers which we expose to userspace through KVM_GET_MSRS
  * and KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST.
  *
- * This list is modified at module load time to reflect the
+ * The three MSR lists(msrs_to_save, emulated_msrs, msr_based_features)
+ * extract the supported MSRs from the related const lists.
+ * msrs_to_save is selected from the msrs_to_save_all to reflect the
  * capabilities of the host cpu. This capabilities test skips MSRs that are
- * kvm-specific. Those are put in emulated_msrs; filtering of emulated_msrs
+ * kvm-specific. Those are put in emulated_msrs_all; filtering of emulated_msrs
  * may depend on host virtualization features rather than host cpu features.
  */
 
-static u32 msrs_to_save[] = {
+static const u32 msrs_to_save_all[] = {
 	MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,
 	MSR_STAR,
 #ifdef CONFIG_X86_64
@@ -1185,9 +1187,10 @@ static u32 msrs_to_save[] = {
 	MSR_ARCH_PERFMON_EVENTSEL0 + 16, MSR_ARCH_PERFMON_EVENTSEL0 + 17,
 };
 
+static u32 msrs_to_save[ARRAY_SIZE(msrs_to_save_all)];
 static unsigned num_msrs_to_save;
 
-static u32 emulated_msrs[] = {
+static const u32 emulated_msrs_all[] = {
 	MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK,
 	MSR_KVM_SYSTEM_TIME_NEW, MSR_KVM_WALL_CLOCK_NEW,
 	HV_X64_MSR_GUEST_OS_ID, HV_X64_MSR_HYPERCALL,
@@ -1226,7 +1229,7 @@ static u32 emulated_msrs[] = {
 	 * by arch/x86/kvm/vmx/nested.c based on CPUID or other MSRs.
 	 * We always support the "true" VMX control MSRs, even if the host
 	 * processor does not, so I am putting these registers here rather
-	 * than in msrs_to_save.
+	 * than in msrs_to_save_all.
 	 */
 	MSR_IA32_VMX_BASIC,
 	MSR_IA32_VMX_TRUE_PINBASED_CTLS,
@@ -1245,13 +1248,14 @@ static u32 emulated_msrs[] = {
 	MSR_KVM_POLL_CONTROL,
 };
 
+static u32 emulated_msrs[ARRAY_SIZE(emulated_msrs_all)];
 static unsigned num_emulated_msrs;
 
 /*
  * List of msr numbers which are used to expose MSR-based features that
  * can be used by a hypervisor to validate requested CPU features.
  */
-static u32 msr_based_features[] = {
+static const u32 msr_based_features_all[] = {
 	MSR_IA32_VMX_BASIC,
 	MSR_IA32_VMX_TRUE_PINBASED_CTLS,
 	MSR_IA32_VMX_PINBASED_CTLS,
@@ -1276,6 +1280,7 @@ static u32 msr_based_features[] = {
 	MSR_IA32_ARCH_CAPABILITIES,
 };
 
+static u32 msr_based_features[ARRAY_SIZE(msr_based_features_all)];
 static unsigned int num_msr_based_features;
 
 static u64 kvm_get_arch_capabilities(void)
@@ -5131,19 +5136,19 @@ static void kvm_init_msr_list(void)
 	unsigned i, j;
 
 	BUILD_BUG_ON_MSG(INTEL_PMC_MAX_FIXED != 4,
-			 "Please update the fixed PMCs in msrs_to_save[]");
+			 "Please update the fixed PMCs in msrs_to_saved_all[]");
 
 	perf_get_x86_pmu_capability(&x86_pmu);
 
-	for (i = j = 0; i < ARRAY_SIZE(msrs_to_save); i++) {
-		if (rdmsr_safe(msrs_to_save[i], &dummy[0], &dummy[1]) < 0)
+	for (i = j = 0; i < ARRAY_SIZE(msrs_to_save_all); i++) {
+		if (rdmsr_safe(msrs_to_save_all[i], &dummy[0], &dummy[1]) < 0)
 			continue;
 
 		/*
 		 * Even MSRs that are valid in the host may not be exposed
 		 * to the guests in some cases.
 		 */
-		switch (msrs_to_save[i]) {
+		switch (msrs_to_save_all[i]) {
 		case MSR_IA32_BNDCFGS:
 			if (!kvm_mpx_supported())
 				continue;
@@ -5171,17 +5176,17 @@ static void kvm_init_msr_list(void)
 			break;
 		case MSR_IA32_RTIT_ADDR0_A ... MSR_IA32_RTIT_ADDR3_B: {
 			if (!kvm_x86_ops->pt_supported() ||
-				msrs_to_save[i] - MSR_IA32_RTIT_ADDR0_A >=
+				msrs_to_save_all[i] - MSR_IA32_RTIT_ADDR0_A >=
 				intel_pt_validate_hw_cap(PT_CAP_num_address_ranges) * 2)
 				continue;
 			break;
 		case MSR_ARCH_PERFMON_PERFCTR0 ... MSR_ARCH_PERFMON_PERFCTR0 + 17:
-			if (msrs_to_save[i] - MSR_ARCH_PERFMON_PERFCTR0 >=
+			if (msrs_to_save_all[i] - MSR_ARCH_PERFMON_PERFCTR0 >=
 			    min(INTEL_PMC_MAX_GENERIC, x86_pmu.num_counters_gp))
 				continue;
 			break;
 		case MSR_ARCH_PERFMON_EVENTSEL0 ... MSR_ARCH_PERFMON_EVENTSEL0 + 17:
-			if (msrs_to_save[i] - MSR_ARCH_PERFMON_EVENTSEL0 >=
+			if (msrs_to_save_all[i] - MSR_ARCH_PERFMON_EVENTSEL0 >=
 			    min(INTEL_PMC_MAX_GENERIC, x86_pmu.num_counters_gp))
 				continue;
 		}
@@ -5189,31 +5194,31 @@ static void kvm_init_msr_list(void)
 			break;
 		}
 
-		if (j < i)
-			msrs_to_save[j] = msrs_to_save[i];
+		if (j <= i)
+			msrs_to_save[j] = msrs_to_save_all[i];
 		j++;
 	}
 	num_msrs_to_save = j;
 
-	for (i = j = 0; i < ARRAY_SIZE(emulated_msrs); i++) {
-		if (!kvm_x86_ops->has_emulated_msr(emulated_msrs[i]))
+	for (i = j = 0; i < ARRAY_SIZE(emulated_msrs_all); i++) {
+		if (!kvm_x86_ops->has_emulated_msr(emulated_msrs_all[i]))
 			continue;
 
-		if (j < i)
-			emulated_msrs[j] = emulated_msrs[i];
+		if (j <= i)
+			emulated_msrs[j] = emulated_msrs_all[i];
 		j++;
 	}
 	num_emulated_msrs = j;
 
-	for (i = j = 0; i < ARRAY_SIZE(msr_based_features); i++) {
+	for (i = j = 0; i < ARRAY_SIZE(msr_based_features_all); i++) {
 		struct kvm_msr_entry msr;
 
-		msr.index = msr_based_features[i];
+		msr.index = msr_based_features_all[i];
 		if (kvm_get_msr_feature(&msr))
 			continue;
 
-		if (j < i)
-			msr_based_features[j] = msr_based_features[i];
+		if (j <= i)
+			msr_based_features[j] = msr_based_features_all[i];
 		j++;
 	}
 	num_msr_based_features = j;
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH v2] KVM: X86: Fix initialization of MSR lists(msrs_to_save[], emulated_msrs[] and msr_based_features[])
  2019-11-06  6:35 [PATCH v2] KVM: X86: Fix initialization of MSR lists(msrs_to_save[], emulated_msrs[] and msr_based_features[]) Chenyi Qiang
@ 2019-11-11  5:10 ` cqiang
  2019-11-11 13:30 ` Paolo Bonzini
  1 sibling, 0 replies; 3+ messages in thread
From: cqiang @ 2019-11-11  5:10 UTC (permalink / raw)
  To: Paolo Bonzini, Radim Krčmář,
	Sean Christopherson, Vitaly Kuznetsov, Jim Mattson, Joerg Roedel
  Cc: Xiaoyao Li, kvm, linux-kernel, stable

Ping for comments :)

On 11/6/2019 2:35 PM, Chenyi Qiang wrote:
> The three MSR lists(msrs_to_save[], emulated_msrs[] and
> msr_based_features[]) are global arrays of kvm.ko, which are
> adjusted (copy supported MSRs forward to override the unsupported MSRs)
> when insmod kvm-{intel,amd}.ko, but it doesn't reset these three arrays
> to their initial value when rmmod kvm-{intel,amd}.ko. Thus, at the next
> installation, kvm-{intel,amd}.ko will do operations on the modified
> arrays with some MSRs lost and some MSRs duplicated.
> 
> So define three constant arrays to hold the initial MSR lists and
> initialize msrs_to_save[], emulated_msrs[] and msr_based_features[]
> based on the constant arrays.
> 
> Cc: stable@vger.kernel.org
> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
> Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
> ---
> Changes in v2:
>   - define initial MSR lists with static const.
>   - change the dynamic allocation of supported MSR lists to static allocation.
> 
>   arch/x86/kvm/x86.c | 51 +++++++++++++++++++++++++---------------------
>   1 file changed, 28 insertions(+), 23 deletions(-)
> 
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 89621025577a..0b4b6db5b13f 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -1138,13 +1138,15 @@ EXPORT_SYMBOL_GPL(kvm_rdpmc);
>    * List of msr numbers which we expose to userspace through KVM_GET_MSRS
>    * and KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST.
>    *
> - * This list is modified at module load time to reflect the
> + * The three MSR lists(msrs_to_save, emulated_msrs, msr_based_features)
> + * extract the supported MSRs from the related const lists.
> + * msrs_to_save is selected from the msrs_to_save_all to reflect the
>    * capabilities of the host cpu. This capabilities test skips MSRs that are
> - * kvm-specific. Those are put in emulated_msrs; filtering of emulated_msrs
> + * kvm-specific. Those are put in emulated_msrs_all; filtering of emulated_msrs
>    * may depend on host virtualization features rather than host cpu features.
>    */
>   
> -static u32 msrs_to_save[] = {
> +static const u32 msrs_to_save_all[] = {
>   	MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,
>   	MSR_STAR,
>   #ifdef CONFIG_X86_64
> @@ -1185,9 +1187,10 @@ static u32 msrs_to_save[] = {
>   	MSR_ARCH_PERFMON_EVENTSEL0 + 16, MSR_ARCH_PERFMON_EVENTSEL0 + 17,
>   };
>   
> +static u32 msrs_to_save[ARRAY_SIZE(msrs_to_save_all)];
>   static unsigned num_msrs_to_save;
>   
> -static u32 emulated_msrs[] = {
> +static const u32 emulated_msrs_all[] = {
>   	MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK,
>   	MSR_KVM_SYSTEM_TIME_NEW, MSR_KVM_WALL_CLOCK_NEW,
>   	HV_X64_MSR_GUEST_OS_ID, HV_X64_MSR_HYPERCALL,
> @@ -1226,7 +1229,7 @@ static u32 emulated_msrs[] = {
>   	 * by arch/x86/kvm/vmx/nested.c based on CPUID or other MSRs.
>   	 * We always support the "true" VMX control MSRs, even if the host
>   	 * processor does not, so I am putting these registers here rather
> -	 * than in msrs_to_save.
> +	 * than in msrs_to_save_all.
>   	 */
>   	MSR_IA32_VMX_BASIC,
>   	MSR_IA32_VMX_TRUE_PINBASED_CTLS,
> @@ -1245,13 +1248,14 @@ static u32 emulated_msrs[] = {
>   	MSR_KVM_POLL_CONTROL,
>   };
>   
> +static u32 emulated_msrs[ARRAY_SIZE(emulated_msrs_all)];
>   static unsigned num_emulated_msrs;
>   
>   /*
>    * List of msr numbers which are used to expose MSR-based features that
>    * can be used by a hypervisor to validate requested CPU features.
>    */
> -static u32 msr_based_features[] = {
> +static const u32 msr_based_features_all[] = {
>   	MSR_IA32_VMX_BASIC,
>   	MSR_IA32_VMX_TRUE_PINBASED_CTLS,
>   	MSR_IA32_VMX_PINBASED_CTLS,
> @@ -1276,6 +1280,7 @@ static u32 msr_based_features[] = {
>   	MSR_IA32_ARCH_CAPABILITIES,
>   };
>   
> +static u32 msr_based_features[ARRAY_SIZE(msr_based_features_all)];
>   static unsigned int num_msr_based_features;
>   
>   static u64 kvm_get_arch_capabilities(void)
> @@ -5131,19 +5136,19 @@ static void kvm_init_msr_list(void)
>   	unsigned i, j;
>   
>   	BUILD_BUG_ON_MSG(INTEL_PMC_MAX_FIXED != 4,
> -			 "Please update the fixed PMCs in msrs_to_save[]");
> +			 "Please update the fixed PMCs in msrs_to_saved_all[]");
>   
>   	perf_get_x86_pmu_capability(&x86_pmu);
>   
> -	for (i = j = 0; i < ARRAY_SIZE(msrs_to_save); i++) {
> -		if (rdmsr_safe(msrs_to_save[i], &dummy[0], &dummy[1]) < 0)
> +	for (i = j = 0; i < ARRAY_SIZE(msrs_to_save_all); i++) {
> +		if (rdmsr_safe(msrs_to_save_all[i], &dummy[0], &dummy[1]) < 0)
>   			continue;
>   
>   		/*
>   		 * Even MSRs that are valid in the host may not be exposed
>   		 * to the guests in some cases.
>   		 */
> -		switch (msrs_to_save[i]) {
> +		switch (msrs_to_save_all[i]) {
>   		case MSR_IA32_BNDCFGS:
>   			if (!kvm_mpx_supported())
>   				continue;
> @@ -5171,17 +5176,17 @@ static void kvm_init_msr_list(void)
>   			break;
>   		case MSR_IA32_RTIT_ADDR0_A ... MSR_IA32_RTIT_ADDR3_B: {
>   			if (!kvm_x86_ops->pt_supported() ||
> -				msrs_to_save[i] - MSR_IA32_RTIT_ADDR0_A >=
> +				msrs_to_save_all[i] - MSR_IA32_RTIT_ADDR0_A >=
>   				intel_pt_validate_hw_cap(PT_CAP_num_address_ranges) * 2)
>   				continue;
>   			break;
>   		case MSR_ARCH_PERFMON_PERFCTR0 ... MSR_ARCH_PERFMON_PERFCTR0 + 17:
> -			if (msrs_to_save[i] - MSR_ARCH_PERFMON_PERFCTR0 >=
> +			if (msrs_to_save_all[i] - MSR_ARCH_PERFMON_PERFCTR0 >=
>   			    min(INTEL_PMC_MAX_GENERIC, x86_pmu.num_counters_gp))
>   				continue;
>   			break;
>   		case MSR_ARCH_PERFMON_EVENTSEL0 ... MSR_ARCH_PERFMON_EVENTSEL0 + 17:
> -			if (msrs_to_save[i] - MSR_ARCH_PERFMON_EVENTSEL0 >=
> +			if (msrs_to_save_all[i] - MSR_ARCH_PERFMON_EVENTSEL0 >=
>   			    min(INTEL_PMC_MAX_GENERIC, x86_pmu.num_counters_gp))
>   				continue;
>   		}
> @@ -5189,31 +5194,31 @@ static void kvm_init_msr_list(void)
>   			break;
>   		}
>   
> -		if (j < i)
> -			msrs_to_save[j] = msrs_to_save[i];
> +		if (j <= i)
> +			msrs_to_save[j] = msrs_to_save_all[i];
>   		j++;
>   	}
>   	num_msrs_to_save = j;
>   
> -	for (i = j = 0; i < ARRAY_SIZE(emulated_msrs); i++) {
> -		if (!kvm_x86_ops->has_emulated_msr(emulated_msrs[i]))
> +	for (i = j = 0; i < ARRAY_SIZE(emulated_msrs_all); i++) {
> +		if (!kvm_x86_ops->has_emulated_msr(emulated_msrs_all[i]))
>   			continue;
>   
> -		if (j < i)
> -			emulated_msrs[j] = emulated_msrs[i];
> +		if (j <= i)
> +			emulated_msrs[j] = emulated_msrs_all[i];
>   		j++;
>   	}
>   	num_emulated_msrs = j;
>   
> -	for (i = j = 0; i < ARRAY_SIZE(msr_based_features); i++) {
> +	for (i = j = 0; i < ARRAY_SIZE(msr_based_features_all); i++) {
>   		struct kvm_msr_entry msr;
>   
> -		msr.index = msr_based_features[i];
> +		msr.index = msr_based_features_all[i];
>   		if (kvm_get_msr_feature(&msr))
>   			continue;
>   
> -		if (j < i)
> -			msr_based_features[j] = msr_based_features[i];
> +		if (j <= i)
> +			msr_based_features[j] = msr_based_features_all[i];
>   		j++;
>   	}
>   	num_msr_based_features = j;
> 

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH v2] KVM: X86: Fix initialization of MSR lists(msrs_to_save[], emulated_msrs[] and msr_based_features[])
  2019-11-06  6:35 [PATCH v2] KVM: X86: Fix initialization of MSR lists(msrs_to_save[], emulated_msrs[] and msr_based_features[]) Chenyi Qiang
  2019-11-11  5:10 ` cqiang
@ 2019-11-11 13:30 ` Paolo Bonzini
  1 sibling, 0 replies; 3+ messages in thread
From: Paolo Bonzini @ 2019-11-11 13:30 UTC (permalink / raw)
  To: Chenyi Qiang, Radim Krčmář,
	Sean Christopherson, Vitaly Kuznetsov, Jim Mattson, Joerg Roedel
  Cc: Xiaoyao Li, kvm, linux-kernel, stable

On 06/11/19 07:35, Chenyi Qiang wrote:
> The three MSR lists(msrs_to_save[], emulated_msrs[] and
> msr_based_features[]) are global arrays of kvm.ko, which are
> adjusted (copy supported MSRs forward to override the unsupported MSRs)
> when insmod kvm-{intel,amd}.ko, but it doesn't reset these three arrays
> to their initial value when rmmod kvm-{intel,amd}.ko. Thus, at the next
> installation, kvm-{intel,amd}.ko will do operations on the modified
> arrays with some MSRs lost and some MSRs duplicated.
> 
> So define three constant arrays to hold the initial MSR lists and
> initialize msrs_to_save[], emulated_msrs[] and msr_based_features[]
> based on the constant arrays.
> 
> Cc: stable@vger.kernel.org
> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
> Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
> ---
> Changes in v2:
>  - define initial MSR lists with static const.
>  - change the dynamic allocation of supported MSR lists to static allocation.
> 
>  arch/x86/kvm/x86.c | 51 +++++++++++++++++++++++++---------------------
>  1 file changed, 28 insertions(+), 23 deletions(-)
> 
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 89621025577a..0b4b6db5b13f 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -1138,13 +1138,15 @@ EXPORT_SYMBOL_GPL(kvm_rdpmc);
>   * List of msr numbers which we expose to userspace through KVM_GET_MSRS
>   * and KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST.
>   *
> - * This list is modified at module load time to reflect the
> + * The three MSR lists(msrs_to_save, emulated_msrs, msr_based_features)
> + * extract the supported MSRs from the related const lists.
> + * msrs_to_save is selected from the msrs_to_save_all to reflect the
>   * capabilities of the host cpu. This capabilities test skips MSRs that are
> - * kvm-specific. Those are put in emulated_msrs; filtering of emulated_msrs
> + * kvm-specific. Those are put in emulated_msrs_all; filtering of emulated_msrs
>   * may depend on host virtualization features rather than host cpu features.
>   */
>  
> -static u32 msrs_to_save[] = {
> +static const u32 msrs_to_save_all[] = {
>  	MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,
>  	MSR_STAR,
>  #ifdef CONFIG_X86_64
> @@ -1185,9 +1187,10 @@ static u32 msrs_to_save[] = {
>  	MSR_ARCH_PERFMON_EVENTSEL0 + 16, MSR_ARCH_PERFMON_EVENTSEL0 + 17,
>  };
>  
> +static u32 msrs_to_save[ARRAY_SIZE(msrs_to_save_all)];
>  static unsigned num_msrs_to_save;
>  
> -static u32 emulated_msrs[] = {
> +static const u32 emulated_msrs_all[] = {
>  	MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK,
>  	MSR_KVM_SYSTEM_TIME_NEW, MSR_KVM_WALL_CLOCK_NEW,
>  	HV_X64_MSR_GUEST_OS_ID, HV_X64_MSR_HYPERCALL,
> @@ -1226,7 +1229,7 @@ static u32 emulated_msrs[] = {
>  	 * by arch/x86/kvm/vmx/nested.c based on CPUID or other MSRs.
>  	 * We always support the "true" VMX control MSRs, even if the host
>  	 * processor does not, so I am putting these registers here rather
> -	 * than in msrs_to_save.
> +	 * than in msrs_to_save_all.
>  	 */
>  	MSR_IA32_VMX_BASIC,
>  	MSR_IA32_VMX_TRUE_PINBASED_CTLS,
> @@ -1245,13 +1248,14 @@ static u32 emulated_msrs[] = {
>  	MSR_KVM_POLL_CONTROL,
>  };
>  
> +static u32 emulated_msrs[ARRAY_SIZE(emulated_msrs_all)];
>  static unsigned num_emulated_msrs;
>  
>  /*
>   * List of msr numbers which are used to expose MSR-based features that
>   * can be used by a hypervisor to validate requested CPU features.
>   */
> -static u32 msr_based_features[] = {
> +static const u32 msr_based_features_all[] = {
>  	MSR_IA32_VMX_BASIC,
>  	MSR_IA32_VMX_TRUE_PINBASED_CTLS,
>  	MSR_IA32_VMX_PINBASED_CTLS,
> @@ -1276,6 +1280,7 @@ static u32 msr_based_features[] = {
>  	MSR_IA32_ARCH_CAPABILITIES,
>  };
>  
> +static u32 msr_based_features[ARRAY_SIZE(msr_based_features_all)];
>  static unsigned int num_msr_based_features;
>  
>  static u64 kvm_get_arch_capabilities(void)
> @@ -5131,19 +5136,19 @@ static void kvm_init_msr_list(void)
>  	unsigned i, j;
>  
>  	BUILD_BUG_ON_MSG(INTEL_PMC_MAX_FIXED != 4,
> -			 "Please update the fixed PMCs in msrs_to_save[]");
> +			 "Please update the fixed PMCs in msrs_to_saved_all[]");
>  
>  	perf_get_x86_pmu_capability(&x86_pmu);
>  
> -	for (i = j = 0; i < ARRAY_SIZE(msrs_to_save); i++) {
> -		if (rdmsr_safe(msrs_to_save[i], &dummy[0], &dummy[1]) < 0)
> +	for (i = j = 0; i < ARRAY_SIZE(msrs_to_save_all); i++) {
> +		if (rdmsr_safe(msrs_to_save_all[i], &dummy[0], &dummy[1]) < 0)
>  			continue;
>  
>  		/*
>  		 * Even MSRs that are valid in the host may not be exposed
>  		 * to the guests in some cases.
>  		 */
> -		switch (msrs_to_save[i]) {
> +		switch (msrs_to_save_all[i]) {
>  		case MSR_IA32_BNDCFGS:
>  			if (!kvm_mpx_supported())
>  				continue;
> @@ -5171,17 +5176,17 @@ static void kvm_init_msr_list(void)
>  			break;
>  		case MSR_IA32_RTIT_ADDR0_A ... MSR_IA32_RTIT_ADDR3_B: {
>  			if (!kvm_x86_ops->pt_supported() ||
> -				msrs_to_save[i] - MSR_IA32_RTIT_ADDR0_A >=
> +				msrs_to_save_all[i] - MSR_IA32_RTIT_ADDR0_A >=
>  				intel_pt_validate_hw_cap(PT_CAP_num_address_ranges) * 2)
>  				continue;
>  			break;
>  		case MSR_ARCH_PERFMON_PERFCTR0 ... MSR_ARCH_PERFMON_PERFCTR0 + 17:
> -			if (msrs_to_save[i] - MSR_ARCH_PERFMON_PERFCTR0 >=
> +			if (msrs_to_save_all[i] - MSR_ARCH_PERFMON_PERFCTR0 >=
>  			    min(INTEL_PMC_MAX_GENERIC, x86_pmu.num_counters_gp))
>  				continue;
>  			break;
>  		case MSR_ARCH_PERFMON_EVENTSEL0 ... MSR_ARCH_PERFMON_EVENTSEL0 + 17:
> -			if (msrs_to_save[i] - MSR_ARCH_PERFMON_EVENTSEL0 >=
> +			if (msrs_to_save_all[i] - MSR_ARCH_PERFMON_EVENTSEL0 >=
>  			    min(INTEL_PMC_MAX_GENERIC, x86_pmu.num_counters_gp))
>  				continue;
>  		}
> @@ -5189,31 +5194,31 @@ static void kvm_init_msr_list(void)
>  			break;
>  		}
>  
> -		if (j < i)
> -			msrs_to_save[j] = msrs_to_save[i];
> +		if (j <= i)
> +			msrs_to_save[j] = msrs_to_save_all[i];

J is always <= i, so we can remove the ifs.

>  		j++;
>  	}
>  	num_msrs_to_save = j;
>  
> -	for (i = j = 0; i < ARRAY_SIZE(emulated_msrs); i++) {
> -		if (!kvm_x86_ops->has_emulated_msr(emulated_msrs[i]))
> +	for (i = j = 0; i < ARRAY_SIZE(emulated_msrs_all); i++) {
> +		if (!kvm_x86_ops->has_emulated_msr(emulated_msrs_all[i]))
>  			continue;
>  
> -		if (j < i)
> -			emulated_msrs[j] = emulated_msrs[i];
> +		if (j <= i)
> +			emulated_msrs[j] = emulated_msrs_all[i];
>  		j++;
>  	}
>  	num_emulated_msrs = j;
>  
> -	for (i = j = 0; i < ARRAY_SIZE(msr_based_features); i++) {
> +	for (i = j = 0; i < ARRAY_SIZE(msr_based_features_all); i++) {
>  		struct kvm_msr_entry msr;
>  
> -		msr.index = msr_based_features[i];
> +		msr.index = msr_based_features_all[i];
>  		if (kvm_get_msr_feature(&msr))
>  			continue;
>  
> -		if (j < i)
> -			msr_based_features[j] = msr_based_features[i];
> +		if (j <= i)
> +			msr_based_features[j] = msr_based_features_all[i];
>  		j++;
>  	}
>  	num_msr_based_features = j;
> 

Queued, thanks.

Paolo


^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2019-11-11 13:30 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-11-06  6:35 [PATCH v2] KVM: X86: Fix initialization of MSR lists(msrs_to_save[], emulated_msrs[] and msr_based_features[]) Chenyi Qiang
2019-11-11  5:10 ` cqiang
2019-11-11 13:30 ` Paolo Bonzini

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