On 04/06/20 17:12, Sean Christopherson wrote:
> On Thu, Jun 04, 2020 at 12:16:36PM +0800, Xiaoyao Li wrote:
>> Delay the assignment of array.maxnent to use correct value for the case
>> cpuid->nent > KVM_MAX_CPUID_ENTRIES.
>>
>> Fixes: e53c95e8d41e ("KVM: x86: Encapsulate CPUID entries and metadata in struct")
>> Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
>> ---
>> v2:
>> - remove "const" of maxnent to fix build error.
>> ---
>> arch/x86/kvm/cpuid.c | 5 +++--
>> 1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
>> index 253b8e875ccd..3d88ddf781d0 100644
>> --- a/arch/x86/kvm/cpuid.c
>> +++ b/arch/x86/kvm/cpuid.c
>> @@ -426,7 +426,7 @@ EXPORT_SYMBOL_GPL(kvm_set_cpu_caps);
>>
>> struct kvm_cpuid_array {
>> struct kvm_cpuid_entry2 *entries;
>> - const int maxnent;
>> + int maxnent;
>> int nent;
>> };
>>
>> @@ -870,7 +870,6 @@ int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
>>
>> struct kvm_cpuid_array array = {
>> .nent = 0,
>> - .maxnent = cpuid->nent,
>> };
>> int r, i;
>>
>> @@ -887,6 +886,8 @@ int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
>> if (!array.entries)
>> return -ENOMEM;
>>
>> + array.maxnent = cpuid->nent;
>
> Eh, I'd vote to just do:
>
> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> index 253b8e875ccd..1e5b1ee75a76 100644
> --- a/arch/x86/kvm/cpuid.c
> +++ b/arch/x86/kvm/cpuid.c
> @@ -870,7 +870,7 @@ int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
>
> struct kvm_cpuid_array array = {
> .nent = 0,
> - .maxnent = cpuid->nent,
> + .maxnent = min(cpuid->nent, (u32)KVM_MAX_CPUID_ENTRIES),
> };
> int r, i;
>
Both are fine, I've queued Xiaoyao's patch.
Paolo
