Re: [PATCH v2 11/14] KVM: SVM: Move SEV VMCB tracking allocation to sev.c

Tom Lendacky
2021-01-14T21:55:09Z

On 1/14/21 3:37 PM, Brijesh Singh wrote:
>
> On 1/13/21 6:37 PM, Sean Christopherson wrote:
>> Move the allocation of the SEV VMCB array to sev.c to help pave the way
>> toward encapsulating SEV enabling wholly within sev.c.
>>
>> No functional change intended.
>>
>> Signed-off-by: Sean Christopherson <seanjc@google.com>
>> ---
>> arch/x86/kvm/svm/sev.c | 13 +++++++++++++
>> arch/x86/kvm/svm/svm.c | 17 ++++++++---------
>> arch/x86/kvm/svm/svm.h | 1 +
>> 3 files changed, 22 insertions(+), 9 deletions(-)
>>
>> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
>> index 1a143340103e..a2c3e2d42a7f 100644
>> --- a/arch/x86/kvm/svm/sev.c
>> +++ b/arch/x86/kvm/svm/sev.c
>> @@ -1330,6 +1330,19 @@ void sev_hardware_teardown(void)
>> sev_flush_asids();
>> }
>>
>> +int sev_cpu_init(struct svm_cpu_data *sd)
>> +{
>> + if (!svm_sev_enabled())
>> + return 0;
>> +
>> + sd->sev_vmcbs = kmalloc_array(max_sev_asid + 1, sizeof(void *),
>> + GFP_KERNEL | __GFP_ZERO);
>
>
> I saw Tom recommended to use kzalloc.. instead of __GFP_ZERO in previous

kcalloc :)

Thanks,
Tom

> patch. With that fixed,
>
> Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
>
>
>> + if (!sd->sev_vmcbs)
>> + return -ENOMEM;
>> +
>> + return 0;
>> +}
>> +
>> /*
>> * Pages used by hardware to hold guest encrypted state must be flushed before
>> * returning them to the system.
>> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
>> index bb7b99743bea..89b95fb87a0c 100644
>> --- a/arch/x86/kvm/svm/svm.c
>> +++ b/arch/x86/kvm/svm/svm.c
>> @@ -552,23 +552,22 @@ static void svm_cpu_uninit(int cpu)
>> static int svm_cpu_init(int cpu)
>> {
>> struct svm_cpu_data *sd;
>> + int ret;
>>
>> sd = kzalloc(sizeof(struct svm_cpu_data), GFP_KERNEL);
>> if (!sd)
>> return -ENOMEM;
>> sd->cpu = cpu;
>> sd->save_area = alloc_page(GFP_KERNEL);
>> - if (!sd->save_area)
>> + if (!sd->save_area) {
>> + ret = -ENOMEM;
>> goto free_cpu_data;
>> + }
>> clear_page(page_address(sd->save_area));
>>
>> - if (svm_sev_enabled()) {
>> - sd->sev_vmcbs = kmalloc_array(max_sev_asid + 1,
>> - sizeof(void *),
>> - GFP_KERNEL | __GFP_ZERO);
>> - if (!sd->sev_vmcbs)
>> - goto free_save_area;
>> - }
>> + ret = sev_cpu_init(sd);
>> + if (ret)
>> + goto free_save_area;
>>
>> per_cpu(svm_data, cpu) = sd;
>>
>> @@ -578,7 +577,7 @@ static int svm_cpu_init(int cpu)
>> __free_page(sd->save_area);
>> free_cpu_data:
>> kfree(sd);
>> - return -ENOMEM;
>> + return ret;
>>
>> }
>>
>> diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
>> index 8e169835f52a..4eb4bab0ca3e 100644
>> --- a/arch/x86/kvm/svm/svm.h
>> +++ b/arch/x86/kvm/svm/svm.h
>> @@ -583,6 +583,7 @@ int svm_unregister_enc_region(struct kvm *kvm,
>> void pre_sev_run(struct vcpu_svm *svm, int cpu);
>> void __init sev_hardware_setup(void);
>> void sev_hardware_teardown(void);
>> +int sev_cpu_init(struct svm_cpu_data *sd);
>> void sev_free_vcpu(struct kvm_vcpu *vcpu);
>> int sev_handle_vmgexit(struct vcpu_svm *svm);
>> int sev_es_string_io(struct vcpu_svm *svm, int size, unsigned int port, int in);