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

Brijesh Singh
2021-01-14T21:38:21Z

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
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);