Re: [PATCH v4 03/16] KVM: Add KVM_CAP_MEMORY_FAULT_INFO

[Isaku Yamahata <isaku.yamahata@gmail.com>]

On Fri, Jun 02, 2023 at 04:19:08PM +0000,
Anish Moorthy <amoorthy@google.com> wrote:

> diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
> index add067793b90..5b24059143b3 100644
> --- a/Documentation/virt/kvm/api.rst
> +++ b/Documentation/virt/kvm/api.rst
> @@ -6700,6 +6700,18 @@ array field represents return values. The userspace should update the return
>  values of SBI call before resuming the VCPU. For more details on RISC-V SBI
>  spec refer, https://github.com/riscv/riscv-sbi-doc.
>  
> +::
> +
> +		/* KVM_EXIT_MEMORY_FAULT */
> +		struct {
> +			__u64 flags;
> +			__u64 gpa;
> +			__u64 len; /* in bytes */


UPM or gmem uses size instead of len. Personally I don't have any strong
preference.  It's better to converge. (or use union to accept both?)

I check the existing one.
KVM_EXIT_IO: size.
KVM_EXIT_MMIO: len.
KVM_INTERNAL_ERROR_EMULATION: insn_size
struct kvm_coalesced_mmio_zone: size
struct kvm_coalesced_mmio: len
struct kvm_ioeventfd: len
struct kvm_enc_region: size
struct kvm_sev_*: len
struct kvm_memory_attributes: size
struct kvm_create_guest_memfd: size


> +		} memory_fault;
> +
> +Indicates a vCPU memory fault on the guest physical address range
> +[gpa, gpa + len). See KVM_CAP_MEMORY_FAULT_INFO for more details.
> +
>  ::
>  
>      /* KVM_EXIT_NOTIFY */


-- 
Isaku Yamahata <isaku.yamahata@gmail.com>