| Message ID | 20231109210325.3806151-3-amoorthy@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Improve KVM + userfaultfd performance via KVM_MEMORY_FAULT_EXITs on stage-2 faults | expand |
Same "Documentation" issue. And the purpose of the change isn't to add docstrings,
the purpose is to clarify the goofy/strange parameters:
KVM: Add comment to clarify param usage for __kvm{read,_write}_guest_page()
On Thu, Nov 09, 2023, Anish Moorthy wrote:
> The (gfn, data, offset, len) order of parameters is a little strange
> since "offset" applies to "gfn" rather than to "data". Add docstrings to
s/docstrings/function comments/. This change has value and impact even if the
kernel suddenly stops generating documentation from code.
> make things perfectly clear.
>
> Signed-off-by: Anish Moorthy <amoorthy@google.com>
> ---
> virt/kvm/kvm_main.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 687374138cfd..f521b6fd808f 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -3328,6 +3328,7 @@ static int next_segment(unsigned long len, int offset)
> return len;
> }
>
> +/* Copy @len bytes from guest memory at '(@gfn * PAGE_SIZE) + @offset' to @data */
> static int __kvm_read_guest_page(struct kvm_memory_slot *slot, gfn_t gfn,
> void *data, int offset, int len)
> {
> @@ -3429,6 +3430,7 @@ int kvm_vcpu_read_guest_atomic(struct kvm_vcpu *vcpu, gpa_t gpa,
> }
> EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_atomic);
>
> +/* Copy @len bytes from @data into guest memory at '(@gfn * PAGE_SIZE) + @offset' */
> static int __kvm_write_guest_page(struct kvm *kvm,
> struct kvm_memory_slot *memslot, gfn_t gfn,
> const void *data, int offset, int len)
> --
> 2.42.0.869.gea05f2083d-goog
>
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 687374138cfd..f521b6fd808f 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -3328,6 +3328,7 @@ static int next_segment(unsigned long len, int offset) return len; } +/* Copy @len bytes from guest memory at '(@gfn * PAGE_SIZE) + @offset' to @data */ static int __kvm_read_guest_page(struct kvm_memory_slot *slot, gfn_t gfn, void *data, int offset, int len) { @@ -3429,6 +3430,7 @@ int kvm_vcpu_read_guest_atomic(struct kvm_vcpu *vcpu, gpa_t gpa, } EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_atomic); +/* Copy @len bytes from @data into guest memory at '(@gfn * PAGE_SIZE) + @offset' */ static int __kvm_write_guest_page(struct kvm *kvm, struct kvm_memory_slot *memslot, gfn_t gfn, const void *data, int offset, int len)
The (gfn, data, offset, len) order of parameters is a little strange since "offset" applies to "gfn" rather than to "data". Add docstrings to make things perfectly clear. Signed-off-by: Anish Moorthy <amoorthy@google.com> --- virt/kvm/kvm_main.c | 2 ++ 1 file changed, 2 insertions(+)