On 19/11/19 09:49, Yang Weijiang wrote:
> +
> +#define SUBPAGE_MAX_BITMAP 64
Please rename this to KVM_SUBPAGE_MAX_PAGES
> +struct kvm_subpage_info {
> + __u64 gfn; /* the first page gfn of the contiguous pages */
> + __u64 npages; /* number of 4K pages */
This can be
u32 npages;
u32 flags;
Check that the flags are 0, and fail the ioctl if they aren't. This
will make it easy to extend the API in the future.
> + __u32 access_map[SUBPAGE_MAX_BITMAP]; /* sub-page write-access bitmap array */
> +};
Please make this access_map[0], since the number of entries actually
depends on npages.
Likewise, kvm_arch_vm_ioctl should read the header first, then allocate
memory for the access_map and read into it. It's probably simpler if
you make kvm_vm_ioctl_get_subpages/kvm_vm_ioctl_set_subpages take
parameters like
int kvm_vm_ioctl_get_subpages(struct kvm *kvm, u64 gfn, u32 npages,
u32 *access_map);
int kvm_vm_ioctl_set_subpages(struct kvm *kvm, u64 gfn, u32 npages,
u32 *access_map);
Thanks,
Paolo
