Re: [RFC PATCH 2/9] kvm.h: introduce KVM_SET_USER_MEMORY_REGION_LIST ioctl

Paolo Bonzini
2022-09-28T16:42:12Z

On 9/9/22 12:44, Emanuele Giuseppe Esposito wrote:
> This IOCTL enables atomic update of multiple memslots.
> The userspace application provides a kvm_userspace_memory_region_list
> containing a list of entries, each representing a modification to be
> performed to a memslot.
>
> Requests with invalidate_slot == 1 are pre-processed, because they
> are ther DELETE or MOVE, and therefore the memslot must be first
> replaced with a copy marked as KVM_MEMSLOT_INVALID, and then replaced.
>
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> ---
> include/uapi/linux/kvm.h | 21 ++++++++++++++++++++-
> 1 file changed, 20 insertions(+), 1 deletion(-)
>
> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index a36e78710382..673496b91a25 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -103,6 +103,24 @@ struct kvm_userspace_memory_region {
> __u64 userspace_addr; /* start of the userspace allocated memory */
> };
>
> +/* for KVM_SET_USER_MEMORY_REGION_LIST */
> +struct kvm_userspace_memory_region_entry {
> + __u32 slot;
> + __u32 flags;
> + __u64 guest_phys_addr;
> + __u64 memory_size; /* bytes */
> + __u64 userspace_addr; /* start of the userspace allocated memory */
> + __u8 invalidate_slot;
> + __u8 padding[31];
> +};
> +
> +/* for KVM_SET_USER_MEMORY_REGION_LIST */
> +struct kvm_userspace_memory_region_list {
> + __u32 nent;
> + __u32 flags;
> + struct kvm_userspace_memory_region_entry entries[0];
> +};
> +
> /*
> * The bit 0 ~ bit 15 of kvm_memory_region::flags are visible for userspace,
> * other bits are reserved for kvm internal use which are defined in
> @@ -1444,7 +1462,8 @@ struct kvm_vfio_spapr_tce {
> struct kvm_userspace_memory_region)
> #define KVM_SET_TSS_ADDR _IO(KVMIO, 0x47)
> #define KVM_SET_IDENTITY_MAP_ADDR _IOW(KVMIO, 0x48, __u64)
> -
> +#define KVM_SET_USER_MEMORY_REGION_LIST _IOW(KVMIO, 0x49, \
> + struct kvm_userspace_memory_region_list)
> /* enable ucontrol for s390 */
> struct kvm_s390_ucas_mapping {
> __u64 user_addr;

Looks good; however, in the non-RFC I suggest adding documentation in
this patch already (so no Reviewed-by yet).

Paolo