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

Emanuele Giuseppe Esposito
2022-09-09T10:45:33Z

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;
--
2.31.1