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authorSean Christopherson <seanjc@google.com>2023-10-27 11:21:50 -0700
committerPaolo Bonzini <pbonzini@redhat.com>2023-11-13 05:30:41 -0500
commitbb58b90b1a8f753b582055adaf448214a8e22c31 (patch)
tree2bbab991e28e400059c13d9946ef846fb749a8b6 /Documentation/virt
parentf128cf8cfbecccf95e891ae90d9c917df5117c7a (diff)
KVM: Introduce KVM_SET_USER_MEMORY_REGION2
Introduce a "version 2" of KVM_SET_USER_MEMORY_REGION so that additional information can be supplied without setting userspace up to fail. The padding in the new kvm_userspace_memory_region2 structure will be used to pass a file descriptor in addition to the userspace_addr, i.e. allow userspace to point at a file descriptor and map memory into a guest that is NOT mapped into host userspace. Alternatively, KVM could simply add "struct kvm_userspace_memory_region2" without a new ioctl(), but as Paolo pointed out, adding a new ioctl() makes detection of bad flags a bit more robust, e.g. if the new fd field is guarded only by a flag and not a new ioctl(), then a userspace bug (setting a "bad" flag) would generate out-of-bounds access instead of an -EINVAL error. Cc: Jarkko Sakkinen <jarkko@kernel.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> Message-Id: <20231027182217.3615211-9-seanjc@google.com> Acked-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'Documentation/virt')
-rw-r--r--Documentation/virt/kvm/api.rst22
1 files changed, 22 insertions, 0 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 7025b3751027..9edd9e436bab 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -6192,6 +6192,28 @@ to know what fields can be changed for the system register described by
``op0, op1, crn, crm, op2``. KVM rejects ID register values that describe a
superset of the features supported by the system.
+4.140 KVM_SET_USER_MEMORY_REGION2
+---------------------------------
+
+:Capability: KVM_CAP_USER_MEMORY2
+:Architectures: all
+:Type: vm ioctl
+:Parameters: struct kvm_userspace_memory_region2 (in)
+:Returns: 0 on success, -1 on error
+
+::
+
+ struct kvm_userspace_memory_region2 {
+ __u32 slot;
+ __u32 flags;
+ __u64 guest_phys_addr;
+ __u64 memory_size; /* bytes */
+ __u64 userspace_addr; /* start of the userspace allocated memory */
+ __u64 pad[16];
+ };
+
+See KVM_SET_USER_MEMORY_REGION.
+
5. The kvm_run structure
========================