| Message ID | 20230509204801.2824351-16-quic_eberman@quicinc.com |
|---|---|
| State | New |
| Headers | show |
| Series | Drivers for Gunyah hypervisor | expand |
On 5/9/23 3:47 PM, Elliot Berman wrote: > Document the ioctls and usage of Gunyah VM Manager driver. > > Signed-off-by: Elliot Berman <quic_eberman@quicinc.com> This patch does not apply, because at this point in the series, "Documentation/virt/gunyah/index.rst" does not exist. I'm going to ignore that. I have some suggestions, but this generally looks good. I'll wait to see v14 with the full "index.rst" before I give my Reviewed-by. -Alex > --- > Documentation/virt/gunyah/index.rst | 1 + > Documentation/virt/gunyah/vm-manager.rst | 82 ++++++++++++++++++++++++ > 2 files changed, 83 insertions(+) > create mode 100644 Documentation/virt/gunyah/vm-manager.rst > > diff --git a/Documentation/virt/gunyah/index.rst b/Documentation/virt/gunyah/index.rst > index 74aa345e0a14..7058249825b1 100644 > --- a/Documentation/virt/gunyah/index.rst > +++ b/Documentation/virt/gunyah/index.rst > @@ -7,6 +7,7 @@ Gunyah Hypervisor > .. toctree:: > :maxdepth: 1 > > + vm-manager > message-queue > > Gunyah is a Type-1 hypervisor which is independent of any OS kernel, and runs in > diff --git a/Documentation/virt/gunyah/vm-manager.rst b/Documentation/virt/gunyah/vm-manager.rst > new file mode 100644 > index 000000000000..50d8ae7fabcd > --- /dev/null > +++ b/Documentation/virt/gunyah/vm-manager.rst > @@ -0,0 +1,82 @@ > +.. SPDX-License-Identifier: GPL-2.0 > + > +======================= > +Virtual Machine Manager > +======================= > + > +The Gunyah Virtual Machine Manager is a Linux driver to support launching > +virtual machines using Gunyah. It presently supports launching non-proxy > +scheduled Linux-like virtual machines. Does everyone know what "non-proxy-scheduled virtual machines" are? > +Except for some basic information about the location of initial binaries, > +most of the configuration about a Gunyah virtual machine is described in the > +VM's devicetree. The devicetree is generated by userspace. Interacting with the > +virtual machine is still done via the kernel and VM configuration requires some > +of the corresponding functionality to be set up in the kernel. For instance, > +sharing userspace memory with a VM is done via the `GH_VM_SET_USER_MEM_REGION`_ > +ioctl. The VM itself is configured to use the memory region via the > +devicetree. Without looking at the code, I'm a little unsure what that last sentence reallly means. > + > +Sample Userspace VMM > +==================== > + > +A sample userspace VMM is included in samples/gunyah/ along with a minimal > +devicetree that can be used to launch a VM. To build this sample, enable > +CONFIG_SAMPLE_GUNYAH. > + > +IOCTLs and userspace VMM flows > +============================== > + > +The kernel exposes a char device interface at /dev/gunyah. > + > +To create a VM, use the `GH_CREATE_VM`_ ioctl. A successful call will return a > +"Gunyah VM" file descriptor. > + > +/dev/gunyah API Descriptions > +---------------------------- > + > +GH_CREATE_VM > +~~~~~~~~~~~~ > + > +Creates a Gunyah VM. The argument is reserved for future use and must be 0. Maybe mention it returns a file descriptor representing the created VM? > + > +Gunyah VM API Descriptions > +-------------------------- > + > +GH_VM_SET_USER_MEM_REGION > +~~~~~~~~~~~~~~~~~~~~~~~~~ > + > +This ioctl allows the user to create or delete a memory parcel for a guest > +virtual machine. Each memory region is uniquely identified by a label; > +attempting to create two regions with the same label is not allowed. Labels are > +unique per virtual machine. > + > +While VMM is guest-agnostic and allows runtime addition of memory regions, > +Linux guest virtual machines do not support accepting memory regions at runtime. > +Thus, memory regions should be provided before starting the VM and the VM must Thus, for Linux guests, memory regions must be provided... > +be configured to accept these at boot-up. > + > +The guest physical address is used by Linux kernel to check that the requested > +user regions do not overlap and to help find the corresponding memory region > +for calls like `GH_VM_SET_DTB_CONFIG`_. It must be page aligned. > + > +To add a memory region, call `GH_VM_SET_USER_MEM_REGION`_ with fields set as > +described above. > + > +.. kernel-doc:: include/uapi/linux/gunyah.h > + :identifiers: gh_userspace_memory_region gh_mem_flags > + > +GH_VM_SET_DTB_CONFIG > +~~~~~~~~~~~~~~~~~~~~ > + > +This ioctl sets the location of the VM's devicetree blob and is used by Gunyah > +Resource Manager to allocate resources. The guest physical memory should be part s/should/must/ /* ? */ > +of the primary memory parcel provided to the VM prior to GH_VM_START. Is it possible to provide multiple memory parcels? If so, is the "primary" memory parcel the first? > + > +.. kernel-doc:: include/uapi/linux/gunyah.h > + :identifiers: gh_vm_dtb_config > + > +GH_VM_START > +~~~~~~~~~~~ > + > +This ioctl starts the VM.
diff --git a/Documentation/virt/gunyah/index.rst b/Documentation/virt/gunyah/index.rst index 74aa345e0a14..7058249825b1 100644 --- a/Documentation/virt/gunyah/index.rst +++ b/Documentation/virt/gunyah/index.rst @@ -7,6 +7,7 @@ Gunyah Hypervisor .. toctree:: :maxdepth: 1 + vm-manager message-queue Gunyah is a Type-1 hypervisor which is independent of any OS kernel, and runs in diff --git a/Documentation/virt/gunyah/vm-manager.rst b/Documentation/virt/gunyah/vm-manager.rst new file mode 100644 index 000000000000..50d8ae7fabcd --- /dev/null +++ b/Documentation/virt/gunyah/vm-manager.rst @@ -0,0 +1,82 @@ +.. SPDX-License-Identifier: GPL-2.0 + +======================= +Virtual Machine Manager +======================= + +The Gunyah Virtual Machine Manager is a Linux driver to support launching +virtual machines using Gunyah. It presently supports launching non-proxy +scheduled Linux-like virtual machines. + +Except for some basic information about the location of initial binaries, +most of the configuration about a Gunyah virtual machine is described in the +VM's devicetree. The devicetree is generated by userspace. Interacting with the +virtual machine is still done via the kernel and VM configuration requires some +of the corresponding functionality to be set up in the kernel. For instance, +sharing userspace memory with a VM is done via the `GH_VM_SET_USER_MEM_REGION`_ +ioctl. The VM itself is configured to use the memory region via the +devicetree. + +Sample Userspace VMM +==================== + +A sample userspace VMM is included in samples/gunyah/ along with a minimal +devicetree that can be used to launch a VM. To build this sample, enable +CONFIG_SAMPLE_GUNYAH. + +IOCTLs and userspace VMM flows +============================== + +The kernel exposes a char device interface at /dev/gunyah. + +To create a VM, use the `GH_CREATE_VM`_ ioctl. A successful call will return a +"Gunyah VM" file descriptor. + +/dev/gunyah API Descriptions +---------------------------- + +GH_CREATE_VM +~~~~~~~~~~~~ + +Creates a Gunyah VM. The argument is reserved for future use and must be 0. + +Gunyah VM API Descriptions +-------------------------- + +GH_VM_SET_USER_MEM_REGION +~~~~~~~~~~~~~~~~~~~~~~~~~ + +This ioctl allows the user to create or delete a memory parcel for a guest +virtual machine. Each memory region is uniquely identified by a label; +attempting to create two regions with the same label is not allowed. Labels are +unique per virtual machine. + +While VMM is guest-agnostic and allows runtime addition of memory regions, +Linux guest virtual machines do not support accepting memory regions at runtime. +Thus, memory regions should be provided before starting the VM and the VM must +be configured to accept these at boot-up. + +The guest physical address is used by Linux kernel to check that the requested +user regions do not overlap and to help find the corresponding memory region +for calls like `GH_VM_SET_DTB_CONFIG`_. It must be page aligned. + +To add a memory region, call `GH_VM_SET_USER_MEM_REGION`_ with fields set as +described above. + +.. kernel-doc:: include/uapi/linux/gunyah.h + :identifiers: gh_userspace_memory_region gh_mem_flags + +GH_VM_SET_DTB_CONFIG +~~~~~~~~~~~~~~~~~~~~ + +This ioctl sets the location of the VM's devicetree blob and is used by Gunyah +Resource Manager to allocate resources. The guest physical memory should be part +of the primary memory parcel provided to the VM prior to GH_VM_START. + +.. kernel-doc:: include/uapi/linux/gunyah.h + :identifiers: gh_vm_dtb_config + +GH_VM_START +~~~~~~~~~~~ + +This ioctl starts the VM.
Document the ioctls and usage of Gunyah VM Manager driver. Signed-off-by: Elliot Berman <quic_eberman@quicinc.com> --- Documentation/virt/gunyah/index.rst | 1 + Documentation/virt/gunyah/vm-manager.rst | 82 ++++++++++++++++++++++++ 2 files changed, 83 insertions(+) create mode 100644 Documentation/virt/gunyah/vm-manager.rst