Messages in this thread | | | Date | Wed, 2 Nov 2022 11:04:12 -0700 | Subject | Re: [PATCH v6 21/21] docs: gunyah: Document Gunyah VM Manager | From | Elliot Berman <> |
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On 11/2/2022 6:05 AM, Bagas Sanjaya wrote: > On Wed, Oct 26, 2022 at 11:58:46AM -0700, Elliot Berman wrote: >> diff --git a/Documentation/virt/gunyah/vm-manager.rst b/Documentation/virt/gunyah/vm-manager.rst >> new file mode 100644 >> index 000000000000..c232ba05de7e >> --- /dev/null >> +++ b/Documentation/virt/gunyah/vm-manager.rst >> @@ -0,0 +1,94 @@ >> +.. SPDX-License-Identifier: GPL-2.0 >> + >> +======================= >> +Virtual Machine Manager >> +======================= >> + >> +The Gunyah Virtual Machine Manager is a Linux driver to support launching virtual machines. >> + >> +Summary >> +======= >> + >> +Gunyah VMM presently supports launching non-proxy scheduled Linux-like virtual machines. >> + >> +Sample Userspace VMM >> +==================== >> + >> +A sample userspace VMM is included in samples/gunyah/ along with a sample minimal devicetree >> +that can be used to launch a Linux-like virtual machine under Gunyah. 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 >> +~~~~~~~~~~~~~~~~~~~~~~~~~ >> + >> +:: >> + >> + struct gh_userspace_memory_region { >> + __u32 label; >> + __u32 flags; >> + __u64 guest_phys_addr; >> + __u64 memory_size; >> + __u64 userspace_addr; >> + }; >> + >> +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 memory regions with the same label is not allowed. >> + >> +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 >> +configured to accept those memory regions at boot-up. >> + >> +The guest physical address is used by Linux to check the requested user regions >> +do not overlap and to help find a corresponding memory region for calls like >> +GH_VM_SET_DTB_CONFIG. >> + >> +To delete a memory region, call GH_VM_SET_USER_MEM_REGION with label set to the >> +memory region of interest and memory_size set to 0. >> + >> +The flags field of gh_userspace_memory_region can set the following bits. All >> +other bits must be 0 and are reserved for future use. The ioctl will return >> +-EINVAL if an unsupported bit is detected. >> + >> + - GH_MEM_ALLOW_READ/GH_MEM_ALLOW_WRITE/GH_MEM_ALLOW_EXEC sets read/write/exec permissions >> + for the guest, respectively. >> + >> + - GH_MEM_LENT means that the memory will be unmapped from the host and be unaccessible by >> + the host while the guest has the region. >> + >> +GH_VM_SET_DTB_CONFIG >> +~~~~~~~~~~~~~~~~~~~~ >> + >> +:: >> + >> + struct gh_vm_dtb_config { >> + __u64 gpa; >> + __u64 size; >> + }; >> + >> +This ioctl sets the location of the VM's devicetree blob and is used by Gunyah >> +Resource Manager to allocate resources. >> + >> +GH_VM_START >> +~~~~~~~~~~~ >> + >> +This ioctl starts the virtual machine. > > I think the wording can be better: > > ---- >8 ---- > > diff --git a/Documentation/virt/gunyah/vm-manager.rst b/Documentation/virt/gunyah/vm-manager.rst > index c232ba05de7e96..772fd970b91d7e 100644 > --- a/Documentation/virt/gunyah/vm-manager.rst > +++ b/Documentation/virt/gunyah/vm-manager.rst > @@ -4,18 +4,15 @@ > Virtual Machine Manager > ======================= > > -The Gunyah Virtual Machine Manager is a Linux driver to support launching virtual machines. > - > -Summary > -======= > - > -Gunyah VMM presently supports launching non-proxy scheduled Linux-like virtual machines. > +The Gunyah Virtual Machine Manager is a Linux driver for launching virtual > +machines using Gunyah. It presently supports launching non-proxy scheduled > +Linux-like virtual machines. > > Sample Userspace VMM > ==================== > > -A sample userspace VMM is included in samples/gunyah/ along with a sample minimal devicetree > -that can be used to launch a Linux-like virtual machine under Gunyah. To build this sample, enable > +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 > @@ -23,7 +20,8 @@ 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. > +To create a VM, use the GH_CREATE_VM ioctl. A successful call will return a > +"Gunyah VM" file descriptor. > > /dev/gunyah API Descriptions > ---------------------------- > @@ -51,29 +49,28 @@ 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 memory regions with the same label is not allowed. > +attempting to create two regions with the same label is not allowed. > > 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 > -configured to accept those memory regions at boot-up. > +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 to check the requested user regions > -do not overlap and to help find a corresponding memory region for calls like > -GH_VM_SET_DTB_CONFIG. > +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. > > To delete a memory region, call GH_VM_SET_USER_MEM_REGION with label set to the > -memory region of interest and memory_size set to 0. > +desired region and memory_size set to 0. > > -The flags field of gh_userspace_memory_region can set the following bits. All > +The flags field of gh_userspace_memory_region accepts the following bits. All > other bits must be 0 and are reserved for future use. The ioctl will return > -EINVAL if an unsupported bit is detected. > > - - GH_MEM_ALLOW_READ/GH_MEM_ALLOW_WRITE/GH_MEM_ALLOW_EXEC sets read/write/exec permissions > - for the guest, respectively. > - > - - GH_MEM_LENT means that the memory will be unmapped from the host and be unaccessible by > - the host while the guest has the region. > + - GH_MEM_ALLOW_READ/GH_MEM_ALLOW_WRITE/GH_MEM_ALLOW_EXEC sets read/write/exec > + permissions for the guest, respectively. > + - GH_MEM_LENT means that the memory will be unmapped from the host and be > + unaccessible by the host while the guest has the region.
One side question -- before, you asked that I add newline between the list entries. Here, you've removed them. When do I need the extra newline vs not?
https://lore.kernel.org/all/YzUUaIx+azyzFDNX@debian.me/
> > GH_VM_SET_DTB_CONFIG > ~~~~~~~~~~~~~~~~~~~~ > @@ -91,4 +88,4 @@ Resource Manager to allocate resources. > GH_VM_START > ~~~~~~~~~~~ > > -This ioctl starts the virtual machine. > +This ioctl starts the VM. > > Thanks. >
Thanks for reviewing and providing all the suggestions. I've applied all of them.
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