CPU profiles cpuid (3/3) : CPU profile generation tool #56
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Since enabling AMX tile state components affect the result returned by `Hypervisor::get_supported_cpuid` we want this enabled prior to checking CPUID compatibility between the source and destination VMs. Although this is not required today, it is necessary in order for the upcoming CPU profiles correctly, and it will also be necessary once the check_cpuid_compatibility checks are extended to take state components into account. Signed-off-by: Oliver Anderson <oliver.anderson@cyberus-technology.de> On-behalf-of: SAP oliver.anderson@sap.com
Temporary workaround until we switch over to the WIP fix upstream Signed-off-by: Oliver Anderson <oliver.anderson@cyberus-technology.de> On-behalf-of: SAP oliver.anderson@sap.com
These data structures are required to define CPU profiles. Signed-off-by: Oliver Anderson <oliver.anderson@cyberus-technology.de> On-behalf-of: SAP oliver.anderson@sap.com
We want CPU profiles to keep a record of the hypervisor type and cpu vendor that they are intended to work with. This is made more convenient if all of these types implement common traits (used for serialization). Signed-Off-by: Oliver Anderson <oliver.anderson@cyberus-technology.de> On-behalf-of: SAP oliver.anderson@sap.com
We introduce essential data structures together with basic functionality that is necessary to apply a CPU profile to a host. Signed-off-by: Oliver Anderson <oliver.anderson@cyberus-technology.de> On-behalf-of: SAP oliver.anderson@sap.com
We integrate the CPU profile into the various configs that ultimately get set by the user. This quickly ends up involving multiple files, luckily Rust helps us find which ones via compilation errors. Signed-Off-by: Oliver Anderson <oliver.anderson@cyberus-technology.de> On-behalf-of: SAP oliver.anderson@sap.com
olivereanderson
force-pushed
the
cpu-profiles-cpuid-3
branch
3 times, most recently
from
469be95 to
acd9a0c
Compare
If a CPU profile is configured it should result in guests seeing a restricted subset of CPUID. This is what we finally achieve in this commit. Signed-off-by: Oliver Anderson <oliver.anderson@cyberus-technology.de> On-behalf-of: SAP oliver.anderson@sap.com
We include CPU profiles corresponding to Intel Skylake and Sapphire rapids server that we generated using our WIP CPU profile generation tool. Signed-of-by: Oliver Anderson <oliver.anderson@cyberus-technology.de> On-behalf-of: SAP oliver.anderson@sap.com
We introduce data structures to describe values within the registers modified by the CPUID instruction. These data structures will later be used by the upcoming CPU profile generation tool. Signed-off-by: Oliver Anderson <oliver.anderson@cyberus-technology.de> On-behalf-of: SAP oliver.anderson@sap.com
We introduce CPUID definitions for Intel CPUs that will be utilized by the upcoming CPU Profile generation tool. Signed-off-by: Oliver Anderson <oliver.anderson@cyberus-technology.de> On-behalf-of: SAP oliver.anderson@sap.com
We introduce CPUID definitions defined for the KVM hypervisor. These definitions will later be utilized by the upcoming CPU profile generation tool. Signed-off-by: Oliver Anderson <oliver.anderson@cyberus-technology.de> On-behalf-of: SAP oliver.anderson@sap.com
We use the Intel CPUID definitions to provide more information when CPUID compatibility checks fail (when both the source and destination VM run on Intel CPUs). Signed-off-by: Oliver Anderson <oliver.anderson@cyberus-technology.de> On-behalf-of: SAP oliver.anderson@sap.com
Currently when the user configures AMX the corresponding state components get dynamically enabled directly inside the function body of vmm::cpu::CpuManager::new. With our ongoing work on CPU templates/profiles, there will (likely) be one more binary crate for producing CPU profiles that also needs to do this (without creating a CpuManager) and it may also be the case that we will need to call this function prior to `CpuManager::new` during live migrations. We thus add a method for enabling the AMX tile state components on the hypervisor trait that may be called wherever necessary. We argue that this is beneficial for code clarity independently of the upcoming CPU templates/profiles PR that we are working on. The astute reader will notice that the logic introduced here is not 100% the same as what is done inside the vmm::cpu::Cpumanager::new method. We claim that our approach is more in-line with the official documentation. Signed-off-by: Oliver Anderson <oliver.anderson@cyberus-technology.de> On-behalf-of: SAP oliver.anderson@sap.com
This commit introduces a CLI for generating a CPU profile closely matching the CPU of the machine the CLI is executed on. The idea is to have a simple way to add more CPU profiles corresponding to physical CPUs. Note however that with the current setup one still needs a little bit of manual work to integrate the generated CPU profile data into cloud hypervisor itself. Signed-off-by: Oliver Anderson <oliver.anderson@cyberus-technology.de> On-behalf-of: SAP oliver.anderson@sap.com
olivereanderson
force-pushed
the
cpu-profiles-cpuid-3
branch
from
acd9a0c to
73bf8f9
Compare
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This PR adds the CPU profile generation CLI tool.
It may not be merged before #51
How to generate a CPU profile
New CPU profiles can be generated in a semi automated fashion. All you need to do is to run the newly introduced binary
cargo run --release -p arch --bin generate-cpu-profile --features="cpu_profile_generation" "" > ./arch/src/x86_64/cpu_profiles/my_profile.json
on the host you are interested in being compatible with (the compatibility target) and then you need to manually edit the arch::x86_64::cpu_profile::CpuProfile enum by adding another variant and updating the data method to deserialize the pre-generated json.
The resulting CPU profile should expose a lot of the same functionality as the host where it was generated, but we apply a few extra restrictions to functionality that is either inherently incompatible with live migration, or should not be used in a cloud setting for other reasons. There is currently no way for users to opt-out of these extra restrictions neither during profile generation, nor later when the profile is loaded on a new host.
Note that we also currently only support Intel CPUs and KVM as the hypervisor, but a lot of the logic is agnostic of these things and it should be relatively easy to lift these limitations.