openhcl: support save restore of partition topology from usermode to next openhcl_boot #2030
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| pub struct PersistedStateHeader { | ||
| /// A magic value. If this is not set to [`PersistedStateHeader::MAGIC`], | ||
| /// then the previous instance did not support this region. | ||
| pub magic: u64, | ||
| /// The gpa for the start of the protobuf region. This must be 4K aligned. | ||
| pub protobuf_base: u64, | ||
| /// The size of the protobuf region in bytes. | ||
| pub protobuf_region_len: u64, | ||
| /// The size of the protobuf payload in bytes. | ||
| /// This must be less than or equal to `protobuf_region_len`. | ||
| pub protobuf_payload_len: u64, | ||
| } | ||
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| impl PersistedStateHeader { | ||
| /// "OHCLPHDR" in ASCII. | ||
| pub const MAGIC: u64 = 0x4F48434C50484452; | ||
| } | ||
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| /// A local newtype wrapper that represents a [`igvm_defs::MemoryMapEntryType`]. | ||
| /// | ||
| /// This is required to make it protobuf deriveable. | ||
| #[derive(mesh_protobuf::Protobuf, Clone, Debug, PartialEq)] | ||
| #[mesh(package = "openhcl.openhcl_boot")] | ||
| pub struct IgvmMemoryType(#[mesh(1)] u16); | ||
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| impl From<igvm_defs::MemoryMapEntryType> for IgvmMemoryType { | ||
| fn from(igvm_type: igvm_defs::MemoryMapEntryType) -> Self { | ||
| Self(igvm_type.0) | ||
| } | ||
| } | ||
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| impl From<IgvmMemoryType> for igvm_defs::MemoryMapEntryType { | ||
| fn from(igvm_type: IgvmMemoryType) -> Self { | ||
| igvm_defs::MemoryMapEntryType(igvm_type.0) | ||
| } | ||
| } | ||
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| #[derive(mesh_protobuf::Protobuf, Debug)] | ||
| #[mesh(package = "openhcl.openhcl_boot")] | ||
| pub struct MemoryEntry { | ||
| #[mesh(1)] | ||
| pub range: MemoryRange, | ||
| #[mesh(2)] | ||
| pub vnode: u32, | ||
| #[mesh(3)] | ||
| pub vtl_type: MemoryVtlType, | ||
| #[mesh(4)] | ||
| pub igvm_type: IgvmMemoryType, | ||
| } | ||
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| #[derive(mesh_protobuf::Protobuf, Debug)] | ||
| #[mesh(package = "openhcl.openhcl_boot")] | ||
| pub struct MmioEntry { | ||
| #[mesh(1)] | ||
| pub range: MemoryRange, | ||
| #[mesh(2)] | ||
| pub vtl_type: MemoryVtlType, | ||
| } | ||
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| /// The format for saved state between the previous instance of OpenHCL and the | ||
| /// next. | ||
| #[derive(mesh_protobuf::Protobuf, Debug)] | ||
| #[mesh(package = "openhcl.openhcl_boot")] | ||
| pub struct SavedState { | ||
| #[mesh(1)] | ||
| pub partition_memory: Vec<MemoryEntry>, | ||
| #[mesh(2)] | ||
| pub partition_mmio: Vec<MmioEntry>, | ||
| } |
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Pull Request Overview
This PR adds support for saving and restoring partition topology information from a previous OpenHCL instance to the next openhcl_boot. The implementation reserves the first page in the VTL2 region as a persisted header, followed by a protobuf encoded payload containing the previous instance's topology information.
Key changes include:
- Introduction of persisted state region management in the bootloader
- New protobuf-based serialization for topology data
- Enhanced memory layout to support persisted state across boots
- Integration of saved state reading during boot process
Reviewed Changes
Copilot reviewed 11 out of 12 changed files in this pull request and generated 2 comments.
Show a summary per file
| File | Description |
|---|---|
| vm/loader/src/paravisor.rs | Reserves 2MB persisted state region in memory layout for both x86 and ARM64 |
| vm/loader/loader_defs/src/shim.rs | Defines persisted state structures, protobuf messages, and memory type enums |
| vm/loader/loader_defs/Cargo.toml | Adds mesh_protobuf and memory_range dependencies |
| openhcl/underhill_core/src/loader/vtl2_config/mod.rs | Implements persisted state writing functionality |
| openhcl/underhill_core/Cargo.toml | Adds mesh_protobuf dependency |
| openhcl/openhcl_boot/src/memory.rs | Updates address space manager to handle persisted state regions |
| openhcl/openhcl_boot/src/main.rs | Updates E820 entry generation and test cases for persisted state |
| openhcl/openhcl_boot/src/host_params/shim_params.rs | Adds persisted state region to ShimParams structure |
| openhcl/openhcl_boot/src/host_params/dt/mod.rs | Major refactoring to support topology from persisted state vs host DT |
| openhcl/openhcl_boot/Cargo.toml | Adds mesh_protobuf dependency |
| openhcl/bootloader_fdt_parser/src/lib.rs | Updates FDT parser to handle persisted state regions |
Comments suppressed due to low confidence (1)
openhcl/openhcl_boot/src/host_params/dt/mod.rs:1
- Using
format!in error contexts can be inefficient. Consider using a closure withwith_contextto avoid string formatting unless the error actually occurs:.with_context(|| format!(\"{} missing numa-node-id\", node.name))?
// Copyright (c) Microsoft Corporation.
|
attempt fixing #1345, since i think this PR should fix it? |
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| ); | ||
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| let ranges = [parsed.vtl2_persisted_header]; | ||
| let mapping = |
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nit: inline the two 'ranges' vars and rename the two 'mapping' vars to different names to make it clearer what gets written where.
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|
Paging the memory validation test maintainer, please hold |
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Support save and restore of topology information from a previous instance of OpenHCL to the next
openhcl_boot. This allows supporting correctly persisting any private pool allocated from the address space to the next instance, without relying on the allocation logic being exactly the same.This is done via reserving the first page in the VTL2 region as a persisted header, followed by a protobuf encoded payload containing the previous instance's topology. In the future, we could choose to put more saved state into this region, such as the whole usermode protobuf payload that today goes to the host, via the GET.