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SNP Guest VSM: Start VP hypercall handling #634

Merged
merged 5 commits into from
Feb 26, 2025
Merged

SNP Guest VSM: Start VP hypercall handling #634

merged 5 commits into from
Feb 26, 2025

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sluck-msft
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Start VP hypercall handling for SNP Guest VSM support.

Tested:

  • SNP + Guest VSM boots 8 VPs
  • SNP without Guest VSM boots
  • non-isolated VM still boots

@sluck-msft sluck-msft requested a review from a team as a code owner January 8, 2025 22:52
@sluck-msft sluck-msft force-pushed the gvsm/start-vp branch 2 times, most recently from 88a2f71 to b6b0a88 Compare February 25, 2025 23:06
smalis-msft
smalis-msft reviewed Feb 26, 2025
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openhcl/virt_mshv_vtl/src/lib.rs
@@ -420,6 +420,8 @@ pub struct UhCvmVpInner {
tlb_lock_info: VtlArray<TlbLockInfo, 2>,
/// Whether VTL 1 has been enabled on the vp
vtl1_enabled: Mutex<bool>,
/// Whether the VP has been started via the StartVp hypercall.
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Would it make sense for vtl1_enabled to be a ReadWriteLock instead of a Mutex? It seems like we have a lot of paths that read it, but only one that needs to write to it and have exclusive access.

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@jstarks I think in the past you've said that RwLocks don't scale to a large number of processors, so I interpreted that as be careful when using them. Do you have general guidelines for when you would choose to use or not use a RwLock? Beyond basing it off the ratio of expected readers to writers?

@sluck-msft sluck-msft enabled auto-merge (squash) February 26, 2025 23:02
@sluck-msft sluck-msft merged commit e05da3a into microsoft:main Feb 26, 2025
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@smalis-msft smalis-msft smalis-msft approved these changes

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@sluck-msft @jstarks @smalis-msft