rustup wanted features & bugfixes
#396
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ojeda
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This was referenced Jun 29, 2021
mdaverde
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Nov 7, 2021
The following issue is observed with CONFIG_DEBUG_PREEMPT when KVM loads: KVM: vmx: using Hyper-V Enlightened VMCS BUG: using smp_processor_id() in preemptible [00000000] code: systemd-udevd/488 caller is set_hv_tscchange_cb+0x16/0x80 CPU: 1 PID: 488 Comm: systemd-udevd Not tainted 5.15.0-rc5+ Rust-for-Linux#396 Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.0 12/17/2019 Call Trace: dump_stack_lvl+0x6a/0x9a check_preemption_disabled+0xde/0xe0 ? kvm_gen_update_masterclock+0xd0/0xd0 [kvm] set_hv_tscchange_cb+0x16/0x80 kvm_arch_init+0x23f/0x290 [kvm] kvm_init+0x30/0x310 [kvm] vmx_init+0xaf/0x134 [kvm_intel] ... set_hv_tscchange_cb() can get preempted in between acquiring smp_processor_id() and writing to HV_X64_MSR_REENLIGHTENMENT_CONTROL. This is not an issue by itself: HV_X64_MSR_REENLIGHTENMENT_CONTROL is a partition-wide MSR and it doesn't matter which particular CPU will be used to receive reenlightenment notifications. The only real problem can (in theory) be observed if the CPU whose id was acquired with smp_processor_id() goes offline before we manage to write to the MSR, the logic in hv_cpu_die() won't be able to reassign it correctly. Reported-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Link: https://lore.kernel.org/r/20211012155005.1613352-1-vkuznets@redhat.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
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Features that we would like to see
Required (we almost certainly want them)
Nice to have (not critical, we could workaround if needed, etc.)
Low priority (we will likely not use them in the end)
Done (stabilized, fixed, not needed anymore, etc.)
.rust-toolchain.toml.rust-toolchain.toml#953..rust-toolchain.tomlrust-lang/rustup#3182..rust-toolchain.tomlrust-lang/rustup#3195.Bugs that we would like to see fixed
Required (we almost certainly want them)
Nice to have (probably not critical, we could workaround if needed, etc.)
Low priority (we will likely not use them in the end)
Done (stabilized, fixed, or not needed anymore, etc.)
Clarify in which component and/or profile
rustdocis.rustdocis rust-lang/rustup#2801.Downloading specific betas should be easier.
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