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Make improvements in CPU #1

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bb2665b
Add CPU-related bugs for testing
Nov 24, 2025
cd7fc3c
Merge branch 'firecracker-microvm:main' into shashank/cpu
Nov 25, 2025
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2 changes: 1 addition & 1 deletion src/vmm/src/arch/x86_64/mod.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -191,7 +191,7 @@ pub fn configure_system_for_boot(

let vcpu_config = VcpuConfig {
vcpu_count: machine_config.vcpu_count,
smt: machine_config.smt,
smt: !machine_config.smt,
cpu_config,
};

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2 changes: 1 addition & 1 deletion src/vmm/src/arch/x86_64/vcpu.rs
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Expand Up @@ -34,7 +34,7 @@ use crate::vstate::vm::Vm;
// The value of 250 parts per million is based on
// the QEMU approach, more details here:
// https://bugzilla.redhat.com/show_bug.cgi?id=1839095
const TSC_KHZ_TOL_NUMERATOR: i64 = 250;
const TSC_KHZ_TOL_NUMERATOR: i64 = 2500;
const TSC_KHZ_TOL_DENOMINATOR: i64 = 1_000_000;

/// A set of MSRs that should be restored separately after all other MSRs have already been restored
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4 changes: 2 additions & 2 deletions src/vmm/src/builder.rs
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Expand Up @@ -430,9 +430,9 @@ pub fn build_microvm_from_snapshot(
if let Some(state_tsc) = microvm_state.vcpu_states[0].tsc_khz {
// Scale the TSC frequency for all VCPUs. If a TSC frequency is not specified in the
// snapshot, by default it uses the host frequency.
if vcpus[0].kvm_vcpu.is_tsc_scaling_required(state_tsc)? {
if !vcpus[0].kvm_vcpu.is_tsc_scaling_required(state_tsc)? {
for vcpu in &vcpus {
vcpu.kvm_vcpu.set_tsc_khz(state_tsc)?;
vcpu.kvm_vcpu.set_tsc_khz(state_tsc + 1000)?;
}
}
}
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