Method state

hypervisor/src/kvm/mod.rs:2862–2955

Get the current CPU state Ordering requirements: KVM_GET_MP_STATE calls kvm_apic_accept_events(), which might modify vCPU/LAPIC state. As such, it must be done before most everything else, otherwise we cannot restore everything and expect it to work. KVM_GET_VCPU_EVENTS/KVM_SET_VCPU_EVENTS is unsafe if other vCPUs are still running. KVM_GET_LAPIC may change state of LAPIC before returning it.

(&self)

    /// let state = vcpu.state().unwrap();
    /// ```
    fn state(&self) -> cpu::Result<CpuState> {
        let cpuid = self.get_cpuid2(kvm_bindings::KVM_MAX_CPUID_ENTRIES)?;
        let mp_state = self.get_mp_state()?.into();
        let regs = self.get_regs()?;
        let sregs = self.get_sregs()?;
        let xsave = if self.xsave_size > 0 {
            self.get_xsave2()?
        } else {
            self.get_xsave()?
        };
        let xcrs = self.get_xcrs()?;
        let lapic_state = self.get_lapic()?;
        let fpu = self.get_fpu()?;
        let nested_state = self.nested_state()?;

        // Try to get all MSRs based on the list previously retrieved from KVM.
        // If the number of MSRs obtained from GET_MSRS is different from the
        // expected amount, we fallback onto a slower method by getting MSRs
        // by chunks. This is the only way to make sure we try to get as many
        // MSRs as possible, even if some MSRs are not supported.
        let mut msr_entries = self.msrs.clone();

        // Save extra MSRs if the Hyper-V synthetic interrupt controller is
        // emulated.
        let hyperv_synic = self.hyperv_synic.load(Ordering::Acquire);
        if hyperv_synic {
            let hyperv_synic_msrs = vec![
                0x40000020, 0x40000021, 0x40000080, 0x40000081, 0x40000082, 0x40000083, 0x40000084,
                0x40000090, 0x40000091, 0x40000092, 0x40000093, 0x40000094, 0x40000095, 0x40000096,
                0x40000097, 0x40000098, 0x40000099, 0x4000009a, 0x4000009b, 0x4000009c, 0x4000009d,
                0x4000009e, 0x4000009f, 0x400000b0, 0x400000b1, 0x400000b2, 0x400000b3, 0x400000b4,
                0x400000b5, 0x400000b6, 0x400000b7,
            ];
            for index in hyperv_synic_msrs {
                let msr = kvm_msr_entry {
                    index,
                    ..Default::default()
                };
                msr_entries.push(msr.into());
            }
        }

        let expected_num_msrs = msr_entries.len();
        let num_msrs = self.get_msrs(&mut msr_entries)?;
        let msrs = if num_msrs == expected_num_msrs {
            msr_entries
        } else {
            let mut faulty_msr_index = num_msrs;
            let mut msr_entries_tmp = msr_entries[..faulty_msr_index].to_vec();

            loop {
                warn!(
                    "Detected faulty MSR 0x{:x} while getting MSRs",
                    msr_entries[faulty_msr_index].index
                );

                // Skip the first bad MSR
                let start_pos = faulty_msr_index + 1;