On 10/22/2024 2:06 AM, Chao Gao wrote:
@@ -1503,6 +1503,18 @@ void vmx_vcpu_load_vmcs(struct kvm_vcpu *vcpu, int cpu, (unsigned long)(cpu_entry_stack(cpu) + 1)); } + /* Per-CPU FRED MSRs */ + if (kvm_cpu_cap_has(X86_FEATURE_FRED)) { +#ifdef CONFIG_X86_64 + vmcs_write64(HOST_IA32_FRED_RSP1, __this_cpu_ist_top_va(DB)); + vmcs_write64(HOST_IA32_FRED_RSP2, __this_cpu_ist_top_va(NMI)); + vmcs_write64(HOST_IA32_FRED_RSP3, __this_cpu_ist_top_va(DF)); +#endif + vmcs_write64(HOST_IA32_FRED_SSP1, 0); + vmcs_write64(HOST_IA32_FRED_SSP2, 0); + vmcs_write64(HOST_IA32_FRED_SSP3, 0);Given SSP[1-3] are constant for now, how about asserting that host SSP[1-3] are all zeros when KVM is loaded and moving their writes to vmx_set_constant_host_state()?
I like the idea :)
