search for: kvm_vmx_default_msr_auto_load_count

...MX_MISC is > + * n, then (n + 1) * 512 is the recommended max number of MSRs to be > + * included in the VMExit and VMEntry MSR auto switch list. > + */ > + rdmsrl(MSR_IA32_VMX_MISC, vmx_msr); > + n = ((vmx_msr & 0xe000000) >> 25) + 1; > + msr_autoload_count_max = n * KVM_VMX_DEFAULT_MSR_AUTO_LOAD_COUNT; > +} > + Any reasons to do this if it's unlikely that we'll ever update more than 512 MSRs? Paolo

...MX_MISC is > + * n, then (n + 1) * 512 is the recommended max number of MSRs to be > + * included in the VMExit and VMEntry MSR auto switch list. > + */ > + rdmsrl(MSR_IA32_VMX_MISC, vmx_msr); > + n = ((vmx_msr & 0xe000000) >> 25) + 1; > + msr_autoload_count_max = n * KVM_VMX_DEFAULT_MSR_AUTO_LOAD_COUNT; > +} > + Any reasons to do this if it's unlikely that we'll ever update more than 512 MSRs? Paolo

...100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -158,6 +158,7 @@ module_param_named(preemption_timer, enable_preemption_timer, bool, S_IRUGO); #define KVM_VMX_DEFAULT_PLE_WINDOW_SHRINK 0 #define KVM_VMX_DEFAULT_PLE_WINDOW_MAX \ INT_MAX / KVM_VMX_DEFAULT_PLE_WINDOW_GROW +#define KVM_VMX_DEFAULT_MSR_AUTO_LOAD_COUNT 512 static int ple_gap = KVM_VMX_DEFAULT_PLE_GAP; module_param(ple_gap, int, S_IRUGO); @@ -178,9 +179,10 @@ static int ple_window_actual_max = KVM_VMX_DEFAULT_PLE_WINDOW_MAX; static int ple_window_max = KVM_VMX_DEFAULT_PLE_WINDOW_MAX; module_param(ple_window_max, int, S_IRUGO); +stat...

This patch series enables the Last Branch Recording feature for the guest. Instead of trapping each LBR stack MSR access, the MSRs are passthroughed to the guest. Those MSRs are switched (i.e. load and saved) on VMExit and VMEntry. Test: Try "perf record -b ./test_program" on guest. Wei Wang (4): KVM/vmx: re-write the msr auto switch feature KVM/vmx: auto switch

This patch series enables the Last Branch Recording feature for the guest. Instead of trapping each LBR stack MSR access, the MSRs are passthroughed to the guest. Those MSRs are switched (i.e. load and saved) on VMExit and VMEntry. Test: Try "perf record -b ./test_program" on guest. Wei Wang (4): KVM/vmx: re-write the msr auto switch feature KVM/vmx: auto switch

...n, then (n + 1) * 512 is the recommended max number of MSRs to be >> + * included in the VMExit and VMEntry MSR auto switch list. >> + */ >> + rdmsrl(MSR_IA32_VMX_MISC, vmx_msr); >> + n = ((vmx_msr & 0xe000000) >> 25) + 1; >> + msr_autoload_count_max = n * KVM_VMX_DEFAULT_MSR_AUTO_LOAD_COUNT; >> +} >> + > > Any reasons to do this if it's unlikely that we'll ever update more than > 512 MSRs? > > Paolo It isn't a must to allocate memory for 512 MSRs, but I think it would be good to allocate memory at least for 128 MSRs, because on skylake we have...