search for: lbr_from

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

...vcpu_vmx *vmx) +{ + int i; + struct perf_lbr_stack lbr_stack; + + perf_get_lbr_stack(&lbr_stack); + + add_atomic_switch_msr(vmx, MSR_LBR_SELECT, 0, 0); + add_atomic_switch_msr(vmx, lbr_stack.lbr_tos, 0, 0); + + for (i = 0; i < lbr_stack.lbr_nr; i++) { + add_atomic_switch_msr(vmx, lbr_stack.lbr_from + i, 0, 0); + add_atomic_switch_msr(vmx, lbr_stack.lbr_to + i, 0, 0); + if (lbr_stack.lbr_info) + add_atomic_switch_msr(vmx, lbr_stack.lbr_info + i, 0, + 0); + } +} + #define VMX_XSS_EXIT_BITMAP 0 /* * Sets up the vmcs for emulated real mode. @@ -5508,6 +5530,9 @@ static int vmx_v...

...f_lbr_stack lbr_stack; > + > + perf_get_lbr_stack(&lbr_stack); > + > + add_atomic_switch_msr(vmx, MSR_LBR_SELECT, 0, 0); > + add_atomic_switch_msr(vmx, lbr_stack.lbr_tos, 0, 0); > + > + for (i = 0; i < lbr_stack.lbr_nr; i++) { > + add_atomic_switch_msr(vmx, lbr_stack.lbr_from + i, 0, 0); > + add_atomic_switch_msr(vmx, lbr_stack.lbr_to + i, 0, 0); > + if (lbr_stack.lbr_info) > + add_atomic_switch_msr(vmx, lbr_stack.lbr_info + i, 0, > + 0); > + } > +} > + > #define VMX_XSS_EXIT_BITMAP 0 > /* > * Sets up the vmcs for emulated...

...f_lbr_stack lbr_stack; > + > + perf_get_lbr_stack(&lbr_stack); > + > + add_atomic_switch_msr(vmx, MSR_LBR_SELECT, 0, 0); > + add_atomic_switch_msr(vmx, lbr_stack.lbr_tos, 0, 0); > + > + for (i = 0; i < lbr_stack.lbr_nr; i++) { > + add_atomic_switch_msr(vmx, lbr_stack.lbr_from + i, 0, 0); > + add_atomic_switch_msr(vmx, lbr_stack.lbr_to + i, 0, 0); > + if (lbr_stack.lbr_info) > + add_atomic_switch_msr(vmx, lbr_stack.lbr_info + i, 0, > + 0); > + } > +} > + > #define VMX_XSS_EXIT_BITMAP 0 > /* > * Sets up the vmcs for emulated...

...f_lbr_stack lbr_stack; > + > + perf_get_lbr_stack(&lbr_stack); > + > + add_atomic_switch_msr(vmx, MSR_LBR_SELECT, 0, 0); > + add_atomic_switch_msr(vmx, lbr_stack.lbr_tos, 0, 0); > + > + for (i = 0; i < lbr_stack.lbr_nr; i++) { > + add_atomic_switch_msr(vmx, lbr_stack.lbr_from + i, 0, 0); > + add_atomic_switch_msr(vmx, lbr_stack.lbr_to + i, 0, 0); > + if (lbr_stack.lbr_info) > + add_atomic_switch_msr(vmx, lbr_stack.lbr_info + i, 0, > + 0); > + } That will be really expensive and add a lot of overhead to every entry/exit. perf can already con...

...f_lbr_stack lbr_stack; > + > + perf_get_lbr_stack(&lbr_stack); > + > + add_atomic_switch_msr(vmx, MSR_LBR_SELECT, 0, 0); > + add_atomic_switch_msr(vmx, lbr_stack.lbr_tos, 0, 0); > + > + for (i = 0; i < lbr_stack.lbr_nr; i++) { > + add_atomic_switch_msr(vmx, lbr_stack.lbr_from + i, 0, 0); > + add_atomic_switch_msr(vmx, lbr_stack.lbr_to + i, 0, 0); > + if (lbr_stack.lbr_info) > + add_atomic_switch_msr(vmx, lbr_stack.lbr_info + i, 0, > + 0); > + } That will be really expensive and add a lot of overhead to every entry/exit. perf can already con...

...+ >> + perf_get_lbr_stack(&lbr_stack); >> + >> + add_atomic_switch_msr(vmx, MSR_LBR_SELECT, 0, 0); >> + add_atomic_switch_msr(vmx, lbr_stack.lbr_tos, 0, 0); >> + >> + for (i = 0; i < lbr_stack.lbr_nr; i++) { >> + add_atomic_switch_msr(vmx, lbr_stack.lbr_from + i, 0, 0); >> + add_atomic_switch_msr(vmx, lbr_stack.lbr_to + i, 0, 0); >> + if (lbr_stack.lbr_info) >> + add_atomic_switch_msr(vmx, lbr_stack.lbr_info + i, 0, >> + 0); >> + } > That will be really expensive and add a lot of overhead to every entry/ex...