On Fri, May 20, 2022 at 10:30:40AM +0700, Suthikulpanit, Suravee wrote: >Hi All, > >Currently, we don't have a good way to check whether APICV is active on a VM. >Normally, For AMD SVM AVIC, users either have to check for trace point, or using >"perf kvm stat live" to catch AVIC-related #VMEXIT. > >For KVM, I would like to propose introducing a new IOCTL interface (i.e. KVM_GET_APICV_INFO), >where user-space tools (e.g. QEMU monitor) can query run-time information of APICv for VM and vCPUs >such as APICv inhibit reason flags. > >For QEMU, we can leverage the "info lapic" command, and append the APICV information after >all LAPIC register information: > >For example: > >----- Begin Snippet ----- >(qemu) info lapic 0 >dumping local APIC state for CPU 0 > >LVT0 0x00010700 active-hi edge masked ExtINT (vec 0) >LVT1 0x00000400 active-hi edge NMI >LVTPC 0x00010000 active-hi edge masked Fixed (vec 0) >LVTERR 0x000000fe active-hi edge Fixed (vec 254) >LVTTHMR 0x00010000 active-hi edge masked Fixed (vec 0) >LVTT 0x000400ee active-hi edge tsc-deadline Fixed (vec 238) >Timer DCR=0x0 (divide by 2) initial_count = 0 current_count = 0 >SPIV 0x000001ff APIC enabled, focus=off, spurious vec 255 >ICR 0x000000fd physical edge de-assert no-shorthand >ICR2 0x00000005 cpu 5 (X2APIC ID) >ESR 0x00000000 >ISR (none) >IRR (none) > >APR 0x00 TPR 0x00 DFR 0x0f LDR 0x00PPR 0x00 > >APICV vm inhibit: 0x10 <-- HERE >APICV vcpu inhibit: 0 <-- HERE > >------ End Snippet ------ > >Otherwise, we can have APICv-specific info command (e.g. info apicv). I think this information can be added to kvm per-vm/vcpu debugfs. Then no qemu change is needed.
