KVM adjusts the MPIDR of guest vcpus based on the architecture of the host, 32-bit vs. 64-bit, and, for 64-bit, also on the type of GIC the guest is using. To be consistent and improve SGI efficiency we make the same adjustments for TCG as 64-bit KVM hosts. We neglect to add consistency with 32-bit KVM hosts, as that would reduce SGI efficiency and KVM is expected to change.
As MPIDR is a system register, and thus guest visible, we only make adjustments for current and later versioned machines. Signed-off-by: Andrew Jones <drjo...@redhat.com> --- hw/arm/virt.c | 26 +++++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-) diff --git a/hw/arm/virt.c b/hw/arm/virt.c index c5c125e9204a0..fb0265e31703a 100644 --- a/hw/arm/virt.c +++ b/hw/arm/virt.c @@ -52,7 +52,8 @@ #include "hw/arm/sysbus-fdt.h" #include "hw/platform-bus.h" #include "hw/arm/fdt.h" -#include "hw/intc/arm_gic_common.h" +#include "hw/intc/arm_gic.h" +#include "hw/intc/arm_gicv3_common.h" #include "kvm_arm.h" #include "hw/smbios/smbios.h" #include "qapi/visitor.h" @@ -82,6 +83,7 @@ typedef struct VirtBoardInfo { typedef struct { MachineClass parent; VirtBoardInfo *daughterboard; + bool disallow_affinity_adjustment; } VirtMachineClass; typedef struct { @@ -1164,6 +1166,7 @@ void virt_guest_info_machine_done(Notifier *notifier, void *data) static void machvirt_init(MachineState *machine) { VirtMachineState *vms = VIRT_MACHINE(machine); + VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(machine); qemu_irq pic[NUM_IRQS]; MemoryRegion *sysmem = get_system_memory(); MemoryRegion *secure_sysmem = NULL; @@ -1176,6 +1179,7 @@ static void machvirt_init(MachineState *machine) VirtGuestInfo *guest_info = &guest_info_state->info; char **cpustr; bool firmware_loaded = bios_name || drive_get(IF_PFLASH, 0, 0); + uint8_t clustersz; if (!cpu_model) { cpu_model = "cortex-a15"; @@ -1221,8 +1225,10 @@ static void machvirt_init(MachineState *machine) */ if (gic_version == 3) { virt_max_cpus = vbi->memmap[VIRT_GIC_REDIST].size / 0x20000; + clustersz = GICV3_TARGETLIST_BITS; } else { virt_max_cpus = GIC_NCPU; + clustersz = GIC_TARGETLIST_BITS; } if (max_cpus > virt_max_cpus) { @@ -1271,6 +1277,21 @@ static void machvirt_init(MachineState *machine) } cpuobj = object_new(object_class_get_name(oc)); + if (!vmc->disallow_affinity_adjustment) { + /* Adjust MPIDR like 64-bit KVM hosts, which incorporate the + * GIC's target-list limitations. 32-bit KVM hosts currently + * always create clusters of 4 CPUs, but that is expected to + * change when they gain support for gicv3. When KVM is enabled + * it will override the changes we make here, therefore our + * purposes are to make TCG consistent (with 64-bit KVM hosts) + * and to improve SGI efficiency. + */ + uint8_t aff1 = n / clustersz; + uint8_t aff0 = n % clustersz; + object_property_set_int(cpuobj, (aff1 << ARM_AFF1_SHIFT) | aff0, + "mp-affinity", NULL); + } + /* Handle any CPU options specified by the user */ cc->parse_features(CPU(cpuobj), cpuopts, &err); g_free(cpuopts); @@ -1505,7 +1526,10 @@ static void virt_2_6_instance_init(Object *obj) static void virt_machine_2_6_options(MachineClass *mc) { + VirtMachineClass *vmc = VIRT_MACHINE_CLASS(OBJECT_CLASS(mc)); + virt_machine_2_7_options(mc); SET_MACHINE_COMPAT(mc, VIRT_COMPAT_2_6); + vmc->disallow_affinity_adjustment = true; } DEFINE_VIRT_MACHINE(2, 6) -- 2.7.4