Re: [Qemu-devel] [PATCH v2 18/18] hw/arm/virt: Add board property to enable EL2

[Edgar E. Iglesias]

On Mon, Jan 09, 2017 at 04:05:24PM +0000, Peter Maydell wrote:
> Add a board level property to the virt board which will
> enable EL2 on the CPU if the user asks for it. The
> default is not to provide EL2. If EL2 is enabled then
> we will use SMC as our PSCI conduit, and report the
> virtualization support in the GICv3 device tree node
> and the ACPI tables.
> 
> Signed-off-by: Peter Maydell <address@hidden>
> Reviewed-by: Andrew Jones <address@hidden>

Reviewed-by: Edgar E. Iglesias <address@hidden>


> ---
>  include/hw/arm/virt.h    |  1 +
>  hw/arm/virt-acpi-build.c |  3 +++
>  hw/arm/virt.c            | 44 ++++++++++++++++++++++++++++++++++++++++++--
>  3 files changed, 46 insertions(+), 2 deletions(-)
> 
> diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
> index 53507e6..58ce74e 100644
> --- a/include/hw/arm/virt.h
> +++ b/include/hw/arm/virt.h
> @@ -93,6 +93,7 @@ typedef struct {
>      FWCfgState *fw_cfg;
>      bool secure;
>      bool highmem;
> +    bool virt;
>      int32_t gic_version;
>      struct arm_boot_info bootinfo;
>      const MemMapEntry *memmap;
> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> index ec7f83b..32b660d 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -607,6 +607,9 @@ build_madt(GArray *table_data, BIOSLinker *linker, 
> VirtMachineState *vms)
>          if (arm_feature(&armcpu->env, ARM_FEATURE_PMU)) {
>              gicc->performance_interrupt = cpu_to_le32(PPI(VIRTUAL_PMU_IRQ));
>          }
> +        if (vms->virt && vms->gic_version == 3) {
> +            gicc->vgic_interrupt = cpu_to_le32(PPI(ARCH_GICV3_MAINT_IRQ));
> +        }
>      }
>  
>      if (vms->gic_version == 3) {
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index 46f19cd..709da40 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -444,6 +444,11 @@ static void fdt_add_gic_node(VirtMachineState *vms)
>                                       2, vms->memmap[VIRT_GIC_DIST].size,
>                                       2, vms->memmap[VIRT_GIC_REDIST].base,
>                                       2, vms->memmap[VIRT_GIC_REDIST].size);
> +        if (vms->virt) {
> +            qemu_fdt_setprop_cells(vms->fdt, "/intc", "interrupts",
> +                                   GIC_FDT_IRQ_TYPE_PPI, 
> ARCH_GICV3_MAINT_IRQ,
> +                                   GIC_FDT_IRQ_FLAGS_LEVEL_HI);
> +        }
>      } else {
>          /* 'cortex-a15-gic' means 'GIC v2' */
>          qemu_fdt_setprop_string(vms->fdt, "/intc", "compatible",
> @@ -1240,10 +1245,15 @@ static void machvirt_init(MachineState *machine)
>       * so it doesn't get in the way. Instead of starting secondary
>       * CPUs in PSCI powerdown state we will start them all running and
>       * let the boot ROM sort them out.
> -     * The usual case is that we do use QEMU's PSCI implementation.
> +     * The usual case is that we do use QEMU's PSCI implementation;
> +     * if the guest has EL2 then we will use SMC as the conduit,
> +     * and otherwise we will use HVC (for backwards compatibility and
> +     * because if we're using KVM then we must use HVC).
>       */
>      if (vms->secure && firmware_loaded) {
>          vms->psci_conduit = QEMU_PSCI_CONDUIT_DISABLED;
> +    } else if (vms->virt) {
> +        vms->psci_conduit = QEMU_PSCI_CONDUIT_SMC;
>      } else {
>          vms->psci_conduit = QEMU_PSCI_CONDUIT_HVC;
>      }
> @@ -1273,6 +1283,12 @@ static void machvirt_init(MachineState *machine)
>          exit(1);
>      }
>  
> +    if (vms->virt && kvm_enabled()) {
> +        error_report("mach-virt: KVM does not support providing "
> +                     "Virtualization extensions to the guest CPU");
> +        exit(1);
> +    }
> +
>      if (vms->secure) {
>          if (kvm_enabled()) {
>              error_report("mach-virt: KVM does not support Security 
> extensions");
> @@ -1329,7 +1345,7 @@ static void machvirt_init(MachineState *machine)
>              object_property_set_bool(cpuobj, false, "has_el3", NULL);
>          }
>  
> -        if (object_property_find(cpuobj, "has_el2", NULL)) {
> +        if (!vms->virt && object_property_find(cpuobj, "has_el2", NULL)) {
>              object_property_set_bool(cpuobj, false, "has_el2", NULL);
>          }
>  
> @@ -1435,6 +1451,20 @@ static void virt_set_secure(Object *obj, bool value, 
> Error **errp)
>      vms->secure = value;
>  }
>  
> +static bool virt_get_virt(Object *obj, Error **errp)
> +{
> +    VirtMachineState *vms = VIRT_MACHINE(obj);
> +
> +    return vms->virt;
> +}
> +
> +static void virt_set_virt(Object *obj, bool value, Error **errp)
> +{
> +    VirtMachineState *vms = VIRT_MACHINE(obj);
> +
> +    vms->virt = value;
> +}
> +
>  static bool virt_get_highmem(Object *obj, Error **errp)
>  {
>      VirtMachineState *vms = VIRT_MACHINE(obj);
> @@ -1522,6 +1552,16 @@ static void virt_2_9_instance_init(Object *obj)
>                                      "Security Extensions (TrustZone)",
>                                      NULL);
>  
> +    /* EL2 is also disabled by default, for similar reasons */
> +    vms->virt = false;
> +    object_property_add_bool(obj, "virtualization", virt_get_virt,
> +                             virt_set_virt, NULL);
> +    object_property_set_description(obj, "virtualization",
> +                                    "Set on/off to enable/disable emulating 
> a "
> +                                    "guest CPU which implements the ARM "
> +                                    "Virtualization Extensions",
> +                                    NULL);
> +
>      /* High memory is enabled by default */
>      vms->highmem = true;
>      object_property_add_bool(obj, "highmem", virt_get_highmem,
> -- 
> 2.7.4
>