Re: [Qemu-devel] [RFC PATCH V4 4/6] hw/arm/virt: Use PSCI v0.2 compatible when kernel supports it

[Rob Herring]

On Mon, May 5, 2014 at 3:57 AM, Pranavkumar Sawargaonkar
<address@hidden> wrote:
> If we have in-kernel emulation of PSCI v0.2 for KVM ARM/ARM64 then
> we enable PSCI v0.2 for each VCPU at the time of VCPU init hence we
> need to provide PSCI v0.2 compatible string via generated DTB.
>
> This patch updates generated DTB to have PSCI v0.2 compatible string
> when we have in-kernel emulation PSCI v0.2 for KVM ARM/ARM64.
>
> Signed-off-by: Pranavkumar Sawargaonkar <address@hidden>
> Signed-off-by: Anup Patel <address@hidden>
> ---
>  hw/arm/virt.c |   16 ++++++++++------
>  1 file changed, 10 insertions(+), 6 deletions(-)

This does not compile for me:

  CC    aarch64-softmmu/hw/arm/virt.o
hw/arm/virt.c: In function ‘create_fdt’:
hw/arm/virt.c:186:44: error: ‘KVM_CAP_ARM_PSCI_0_2’ undeclared (first
use in this function)
         if (kvm_check_extension(kvm_state, KVM_CAP_ARM_PSCI_0_2)) {
                                            ^

>
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index 2bbc931..e4ae8ba 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -185,13 +185,17 @@ static void create_fdt(VirtBoardInfo *vbi)
>      /* No PSCI for TCG yet */
>      if (kvm_enabled()) {
>          qemu_fdt_add_subnode(fdt, "/psci");
> -        qemu_fdt_setprop_string(fdt, "/psci", "compatible", "arm,psci");
> -        qemu_fdt_setprop_string(fdt, "/psci", "method", "hvc");
> -        qemu_fdt_setprop_cell(fdt, "/psci", "cpu_suspend",
> +        if (kvm_check_extension(kvm_state, KVM_CAP_ARM_PSCI_0_2)) {
> +            qemu_fdt_setprop_string(fdt, "/psci", "compatible", 
> "arm,psci-0.2");
> +        } else {
> +            qemu_fdt_setprop_string(fdt, "/psci", "compatible", "arm,psci");

As I mentioned in the last version, this is wrong. You may have an old
guest kernel that only supports PSCI 0.1. You need to support either
PSCI 0.1 only OR both PSCI 0.2 and 0.1.

Rob

> +            qemu_fdt_setprop_cell(fdt, "/psci", "cpu_suspend",
>                                    PSCI_FN_CPU_SUSPEND);
> -        qemu_fdt_setprop_cell(fdt, "/psci", "cpu_off", PSCI_FN_CPU_OFF);
> -        qemu_fdt_setprop_cell(fdt, "/psci", "cpu_on", PSCI_FN_CPU_ON);
> -        qemu_fdt_setprop_cell(fdt, "/psci", "migrate", PSCI_FN_MIGRATE);
> +            qemu_fdt_setprop_cell(fdt, "/psci", "cpu_off", PSCI_FN_CPU_OFF);
> +            qemu_fdt_setprop_cell(fdt, "/psci", "cpu_on", PSCI_FN_CPU_ON);
> +            qemu_fdt_setprop_cell(fdt, "/psci", "migrate", PSCI_FN_MIGRATE);
> +        }
> +        qemu_fdt_setprop_string(fdt, "/psci", "method", "hvc");
>      }
>  }
>
> --
> 1.7.9.5
>