[PATCH 7/8] arm64/kexec: Add checks for KVM and EFI

[Sergei Shtylyov]

Hello.

On 11/14/2014 4:22 AM, Geoff Levand wrote:

> Add runtime checks that fail the arm64 kexec syscall for situations that would
> result in system instability do to problems in the KVM and EFI kernel support.
> These checks should be removed when the KVM and EFI problems are fixed.

> Signed-off-by: Geoff Levand <geoff at infradead.org>
> ---
>   arch/arm64/kernel/machine_kexec.c | 22 ++++++++++++++++++++++
>   1 file changed, 22 insertions(+)

> diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c
> index 775bcc3..5b62bd1f 100644
> --- a/arch/arm64/kernel/machine_kexec.c
> +++ b/arch/arm64/kernel/machine_kexec.c
> @@ -16,6 +16,12 @@
>   #include <asm/cacheflush.h>
>   #include <asm/system_misc.h>

> +/* TODO: Remove this include when KVM can support a kexc reboot. */

    s/kexc/kexec/ here and below.

> +#include <asm/virt.h>
> +
> +/* TODO: Remove this include when EFI can support a kexc reboot. */
> +#include <linux/efi.h>
> +
>   /* Global variables for the relocate_kernel routine. */
>   extern const unsigned char relocate_new_kernel[];
>   extern const unsigned long relocate_new_kernel_size;
> @@ -101,6 +107,22 @@ int machine_kexec_prepare(struct kimage *image)
>
>   	kexec_image_info(image);
>
> +	/* TODO: Remove this message when KVM can support a kexc reboot. */
> +	if (IS_ENABLED(CONFIG_KVM) && is_hyp_mode_available()) {
> +		pr_err("%s: Your kernel is configued with KVM support "

    Configured.

> +			"(CONFIG_KVM=y) which currently does not allow for "
> +			"kexec re-boot.\n", __func__);
> +		return -ENOSYS;
> +	}
> +
> +	/* TODO: Remove this message when EFI can support a kexc reboot. */
> +	if (efi_enabled(EFI_BOOT)) {
> +		pr_err("%s: Your kernel is using the Extensible Firmware "
> +			"Interface (EFI) which currently does not allow for "
> +			"kexec re-boot.\n", __func__);
> +		return -ENOSYS;
> +	}
> +
>   	return 0;
>   }

WBR, Sergei