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References: <20190109064727.27936-1-kasong@redhat.com>
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From:   Kairui Song <kasong@redhat.com>
Date:   Wed, 9 Jan 2019 14:55:49 +0800
Message-ID: <CACPcB9eaWRZ5y3xq23cOxJ0oUnVYK=7yRK7C-m1OP4YzMMbohw@mail.gmail.com>
Subject: Re: [PATCH 2/2] x86, kexec_file_load: make it work with efi=noruntime
 or efi=oldmap
To:     linux-kernel@vger.kernel.org
Cc:     tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com,
        x86@kernel.org, Dave Young <dyoung@redhat.com>,
        akpm@linux-foundation.org, robert.moore@intel.com,
        erik.schmauss@intel.com, rafael.j.wysocki@intel.com,
        lenb@kernel.org, kexec@lists.infradead.org,
        Baoquan He <bhe@redhat.com>
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CCing more people

On Wed, Jan 9, 2019 at 2:47 PM Kairui Song <kasong@redhat.com> wrote:
>
> When efi=noruntime or efi=oldmap is used, EFI services won't be available
> in the second kernel, therefore the second kernel will not be able to get
> the ACPI RSDP address from firmware by calling EFI services and won't
> boot. Previously we are expecting the user to set the acpi_rsdp=<addr>
> on kernel command line for second kernel as there was no way to pass RSDP
> address to second kernel.
>
> After commit e6e094e053af ('x86/acpi, x86/boot: Take RSDP address from
> boot params if available'), now it's possible to set a acpi_rsdp_addr
> parameter in the boot_params passed to second kernel, this commit make
> use of it, detect and set the RSDP address when it's required for second
> kernel to boot.
>
> Tested with an EFI enabled KVM VM with efi=noruntime.
>
> Suggested-by: Dave Young <dyoung@redhat.com>
> Signed-off-by: Kairui Song <kasong@redhat.com>
> ---
>  arch/x86/kernel/kexec-bzimage64.c | 21 +++++++++++++++++++++
>  drivers/acpi/acpica/tbxfroot.c    |  3 +--
>  include/acpi/acpixf.h             |  2 +-
>  3 files changed, 23 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
> index 53917a3ebf94..0a90dcbd041f 100644
> --- a/arch/x86/kernel/kexec-bzimage64.c
> +++ b/arch/x86/kernel/kexec-bzimage64.c
> @@ -20,6 +20,7 @@
>  #include <linux/mm.h>
>  #include <linux/efi.h>
>  #include <linux/verification.h>
> +#include <linux/acpi.h>
>
>  #include <asm/bootparam.h>
>  #include <asm/setup.h>
> @@ -255,8 +256,28 @@ setup_boot_parameters(struct kimage *image, struct boot_params *params,
>         /* Setup EFI state */
>         setup_efi_state(params, params_load_addr, efi_map_offset, efi_map_sz,
>                         efi_setup_data_offset);
> +
> +#ifdef CONFIG_ACPI
> +       /* Setup ACPI RSDP pointer in case EFI is not available in second kernel */
> +       if (!acpi_disabled && (!efi_enabled(EFI_RUNTIME_SERVICES) || efi_enabled(EFI_OLD_MEMMAP))) {
> +               /* Copied from acpi_os_get_root_pointer accordingly */
> +               params->acpi_rsdp_addr = boot_params.acpi_rsdp_addr;
> +               if (!params->acpi_rsdp_addr) {
> +                       if (efi_enabled(EFI_CONFIG_TABLES)) {
> +                               if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
> +                                       params->acpi_rsdp_addr = efi.acpi20;
> +                               else if (efi.acpi != EFI_INVALID_TABLE_ADDR)
> +                                       params->acpi_rsdp_addr = efi.acpi;
> +                       } else if (IS_ENABLED(CONFIG_ACPI_LEGACY_TABLES_LOOKUP)) {
> +                               acpi_find_root_pointer(&params->acpi_rsdp_addr);
> +                       }
> +               }
> +               if (!params->acpi_rsdp_addr)
> +                       pr_warn("RSDP is not available for second kernel\n");
> +       }
>  #endif
>
> +#endif
>         /* Setup EDD info */
>         memcpy(params->eddbuf, boot_params.eddbuf,
>                                 EDDMAXNR * sizeof(struct edd_info));
> diff --git a/drivers/acpi/acpica/tbxfroot.c b/drivers/acpi/acpica/tbxfroot.c
> index 483d0ce5180a..dac1e34a931c 100644
> --- a/drivers/acpi/acpica/tbxfroot.c
> +++ b/drivers/acpi/acpica/tbxfroot.c
> @@ -108,8 +108,7 @@ acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp)
>   *
>   ******************************************************************************/
>
> -acpi_status ACPI_INIT_FUNCTION
> -acpi_find_root_pointer(acpi_physical_address *table_address)
> +acpi_status acpi_find_root_pointer(acpi_physical_address *table_address)
>  {
>         u8 *table_ptr;
>         u8 *mem_rover;
> diff --git a/include/acpi/acpixf.h b/include/acpi/acpixf.h
> index 7aa38b648564..869d75ecaf7d 100644
> --- a/include/acpi/acpixf.h
> +++ b/include/acpi/acpixf.h
> @@ -474,7 +474,7 @@ ACPI_EXTERNAL_RETURN_STATUS(acpi_status ACPI_INIT_FUNCTION
>  ACPI_EXTERNAL_RETURN_STATUS(acpi_status ACPI_INIT_FUNCTION
>                             acpi_reallocate_root_table(void))
>
> -ACPI_EXTERNAL_RETURN_STATUS(acpi_status ACPI_INIT_FUNCTION
> +ACPI_EXTERNAL_RETURN_STATUS(acpi_status
>                             acpi_find_root_pointer(acpi_physical_address
>                                                    *rsdp_address))
>  ACPI_EXTERNAL_RETURN_STATUS(acpi_status
> --
> 2.20.1
>


--
Best Regards,
Kairui Song