linux-kernel - Re: [PATCH 2/2] x86, kexec_file_load: make it work with efi=noruntime or efi=oldmap

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Message-ID: <20190115084213.GA6468@dhcp-128-65.nay.redhat.com>
Date:   Tue, 15 Jan 2019 16:42:13 +0800
From:   Dave Young <dyoung@...hat.com>
To:     Kairui Song <kasong@...hat.com>
Cc:     linux-kernel@...r.kernel.org, tglx@...utronix.de, mingo@...hat.com,
        bp@...en8.de, hpa@...or.com, x86@...nel.org,
        akpm@...ux-foundation.org, robert.moore@...el.com,
        erik.schmauss@...el.com, rafael.j.wysocki@...el.com,
        lenb@...nel.org
Subject: Re: [PATCH 2/2] x86, kexec_file_load: make it work with
 efi=noruntime or efi=oldmap

On 01/09/19 at 02:47pm, Kairui Song 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@...hat.com>
> Signed-off-by: Kairui Song <kasong@...hat.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
> 

Kairui, thanks for the patches, did a test, it works for me.

Seems the two patches are not in a thread, can you resend them together?

Dave