RE: [PATCH 2/2] x86, kexec_file_load: make it work with efi=noruntime or efi=oldmap

[Schmauss, Erik]

> -----Original Message-----
> From: Dave Young [mailto:dyoung@xxxxxxxxxx]
> Sent: Tuesday, January 15, 2019 12:42 AM
> To: Kairui Song <kasong@xxxxxxxxxx>
> Cc: linux-kernel@xxxxxxxxxxxxxxx; tglx@xxxxxxxxxxxxx;
> mingo@xxxxxxxxxx; bp@xxxxxxxxx; hpa@xxxxxxxxx; x86@xxxxxxxxxx;
> akpm@xxxxxxxxxxxxxxxxxxxx; Moore, Robert
> <robert.moore@xxxxxxxxx>; Schmauss, Erik
> <erik.schmauss@xxxxxxxxx>; Wysocki, Rafael J
> <rafael.j.wysocki@xxxxxxxxx>; lenb@xxxxxxxxxx
> 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@xxxxxxxxxx>
> > Signed-off-by: Kairui Song <kasong@xxxxxxxxxx>
> > ---
> >  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

@JK

Do you see any issues with this? Does free BSD use ACPI_INIT_FUNCTION?

> >
> 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