Messages in this thread | | | Date | Wed, 16 Jan 2019 11:32:43 +0800 | From | Dave Young <> | Subject | Re: [PATCH v2 2/2] x86, kexec_file_load: make it work with efi=noruntime or efi=old_map |
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On 01/16/19 at 12:10am, Borislav Petkov wrote: > On Tue, Jan 15, 2019 at 05:58:34PM +0800, 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 an 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(¶ms->acpi_rsdp_addr); > > + } > > + } > > + if (!params->acpi_rsdp_addr) > > + pr_warn("RSDP is not available for second kernel\n"); > > + } > > #endif > > Amazing the amount of ACPI RDSP parsing and fiddling patches flying > around these days... > > In any case, this needs to be synchronized with: > > https://lkml.kernel.org/r/20190107032243.25324-1-fanc.fnst@cn.fujitsu.com > > and checked whether the above can be used instead of sprinkling of ACPI > parsing code left and right.
Both Baoquan and Chao are cced for comments. The above KASLR patches seems some early code to parsing acpi, but I think in this patch just call acpi function to get the root pointer no need to add the duplicate logic of if/else/else if.
Kairui, do you have any reason for the checking? Is there some simple acpi function to just return the root pointer?
> > Thx. > > -- > Regards/Gruss, > Boris. > > Good mailing practices for 400: avoid top-posting and trim the reply.
Thanks Dave
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