| Message ID | 20211210154332.11526-25-brijesh.singh@amd.com |
|---|---|
| State | New |
| Headers | show |
| Series | Add AMD Secure Nested Paging (SEV-SNP) Guest Support | expand |
On 2021-12-10 09:43:16 -0600, Brijesh Singh wrote: > From: Michael Roth <michael.roth@amd.com> > > Future patches for SEV-SNP-validated CPUID will also require early > parsing of the EFI configuration. Incrementally move the related code > into a set of helpers that can be re-used for that purpose. > > Signed-off-by: Michael Roth <michael.roth@amd.com> > Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Reviewed-by: Venu Busireddy <venu.busireddy@oracle.com> > --- > arch/x86/boot/compressed/Makefile | 1 + > arch/x86/boot/compressed/acpi.c | 60 ++++++++++---------------- > arch/x86/boot/compressed/efi.c | 72 +++++++++++++++++++++++++++++++ > arch/x86/boot/compressed/misc.h | 14 ++++++ > 4 files changed, 109 insertions(+), 38 deletions(-) > create mode 100644 arch/x86/boot/compressed/efi.c > > diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile > index 431bf7f846c3..d364192c2367 100644 > --- a/arch/x86/boot/compressed/Makefile > +++ b/arch/x86/boot/compressed/Makefile > @@ -100,6 +100,7 @@ endif > vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o > > vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o > +vmlinux-objs-$(CONFIG_EFI) += $(obj)/efi.o > efi-obj-$(CONFIG_EFI_STUB) = $(objtree)/drivers/firmware/efi/libstub/lib.a > > $(obj)/vmlinux: $(vmlinux-objs-y) $(efi-obj-y) FORCE > diff --git a/arch/x86/boot/compressed/acpi.c b/arch/x86/boot/compressed/acpi.c > index 8bcbcee54aa1..9e784bd7b2e6 100644 > --- a/arch/x86/boot/compressed/acpi.c > +++ b/arch/x86/boot/compressed/acpi.c > @@ -86,8 +86,8 @@ static acpi_physical_address kexec_get_rsdp_addr(void) > { > efi_system_table_64_t *systab; > struct efi_setup_data *esd; > - struct efi_info *ei; > - char *sig; > + bool efi_64; > + int ret; > > esd = (struct efi_setup_data *)get_kexec_setup_data_addr(); > if (!esd) > @@ -98,18 +98,16 @@ static acpi_physical_address kexec_get_rsdp_addr(void) > return 0; > } > > - ei = &boot_params->efi_info; > - sig = (char *)&ei->efi_loader_signature; > - if (strncmp(sig, EFI64_LOADER_SIGNATURE, 4)) { > + /* Get systab from boot params. */ > + ret = efi_get_system_table(boot_params, (unsigned long *)&systab, &efi_64); > + if (ret) > + error("EFI system table not found in kexec boot_params."); > + > + if (!efi_64) { > debug_putstr("Wrong kexec EFI loader signature.\n"); > return 0; > } > > - /* Get systab from boot params. */ > - systab = (efi_system_table_64_t *) (ei->efi_systab | ((__u64)ei->efi_systab_hi << 32)); > - if (!systab) > - error("EFI system table not found in kexec boot_params."); > - > return __efi_get_rsdp_addr((unsigned long)esd->tables, systab->nr_tables, true); > } > #else > @@ -119,45 +117,31 @@ static acpi_physical_address kexec_get_rsdp_addr(void) { return 0; } > static acpi_physical_address efi_get_rsdp_addr(void) > { > #ifdef CONFIG_EFI > - unsigned long systab, config_tables; > + unsigned long systab_tbl_pa, config_tables; > unsigned int nr_tables; > - struct efi_info *ei; > bool efi_64; > - char *sig; > - > - ei = &boot_params->efi_info; > - sig = (char *)&ei->efi_loader_signature; > - > - if (!strncmp(sig, EFI64_LOADER_SIGNATURE, 4)) { > - efi_64 = true; > - } else if (!strncmp(sig, EFI32_LOADER_SIGNATURE, 4)) { > - efi_64 = false; > - } else { > - debug_putstr("Wrong EFI loader signature.\n"); > - return 0; > - } > + int ret; > > - /* Get systab from boot params. */ > -#ifdef CONFIG_X86_64 > - systab = ei->efi_systab | ((__u64)ei->efi_systab_hi << 32); > -#else > - if (ei->efi_systab_hi || ei->efi_memmap_hi) { > - debug_putstr("Error getting RSDP address: EFI system table located above 4GB.\n"); > + /* > + * This function is called even for non-EFI BIOSes, and callers expect > + * failure to locate the EFI system table to result in 0 being returned > + * as indication that EFI is not available, rather than outright > + * failure/abort. > + */ > + ret = efi_get_system_table(boot_params, &systab_tbl_pa, &efi_64); > + if (ret == -EOPNOTSUPP) > return 0; > - } > - systab = ei->efi_systab; > -#endif > - if (!systab) > - error("EFI system table not found."); > + if (ret) > + error("EFI support advertised, but unable to locate system table."); > > /* Handle EFI bitness properly */ > if (efi_64) { > - efi_system_table_64_t *stbl = (efi_system_table_64_t *)systab; > + efi_system_table_64_t *stbl = (efi_system_table_64_t *)systab_tbl_pa; > > config_tables = stbl->tables; > nr_tables = stbl->nr_tables; > } else { > - efi_system_table_32_t *stbl = (efi_system_table_32_t *)systab; > + efi_system_table_32_t *stbl = (efi_system_table_32_t *)systab_tbl_pa; > > config_tables = stbl->tables; > nr_tables = stbl->nr_tables; > diff --git a/arch/x86/boot/compressed/efi.c b/arch/x86/boot/compressed/efi.c > new file mode 100644 > index 000000000000..1c626d28f07e > --- /dev/null > +++ b/arch/x86/boot/compressed/efi.c > @@ -0,0 +1,72 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Helpers for early access to EFI configuration table > + * > + * Copyright (C) 2021 Advanced Micro Devices, Inc. > + * > + * Author: Michael Roth <michael.roth@amd.com> > + */ > + > +#include "misc.h" > +#include <linux/efi.h> > +#include <asm/efi.h> > + > +/** > + * efi_get_system_table - Given boot_params, retrieve the physical address of > + * EFI system table. > + * > + * @boot_params: pointer to boot_params > + * @sys_tbl_pa: location to store physical address of system table > + * @is_efi_64: location to store whether using 64-bit EFI or not > + * > + * Return: 0 on success. On error, return params are left unchanged. > + * > + * Note: Existing callers like ACPI will call this unconditionally even for > + * non-EFI BIOSes. In such cases, those callers may treat cases where > + * bootparams doesn't indicate that a valid EFI system table is available as > + * non-fatal errors to allow fall-through to non-EFI alternatives. This > + * class of errors are reported as EOPNOTSUPP and should be kept in sync with > + * callers who check for that specific error. > + */ > +int efi_get_system_table(struct boot_params *boot_params, unsigned long *sys_tbl_pa, > + bool *is_efi_64) > +{ > + unsigned long sys_tbl; > + struct efi_info *ei; > + bool efi_64; > + char *sig; > + > + if (!sys_tbl_pa || !is_efi_64) > + return -EINVAL; > + > + ei = &boot_params->efi_info; > + sig = (char *)&ei->efi_loader_signature; > + > + if (!strncmp(sig, EFI64_LOADER_SIGNATURE, 4)) { > + efi_64 = true; > + } else if (!strncmp(sig, EFI32_LOADER_SIGNATURE, 4)) { > + efi_64 = false; > + } else { > + debug_putstr("Wrong EFI loader signature.\n"); > + return -EOPNOTSUPP; > + } > + > + /* Get systab from boot params. */ > +#ifdef CONFIG_X86_64 > + sys_tbl = ei->efi_systab | ((__u64)ei->efi_systab_hi << 32); > +#else > + if (ei->efi_systab_hi || ei->efi_memmap_hi) { > + debug_putstr("Error: EFI system table located above 4GB.\n"); > + return -EOPNOTSUPP; > + } > + sys_tbl = ei->efi_systab; > +#endif > + if (!sys_tbl) { > + debug_putstr("EFI system table not found."); > + return -ENOENT; > + } > + > + *sys_tbl_pa = sys_tbl; > + *is_efi_64 = efi_64; > + return 0; > +} > diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h > index 01cc13c12059..165640f64b71 100644 > --- a/arch/x86/boot/compressed/misc.h > +++ b/arch/x86/boot/compressed/misc.h > @@ -23,6 +23,7 @@ > #include <linux/screen_info.h> > #include <linux/elf.h> > #include <linux/io.h> > +#include <linux/efi.h> > #include <asm/page.h> > #include <asm/boot.h> > #include <asm/bootparam.h> > @@ -176,4 +177,17 @@ void boot_stage2_vc(void); > > unsigned long sev_verify_cbit(unsigned long cr3); > > +#ifdef CONFIG_EFI > +/* helpers for early EFI config table access */ > +int efi_get_system_table(struct boot_params *boot_params, > + unsigned long *sys_tbl_pa, bool *is_efi_64); > +#else > +static inline int > +efi_get_system_table(struct boot_params *boot_params, > + unsigned long *sys_tbl_pa, bool *is_efi_64) > +{ > + return -ENOENT; > +} > +#endif /* CONFIG_EFI */ > + > #endif /* BOOT_COMPRESSED_MISC_H */ > -- > 2.25.1 >
Hi, I am this Chao Fan, and <fanc.fnst@cn.fujitsu.com> won't be used again. Please add me with fanchao.njupt@gmail.com Many thanks. Thanks, Chao Fan Michael Roth <michael.roth@amd.com> 于2021年12月14日周二 11:46写道： > > On Fri, Dec 10, 2021 at 10:54:35AM -0800, Dave Hansen wrote: > > On 12/10/21 7:43 AM, Brijesh Singh wrote: > > > +/* > > > + * Helpers for early access to EFI configuration table > > > + * > > > + * Copyright (C) 2021 Advanced Micro Devices, Inc. > > > + * > > > + * Author: Michael Roth <michael.roth@amd.com> > > > + */ > > > > It doesn't seem quite right to slap this copyright on a file that's full > > of content that came from other files. It would be one thing if > > arch/x86/boot/compressed/acpi.c had this banner in it already. Also, a > > Yah, acpi.c didn't have any copyright banner so I used my 'default' > template for new files here to cover any additions, but that does give > a misleading impression. > > I'm not sure how this is normally addressed, but I'm planning on just > continuing the acpi.c tradition of *not* adding copyright notices for new > code, and simply document that the contents of the file are mostly movement > from acpi.c > > > arch/x86/boot/compressed/acpi.c had this banner in it already. Also, a > > bunch of the lines in this file seem to come from: > > > > commit 33f0df8d843deb9ec24116dcd79a40ca0ea8e8a9 > > Author: Chao Fan <fanc.fnst@cn.fujitsu.com> > > Date: Wed Jan 23 19:08:46 2019 +0800 > > AFAICT the full author list for the changes in question are, in > alphabetical order: > > Chao Fan <fanc.fnst@cn.fujitsu.com> > Junichi Nomura <j-nomura@ce.jp.nec.com> > Borislav Petkov <bp@suse.de> > > Chao, Junichi, Borislav, > > If you would like to be listed as an author in efi.c (which is mainly just a > movement of EFI config table parsing code from acpi.c into re-usable helper > functions in efi.c), please let me know and I'll add you. > > Otherwise, I'll plan on adopting the acpi.c precedent for this as well, which > is to not list individual authors, since it doesn't seem right to add Author > fields retroactively without their permission.
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 431bf7f846c3..d364192c2367 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -100,6 +100,7 @@ endif vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o +vmlinux-objs-$(CONFIG_EFI) += $(obj)/efi.o efi-obj-$(CONFIG_EFI_STUB) = $(objtree)/drivers/firmware/efi/libstub/lib.a $(obj)/vmlinux: $(vmlinux-objs-y) $(efi-obj-y) FORCE diff --git a/arch/x86/boot/compressed/acpi.c b/arch/x86/boot/compressed/acpi.c index 8bcbcee54aa1..9e784bd7b2e6 100644 --- a/arch/x86/boot/compressed/acpi.c +++ b/arch/x86/boot/compressed/acpi.c @@ -86,8 +86,8 @@ static acpi_physical_address kexec_get_rsdp_addr(void) { efi_system_table_64_t *systab; struct efi_setup_data *esd; - struct efi_info *ei; - char *sig; + bool efi_64; + int ret; esd = (struct efi_setup_data *)get_kexec_setup_data_addr(); if (!esd) @@ -98,18 +98,16 @@ static acpi_physical_address kexec_get_rsdp_addr(void) return 0; } - ei = &boot_params->efi_info; - sig = (char *)&ei->efi_loader_signature; - if (strncmp(sig, EFI64_LOADER_SIGNATURE, 4)) { + /* Get systab from boot params. */ + ret = efi_get_system_table(boot_params, (unsigned long *)&systab, &efi_64); + if (ret) + error("EFI system table not found in kexec boot_params."); + + if (!efi_64) { debug_putstr("Wrong kexec EFI loader signature.\n"); return 0; } - /* Get systab from boot params. */ - systab = (efi_system_table_64_t *) (ei->efi_systab | ((__u64)ei->efi_systab_hi << 32)); - if (!systab) - error("EFI system table not found in kexec boot_params."); - return __efi_get_rsdp_addr((unsigned long)esd->tables, systab->nr_tables, true); } #else @@ -119,45 +117,31 @@ static acpi_physical_address kexec_get_rsdp_addr(void) { return 0; } static acpi_physical_address efi_get_rsdp_addr(void) { #ifdef CONFIG_EFI - unsigned long systab, config_tables; + unsigned long systab_tbl_pa, config_tables; unsigned int nr_tables; - struct efi_info *ei; bool efi_64; - char *sig; - - ei = &boot_params->efi_info; - sig = (char *)&ei->efi_loader_signature; - - if (!strncmp(sig, EFI64_LOADER_SIGNATURE, 4)) { - efi_64 = true; - } else if (!strncmp(sig, EFI32_LOADER_SIGNATURE, 4)) { - efi_64 = false; - } else { - debug_putstr("Wrong EFI loader signature.\n"); - return 0; - } + int ret; - /* Get systab from boot params. */ -#ifdef CONFIG_X86_64 - systab = ei->efi_systab | ((__u64)ei->efi_systab_hi << 32); -#else - if (ei->efi_systab_hi || ei->efi_memmap_hi) { - debug_putstr("Error getting RSDP address: EFI system table located above 4GB.\n"); + /* + * This function is called even for non-EFI BIOSes, and callers expect + * failure to locate the EFI system table to result in 0 being returned + * as indication that EFI is not available, rather than outright + * failure/abort. + */ + ret = efi_get_system_table(boot_params, &systab_tbl_pa, &efi_64); + if (ret == -EOPNOTSUPP) return 0; - } - systab = ei->efi_systab; -#endif - if (!systab) - error("EFI system table not found."); + if (ret) + error("EFI support advertised, but unable to locate system table."); /* Handle EFI bitness properly */ if (efi_64) { - efi_system_table_64_t *stbl = (efi_system_table_64_t *)systab; + efi_system_table_64_t *stbl = (efi_system_table_64_t *)systab_tbl_pa; config_tables = stbl->tables; nr_tables = stbl->nr_tables; } else { - efi_system_table_32_t *stbl = (efi_system_table_32_t *)systab; + efi_system_table_32_t *stbl = (efi_system_table_32_t *)systab_tbl_pa; config_tables = stbl->tables; nr_tables = stbl->nr_tables; diff --git a/arch/x86/boot/compressed/efi.c b/arch/x86/boot/compressed/efi.c new file mode 100644 index 000000000000..1c626d28f07e --- /dev/null +++ b/arch/x86/boot/compressed/efi.c @@ -0,0 +1,72 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Helpers for early access to EFI configuration table + * + * Copyright (C) 2021 Advanced Micro Devices, Inc. + * + * Author: Michael Roth <michael.roth@amd.com> + */ + +#include "misc.h" +#include <linux/efi.h> +#include <asm/efi.h> + +/** + * efi_get_system_table - Given boot_params, retrieve the physical address of + * EFI system table. + * + * @boot_params: pointer to boot_params + * @sys_tbl_pa: location to store physical address of system table + * @is_efi_64: location to store whether using 64-bit EFI or not + * + * Return: 0 on success. On error, return params are left unchanged. + * + * Note: Existing callers like ACPI will call this unconditionally even for + * non-EFI BIOSes. In such cases, those callers may treat cases where + * bootparams doesn't indicate that a valid EFI system table is available as + * non-fatal errors to allow fall-through to non-EFI alternatives. This + * class of errors are reported as EOPNOTSUPP and should be kept in sync with + * callers who check for that specific error. + */ +int efi_get_system_table(struct boot_params *boot_params, unsigned long *sys_tbl_pa, + bool *is_efi_64) +{ + unsigned long sys_tbl; + struct efi_info *ei; + bool efi_64; + char *sig; + + if (!sys_tbl_pa || !is_efi_64) + return -EINVAL; + + ei = &boot_params->efi_info; + sig = (char *)&ei->efi_loader_signature; + + if (!strncmp(sig, EFI64_LOADER_SIGNATURE, 4)) { + efi_64 = true; + } else if (!strncmp(sig, EFI32_LOADER_SIGNATURE, 4)) { + efi_64 = false; + } else { + debug_putstr("Wrong EFI loader signature.\n"); + return -EOPNOTSUPP; + } + + /* Get systab from boot params. */ +#ifdef CONFIG_X86_64 + sys_tbl = ei->efi_systab | ((__u64)ei->efi_systab_hi << 32); +#else + if (ei->efi_systab_hi || ei->efi_memmap_hi) { + debug_putstr("Error: EFI system table located above 4GB.\n"); + return -EOPNOTSUPP; + } + sys_tbl = ei->efi_systab; +#endif + if (!sys_tbl) { + debug_putstr("EFI system table not found."); + return -ENOENT; + } + + *sys_tbl_pa = sys_tbl; + *is_efi_64 = efi_64; + return 0; +} diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h index 01cc13c12059..165640f64b71 100644 --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -23,6 +23,7 @@ #include <linux/screen_info.h> #include <linux/elf.h> #include <linux/io.h> +#include <linux/efi.h> #include <asm/page.h> #include <asm/boot.h> #include <asm/bootparam.h> @@ -176,4 +177,17 @@ void boot_stage2_vc(void); unsigned long sev_verify_cbit(unsigned long cr3); +#ifdef CONFIG_EFI +/* helpers for early EFI config table access */ +int efi_get_system_table(struct boot_params *boot_params, + unsigned long *sys_tbl_pa, bool *is_efi_64); +#else +static inline int +efi_get_system_table(struct boot_params *boot_params, + unsigned long *sys_tbl_pa, bool *is_efi_64) +{ + return -ENOENT; +} +#endif /* CONFIG_EFI */ + #endif /* BOOT_COMPRESSED_MISC_H */