From d2f7cbe7b26a74dbbbf8f325b2a6fd01bc34032c Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Thu, 31 Oct 2013 17:25:08 +0100 Subject: x86/efi: Runtime services virtual mapping We map the EFI regions needed for runtime services non-contiguously, with preserved alignment on virtual addresses starting from -4G down for a total max space of 64G. This way, we provide for stable runtime services addresses across kernels so that a kexec'd kernel can still use them. Thus, they're mapped in a separate pagetable so that we don't pollute the kernel namespace. Add an efi= kernel command line parameter for passing miscellaneous options and chicken bits from the command line. While at it, add a chicken bit called "efi=old_map" which can be used as a fallback to the old runtime services mapping method in case there's some b0rkage with a particular EFI implementation (haha, it is hard to hold up the sarcasm here...). Also, add the UEFI RT VA space to Documentation/x86/x86_64/mm.txt. Signed-off-by: Borislav Petkov Signed-off-by: Matt Fleming --- arch/x86/include/asm/efi.h | 64 ++++++++++++++++++++++++++---------- arch/x86/include/asm/pgtable_types.h | 3 +- 2 files changed, 49 insertions(+), 18 deletions(-) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index 65c6e6e3a552..89a05b0507b9 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -1,6 +1,24 @@ #ifndef _ASM_X86_EFI_H #define _ASM_X86_EFI_H +/* + * We map the EFI regions needed for runtime services non-contiguously, + * with preserved alignment on virtual addresses starting from -4G down + * for a total max space of 64G. This way, we provide for stable runtime + * services addresses across kernels so that a kexec'd kernel can still + * use them. + * + * This is the main reason why we're doing stable VA mappings for RT + * services. + * + * This flag is used in conjuction with a chicken bit called + * "efi=old_map" which can be used as a fallback to the old runtime + * services mapping method in case there's some b0rkage with a + * particular EFI implementation (haha, it is hard to hold up the + * sarcasm here...). + */ +#define EFI_OLD_MEMMAP EFI_ARCH_1 + #ifdef CONFIG_X86_32 #define EFI_LOADER_SIGNATURE "EL32" @@ -69,24 +87,31 @@ extern u64 efi_call6(void *fp, u64 arg1, u64 arg2, u64 arg3, efi_call6((f), (u64)(a1), (u64)(a2), (u64)(a3), \ (u64)(a4), (u64)(a5), (u64)(a6)) +#define _efi_call_virtX(x, f, ...) \ +({ \ + efi_status_t __s; \ + \ + efi_sync_low_kernel_mappings(); \ + preempt_disable(); \ + __s = efi_call##x((void *)efi.systab->runtime->f, __VA_ARGS__); \ + preempt_enable(); \ + __s; \ +}) + #define efi_call_virt0(f) \ - efi_call0((efi.systab->runtime->f)) -#define efi_call_virt1(f, a1) \ - efi_call1((efi.systab->runtime->f), (u64)(a1)) -#define efi_call_virt2(f, a1, a2) \ - efi_call2((efi.systab->runtime->f), (u64)(a1), (u64)(a2)) -#define efi_call_virt3(f, a1, a2, a3) \ - efi_call3((efi.systab->runtime->f), (u64)(a1), (u64)(a2), \ - (u64)(a3)) -#define efi_call_virt4(f, a1, a2, a3, a4) \ - efi_call4((efi.systab->runtime->f), (u64)(a1), (u64)(a2), \ - (u64)(a3), (u64)(a4)) -#define efi_call_virt5(f, a1, a2, a3, a4, a5) \ - efi_call5((efi.systab->runtime->f), (u64)(a1), (u64)(a2), \ - (u64)(a3), (u64)(a4), (u64)(a5)) -#define efi_call_virt6(f, a1, a2, a3, a4, a5, a6) \ - efi_call6((efi.systab->runtime->f), (u64)(a1), (u64)(a2), \ - (u64)(a3), (u64)(a4), (u64)(a5), (u64)(a6)) + _efi_call_virtX(0, f) +#define efi_call_virt1(f, a1) \ + _efi_call_virtX(1, f, (u64)(a1)) +#define efi_call_virt2(f, a1, a2) \ + _efi_call_virtX(2, f, (u64)(a1), (u64)(a2)) +#define efi_call_virt3(f, a1, a2, a3) \ + _efi_call_virtX(3, f, (u64)(a1), (u64)(a2), (u64)(a3)) +#define efi_call_virt4(f, a1, a2, a3, a4) \ + _efi_call_virtX(4, f, (u64)(a1), (u64)(a2), (u64)(a3), (u64)(a4)) +#define efi_call_virt5(f, a1, a2, a3, a4, a5) \ + _efi_call_virtX(5, f, (u64)(a1), (u64)(a2), (u64)(a3), (u64)(a4), (u64)(a5)) +#define efi_call_virt6(f, a1, a2, a3, a4, a5, a6) \ + _efi_call_virtX(6, f, (u64)(a1), (u64)(a2), (u64)(a3), (u64)(a4), (u64)(a5), (u64)(a6)) extern void __iomem *efi_ioremap(unsigned long addr, unsigned long size, u32 type, u64 attribute); @@ -95,12 +120,17 @@ extern void __iomem *efi_ioremap(unsigned long addr, unsigned long size, extern int add_efi_memmap; extern unsigned long x86_efi_facility; +extern struct efi_scratch efi_scratch; extern void efi_set_executable(efi_memory_desc_t *md, bool executable); extern int efi_memblock_x86_reserve_range(void); extern void efi_call_phys_prelog(void); extern void efi_call_phys_epilog(void); extern void efi_unmap_memmap(void); extern void efi_memory_uc(u64 addr, unsigned long size); +extern void __init efi_map_region(efi_memory_desc_t *md); +extern void efi_sync_low_kernel_mappings(void); +extern void efi_setup_page_tables(void); +extern void __init old_map_region(efi_memory_desc_t *md); #ifdef CONFIG_EFI diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index f4843e031131..028e28b6fc2c 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -379,7 +379,8 @@ static inline void update_page_count(int level, unsigned long pages) { } */ extern pte_t *lookup_address(unsigned long address, unsigned int *level); extern phys_addr_t slow_virt_to_phys(void *__address); - +extern int kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address, + unsigned numpages, unsigned long page_flags); #endif /* !__ASSEMBLY__ */ #endif /* _ASM_X86_PGTABLE_DEFS_H */ -- cgit v1.2.2 From 3b2664964bc886ae9d5127c8d3708b1acc0626d2 Mon Sep 17 00:00:00 2001 From: Dave Young Date: Fri, 20 Dec 2013 18:02:14 +0800 Subject: x86/efi: Add a wrapper function efi_map_region_fixed() Kexec kernel will use saved runtime virtual mapping, so add a new function efi_map_region_fixed() for directly mapping a md to md->virt. The md is passed in from 1st kernel, the virtual addr is saved in md->virt_addr. Signed-off-by: Dave Young Acked-by: Borislav Petkov Tested-by: Toshi Kani Signed-off-by: Matt Fleming --- arch/x86/include/asm/efi.h | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index 89a05b0507b9..9fbaeb239bde 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -128,6 +128,7 @@ extern void efi_call_phys_epilog(void); extern void efi_unmap_memmap(void); extern void efi_memory_uc(u64 addr, unsigned long size); extern void __init efi_map_region(efi_memory_desc_t *md); +extern void __init efi_map_region_fixed(efi_memory_desc_t *md); extern void efi_sync_low_kernel_mappings(void); extern void efi_setup_page_tables(void); extern void __init old_map_region(efi_memory_desc_t *md); -- cgit v1.2.2 From 1fec0533693cd74f2d1a46edd29449cfee429df0 Mon Sep 17 00:00:00 2001 From: Dave Young Date: Fri, 20 Dec 2013 18:02:19 +0800 Subject: x86/efi: Pass necessary EFI data for kexec via setup_data Add a new setup_data type SETUP_EFI for kexec use. Passing the saved fw_vendor, runtime, config tables and EFI runtime mappings. When entering virtual mode, directly mapping the EFI runtime regions which we passed in previously. And skip the step to call SetVirtualAddressMap(). Specially for HP z420 workstation we need save the smbios physical address. The kernel boot sequence proceeds in the following order. Step 2 requires efi.smbios to be the physical address. However, I found that on HP z420 EFI system table has a virtual address of SMBIOS in step 1. Hence, we need set it back to the physical address with the smbios in efi_setup_data. (When it is still the physical address, it simply sets the same value.) 1. efi_init() - Set efi.smbios from EFI system table 2. dmi_scan_machine() - Temporary map efi.smbios to access SMBIOS table 3. efi_enter_virtual_mode() - Map EFI ranges Tested on ovmf+qemu, lenovo thinkpad, a dell laptop and an HP z420 workstation. Signed-off-by: Dave Young Tested-by: Toshi Kani Signed-off-by: Matt Fleming --- arch/x86/include/asm/efi.h | 12 ++++++++++++ arch/x86/include/uapi/asm/bootparam.h | 1 + 2 files changed, 13 insertions(+) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index 9fbaeb239bde..4d1ba80b6ff1 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -133,6 +133,18 @@ extern void efi_sync_low_kernel_mappings(void); extern void efi_setup_page_tables(void); extern void __init old_map_region(efi_memory_desc_t *md); +struct efi_setup_data { + u64 fw_vendor; + u64 runtime; + u64 tables; + u64 smbios; + u64 reserved[8]; +}; + +extern u64 efi_setup; +extern u32 efi_data_len; +extern void parse_efi_setup(u64 phys_addr, u32 data_len); + #ifdef CONFIG_EFI static inline bool efi_is_native(void) diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h index 9c3733c5f8f7..64fe421aab65 100644 --- a/arch/x86/include/uapi/asm/bootparam.h +++ b/arch/x86/include/uapi/asm/bootparam.h @@ -6,6 +6,7 @@ #define SETUP_E820_EXT 1 #define SETUP_DTB 2 #define SETUP_PCI 3 +#define SETUP_EFI 4 /* ram_size flags */ #define RAMDISK_IMAGE_START_MASK 0x07FF -- cgit v1.2.2 From 456a29ddada79198c5965300e04103c40c481f62 Mon Sep 17 00:00:00 2001 From: Dave Young Date: Fri, 20 Dec 2013 18:02:20 +0800 Subject: x86: Add xloadflags bit for EFI runtime support on kexec Old kexec-tools can not load new kernels. The reason is kexec-tools does not fill efi_info in x86 setup header previously, thus EFI failed to initialize. In new kexec-tools it will by default to fill efi_info and pass other EFI required infomation to 2nd kernel so kexec kernel EFI initialization can succeed finally. To prevent from breaking userspace, add a new xloadflags bit so kexec-tools can check the flag and switch to old logic. Signed-off-by: Dave Young Acked-by: Borislav Petkov Tested-by: Toshi Kani Signed-off-by: Matt Fleming --- arch/x86/include/uapi/asm/bootparam.h | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/x86/include') diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h index 64fe421aab65..225b0988043a 100644 --- a/arch/x86/include/uapi/asm/bootparam.h +++ b/arch/x86/include/uapi/asm/bootparam.h @@ -24,6 +24,7 @@ #define XLF_CAN_BE_LOADED_ABOVE_4G (1<<1) #define XLF_EFI_HANDOVER_32 (1<<2) #define XLF_EFI_HANDOVER_64 (1<<3) +#define XLF_EFI_KEXEC (1<<4) #ifndef __ASSEMBLY__ -- cgit v1.2.2 From 5c12af0c41e3417e1939095325920463b5f8e726 Mon Sep 17 00:00:00 2001 From: Dave Young Date: Fri, 3 Jan 2014 11:56:49 +0800 Subject: x86/efi: parse_efi_setup() build fix In case without CONFIG_EFI, there will be below build error: arch/x86/built-in.o: In function `setup_arch': (.init.text+0x9dc): undefined reference to `parse_efi_setup' Thus fix it by adding blank inline function in asm/efi.h Also remove an unused declaration for variable efi_data_len. Signed-off-by: Dave Young Signed-off-by: Matt Fleming --- arch/x86/include/asm/efi.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index 4d1ba80b6ff1..3b978c472d08 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -142,8 +142,6 @@ struct efi_setup_data { }; extern u64 efi_setup; -extern u32 efi_data_len; -extern void parse_efi_setup(u64 phys_addr, u32 data_len); #ifdef CONFIG_EFI @@ -153,7 +151,7 @@ static inline bool efi_is_native(void) } extern struct console early_efi_console; - +extern void parse_efi_setup(u64 phys_addr, u32 data_len); #else /* * IF EFI is not configured, have the EFI calls return -ENOSYS. @@ -165,6 +163,7 @@ extern struct console early_efi_console; #define efi_call4(_f, _a1, _a2, _a3, _a4) (-ENOSYS) #define efi_call5(_f, _a1, _a2, _a3, _a4, _a5) (-ENOSYS) #define efi_call6(_f, _a1, _a2, _a3, _a4, _a5, _a6) (-ENOSYS) +static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {} #endif /* CONFIG_EFI */ #endif /* _ASM_X86_EFI_H */ -- cgit v1.2.2