diff options
Diffstat (limited to 'Documentation/x86')
| -rw-r--r-- | Documentation/x86/cpuinfo.rst | 5 | ||||
| -rw-r--r-- | Documentation/x86/exception-tables.rst | 23 | ||||
| -rw-r--r-- | Documentation/x86/ifs.rst | 2 | ||||
| -rw-r--r-- | Documentation/x86/index.rst | 4 | ||||
| -rw-r--r-- | Documentation/x86/intel-iommu.rst | 115 | ||||
| -rw-r--r-- | Documentation/x86/iommu.rst | 151 | ||||
| -rw-r--r-- | Documentation/x86/orc-unwinder.rst | 2 | ||||
| -rw-r--r-- | Documentation/x86/tdx.rst | 218 | ||||
| -rw-r--r-- | Documentation/x86/x86_64/boot-options.rst | 23 | ||||
| -rw-r--r-- | Documentation/x86/x86_64/uefi.rst | 2 | ||||
| -rw-r--r-- | Documentation/x86/zero-page.rst | 2 |
11 files changed, 407 insertions, 140 deletions
diff --git a/Documentation/x86/cpuinfo.rst b/Documentation/x86/cpuinfo.rst index 5d54c39a063f..08246e8ac835 100644 --- a/Documentation/x86/cpuinfo.rst +++ b/Documentation/x86/cpuinfo.rst @@ -140,9 +140,8 @@ from #define X86_FEATURE_UMIP (16*32 + 2). In addition, there exists a variety of custom command-line parameters that disable specific features. The list of parameters includes, but is not limited -to, nofsgsbase, nosmap, and nosmep. 5-level paging can also be disabled using -"no5lvl". SMAP and SMEP are disabled with the aforementioned parameters, -respectively. +to, nofsgsbase, nosgx, noxsave, etc. 5-level paging can also be disabled using +"no5lvl". e: The feature was known to be non-functional. ---------------------------------------------- diff --git a/Documentation/x86/exception-tables.rst b/Documentation/x86/exception-tables.rst index de58110c5ffd..efde1fef4fbd 100644 --- a/Documentation/x86/exception-tables.rst +++ b/Documentation/x86/exception-tables.rst @@ -32,14 +32,14 @@ Whenever the kernel tries to access an address that is currently not accessible, the CPU generates a page fault exception and calls the page fault handler:: - void do_page_fault(struct pt_regs *regs, unsigned long error_code) + void exc_page_fault(struct pt_regs *regs, unsigned long error_code) in arch/x86/mm/fault.c. The parameters on the stack are set up by the low level assembly glue in arch/x86/entry/entry_32.S. The parameter regs is a pointer to the saved registers on the stack, error_code contains a reason code for the exception. -do_page_fault first obtains the unaccessible address from the CPU +exc_page_fault() first obtains the inaccessible address from the CPU control register CR2. If the address is within the virtual address space of the process, the fault probably occurred, because the page was not swapped in, write protected or something similar. However, @@ -57,10 +57,10 @@ Where does fixup point to? Since we jump to the contents of fixup, fixup obviously points to executable code. This code is hidden inside the user access macros. -I have picked the get_user macro defined in arch/x86/include/asm/uaccess.h +I have picked the get_user() macro defined in arch/x86/include/asm/uaccess.h as an example. The definition is somewhat hard to follow, so let's peek at the code generated by the preprocessor and the compiler. I selected -the get_user call in drivers/char/sysrq.c for a detailed examination. +the get_user() call in drivers/char/sysrq.c for a detailed examination. The original code in sysrq.c line 587:: @@ -281,12 +281,15 @@ vma occurs? > c017e7a5 <do_con_write+e1> movb (%ebx),%dl #. MMU generates exception -#. CPU calls do_page_fault -#. do page fault calls search_exception_table (regs->eip == c017e7a5); -#. search_exception_table looks up the address c017e7a5 in the +#. CPU calls exc_page_fault() +#. exc_page_fault() calls do_user_addr_fault() +#. do_user_addr_fault() calls kernelmode_fixup_or_oops() +#. kernelmode_fixup_or_oops() calls fixup_exception() (regs->eip == c017e7a5); +#. fixup_exception() calls search_exception_tables() +#. search_exception_tables() looks up the address c017e7a5 in the exception table (i.e. the contents of the ELF section __ex_table) and returns the address of the associated fault handle code c0199ff5. -#. do_page_fault modifies its own return address to point to the fault +#. fixup_exception() modifies its own return address to point to the fault handle code and returns. #. execution continues in the fault handling code. #. a) EAX becomes -EFAULT (== -14) @@ -298,9 +301,9 @@ The steps 8a to 8c in a certain way emulate the faulting instruction. That's it, mostly. If you look at our example, you might ask why we set EAX to -EFAULT in the exception handler code. Well, the -get_user macro actually returns a value: 0, if the user access was +get_user() macro actually returns a value: 0, if the user access was successful, -EFAULT on failure. Our original code did not test this -return value, however the inline assembly code in get_user tries to +return value, however the inline assembly code in get_user() tries to return -EFAULT. GCC selected EAX to return this value. NOTE: diff --git a/Documentation/x86/ifs.rst b/Documentation/x86/ifs.rst new file mode 100644 index 000000000000..97abb696a680 --- /dev/null +++ b/Documentation/x86/ifs.rst @@ -0,0 +1,2 @@ +.. SPDX-License-Identifier: GPL-2.0 +.. kernel-doc:: drivers/platform/x86/intel/ifs/ifs.h diff --git a/Documentation/x86/index.rst b/Documentation/x86/index.rst index 91b2fa456618..c73d133fd37c 100644 --- a/Documentation/x86/index.rst +++ b/Documentation/x86/index.rst @@ -22,10 +22,11 @@ x86-specific Documentation mtrr pat intel-hfi - intel-iommu + iommu intel_txt amd-memory-encryption amd_hsmp + tdx pti mds microcode @@ -35,6 +36,7 @@ x86-specific Documentation usb-legacy-support i386/index x86_64/index + ifs sva sgx features diff --git a/Documentation/x86/intel-iommu.rst b/Documentation/x86/intel-iommu.rst deleted file mode 100644 index 099f13d51d5f..000000000000 --- a/Documentation/x86/intel-iommu.rst +++ /dev/null @@ -1,115 +0,0 @@ -=================== -Linux IOMMU Support -=================== - -The architecture spec can be obtained from the below location. - -http://www.intel.com/content/dam/www/public/us/en/documents/product-specifications/vt-directed-io-spec.pdf - -This guide gives a quick cheat sheet for some basic understanding. - -Some Keywords - -- DMAR - DMA remapping -- DRHD - DMA Remapping Hardware Unit Definition -- RMRR - Reserved memory Region Reporting Structure -- ZLR - Zero length reads from PCI devices -- IOVA - IO Virtual address. - -Basic stuff ------------ - -ACPI enumerates and lists the different DMA engines in the platform, and -device scope relationships between PCI devices and which DMA engine controls -them. - -What is RMRR? -------------- - -There are some devices the BIOS controls, for e.g USB devices to perform -PS2 emulation. The regions of memory used for these devices are marked -reserved in the e820 map. When we turn on DMA translation, DMA to those -regions will fail. Hence BIOS uses RMRR to specify these regions along with -devices that need to access these regions. OS is expected to setup -unity mappings for these regions for these devices to access these regions. - -How is IOVA generated? ----------------------- - -Well behaved drivers call pci_map_*() calls before sending command to device -that needs to perform DMA. Once DMA is completed and mapping is no longer -required, device performs a pci_unmap_*() calls to unmap the region. - -The Intel IOMMU driver allocates a virtual address per domain. Each PCIE -device has its own domain (hence protection). Devices under p2p bridges -share the virtual address with all devices under the p2p bridge due to -transaction id aliasing for p2p bridges. - -IOVA generation is pretty generic. We used the same technique as vmalloc() -but these are not global address spaces, but separate for each domain. -Different DMA engines may support different number of domains. - -We also allocate guard pages with each mapping, so we can attempt to catch -any overflow that might happen. - - -Graphics Problems? ------------------- -If you encounter issues with graphics devices, you can try adding -option intel_iommu=igfx_off to turn off the integrated graphics engine. -If this fixes anything, please ensure you file a bug reporting the problem. - -Some exceptions to IOVA ------------------------ -Interrupt ranges are not address translated, (0xfee00000 - 0xfeefffff). -The same is true for peer to peer transactions. Hence we reserve the -address from PCI MMIO ranges so they are not allocated for IOVA addresses. - - -Fault reporting ---------------- -When errors are reported, the DMA engine signals via an interrupt. The fault -reason and device that caused it with fault reason is printed on console. - -See below for sample. - - -Boot Message Sample -------------------- - -Something like this gets printed indicating presence of DMAR tables -in ACPI. - -ACPI: DMAR (v001 A M I OEMDMAR 0x00000001 MSFT 0x00000097) @ 0x000000007f5b5ef0 - -When DMAR is being processed and initialized by ACPI, prints DMAR locations -and any RMRR's processed:: - - ACPI DMAR:Host address width 36 - ACPI DMAR:DRHD (flags: 0x00000000)base: 0x00000000fed90000 - ACPI DMAR:DRHD (flags: 0x00000000)base: 0x00000000fed91000 - ACPI DMAR:DRHD (flags: 0x00000001)base: 0x00000000fed93000 - ACPI DMAR:RMRR base: 0x00000000000ed000 end: 0x00000000000effff - ACPI DMAR:RMRR base: 0x000000007f600000 end: 0x000000007fffffff - -When DMAR is enabled for use, you will notice.. - -PCI-DMA: Using DMAR IOMMU -------------------------- - -Fault reporting -^^^^^^^^^^^^^^^ - -:: - - DMAR:[DMA Write] Request device [00:02.0] fault addr 6df084000 - DMAR:[fault reason 05] PTE Write access is not set - DMAR:[DMA Write] Request device [00:02.0] fault addr 6df084000 - DMAR:[fault reason 05] PTE Write access is not set - -TBD ----- - -- For compatibility testing, could use unity map domain for all devices, just - provide a 1-1 for all useful memory under a single domain for all devices. -- API for paravirt ops for abstracting functionality for VMM folks. diff --git a/Documentation/x86/iommu.rst b/Documentation/x86/iommu.rst new file mode 100644 index 000000000000..42c7a6faa39a --- /dev/null +++ b/Documentation/x86/iommu.rst @@ -0,0 +1,151 @@ +================= +x86 IOMMU Support +================= + +The architecture specs can be obtained from the below locations. + +- Intel: http://www.intel.com/content/dam/www/public/us/en/documents/product-specifications/vt-directed-io-spec.pdf +- AMD: https://www.amd.com/system/files/TechDocs/48882_IOMMU.pdf + +This guide gives a quick cheat sheet for some basic understanding. + +Basic stuff +----------- + +ACPI enumerates and lists the different IOMMUs on the platform, and +device scope relationships between devices and which IOMMU controls +them. + +Some ACPI Keywords: + +- DMAR - Intel DMA Remapping table +- DRHD - Intel DMA Remapping Hardware Unit Definition +- RMRR - Intel Reserved Memory Region Reporting Structure +- IVRS - AMD I/O Virtualization Reporting Structure +- IVDB - AMD I/O Virtualization Definition Block +- IVHD - AMD I/O Virtualization Hardware Definition + +What is Intel RMRR? +^^^^^^^^^^^^^^^^^^^ + +There are some devices the BIOS controls, for e.g USB devices to perform +PS2 emulation. The regions of memory used for these devices are marked +reserved in the e820 map. When we turn on DMA translation, DMA to those +regions will fail. Hence BIOS uses RMRR to specify these regions along with +devices that need to access these regions. OS is expected to setup +unity mappings for these regions for these devices to access these regions. + +What is AMD IVRS? +^^^^^^^^^^^^^^^^^ + +The architecture defines an ACPI-compatible data structure called an I/O +Virtualization Reporting Structure (IVRS) that is used to convey information +related to I/O virtualization to system software. The IVRS describes the +configuration and capabilities of the IOMMUs contained in the platform as +well as information about the devices that each IOMMU virtualizes. + +The IVRS provides information about the following: + +- IOMMUs present in the platform including their capabilities and proper configuration +- System I/O topology relevant to each IOMMU +- Peripheral devices that cannot be otherwise enumerated +- Memory regions used by SMI/SMM, platform firmware, and platform hardware. These are generally exclusion ranges to be configured by system software. + +How is an I/O Virtual Address (IOVA) generated? +----------------------------------------------- + +Well behaved drivers call dma_map_*() calls before sending command to device +that needs to perform DMA. Once DMA is completed and mapping is no longer +required, driver performs dma_unmap_*() calls to unmap the region. + +Intel Specific Notes +-------------------- + +Graphics Problems? +^^^^^^^^^^^^^^^^^^ + +If you encounter issues with graphics devices, you can try adding +option intel_iommu=igfx_off to turn off the integrated graphics engine. +If this fixes anything, please ensure you file a bug reporting the problem. + +Some exceptions to IOVA +^^^^^^^^^^^^^^^^^^^^^^^ + +Interrupt ranges are not address translated, (0xfee00000 - 0xfeefffff). +The same is true for peer to peer transactions. Hence we reserve the +address from PCI MMIO ranges so they are not allocated for IOVA addresses. + +AMD Specific Notes +------------------ + +Graphics Problems? +^^^^^^^^^^^^^^^^^^ + +If you encounter issues with integrated graphics devices, you can try adding +option iommu=pt to the kernel command line use a 1:1 mapping for the IOMMU. If +this fixes anything, please ensure you file a bug reporting the problem. + +Fault reporting +--------------- +When errors are reported, the IOMMU signals via an interrupt. The fault +reason and device that caused it is printed on the console. + + +Kernel Log Samples +------------------ + +Intel Boot Messages +^^^^^^^^^^^^^^^^^^^ + +Something like this gets printed indicating presence of DMAR tables +in ACPI: + +:: + + ACPI: DMAR (v001 A M I OEMDMAR 0x00000001 MSFT 0x00000097) @ 0x000000007f5b5ef0 + +When DMAR is being processed and initialized by ACPI, prints DMAR locations +and any RMRR's processed: + +:: + + ACPI DMAR:Host address width 36 + ACPI DMAR:DRHD (flags: 0x00000000)base: 0x00000000fed90000 + ACPI DMAR:DRHD (flags: 0x00000000)base: 0x00000000fed91000 + ACPI DMAR:DRHD (flags: 0x00000001)base: 0x00000000fed93000 + ACPI DMAR:RMRR base: 0x00000000000ed000 end: 0x00000000000effff + ACPI DMAR:RMRR base: 0x000000007f600000 end: 0x000000007fffffff + +When DMAR is enabled for use, you will notice: + +:: + + PCI-DMA: Using DMAR IOMMU + +Intel Fault reporting +^^^^^^^^^^^^^^^^^^^^^ + +:: + + DMAR:[DMA Write] Request device [00:02.0] fault addr 6df084000 + DMAR:[fault reason 05] PTE Write access is not set + DMAR:[DMA Write] Request device [00:02.0] fault addr 6df084000 + DMAR:[fault reason 05] PTE Write access is not set + +AMD Boot Messages +^^^^^^^^^^^^^^^^^ + +Something like this gets printed indicating presence of the IOMMU: + +:: + + iommu: Default domain type: Translated + iommu: DMA domain TLB invalidation policy: lazy mode + +AMD Fault reporting +^^^^^^^^^^^^^^^^^^^ + +:: + + AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x0007 address=0xffffc02000 flags=0x0000] + AMD-Vi: Event logged [IO_PAGE_FAULT device=07:00.0 domain=0x0007 address=0xffffc02000 flags=0x0000] diff --git a/Documentation/x86/orc-unwinder.rst b/Documentation/x86/orc-unwinder.rst index 9a66a88be765..cdb257015bd9 100644 --- a/Documentation/x86/orc-unwinder.rst +++ b/Documentation/x86/orc-unwinder.rst @@ -140,7 +140,7 @@ Unwinder implementation details Objtool generates the ORC data by integrating with the compile-time stack metadata validation feature, which is described in detail in -tools/objtool/Documentation/stack-validation.txt. After analyzing all +tools/objtool/Documentation/objtool.txt. After analyzing all the code paths of a .o file, it creates an array of orc_entry structs, and a parallel array of instruction addresses associated with those structs, and writes them to the .orc_unwind and .orc_unwind_ip sections diff --git a/Documentation/x86/tdx.rst b/Documentation/x86/tdx.rst new file mode 100644 index 000000000000..b8fa4329e1a5 --- /dev/null +++ b/Documentation/x86/tdx.rst @@ -0,0 +1,218 @@ +.. SPDX-License-Identifier: GPL-2.0 + +===================================== +Intel Trust Domain Extensions (TDX) +===================================== + +Intel's Trust Domain Extensions (TDX) protect confidential guest VMs from +the host and physical attacks by isolating the guest register state and by +encrypting the guest memory. In TDX, a special module running in a special +mode sits between the host and the guest and manages the guest/host +separation. + +Since the host cannot directly access guest registers or memory, much +normal functionality of a hypervisor must be moved into the guest. This is +implemented using a Virtualization Exception (#VE) that is handled by the +guest kernel. A #VE is handled entirely inside the guest kernel, but some +require the hypervisor to be consulted. + +TDX includes new hypercall-like mechanisms for communicating from the +guest to the hypervisor or the TDX module. + +New TDX Exceptions +================== + +TDX guests behave differently from bare-metal and traditional VMX guests. +In TDX guests, otherwise normal instructions or memory accesses can cause +#VE or #GP exceptions. + +Instructions marked with an '*' conditionally cause exceptions. The +details for these instructions are discussed below. + +Instruction-based #VE +--------------------- + +- Port I/O (INS, OUTS, IN, OUT) +- HLT +- MONITOR, MWAIT +- WBINVD, INVD +- VMCALL +- RDMSR*,WRMSR* +- CPUID* + +Instruction-based #GP +--------------------- + +- All VMX instructions: INVEPT, INVVPID, VMCLEAR, VMFUNC, VMLAUNCH, + VMPTRLD, VMPTRST, VMREAD, VMRESUME, VMWRITE, VMXOFF, VMXON +- ENCLS, ENCLU +- GETSEC +- RSM +- ENQCMD +- RDMSR*,WRMSR* + +RDMSR/WRMSR Behavior +-------------------- + +MSR access behavior falls into three categories: + +- #GP generated +- #VE generated +- "Just works" + +In general, the #GP MSRs should not be used in guests. Their use likely +indicates a bug in the guest. The guest may try to handle the #GP with a +hypercall but it is unlikely to succeed. + +The #VE MSRs are typically able to be handled by the hypervisor. Guests +can make a hypercall to the hypervisor to handle the #VE. + +The "just works" MSRs do not need any special guest handling. They might +be implemented by directly passing through the MSR to the hardware or by +trapping and handling in the TDX module. Other than possibly being slow, +these MSRs appear to function just as they would on bare metal. + +CPUID Behavior +-------------- + +For some CPUID leaves and sub-leaves, the virtualized bit fields of CPUID +return values (in guest EAX/EBX/ECX/EDX) are configurable by the +hypervisor. For such cases, the Intel TDX module architecture defines two +virtualization types: + +- Bit fields for which the hypervisor controls the value seen by the guest + TD. + +- Bit fields for which the hypervisor configures the value such that the + guest TD either sees their native value or a value of 0. For these bit + fields, the hypervisor can mask off the native values, but it can not + turn *on* values. + +A #VE is generated for CPUID leaves and sub-leaves that the TDX module does +not know how to handle. The guest kernel may ask the hypervisor for the +value with a hypercall. + +#VE on Memory Accesses +====================== + +There are essentially two classes of TDX memory: private and shared. +Private memory receives full TDX protections. Its content is protected +against access from the hypervisor. Shared memory is expected to be +shared between guest and hypervisor and does not receive full TDX +protections. + +A TD guest is in control of whether its memory accesses are treated as +private or shared. It selects the behavior with a bit in its page table +entries. This helps ensure that a guest does not place sensitive +information in shared memory, exposing it to the untrusted hypervisor. + +#VE on Shared Memory +-------------------- + +Access to shared mappings can cause a #VE. The hypervisor ultimately +controls whether a shared memory access causes a #VE, so the guest must be +careful to only reference shared pages it can safely handle a #VE. For +instance, the guest should be careful not to access shared memory in the +#VE handler before it reads the #VE info structure (TDG.VP.VEINFO.GET). + +Shared mapping content is entirely controlled by the hypervisor. The guest +should only use shared mappings for communicating with the hypervisor. +Shared mappings must never be used for sensitive memory content like kernel +stacks. A good rule of thumb is that hypervisor-shared memory should be +treated the same as memory mapped to userspace. Both the hypervisor and +userspace are completely untrusted. + +MMIO for virtual devices is implemented as shared memory. The guest must +be careful not to access device MMIO regions unless it is also prepared to +handle a #VE. + +#VE on Private Pages +-------------------- + +An access to private mappings can also cause a #VE. Since all kernel +memory is also private memory, the kernel might theoretically need to +handle a #VE on arbitrary kernel memory accesses. This is not feasible, so +TDX guests ensure that all guest memory has been "accepted" before memory +is used by the kernel. + +A modest amount of memory (typically 512M) is pre-accepted by the firmware +before the kernel runs to ensure that the kernel can start up without +being subjected to a #VE. + +The hypervisor is permitted to unilaterally move accepted pages to a +"blocked" state. However, if it does this, page access will not generate a +#VE. It will, instead, cause a "TD Exit" where the hypervisor is required +to handle the exception. + +Linux #VE handler +================= + +Just like page faults or #GP's, #VE exceptions can be either handled or be +fatal. Typically, an unhandled userspace #VE results in a SIGSEGV. +An unhandled kernel #VE results in an oops. + +Handling nested exceptions on x86 is typically nasty business. A #VE +could be interrupted by an NMI which triggers another #VE and hilarity +ensues. The TDX #VE architecture anticipated this scenario and includes a +feature to make it slightly less nasty. + +During #VE handling, the TDX module ensures that all interrupts (including +NMIs) are blocked. The block remains in place until the guest makes a +TDG.VP.VEINFO.GET TDCALL. This allows the guest to control when interrupts +or a new #VE can be delivered. + +However, the guest kernel must still be careful to avoid potential +#VE-triggering actions (discussed above) while this block is in place. +While the block is in place, any #VE is elevated to a double fault (#DF) +which is not recoverable. + +MMIO handling +============= + +In non-TDX VMs, MMIO is usually implemented by giving a guest access to a +mapping which will cause a VMEXIT on access, and then the hypervisor +emulates the access. That is not possible in TDX guests because VMEXIT +will expose the register state to the host. TDX guests don't trust the host +and can't have their state exposed to the host. + +In TDX, MMIO regions typically trigger a #VE exception in the guest. The +guest #VE handler then emulates the MMIO instruction inside the guest and +converts it into a controlled TDCALL to the host, rather than exposing +guest state to the host. + +MMIO addresses on x86 are just special physical addresses. They can +theoretically be accessed with any instruction that accesses memory. +However, the kernel instruction decoding method is limited. It is only +designed to decode instructions like those generated by io.h macros. + +MMIO access via other means (like structure overlays) may result in an +oops. + +Shared Memory Conversions +========================= + +All TDX guest memory starts out as private at boot. This memory can not +be accessed by the hypervisor. However, some kernel users like device +drivers might have a need to share data with the hypervisor. To do this, +memory must be converted between shared and private. This can be +accomplished using some existing memory encryption helpers: + + * set_memory_decrypted() converts a range of pages to shared. + * set_memory_encrypted() converts memory back to private. + +Device drivers are the primary user of shared memory, but there's no need +to touch every driver. DMA buffers and ioremap() do the conversions +automatically. + +TDX uses SWIOTLB for most DMA allocations. The SWIOTLB buffer is +converted to shared on boot. + +For coherent DMA allocation, the DMA buffer gets converted on the +allocation. Check force_dma_unencrypted() for details. + +References +========== + +TDX reference material is collected here: + +https://www.intel.com/content/www/us/en/developer/articles/technical/intel-trust-domain-extensions.html diff --git a/Documentation/x86/x86_64/boot-options.rst b/Documentation/x86/x86_64/boot-options.rst index 07aa0007f346..03ec9cf01181 100644 --- a/Documentation/x86/x86_64/boot-options.rst +++ b/Documentation/x86/x86_64/boot-options.rst @@ -157,15 +157,6 @@ Rebooting newer BIOS, or newer board) using this option will ignore the built-in quirk table, and use the generic default reboot actions. -Non Executable Mappings -======================= - - noexec=on|off - on - Enable(default) - off - Disable - NUMA ==== @@ -310,3 +301,17 @@ Miscellaneous Do not use GB pages for kernel direct mappings. gbpages Use GB pages for kernel direct mappings. + + +AMD SEV (Secure Encrypted Virtualization) +========================================= +Options relating to AMD SEV, specified via the following format: + +:: + + sev=option1[,option2] + +The available options are: + + debug + Enable debug messages. diff --git a/Documentation/x86/x86_64/uefi.rst b/Documentation/x86/x86_64/uefi.rst index 3b894103a734..fbc30c9a071d 100644 --- a/Documentation/x86/x86_64/uefi.rst +++ b/Documentation/x86/x86_64/uefi.rst @@ -29,7 +29,7 @@ Mechanics be selected:: CONFIG_EFI=y - CONFIG_EFI_VARS=y or m # optional + CONFIG_EFIVAR_FS=y or m # optional - Create a VFAT partition on the disk - Copy the following to the VFAT partition: diff --git a/Documentation/x86/zero-page.rst b/Documentation/x86/zero-page.rst index f088f5881666..45aa9cceb4f1 100644 --- a/Documentation/x86/zero-page.rst +++ b/Documentation/x86/zero-page.rst @@ -19,6 +19,7 @@ Offset/Size Proto Name Meaning 058/008 ALL tboot_addr Physical address of tboot shared page 060/010 ALL ist_info Intel SpeedStep (IST) BIOS support information (struct ist_info) +070/008 ALL acpi_rsdp_addr Physical address of ACPI RSDP table 080/010 ALL hd0_info hd0 disk parameter, OBSOLETE!! 090/010 ALL hd1_info hd1 disk parameter, OBSOLETE!! 0A0/010 ALL sys_desc_table System description table (struct sys_desc_table), @@ -27,6 +28,7 @@ Offset/Size Proto Name Meaning 0C0/004 ALL ext_ramdisk_image ramdisk_image high 32bits 0C4/004 ALL ext_ramdisk_size ramdisk_size high 32bits 0C8/004 ALL ext_cmd_line_ptr cmd_line_ptr high 32bits +13C/004 ALL cc_blob_address Physical address of Confidential Computing blob 140/080 ALL edid_info Video mode setup (struct edid_info) 1C0/020 ALL efi_info EFI 32 information (struct efi_info) 1E0/004 ALL alt_mem_k Alternative mem check, in KB |