user/sven/linux.git - Linux Kernel

Age	Commit message (Collapse)	Author
2024-12-05	x86/tdx: Dump attributes and TD_CTLS on boot	Kirill A. Shutemov
	Dump TD configuration on boot. Attributes and TD_CTLS define TD behavior. This information is useful for tracking down bugs. The output ends up looking like this in practice: [ 0.000000] tdx: Guest detected [ 0.000000] tdx: Attributes: SEPT_VE_DISABLE [ 0.000000] tdx: TD_CTLS: PENDING_VE_DISABLE ENUM_TOPOLOGY VIRT_CPUID2 REDUCE_VE Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Nikolay Borisov <nik.borisov@suse.com> Link: https://lore.kernel.org/all/20241202072458.447455-1-kirill.shutemov%40linux.intel.com
2023-06-06	x86/tdx: Add unaccepted memory support	Kirill A. Shutemov
	Hookup TDX-specific code to accept memory. Accepting the memory is done with ACCEPT_PAGE module call on every page in the range. MAP_GPA hypercall is not required as the unaccepted memory is considered private already. Extract the part of tdx_enc_status_changed() that does memory acceptance in a new helper. Move the helper tdx-shared.c. It is going to be used by both main kernel and decompressor. [ bp: Fix the INTEL_TDX_GUEST=y, KVM_GUEST=n build. ] Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20230606142637.5171-10-kirill.shutemov@linux.intel.com
2022-04-07	x86/tdx: Add __tdx_module_call() and __tdx_hypercall() helper functions	Kuppuswamy Sathyanarayanan
	Guests communicate with VMMs with hypercalls. Historically, these are implemented using instructions that are known to cause VMEXITs like VMCALL, VMLAUNCH, etc. However, with TDX, VMEXITs no longer expose the guest state to the host. This prevents the old hypercall mechanisms from working. So, to communicate with VMM, TDX specification defines a new instruction called TDCALL. In a TDX based VM, since the VMM is an untrusted entity, an intermediary layer -- TDX module -- facilitates secure communication between the host and the guest. TDX module is loaded like a firmware into a special CPU mode called SEAM. TDX guests communicate with the TDX module using the TDCALL instruction. A guest uses TDCALL to communicate with both the TDX module and VMM. The value of the RAX register when executing the TDCALL instruction is used to determine the TDCALL type. A leaf of TDCALL used to communicate with the VMM is called TDVMCALL. Add generic interfaces to communicate with the TDX module and VMM (using the TDCALL instruction). __tdx_module_call() - Used to communicate with the TDX module (via TDCALL instruction). __tdx_hypercall() - Used by the guest to request services from the VMM (via TDVMCALL leaf of TDCALL). Also define an additional wrapper _tdx_hypercall(), which adds error handling support for the TDCALL failure. The __tdx_module_call() and __tdx_hypercall() helper functions are implemented in assembly in a .S file. The TDCALL ABI requires shuffling arguments in and out of registers, which proved to be awkward with inline assembly. Just like syscalls, not all TDVMCALL use cases need to use the same number of argument registers. The implementation here picks the current worst-case scenario for TDCALL (4 registers). For TDCALLs with fewer than 4 arguments, there will end up being a few superfluous (cheap) instructions. But, this approach maximizes code reuse. For registers used by the TDCALL instruction, please check TDX GHCI specification, the section titled "TDCALL instruction" and "TDG.VP.VMCALL Interface". Based on previous patch by Sean Christopherson. Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20220405232939.73860-4-kirill.shutemov@linux.intel.com
2022-04-07	x86/tdx: Detect running as a TDX guest in early boot	Kuppuswamy Sathyanarayanan
	In preparation of extending cc_platform_has() API to support TDX guest, use CPUID instruction to detect support for TDX guests in the early boot code (via tdx_early_init()). Since copy_bootdata() is the first user of cc_platform_has() API, detect the TDX guest status before it. Define a synthetic feature flag (X86_FEATURE_TDX_GUEST) and set this bit in a valid TDX guest platform. Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20220405232939.73860-2-kirill.shutemov@linux.intel.com