Nikunj A Dadhania 2d4c140e9a x86/sev: Add SEV-SNP guest feature negotiation support ... commit 8c29f01654 upstream. The hypervisor can enable various new features (SEV_FEATURES[1:63]) and start a SNP guest. Some of these features need guest side implementation. If any of these features are enabled without it, the behavior of the SNP guest will be undefined. It may fail booting in a non-obvious way making it difficult to debug. Instead of allowing the guest to continue and have it fail randomly later, detect this early and fail gracefully. The SEV_STATUS MSR indicates features which the hypervisor has enabled. While booting, SNP guests should ascertain that all the enabled features have guest side implementation. In case a feature is not implemented in the guest, the guest terminates booting with GHCB protocol Non-Automatic Exit(NAE) termination request event, see "SEV-ES Guest-Hypervisor Communication Block Standardization" document (currently at https://developer.amd.com/wp-content/resources/56421.pdf), section "Termination Request". Populate SW_EXITINFO2 with mask of unsupported features that the hypervisor can easily report to the user. More details in the AMD64 APM Vol 2, Section "SEV_STATUS MSR". [ bp: - Massage. - Move snp_check_features() call to C code. Note: the CC:stable@ aspect here is to be able to protect older, stable kernels when running on newer hypervisors. Or not "running" but fail reliably and in a well-defined manner instead of randomly. ] Fixes: cbd3d4f7c4 ("x86/sev: Check SEV-SNP features support") Signed-off-by: Nikunj A Dadhania <nikunj@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Cc: <stable@kernel.org> Link: https://lore.kernel.org/r/20230118061943.534309-1-nikunj@amd.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2023-02-01 08:34:50 +01:00
..
i386
x86_64	dma-mapping updates	2022-08-06 10:56:45 -07:00
amd-memory-encryption.rst	x86/sev: Add SEV-SNP guest feature negotiation support	2023-02-01 08:34:50 +01:00
amd_hsmp.rst
boot.rst
booting-dt.rst
buslock.rst
cpuinfo.rst	x86/cpu: Remove "nosmep"	2022-04-04 10:17:00 +02:00
earlyprintk.rst
elf_auxvec.rst
entry_64.rst	docs: x86: replace do_IRQ int the entry_64.rst with common_interrupt()	2022-09-27 13:21:44 -06:00
exception-tables.rst	Documentation: x86: Fix obsolete name of page fault handler	2022-04-05 10:28:36 -06:00
features.rst
ifs.rst	Documentation: In-Field Scan	2022-05-12 15:35:29 +02:00
index.rst	It was a moderately busy cycle for documentation; highlights include:	2022-05-25 11:17:41 -07:00
intel-hfi.rst
intel_txt.rst
iommu.rst	Documentation: x86: rework IOMMU documentation	2022-04-28 07:59:45 -06:00
kernel-stacks.rst
mds.rst
microcode.rst	x86/microcode: Document the whole late loading problem	2022-08-18 15:57:53 +02:00
mtrr.rst
orc-unwinder.rst	objtool: update objtool.txt references	2022-07-07 13:10:00 -06:00
pat.rst
pti.rst
resctrl.rst
sgx.rst	Documentation/x86: Introduce enclave runtime management section	2022-07-07 10:13:03 -07:00
sva.rst
tdx.rst	Documentation/x86: Document TDX kernel architecture	2022-04-08 06:57:09 -07:00
tlb.rst
topology.rst
tsx_async_abort.rst
usb-legacy-support.rst
xstate.rst
zero-page.rst	x86/boot: Add a pointer to Confidential Computing blob in bootparams	2022-04-07 16:47:11 +02:00