On 1/26/2024 6:30 AM, Dionna Amalie Glaze wrote: > On Wed, Jan 24, 2024 at 10:08 PM Nikunj A. Dadhania <nikunj@xxxxxxx> wrote: >> >> On 12/20/2023 8:43 PM, Nikunj A Dadhania wrote: >>> Secure TSC allows guests to securely use RDTSC/RDTSCP instructions as the >>> parameters being used cannot be changed by hypervisor once the guest is >>> launched. More details in the AMD64 APM Vol 2, Section "Secure TSC". >>> >>> During the boot-up of the secondary cpus, SecureTSC enabled guests need to >>> query TSC info from AMD Security Processor. This communication channel is >>> encrypted between the AMD Security Processor and the guest, the hypervisor >>> is just the conduit to deliver the guest messages to the AMD Security >>> Processor. Each message is protected with an AEAD (AES-256 GCM). See "SEV >>> Secure Nested Paging Firmware ABI Specification" document (currently at >>> https://www.amd.com/system/files/TechDocs/56860.pdf) section "TSC Info" >>> >>> Use a minimal GCM library to encrypt/decrypt SNP Guest messages to >>> communicate with the AMD Security Processor which is available at early >>> boot. >>> >>> SEV-guest driver has the implementation for guest and AMD Security >>> Processor communication. As the TSC_INFO needs to be initialized during >>> early boot before smp cpus are started, move most of the sev-guest driver >>> code to kernel/sev.c and provide well defined APIs to the sev-guest driver >>> to use the interface to avoid code-duplication. >>> >>> Patches: >>> 01-08: Preparation and movement of sev-guest driver code >>> 09-16: SecureTSC enablement patches. >>> >>> Testing SecureTSC >>> ----------------- >>> >>> SecureTSC hypervisor patches based on top of SEV-SNP Guest MEMFD series: >>> https://github.com/nikunjad/linux/tree/snp-host-latest-securetsc_v5 >>> >>> QEMU changes: >>> https://github.com/nikunjad/qemu/tree/snp_securetsc_v5 >>> >>> QEMU commandline SEV-SNP-UPM with SecureTSC: >>> >>> qemu-system-x86_64 -cpu EPYC-Milan-v2,+secure-tsc,+invtsc -smp 4 \ >>> -object memory-backend-memfd-private,id=ram1,size=1G,share=true \ >>> -object sev-snp-guest,id=sev0,cbitpos=51,reduced-phys-bits=1,secure-tsc=on \ >>> -machine q35,confidential-guest-support=sev0,memory-backend=ram1,kvm-type=snp \ >>> ... >>> >>> Changelog: >>> ---------- >>> v7: >>> * Drop mutex from the snp_dev and add snp_guest_cmd_{lock,unlock} API >>> * Added comments for secrets page failure >>> * Added define for maximum supported VMPCK >>> * Updated comments why sev_status is used directly instead of >>> cpu_feature_enabled() I missed this in the change log: * Added Tested-by from Peter Gonda (https://lore.kernel.org/lkml/CAMkAt6pULjLVUO6Ys4Sq1a79d93_5w5URgLYNXY-aW2jSemruA@xxxxxxxxxxxxxx/) >> >> A gentle reminder. >> > > From the Google testing side of things, we may not get to this for > another while. Thanks Dionna Regards Nikunj
