This patchset is also available at: https://github.com/AMDESE/linux-kvm/tree/sectsc-guest-latest and is based on commit: 1613e604df0c ("Linux 6.10-rc1") Overview -------- 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: 01-09: Preparatory patches for code movement and general cleanup/fixups 10-13: Patches moving SNP guest messaging code from SEV guest driver to SEV common code 14-16: Error handling and caching secrets page 17-24: SecureTSC enablement patches. Testing SecureTSC ----------------- SecureTSC hypervisor patches based on top of SEV-SNP Guest MEMFD series: https://github.com/AMDESE/linux-kvm/tree/sectsc-host-latest QEMU changes: https://github.com/nikunjad/qemu/tree/snp-securetsc-latest QEMU commandline SEV-SNP with SecureTSC: qemu-system-x86_64 -cpu EPYC-Milan-v2,+invtsc -smp 4 \ -object memory-backend-memfd,id=ram1,size=1G,share=true,prealloc=false,reserve=false \ -object sev-snp-guest,id=sev0,cbitpos=51,reduced-phys-bits=1,secure-tsc=on \ -machine q35,confidential-guest-support=sev0,memory-backend=ram1 \ ... Changelog: ---------- v9: * Added Acked-by/Reviewed-by * Removed Reviewed-by/Tested-by from patches that had significant changes * Added patch to make payload a variable length array in snp_guest_msg * Fix all your user-visible strings (vmpck => VMPCK) and readabilty. * Separated patch for message sequence handling * Handle failures from snp_init() in sme_enable() * Preparatory patches: * Carved out simplify VMPCK and OS message sequence changes * Carved out SNP guest messaging init/exit for proper initialization and cleanup. * Move SNP command mutex down and make it private to sev.c * Pure code movement patch and subsequent code changes patches * Drop patches adding guest initiation hook enc_init() and call snp_secure_tsc_prepare() from mem_encrypt.c * Use CC_ATTR_GUEST_SECURE_TSC and drop synthetic SecureTSC feature bit v8: https://lore.kernel.org/lkml/20240215113128.275608-1-nikunj@xxxxxxx/ * Rebased on top of tip/x86/sev * Use minimum size of IV or msg_seqno in memcpy * Use arch/x86/include/asm/sev.h instead of sev-guest.h * Use DEFINE_MUTEX for snp_guest_cmd_mutex * Added Reviewed-by from Tom. * Dropped Tested-by from patch 3/16 v7: https://lore.kernel.org/kvm/20231220151358.2147066-1-nikunj@xxxxxxx/ v6: https://lore.kernel.org/lkml/20231128125959.1810039-1-nikunj@xxxxxxx/ v5: https://lore.kernel.org/lkml/20231030063652.68675-1-nikunj@xxxxxxx/ v4: https://lore.kernel.org/lkml/20230814055222.1056404-1-nikunj@xxxxxxx/ v3: https://lore.kernel.org/lkml/20230722111909.15166-1-nikunj@xxxxxxx/ v2: https://lore.kernel.org/r/20230307192449.24732-1-bp@xxxxxxxxx/ v1: https://lore.kernel.org/r/20230130120327.977460-1-nikunj@xxxxxxx Nikunj A Dadhania (24): virt: sev-guest: Use AES GCM crypto library virt: sev-guest: Replace dev_dbg with pr_debug virt: sev-guest: Make payload a variable length array virt: sev-guest: Add SNP guest request structure virt: sev-guest: Fix user-visible strings virt: sev-guest: Simplify VMPCK and sequence number assignments virt: sev-guest: Store VMPCK index to SNP guest device structure virt: sev-guest: Take mutex in snp_send_guest_request() virt: sev-guest: Carve out SNP guest messaging init/exit x86/sev: Move core SEV guest driver routines to common code x86/sev: Replace dev_[err,alert] with pr_[err,alert] x86/sev: Make snp_issue_guest_request() static x86/sev: Make sev-guest driver functional again x86/sev: Handle failures from snp_init() x86/sev: Cache the secrets page address x86/sev: Drop sev_guest_platform_data structure x86/cc: Add CC_ATTR_GUEST_SECURE_TSC x86/sev: Add Secure TSC support for SNP guests x86/sev: Change TSC MSR behavior for Secure TSC enabled guests x86/sev: Prevent RDTSC/RDTSCP interception for Secure TSC enabled guests x86/kvmclock: Skip kvmclock when Secure TSC is available x86/sev: Mark Secure TSC as reliable x86/cpu/amd: Do not print FW_BUG for Secure TSC x86/sev: Enable Secure TSC for SNP guests arch/x86/include/asm/sev-common.h | 1 + arch/x86/include/asm/sev.h | 197 ++++++- arch/x86/include/asm/svm.h | 6 +- drivers/virt/coco/sev-guest/sev-guest.h | 63 --- include/linux/cc_platform.h | 8 + arch/x86/boot/compressed/sev.c | 3 +- arch/x86/coco/core.c | 3 + arch/x86/kernel/cpu/amd.c | 3 +- arch/x86/kernel/kvmclock.c | 2 +- arch/x86/kernel/sev-shared.c | 10 + arch/x86/kernel/sev.c | 581 +++++++++++++++++-- arch/x86/mm/mem_encrypt.c | 4 + arch/x86/mm/mem_encrypt_amd.c | 4 + arch/x86/mm/mem_encrypt_identity.c | 7 + drivers/virt/coco/sev-guest/sev-guest.c | 711 +++--------------------- arch/x86/Kconfig | 1 + drivers/virt/coco/sev-guest/Kconfig | 3 - 17 files changed, 843 insertions(+), 764 deletions(-) delete mode 100644 drivers/virt/coco/sev-guest/sev-guest.h base-commit: 1613e604df0cd359cf2a7fbd9be7a0bcfacfabd0 -- 2.34.1
