| Message ID | 20220224165625.2175020-1-brijesh.singh@amd.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Add AMD Secure Nested Paging (SEV-SNP) Guest Support | expand |
On Thu, Feb 24, 2022 at 10:55:40AM -0600, Brijesh Singh wrote: > This part of Secure Encrypted Paging (SEV-SNP) series focuses on the changes > required in a guest OS for SEV-SNP support. So the first 4 are KVM material. Paolo, what's the story here, are you gonna take them and give me an immutable branch or do you have another idea? Thx.
On 3/2/22 15:22, Borislav Petkov wrote: > On Thu, Feb 24, 2022 at 10:55:40AM -0600, Brijesh Singh wrote: >> This part of Secure Encrypted Paging (SEV-SNP) series focuses on the changes >> required in a guest OS for SEV-SNP support. > > So the first 4 are KVM material. > > Paolo, what's the story here, are you gonna take them and give me an > immutable branch or do you have another idea? Sure: https://git.kernel.org/pub/scm/virt/kvm/kvm.git, branch svm-for-snp. $ git log -4 --oneline --reverse 3c95d3fab229 KVM: SVM: Define sev_features and vmpl field in the VMSA 0c86f9cf27f7 KVM: SVM: Create a separate mapping for the SEV-ES save area c5e0ec4c742d KVM: SVM: Create a separate mapping for the GHCB save area 88c955d1fc93 (HEAD -> kvm/svm-for-snp) KVM: SVM: Update the SEV-ES save area mapping Paolo
On Wed, Mar 02, 2022 at 05:09:34PM +0100, Paolo Bonzini wrote: > Sure: https://git.kernel.org/pub/scm/virt/kvm/kvm.git, branch svm-for-snp. > > $ git log -4 --oneline --reverse > 3c95d3fab229 KVM: SVM: Define sev_features and vmpl field in the VMSA > 0c86f9cf27f7 KVM: SVM: Create a separate mapping for the SEV-ES save area > c5e0ec4c742d KVM: SVM: Create a separate mapping for the GHCB save area > 88c955d1fc93 (HEAD -> kvm/svm-for-snp) KVM: SVM: Update the SEV-ES save area mapping Thanks!
On Wed, Mar 02, 2022 at 05:14:57PM +0100, Borislav Petkov wrote: > On Wed, Mar 02, 2022 at 05:09:34PM +0100, Paolo Bonzini wrote: > > Sure: https://git.kernel.org/pub/scm/virt/kvm/kvm.git, branch svm-for-snp. > > > > $ git log -4 --oneline --reverse > > 3c95d3fab229 KVM: SVM: Define sev_features and vmpl field in the VMSA > > 0c86f9cf27f7 KVM: SVM: Create a separate mapping for the SEV-ES save area > > c5e0ec4c742d KVM: SVM: Create a separate mapping for the GHCB save area > > 88c955d1fc93 (HEAD -> kvm/svm-for-snp) KVM: SVM: Update the SEV-ES save area mapping > > Thanks! Err, wasn't this supposed to go to Linus this merge window? I don't see it...
This part of Secure Encrypted Paging (SEV-SNP) series focuses on the changes required in a guest OS for SEV-SNP support. SEV-SNP builds upon existing SEV and SEV-ES functionality while adding new hardware-based memory protections. SEV-SNP adds strong memory integrity protection to help prevent malicious hypervisor-based attacks like data replay, memory re-mapping and more in order to create an isolated memory encryption environment. This series provides the basic building blocks to support booting the SEV-SNP VMs, it does not cover all the security enhancement introduced by the SEV-SNP such as interrupt protection. Many of the integrity guarantees of SEV-SNP are enforced through a new structure called the Reverse Map Table (RMP). Adding a new page to SEV-SNP VM requires a 2-step process. First, the hypervisor assigns a page to the guest using the new RMPUPDATE instruction. This transitions the page to guest-invalid. Second, the guest validates the page using the new PVALIDATE instruction. The SEV-SNP VMs can use the new "Page State Change Request NAE" defined in the GHCB specification to ask hypervisor to add or remove page from the RMP table. Each page assigned to the SEV-SNP VM can either be validated or unvalidated, as indicated by the Validated flag in the page's RMP entry. There are two approaches that can be taken for the page validation: Pre-validation and Lazy Validation. Under pre-validation, the pages are validated prior to first use. And under lazy validation, pages are validated when first accessed. An access to a unvalidated page results in a #VC exception, at which time the exception handler may validate the page. Lazy validation requires careful tracking of the validated pages to avoid validating the same GPA more than once. The recently introduced "Unaccepted" memory type can be used to communicate the unvalidated memory ranges to the Guest OS. At this time we only support the pre-validation, the OVMF guest BIOS validates the entire RAM before the control is handed over to the guest kernel. The early_set_memory_{encrypted,decrypted} and set_memory_{encrypted,decrypted} are enlightened to perform the page validation or invalidation while setting or clearing the encryption attribute from the page table. This series does not provide support for the Interrupt security yet which will be added after the base support. The complete branch is at https://github.com/AMDESE/linux/tree/sev-snp-v11 Patch 1-4 defines multiple VMSA save area to support SEV,SEV-ES and SEV-SNP guests. It is a pre-requisite for the SEV-SNP guest support, and included in the series for the completeness. These patch apply cleanly to kvm/next. It is also posted on KVM mailing list: https://lore.kernel.org/lkml/20211213173356.138726-3-brijesh.singh@amd.com/T/#m7d6868f3e81624323ea933d3a63a68949b286103 Additional resources --------------------- SEV-SNP whitepaper https://www.amd.com/system/files/TechDocs/SEV-SNP-strengthening-vm-isolation-with-integrity-protection-and-more.pdf APM 2: https://www.amd.com/system/files/TechDocs/24593.pdf (section 15.36) GHCB spec: https://developer.amd.com/wp-content/resources/56421.pdf SEV-SNP firmware specification: https://developer.amd.com/sev/ v10: https://lore.kernel.org/linux-mm/20220209181039.1262882-32-brijesh.singh@amd.com/T/ v9: https://lore.kernel.org/linux-mm/20220208052542.3g6nskck7uhjnfji@amd.com v8: https://lore.kernel.org/lkml/20211210154332.11526-1-brijesh.singh@amd.com/ v7: https://lore.kernel.org/linux-mm/20211110220731.2396491-40-brijesh.singh@amd.com/ v6: https://lore.kernel.org/linux-mm/20211008180453.462291-1-brijesh.singh@amd.com/ v5: https://lore.kernel.org/lkml/20210820151933.22401-1-brijesh.singh@amd.com/ Changes since v10: * Rebase patches to x86/cc. * Integerate the SNP page state change functions in x86_platform.guest_{prepare,finish} hook. Changes since v9: * Removed unecessary checks on CPUID table contents, added kernel param to dump CPUID table during boot * Added boot_{rd,wr}msr() helpers * Renamed/refactored SNP CPUID code/definitions for clarity/consistency * Re-worked comments for clarity and avoid redundancies * Moved SNP CPUID table documentation to Documentation/virt/coco/sevguest.rst * Documented cc_blob_address/acpi_rsdp_addr in zero-page.rst Changes since v8: * Setup the GHCB before taking the first #VC. * Make the CC blob structure size invariant. * Define the AP INIT macro and update the AP creation to use those macro instead of the hardcoded values. * Expand the comments to cover some of previous feedbacks. * Fix the commit messages based on the feedbacks. * Multiple fixes/cleanup on cpuid patches (based on Boris and Dave feedback) * drop is_efi64 return arguments in favor of a separate efi_get_type() helper. * drop is_efi64 input arguments in favor of calling efi_get_type() as-needed. * move acpi.c's kexec-specific handling into library code. * fix stack protection for 32/64-bit builds. * Export add_identity_map() to avoid SEV-specific code in ident_map_64.c. * use snp_abort() when terminating via initial ccblob scan. * fix the copyright header after the code refactor. * remove code duplication whereever possible. Changes since v7: * sevguest: extend the get report structure to accept the vmpl from userspace. * In the compressed path, move the GHCB protocol negotiation from VC handler to sev_enable(). * sev_enable(): don't expect SEV bit in status MSR when cpuid bit is present, update comments. * sme_enable(): call directly from head_64.S rather than as part of startup_64_setup_env, add comments * snp_find_cc_blob(), sev_prep_identity_maps(): add missing 'static' keywords to function prototypes Changes since v6: * Add rmpadjust() helper to be used by AP creation and vmpl0 detect function. * Clear the VM communication key if guest detects that hypervisor is modifying the SNP_GUEST_REQ response header. * Move the per-cpu GHCB registration from first #VC to idt setup. * Consolidate initial SEV/SME setup into a common entry point that gets called early enough to also be used for SEV-SNP CPUID table setup. * SNP CPUID: separate initial SEV-SNP feature detection out into standalone snp_init() routines, then add CPUID table setup to it as a separate patch. * SNP CPUID: fix boot issue with Seabios due to ACPI relying on certain EFI config table lookup failures as fallthrough cases rather than error cases. * SNP CPUID: drop the use of a separate init routines to handle pointer fixups after switching to kernel virtual addresses, instead use a helper that uses RIP-relative addressing to access CPUID table when either on identity mapping or kernel virtual addresses. Changes since v5: * move the seqno allocation in the sevguest driver. * extend snp_issue_guest_request() to accept the exit_info to simplify the logic. * use smaller structure names based on feedback. * explicitly clear the memory after the SNP guest request is completed. * cpuid validation: use a local copy of cpuid table instead of keeping firmware table mapped throughout boot. * cpuid validation: coding style fix-ups and refactor cpuid-related helpers as suggested. * cpuid validation: drop a number of BOOT_COMPRESSED-guarded defs/declarations by moving things like snp_cpuid_init*() out of sev-shared.c and keeping only the common bits there. * Break up EFI config table helpers and related acpi.c changes into separate patches. * re-enable stack protection for 32-bit kernels as well, not just 64-bit Changes since v4: * Address the cpuid specific review comment * Simplified the macro based on the review feedback * Move macro definition to the patch that needs it * Fix the issues reported by the checkpath * Address the AP creation specific review comment Changes since v3: * Add support to use the PSP filtered CPUID. * Add support for the extended guest request. * Move sevguest driver in driver/virt/coco. * Add documentation for sevguest ioctl. * Add support to check the vmpl0. * Pass the VM encryption key and id to be used for encrypting guest messages through the platform drv data. * Multiple cleanup and fixes to address the review feedbacks. Changes since v2: * Add support for AP startup using SNP specific vmgexit. * Add snp_prep_memory() helper. * Drop sev_snp_active() helper. * Add sev_feature_enabled() helper to check which SEV feature is active. * Sync the SNP guest message request header with latest SNP FW spec. * Multiple cleanup and fixes to address the review feedbacks. Changes since v1: * Integerate the SNP support in sev.{ch}. * Add support to query the hypervisor feature and detect whether SNP is supported. * Define Linux specific reason code for the SNP guest termination. * Extend the setup_header provide a way for hypervisor to pass secret and cpuid page. * Add support to create a platform device and driver to query the attestation report and the derive a key. * Multiple cleanup and fixes to address Boris's review fedback. Brijesh Singh (20): KVM: SVM: Define sev_features and vmpl field in the VMSA x86/mm: Extend cc_attr to include AMD SEV-SNP x86/sev: Define the Linux specific guest termination reasons x86/sev: Save the negotiated GHCB version x86/sev: Check SEV-SNP features support x86/sev: Add a helper for the PVALIDATE instruction x86/sev: Check the vmpl level x86/compressed: Add helper for validating pages in the decompression stage x86/compressed: Register GHCB memory when SEV-SNP is active x86/sev: Register GHCB memory when SEV-SNP is active x86/sev: Add helper for validating pages in early enc attribute changes x86/kernel: Make the .bss..decrypted section shared in RMP table x86/kernel: Validate ROM memory before accessing when SEV-SNP is active x86/mm: Validate memory when changing the C-bit x86/boot: Add Confidential Computing type to setup_data x86/sev: Provide support for SNP guest request NAEs x86/sev: Register SEV-SNP guest request platform device virt: Add SEV-SNP guest driver virt: sevguest: Add support to derive key virt: sevguest: Add support to get extended report Michael Roth (21): x86/boot: Introduce helpers for MSR reads/writes x86/boot: Use MSR read/write helpers instead of inline assembly x86/compressed/64: Detect/setup SEV/SME features earlier in boot x86/sev: Detect/setup SEV/SME features earlier in boot x86/head/64: Re-enable stack protection x86/compressed/acpi: Move EFI detection to helper x86/compressed/acpi: Move EFI system table lookup to helper x86/compressed/acpi: Move EFI config table lookup to helper x86/compressed/acpi: Move EFI vendor table lookup to helper x86/compressed/acpi: Move EFI kexec handling into common code KVM: x86: Move lookup of indexed CPUID leafs to helper x86/sev: Move MSR-based VMGEXITs for CPUID to helper x86/compressed/64: Add support for SEV-SNP CPUID table in #VC handlers x86/boot: Add a pointer to Confidential Computing blob in bootparams x86/compressed: Add SEV-SNP feature detection/setup x86/compressed: Use firmware-validated CPUID leaves for SEV-SNP guests x86/compressed: Export and rename add_identity_map() x86/compressed/64: Add identity mapping for Confidential Computing blob x86/sev: Add SEV-SNP feature detection/setup x86/sev: Use firmware-validated CPUID for SEV-SNP guests virt: sevguest: Add documentation for SEV-SNP CPUID Enforcement Tom Lendacky (4): KVM: SVM: Create a separate mapping for the SEV-ES save area KVM: SVM: Create a separate mapping for the GHCB save area KVM: SVM: Update the SEV-ES save area mapping x86/sev: Use SEV-SNP AP creation to start secondary CPUs .../admin-guide/kernel-parameters.txt | 4 + Documentation/virt/coco/sevguest.rst | 155 ++++ Documentation/virt/index.rst | 1 + Documentation/x86/zero-page.rst | 2 + arch/x86/boot/compressed/Makefile | 1 + arch/x86/boot/compressed/acpi.c | 173 +--- arch/x86/boot/compressed/efi.c | 238 ++++++ arch/x86/boot/compressed/head_64.S | 37 +- arch/x86/boot/compressed/ident_map_64.c | 39 +- arch/x86/boot/compressed/idt_64.c | 18 +- arch/x86/boot/compressed/mem_encrypt.S | 36 - arch/x86/boot/compressed/misc.h | 55 +- arch/x86/boot/compressed/sev.c | 263 +++++- arch/x86/boot/cpucheck.c | 30 +- arch/x86/boot/msr.h | 28 + arch/x86/coco/core.c | 3 + arch/x86/include/asm/bootparam_utils.h | 1 + arch/x86/include/asm/cpuid.h | 34 + arch/x86/include/asm/msr-index.h | 2 + arch/x86/include/asm/msr.h | 11 +- arch/x86/include/asm/setup.h | 1 - arch/x86/include/asm/sev-common.h | 82 ++ arch/x86/include/asm/sev.h | 102 ++- arch/x86/include/asm/shared/msr.h | 15 + arch/x86/include/asm/svm.h | 171 +++- arch/x86/include/uapi/asm/bootparam.h | 4 +- arch/x86/include/uapi/asm/svm.h | 13 + arch/x86/kernel/Makefile | 2 - arch/x86/kernel/cpu/common.c | 4 + arch/x86/kernel/head64.c | 29 +- arch/x86/kernel/head_64.S | 37 +- arch/x86/kernel/probe_roms.c | 13 +- arch/x86/kernel/sev-shared.c | 529 +++++++++++- arch/x86/kernel/sev.c | 802 +++++++++++++++++- arch/x86/kernel/smpboot.c | 3 + arch/x86/kvm/cpuid.c | 19 +- arch/x86/kvm/svm/sev.c | 24 +- arch/x86/kvm/svm/svm.c | 4 +- arch/x86/kvm/svm/svm.h | 2 +- arch/x86/mm/mem_encrypt.c | 4 + arch/x86/mm/mem_encrypt_amd.c | 71 +- arch/x86/mm/mem_encrypt_identity.c | 8 + drivers/virt/Kconfig | 3 + drivers/virt/Makefile | 1 + drivers/virt/coco/sevguest/Kconfig | 12 + drivers/virt/coco/sevguest/Makefile | 2 + drivers/virt/coco/sevguest/sevguest.c | 736 ++++++++++++++++ drivers/virt/coco/sevguest/sevguest.h | 98 +++ include/linux/cc_platform.h | 8 + include/linux/efi.h | 1 + include/uapi/linux/sev-guest.h | 80 ++ 51 files changed, 3638 insertions(+), 373 deletions(-) create mode 100644 Documentation/virt/coco/sevguest.rst create mode 100644 arch/x86/boot/compressed/efi.c create mode 100644 arch/x86/boot/msr.h create mode 100644 arch/x86/include/asm/cpuid.h create mode 100644 arch/x86/include/asm/shared/msr.h create mode 100644 drivers/virt/coco/sevguest/Kconfig create mode 100644 drivers/virt/coco/sevguest/Makefile create mode 100644 drivers/virt/coco/sevguest/sevguest.c create mode 100644 drivers/virt/coco/sevguest/sevguest.h create mode 100644 include/uapi/linux/sev-guest.h