[RFC PATCH v1 00/28] x86: Secure Encrypted Virtualization (AMD)
Brijesh Singh
brijesh.singh at amd.com
Mon Aug 22 23:21:52 UTC 2016
This RFC series provides support for AMD's new Secure Encrypted
Virtualization (SEV) feature. This RFC is build upon Secure Memory
Encryption (SME) RFC.
SEV is an extension to the AMD-V architecture which supports running
multiple VMs under the control of a hypervisor. When enabled, SEV
hardware tags all code and data with its VM ASID which indicates which
VM the data originated from or is intended for. This tag is kept with
the data at all times when inside the SOC, and prevents that data from
being used by anyone other than the owner. While the tag protects VM
data inside the SOC, AES with 128 bit encryption protects data outside
the SOC. When data leaves or enters the SOC, it is encrypted/decrypted
respectively by hardware with a key based on the associated tag.
SEV guest VMs have the concept of private and shared memory. Private memory
is encrypted with the guest-specific key, while shared memory may be encrypted
with hypervisor key. Certain types of memory (namely instruction pages and
guest page tables) are always treated as private memory by the hardware.
For data memory, SEV guest VMs can choose which pages they would like to
be private. The choice is done using the standard CPU page tables using
the C-bit, and is fully controlled by the guest. Due to security reasons
all the DMA operations inside the guest must be performed on shared pages
(C-bit clear). Note that since C-bit is only controllable by the guest OS
when it is operating in 64-bit or 32-bit PAE mode, in all other modes the
SEV hardware forces the C-bit to a 1.
SEV is designed to protect guest VMs from a benign but vulnerable
(i.e. not fully malicious) hypervisor. In particular, it reduces the attack
surface of guest VMs and can prevent certain types of VM-escape bugs
(e.g. hypervisor read-anywhere) from being used to steal guest data.
The RFC series also includes a crypto driver (psp.ko) which communicates
with SEV firmware that runs within the AMD secure processor provides a
secure key management interfaces. The hypervisor uses this interface to
enable SEV for secure guest and perform common hypervisor activities
such as launching, running, snapshotting , migrating and debugging a
guest. A new ioctl (KVM_SEV_ISSUE_CMD) is introduced which will enable
Qemu to send commands to the SEV firmware during guest life cycle.
The RFC series also includes patches required in guest OS to enable SEV
feature. A guest OS can check SEV support by calling KVM_FEATURE cpuid
instruction.
The following links provide additional details:
AMD Memory Encryption whitepaper:
http://amd-dev.wpengine.netdna-cdn.com/wordpress/media/2013/12/AMD_Memory_Encryption_Whitepaper_v7-Public.pdf
AMD64 Architecture Programmer's Manual:
http://support.amd.com/TechDocs/24593.pdf
SME is section 7.10
SEV is section 15.34
Secure Encrypted Virutualization Key Management:
http://support.amd.com/TechDocs/55766_SEV-KM API_Spec.pdf
---
TODO:
- send qemu/seabios RFC's on respective mailing list
- integrate the psp driver with CCP driver (they share the PCI id's)
- add SEV guest migration command support
- add SEV snapshotting command support
- determine how to do ioremap of physical memory with mem encryption enabled
(e.g acpi tables)
- determine how to share the guest memory with hypervisor for to support
pvclock driver
Brijesh Singh (11):
crypto: add AMD Platform Security Processor driver
KVM: SVM: prepare to reserve asid for SEV guest
KVM: SVM: prepare for SEV guest management API support
KVM: introduce KVM_SEV_ISSUE_CMD ioctl
KVM: SVM: add SEV launch start command
KVM: SVM: add SEV launch update command
KVM: SVM: add SEV_LAUNCH_FINISH command
KVM: SVM: add KVM_SEV_GUEST_STATUS command
KVM: SVM: add KVM_SEV_DEBUG_DECRYPT command
KVM: SVM: add KVM_SEV_DEBUG_ENCRYPT command
KVM: SVM: add command to query SEV API version
Tom Lendacky (17):
kvm: svm: Add support for additional SVM NPF error codes
kvm: svm: Add kvm_fast_pio_in support
kvm: svm: Use the hardware provided GPA instead of page walk
x86: Secure Encrypted Virtualization (SEV) support
KVM: SVM: prepare for new bit definition in nested_ctl
KVM: SVM: Add SEV feature definitions to KVM
x86: Do not encrypt memory areas if SEV is enabled
Access BOOT related data encrypted with SEV active
x86/efi: Access EFI data as encrypted when SEV is active
x86: Change early_ioremap to early_memremap for BOOT data
x86: Don't decrypt trampoline area if SEV is active
x86: DMA support for SEV memory encryption
iommu/amd: AMD IOMMU support for SEV
x86: Don't set the SME MSR bit when SEV is active
x86: Unroll string I/O when SEV is active
x86: Add support to determine if running with SEV enabled
KVM: SVM: Enable SEV by setting the SEV_ENABLE cpu feature
arch/x86/boot/compressed/Makefile | 2
arch/x86/boot/compressed/head_64.S | 19 +
arch/x86/boot/compressed/mem_encrypt.S | 123 ++++
arch/x86/include/asm/io.h | 26 +
arch/x86/include/asm/kvm_emulate.h | 3
arch/x86/include/asm/kvm_host.h | 27 +
arch/x86/include/asm/mem_encrypt.h | 3
arch/x86/include/asm/svm.h | 3
arch/x86/include/uapi/asm/hyperv.h | 4
arch/x86/include/uapi/asm/kvm_para.h | 4
arch/x86/kernel/acpi/boot.c | 4
arch/x86/kernel/head64.c | 4
arch/x86/kernel/mem_encrypt.S | 44 ++
arch/x86/kernel/mpparse.c | 10
arch/x86/kernel/setup.c | 7
arch/x86/kernel/x8664_ksyms_64.c | 1
arch/x86/kvm/cpuid.c | 4
arch/x86/kvm/mmu.c | 20 +
arch/x86/kvm/svm.c | 906 ++++++++++++++++++++++++++++++++
arch/x86/kvm/x86.c | 73 +++
arch/x86/mm/ioremap.c | 7
arch/x86/mm/mem_encrypt.c | 50 ++
arch/x86/platform/efi/efi_64.c | 14
arch/x86/realmode/init.c | 11
drivers/crypto/Kconfig | 11
drivers/crypto/Makefile | 1
drivers/crypto/psp/Kconfig | 8
drivers/crypto/psp/Makefile | 3
drivers/crypto/psp/psp-dev.c | 220 ++++++++
drivers/crypto/psp/psp-dev.h | 95 +++
drivers/crypto/psp/psp-ops.c | 454 ++++++++++++++++
drivers/crypto/psp/psp-pci.c | 376 +++++++++++++
drivers/sfi/sfi_core.c | 6
include/linux/ccp-psp.h | 833 +++++++++++++++++++++++++++++
include/uapi/linux/Kbuild | 1
include/uapi/linux/ccp-psp.h | 182 ++++++
include/uapi/linux/kvm.h | 125 ++++
37 files changed, 3643 insertions(+), 41 deletions(-)
create mode 100644 arch/x86/boot/compressed/mem_encrypt.S
create mode 100644 drivers/crypto/psp/Kconfig
create mode 100644 drivers/crypto/psp/Makefile
create mode 100644 drivers/crypto/psp/psp-dev.c
create mode 100644 drivers/crypto/psp/psp-dev.h
create mode 100644 drivers/crypto/psp/psp-ops.c
create mode 100644 drivers/crypto/psp/psp-pci.c
create mode 100644 include/linux/ccp-psp.h
create mode 100644 include/uapi/linux/ccp-psp.h
--
Brijesh Singh
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