added AMD SEV documentation for "[PATCH qemu-server] QEMU AMD SEV enable"
Signed-off-by: Markus Frank <m.fr...@proxmox.com> --- qm.adoc | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) diff --git a/qm.adoc b/qm.adoc index e666d7d..027d0a1 100644 --- a/qm.adoc +++ b/qm.adoc @@ -583,6 +583,65 @@ systems. When allocating RAM to your VMs, a good rule of thumb is always to leave 1GB of RAM available to the host. +[[qm_memory_encryption]] +Memory Encryption +~~~~~~~~~~~~~~~~~ + +AMD SEV +^^^^^^^ + +Memory Encryption using AES-128 Encryption and the AMD Secure Processor. +See https://developer.amd.com/sev/[AMD SEV] + +Requirements: + +* AMD EPYC/Ryzen PRO CPU +* configured SEV BIOS Settings on Host Machine +* add Kernel Parameters: "mem_encrypt=on kvm_amd.sev=1" + +Example Configuration: + +---- +# qm set <vmid> -memory_encryption type=sev,cbitpos=47,policy=0x0005,reduced-phys-bits=1 +---- + +"type" defines the encryption technology ("type=" is not necessary): sev, sev-snp, mktme + +"reduced-phys-bios", "cbitpos" and "policy" correspond to the variables with the +same name in qemu. + +"reduced-phys-bios" and "cbitpos" are system specific and can be read out +with QMP. If not set, qm starts a dummy-vm to read QMP +for these variables out and saves them to config. + +"policy" can be calculated with +https://www.amd.com/system/files/TechDocs/55766_SEV-KM_API_Specification.pdf[AMD SEV API Specification Chapter 3] + +To use SEV-ES (CPU register encryption) the "policy" should be set +somewhere between 0x4 and 0x7 or 0xC and 0xF, etc. +(Bit-2 has to be set 1 (LSB 0 bit numbering)) + +Limitations: + +* Memory usage on host is always wrong and around 82% Usage +* Snapshots do not work +* edk2-OVMF required +* Recommendable: VirtIO RNG for more entropy (VMs sometimes will not +boot without) + +Links: + +* https://github.com/AMDESE/AMDSEV +* https://www.qemu.org/docs/master/system/i386/amd-memory-encryption.html +* https://www.amd.com/system/files/TechDocs/55766_SEV-KM_API_Specification.pdf + +AMD SEV-SNP +^^^^^^^^^^^ + +* SEV-SNP support is not in the Linux Kernel yet and needs EPYC 7003 "Milan" +processors. +* SEV-SNP should be in Kernel 5.19: https://www.phoronix.com/scan.php?page=news_item&px=AMD-SEV-SNP-Arrives-Linux-5.19 +* patched Kernel: https://github.com/AMDESE/linux/tree/sev-snp-5.18-rc3 [[qm_network_device]] Network Device -- 2.30.2 _______________________________________________ pve-devel mailing list pve-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
