diff options
Diffstat (limited to 'gitlab/issues/target_missing/host_missing/accel_missing/1142.toml')
| -rw-r--r-- | gitlab/issues/target_missing/host_missing/accel_missing/1142.toml | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/gitlab/issues/target_missing/host_missing/accel_missing/1142.toml b/gitlab/issues/target_missing/host_missing/accel_missing/1142.toml new file mode 100644 index 00000000..7813e980 --- /dev/null +++ b/gitlab/issues/target_missing/host_missing/accel_missing/1142.toml @@ -0,0 +1,54 @@ +id = 1142 +title = "Measurements fail with direct kernel boot for AMD SEV confidential virtualization with 7.1 machine type" +state = "closed" +created_at = "2022-08-04T12:08:56.036Z" +closed_at = "2022-11-07T12:53:17.474Z" +labels = ["kind::Bug"] +url = "https://gitlab.com/qemu-project/qemu/-/issues/1142" +host-os = "n/a" +host-arch = "x86_64" +qemu-version = "git 2480f3bbd03814b0651a1f74959f5c6631ee5819" +guest-os = "n/a" +guest-arch = "n/a" +description = """When booting the QEMU with the 'kernel-hashes:true' property set for 'sev-guest' confidential virtualization, the contents of the `-kernel` file are measured by the firmware. + +A remote tenant can then validate the measurement against its expected contents to see if the boot was trustworthy. + +With the pc-q35-7.1 machine type the measurement always fails to validate against expected state. + +Making the following code change + +``` +diff --git a/hw/i386/pc.c b/hw/i386/pc.c +index 7280c02ce3..3a4bf5cba3 100644 +--- a/hw/i386/pc.c ++++ b/hw/i386/pc.c +@@ -1899,6 +1899,8 @@ static void pc_machine_class_init(ObjectClass *oc, void *data) + pcmc->rsdp_in_ram = true; + pcmc->smbios_defaults = true; + pcmc->smbios_uuid_encoded = true; ++ pcmc->legacy_no_rng_seed = true; ++ + pcmc->gigabyte_align = true; + pcmc->has_reserved_memory = true; + pcmc->kvmclock_enabled = true; +``` + +results in successfully validating the measurement. + +THis is not surprising, the RNG seed patch introduced in + +``` +commit 67f7e426e53833a5db75b0d813e8d537b8a75bd2 +Author: Jason A. Donenfeld <Jason@zx2c4.com> +Date: Thu Jul 21 14:56:36 2022 +0200 + + hw/i386: pass RNG seed via setup_data entry +``` + +intentionally modifies the contents of the kernel image before passing it to the firmware, to inject a random seed. This will ensure the boot measuremnts are different every time. + +This RNG seed functionality must NOT be used when AMD SEV is active.""" +reproduce = """1. Create an AMD SEV guest with kernel-hashes=true and pc-q35-7.1 machine type +2. Attempt to validate the boot measurement""" +additional = """""" |