Backport CPU template/CPUID normalization fixes to v1.4 #3935
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Sets FDP_EXCPTN_ONLY bit (CPUID.7h.0:EBX[6]) and ZERO_FCS_FDS bit (CPUID.7h.0:EBX[13]) in Intel's CPUID normalization as recommended in kernel doc. For more details, please refer to https://lore.kernel.org/all/20220322110712.222449-3-pbonzini@redhat.com/ Signed-off-by: Takahiro Itazuri <itazur@amazon.com>
We updated the fingerprint files in PR firecracker-microvm#3813, since Intel microcode release (microcode-20230512) changed to set IA32_ARCH_CAPABILITIES.RRSBA (bit 19) to 1 on Intel CascadeLake CPU. The mitigation itself is already in place which is eIBRS. Since the kernel enables eIBRS by default using SPECTRE_V2_EIBRS mode regardless of the IA32_ARCH_CAPABILITIES.RRSBA bit, hosts and guests should not get impacted by this change. However, it has a role to inform softwares whether the part has the RRSBA behavior. The T2S template has set it to 0 explicitly before, but this commit changes to set it to 1 so that guest kernels and applications can know that the processor has the RRSBA behavior. The reason why it sets the bit to 1 instead of passing through it from the host is that it aims to provide the ability to securely migrate snapshots between Intel Skylake and Intel CascadeLake. Signed-off-by: Takahiro Itazuri <itazur@amazon.com>
We updated the fingerprint files in PR firecracker-microvm#3813, since Intel microcode release (microcode-20230512) changed to set IA32_ARCH_CAPABILITIES.RRSBA (bit 19) to 1 on Intel CascadeLake CPU. The mitigation itself is already in place which is eIBRS. Since the kernel enables eIBRS by default using SPECTRE_V2_EIBRS mode regardless of the IA32_ARCH_CAPABILITIES.RRSBA bit, hosts and guests should not get impacted by this change. However, it has a role to inform softwares whether the part has the RRSBA behavior. The T2CL template has set the RRSBA bit to 0 explicitly before, but this commit changes to pass through the bit from the host so that guest kernels and applications can know that the processor has the RRSBA behavior. The reason why it passes through the bit from the host opposed to the T2S template is that the T2CL template is not designed to allow snapshot migration between different CPU models. In addition to the RRSBA bit, this comit also changes to pass through the RSBA bit, as it is safer to let guest know these informative bits of the host CPU than to overwrite them with templates. Signed-off-by: Takahiro Itazuri <itazur@amazon.com>
m6a.metal tests have been timing out due to too many different combinations of firecracker versions being tested in the snapshot tests. Signed-off-by: Patrick Roy <roypat@amazon.co.uk>
Removing as it is a microbenchmark and not representative or a real workload. If there is a performance regression on this piece, the snapshot/restore should be able to detect it. Signed-off-by: Pablo Barbáchano <pablob@amazon.com>
kalyazin
approved these changes
Jul 5, 2023
roypat
approved these changes
Jul 7, 2023
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CONTRIBUTING.md.PR Checklist
[ ] If a specific issue led to this PR, this PR closes the issue.[ ] Any required documentation changes (code and docs) are included in this PR.[ ] API changes follow the Runbook for Firecracker API changes.CHANGELOG.md.[ ] NewTODOs link to an issue.rust-vmm.