6 ms·

I thought AWS uses KVM, which is the same VM that QEMU would use? Or am I mistaken?

by _rs 2y ago

bonzini 2y ago
AWS uses KVM in the kernel but they have a different, non-open source userspace stack for EC2; plus Firecracker which is open source but is only used for Lambda, and runs on EC2 bare metal instances. Google also uses KVM with a variety of userspace stacks: a proprietary one (tied to a lot of internal Google infrastructure but overall a lot more similar to QEMU than Amazon's) for GCE, gVisor for AppEngine or whatever it is called these days, crosvm for ChromeOS, and QEMU for Android Emulator.
- tptacek 2y ago
  Lambda and Fargate.
  - dastbe 2y ago
    unless something has changed in the past year, fargate still runs each task in a single use ec2 vm with no further isolation around containers in a task.
    - deleted 2y ago
      [deleted]
  - my123 2y ago
    It was true for Fargate some time ago, but is not true anymore since quite a while. All Fargate tasks run on EC2 instances today.
    - easton 2y ago
      …which is probably the reason why task launches take 3-5 business weeks
    - tptacek 2y ago
      Ah, interesting. Thanks for the correction!
- 9front 2y ago
  EC2 instances are using the Xen hypervisor. At least that's what reported by hostnamectl.
  - wmf 2y ago
    EC2 migrated off Xen around ten years ago. Only really old instances should be using Xen or Xen emulation.
    - 9front 2y ago
      I'm puzzled by your comment. On an EC2 instance of AL2023 deployed on us-east-1 region this is the output of hostnamectl: [ec2-user][~]$ hostnamectl Static hostname: ip-x-x-x-x.ec2.internal Icon name: computer-vm Chassis: vm Machine ID: ec2d54f27fc534ea74980638ccc33d96 Boot ID: 6caf18b7ed3647819c1985c11f128142 Virtualization: xen Operating System: Amazon Linux 2023.5.20240903 CPE OS Name: cpe:2.3:o:amazon:amazon_linux:2023 Kernel: Linux 6.1.106-116.188.amzn2023.x86_64 Architecture: x86-64 Hardware Vendor: Xen Hardware Model: HVM domU Firmware Version: 4.11.amazon
      - wmf 2y ago
        What instance type is it?
      - bonzini 2y ago
        KVM can emulate the Xen hypercall interface. Amazon is not using Xen anymore.
      - simcop2387 2y ago
        I'm not quite sure the status of it at least, but reported back in 2017 that they are moving off Xen https://www.theregister.com/2017/11/07/aws_writes_new_kvm_based_hypervisor_to_make_its_cloud_go_faster https://www.theregister.com/2017/11/07/aws_writes_new_kvm_ba... It could be that it's not all over and tied to specific machine types still, or there's something they've done to make it report to the guest still that it's xen based for some compatibility reasons.
daneel_w 2y ago
QEMU can use a number of different hypervisors, KVM and Xen being the two most common ones. Additionally it can also emulate any architecture if one would want/need that.

I thought AWS uses KVM, which is the same VM that QEMU would use? Or am I mistaken?

by _rs 2y ago

I thought AWS uses KVM, which is the same VM that QEMU would use? Or am I mistaken?

AWS uses KVM in the kernel but they have a different, non-open source userspace stack for EC2; plus Firecracker which is open source but is only used for Lambda, and runs on EC2 bare metal instances. Google also uses KVM with a variety of userspace stacks: a proprietary one (tied to a lot of internal Google infrastructure but overall a lot more similar to QEMU than Amazon's) for GCE, gVisor for AppEngine or whatever it is called these days, crosvm for ChromeOS, and QEMU for Android Emulator.

tptacek 2y ago
Lambda and Fargate.
- dastbe 2y ago
  unless something has changed in the past year, fargate still runs each task in a single use ec2 vm with no further isolation around containers in a task.
  - deleted 2y ago
    [deleted]
- my123 2y ago
  It was true for Fargate some time ago, but is not true anymore since quite a while. All Fargate tasks run on EC2 instances today.
  - easton 2y ago
    …which is probably the reason why task launches take 3-5 business weeks
  - tptacek 2y ago
    Ah, interesting. Thanks for the correction!
9front 2y ago
EC2 instances are using the Xen hypervisor. At least that's what reported by hostnamectl.
- wmf 2y ago
  EC2 migrated off Xen around ten years ago. Only really old instances should be using Xen or Xen emulation.
  - 9front 2y ago
    I'm puzzled by your comment. On an EC2 instance of AL2023 deployed on us-east-1 region this is the output of hostnamectl: [ec2-user][~]$ hostnamectl Static hostname: ip-x-x-x-x.ec2.internal Icon name: computer-vm Chassis: vm Machine ID: ec2d54f27fc534ea74980638ccc33d96 Boot ID: 6caf18b7ed3647819c1985c11f128142 Virtualization: xen Operating System: Amazon Linux 2023.5.20240903 CPE OS Name: cpe:2.3:o:amazon:amazon_linux:2023 Kernel: Linux 6.1.106-116.188.amzn2023.x86_64 Architecture: x86-64 Hardware Vendor: Xen Hardware Model: HVM domU Firmware Version: 4.11.amazon
    - wmf 2y ago
      What instance type is it?
    - bonzini 2y ago
      KVM can emulate the Xen hypercall interface. Amazon is not using Xen anymore.
    - simcop2387 2y ago
      I'm not quite sure the status of it at least, but reported back in 2017 that they are moving off Xen https://www.theregister.com/2017/11/07/aws_writes_new_kvm_based_hypervisor_to_make_its_cloud_go_faster https://www.theregister.com/2017/11/07/aws_writes_new_kvm_ba... It could be that it's not all over and tied to specific machine types still, or there's something they've done to make it report to the guest still that it's xen based for some compatibility reasons.

daneel_w 2y ago

QEMU can use a number of different hypervisors, KVM and Xen being the two most common ones. Additionally it can also emulate any architecture if one would want/need that.