Virtual machines can exploit Intel ISA characterstics to cause
functional denial of service to the VMM. This series introduces a new
feature named Notify VM exit, which can help mitigate such kind of
attacks.
Patch 1: An extension of KVM_SET_VCPU_EVENTS ioctl to inject a
synthesized shutdown event from user space. This is also a fix for other
synthesized triple fault, e.g. the RSM patch or nested_vmx_abort(),
which could get lost when exit to userspace to do migrate.
Patch 2: A selftest about get/set triple fault event.
Patch 3: The main patch to enable Notify VM exit.
---
Change logs:
v5 -> v6
- Do some changes in document.
- Add a selftest about get/set triple fault event. (Sean)
- extend the argument to include both the notify window and some flags
when enabling KVM_CAP_X86_BUS_LOCK_EXIT CAP. (Sean)
- Change to use KVM_VCPUEVENT_VALID_TRIPE_FAULT in flags field and add
pending_triple_fault field in struct kvm_vcpu_events, which allows
userspace to make/clear triple fault request. (Sean)
- Add a flag in kvm_x86_ops to avoid the kvm_has_notify_vmexit global
varialbe and its export.(Sean)
- v5: https://lore.kernel.org/lkml/[email protected]/
v4 -> v5
- rename KVM_VCPUEVENTS_SHUTDOWN to KVM_VCPUEVENTS_TRIPLE_FAULT. Make it
bidirection and add it to get_vcpu_events. (Sean)
- v4: https://lore.kernel.org/all/[email protected]/
v3 -> v4
- Change this feature to per-VM scope. (Jim)
- Once VM_CONTEXT_INVALID set in exit_qualification, exit to user space
notify this fatal case, especially the notify VM exit happens in L2.
(Jim)
- extend KVM_SET_VCPU_EVENTS to allow user space to inject a shutdown
event. (Jim)
- A minor code changes.
- Add document for the new KVM capability.
- v3: https://lore.kernel.org/lkml/[email protected]/
v2 -> v3
- add a vcpu state notify_window_exits to record the number of
occurence as well as a pr_warn output. (Sean)
- Add the handling in nested VM to prevent L1 bypassing the restriction
through launching a L2. (Sean)
- Only kill L2 when L2 VM is context invalid, synthesize a
EXIT_REASON_TRIPLE_FAULT to L1 (Sean)
- To ease the current implementation, make module parameter
notify_window read-only. (Sean)
- Disable notify window exit by default.
- v2: https://lore.kernel.org/lkml/[email protected]/
v1 -> v2
- Default set notify window to 0, less than 0 to disable.
- Add more description in commit message.
---
Chenyi Qiang (2):
KVM: X86: Save&restore the triple fault request
KVM: selftests: Add a test to get/set triple fault event
Tao Xu (1):
KVM: VMX: Enable Notify VM exit
Documentation/virt/kvm/api.rst | 55 +++++++++++
arch/x86/include/asm/kvm_host.h | 9 ++
arch/x86/include/asm/vmx.h | 7 ++
arch/x86/include/asm/vmxfeatures.h | 1 +
arch/x86/include/uapi/asm/kvm.h | 4 +-
arch/x86/include/uapi/asm/vmx.h | 4 +-
arch/x86/kvm/vmx/capabilities.h | 6 ++
arch/x86/kvm/vmx/nested.c | 8 ++
arch/x86/kvm/vmx/vmx.c | 48 +++++++++-
arch/x86/kvm/x86.c | 33 ++++++-
arch/x86/kvm/x86.h | 5 +
include/uapi/linux/kvm.h | 10 ++
tools/testing/selftests/kvm/.gitignore | 1 +
tools/testing/selftests/kvm/Makefile | 1 +
.../kvm/x86_64/triple_fault_event_test.c | 96 +++++++++++++++++++
15 files changed, 280 insertions(+), 8 deletions(-)
create mode 100644 tools/testing/selftests/kvm/x86_64/triple_fault_event_test.c
--
2.17.1
Kindly ping for the comments.
On 4/21/2022 3:29 PM, Chenyi Qiang wrote:
> Virtual machines can exploit Intel ISA characterstics to cause
> functional denial of service to the VMM. This series introduces a new
> feature named Notify VM exit, which can help mitigate such kind of
> attacks.
>
> Patch 1: An extension of KVM_SET_VCPU_EVENTS ioctl to inject a
> synthesized shutdown event from user space. This is also a fix for other
> synthesized triple fault, e.g. the RSM patch or nested_vmx_abort(),
> which could get lost when exit to userspace to do migrate.
>
> Patch 2: A selftest about get/set triple fault event.
>
> Patch 3: The main patch to enable Notify VM exit.
>
> ---
> Change logs:
> v5 -> v6
> - Do some changes in document.
> - Add a selftest about get/set triple fault event. (Sean)
> - extend the argument to include both the notify window and some flags
> when enabling KVM_CAP_X86_BUS_LOCK_EXIT CAP. (Sean)
> - Change to use KVM_VCPUEVENT_VALID_TRIPE_FAULT in flags field and add
> pending_triple_fault field in struct kvm_vcpu_events, which allows
> userspace to make/clear triple fault request. (Sean)
> - Add a flag in kvm_x86_ops to avoid the kvm_has_notify_vmexit global
> varialbe and its export.(Sean)
> - v5: https://lore.kernel.org/lkml/[email protected]/
>
> v4 -> v5
> - rename KVM_VCPUEVENTS_SHUTDOWN to KVM_VCPUEVENTS_TRIPLE_FAULT. Make it
> bidirection and add it to get_vcpu_events. (Sean)
> - v4: https://lore.kernel.org/all/[email protected]/
>
> v3 -> v4
> - Change this feature to per-VM scope. (Jim)
> - Once VM_CONTEXT_INVALID set in exit_qualification, exit to user space
> notify this fatal case, especially the notify VM exit happens in L2.
> (Jim)
> - extend KVM_SET_VCPU_EVENTS to allow user space to inject a shutdown
> event. (Jim)
> - A minor code changes.
> - Add document for the new KVM capability.
> - v3: https://lore.kernel.org/lkml/[email protected]/
>
> v2 -> v3
> - add a vcpu state notify_window_exits to record the number of
> occurence as well as a pr_warn output. (Sean)
> - Add the handling in nested VM to prevent L1 bypassing the restriction
> through launching a L2. (Sean)
> - Only kill L2 when L2 VM is context invalid, synthesize a
> EXIT_REASON_TRIPLE_FAULT to L1 (Sean)
> - To ease the current implementation, make module parameter
> notify_window read-only. (Sean)
> - Disable notify window exit by default.
> - v2: https://lore.kernel.org/lkml/[email protected]/
>
> v1 -> v2
> - Default set notify window to 0, less than 0 to disable.
> - Add more description in commit message.
> ---
>
> Chenyi Qiang (2):
> KVM: X86: Save&restore the triple fault request
> KVM: selftests: Add a test to get/set triple fault event
>
> Tao Xu (1):
> KVM: VMX: Enable Notify VM exit
>
> Documentation/virt/kvm/api.rst | 55 +++++++++++
> arch/x86/include/asm/kvm_host.h | 9 ++
> arch/x86/include/asm/vmx.h | 7 ++
> arch/x86/include/asm/vmxfeatures.h | 1 +
> arch/x86/include/uapi/asm/kvm.h | 4 +-
> arch/x86/include/uapi/asm/vmx.h | 4 +-
> arch/x86/kvm/vmx/capabilities.h | 6 ++
> arch/x86/kvm/vmx/nested.c | 8 ++
> arch/x86/kvm/vmx/vmx.c | 48 +++++++++-
> arch/x86/kvm/x86.c | 33 ++++++-
> arch/x86/kvm/x86.h | 5 +
> include/uapi/linux/kvm.h | 10 ++
> tools/testing/selftests/kvm/.gitignore | 1 +
> tools/testing/selftests/kvm/Makefile | 1 +
> .../kvm/x86_64/triple_fault_event_test.c | 96 +++++++++++++++++++
> 15 files changed, 280 insertions(+), 8 deletions(-)
> create mode 100644 tools/testing/selftests/kvm/x86_64/triple_fault_event_test.c
>
On 4/21/22 09:29, Chenyi Qiang wrote:
> Virtual machines can exploit Intel ISA characterstics to cause
> functional denial of service to the VMM. This series introduces a new
> feature named Notify VM exit, which can help mitigate such kind of
> attacks.
>
> Patch 1: An extension of KVM_SET_VCPU_EVENTS ioctl to inject a
> synthesized shutdown event from user space. This is also a fix for other
> synthesized triple fault, e.g. the RSM patch or nested_vmx_abort(),
> which could get lost when exit to userspace to do migrate.
>
> Patch 2: A selftest about get/set triple fault event.
>
> Patch 3: The main patch to enable Notify VM exit.
Chenyi, can you send v7 for inclusion?
Paolo
> ---
> Change logs:
> v5 -> v6
> - Do some changes in document.
> - Add a selftest about get/set triple fault event. (Sean)
> - extend the argument to include both the notify window and some flags
> when enabling KVM_CAP_X86_BUS_LOCK_EXIT CAP. (Sean)
> - Change to use KVM_VCPUEVENT_VALID_TRIPE_FAULT in flags field and add
> pending_triple_fault field in struct kvm_vcpu_events, which allows
> userspace to make/clear triple fault request. (Sean)
> - Add a flag in kvm_x86_ops to avoid the kvm_has_notify_vmexit global
> varialbe and its export.(Sean)
> - v5: https://lore.kernel.org/lkml/[email protected]/
>
> v4 -> v5
> - rename KVM_VCPUEVENTS_SHUTDOWN to KVM_VCPUEVENTS_TRIPLE_FAULT. Make it
> bidirection and add it to get_vcpu_events. (Sean)
> - v4: https://lore.kernel.org/all/[email protected]/
>
> v3 -> v4
> - Change this feature to per-VM scope. (Jim)
> - Once VM_CONTEXT_INVALID set in exit_qualification, exit to user space
> notify this fatal case, especially the notify VM exit happens in L2.
> (Jim)
> - extend KVM_SET_VCPU_EVENTS to allow user space to inject a shutdown
> event. (Jim)
> - A minor code changes.
> - Add document for the new KVM capability.
> - v3: https://lore.kernel.org/lkml/[email protected]/
>
> v2 -> v3
> - add a vcpu state notify_window_exits to record the number of
> occurence as well as a pr_warn output. (Sean)
> - Add the handling in nested VM to prevent L1 bypassing the restriction
> through launching a L2. (Sean)
> - Only kill L2 when L2 VM is context invalid, synthesize a
> EXIT_REASON_TRIPLE_FAULT to L1 (Sean)
> - To ease the current implementation, make module parameter
> notify_window read-only. (Sean)
> - Disable notify window exit by default.
> - v2: https://lore.kernel.org/lkml/[email protected]/
>
> v1 -> v2
> - Default set notify window to 0, less than 0 to disable.
> - Add more description in commit message.
> ---
>
> Chenyi Qiang (2):
> KVM: X86: Save&restore the triple fault request
> KVM: selftests: Add a test to get/set triple fault event
>
> Tao Xu (1):
> KVM: VMX: Enable Notify VM exit
>
> Documentation/virt/kvm/api.rst | 55 +++++++++++
> arch/x86/include/asm/kvm_host.h | 9 ++
> arch/x86/include/asm/vmx.h | 7 ++
> arch/x86/include/asm/vmxfeatures.h | 1 +
> arch/x86/include/uapi/asm/kvm.h | 4 +-
> arch/x86/include/uapi/asm/vmx.h | 4 +-
> arch/x86/kvm/vmx/capabilities.h | 6 ++
> arch/x86/kvm/vmx/nested.c | 8 ++
> arch/x86/kvm/vmx/vmx.c | 48 +++++++++-
> arch/x86/kvm/x86.c | 33 ++++++-
> arch/x86/kvm/x86.h | 5 +
> include/uapi/linux/kvm.h | 10 ++
> tools/testing/selftests/kvm/.gitignore | 1 +
> tools/testing/selftests/kvm/Makefile | 1 +
> .../kvm/x86_64/triple_fault_event_test.c | 96 +++++++++++++++++++
> 15 files changed, 280 insertions(+), 8 deletions(-)
> create mode 100644 tools/testing/selftests/kvm/x86_64/triple_fault_event_test.c
>
On 5/24/2022 3:30 AM, Paolo Bonzini wrote:
> On 4/21/22 09:29, Chenyi Qiang wrote:
>> Virtual machines can exploit Intel ISA characterstics to cause
>> functional denial of service to the VMM. This series introduces a new
>> feature named Notify VM exit, which can help mitigate such kind of
>> attacks.
>>
>> Patch 1: An extension of KVM_SET_VCPU_EVENTS ioctl to inject a
>> synthesized shutdown event from user space. This is also a fix for other
>> synthesized triple fault, e.g. the RSM patch or nested_vmx_abort(),
>> which could get lost when exit to userspace to do migrate.
>>
>> Patch 2: A selftest about get/set triple fault event.
>>
>> Patch 3: The main patch to enable Notify VM exit.
>
> Chenyi, can you send v7 for inclusion?
>
> Paolo
>
Hi Paolo
v7 is sent out at
https://lore.kernel.org/lkml/[email protected]/
>> ---
>> Change logs:
>> v5 -> v6
>> - Do some changes in document.
>> - Add a selftest about get/set triple fault event. (Sean)
>> - extend the argument to include both the notify window and some flags
>> when enabling KVM_CAP_X86_BUS_LOCK_EXIT CAP. (Sean)
>> - Change to use KVM_VCPUEVENT_VALID_TRIPE_FAULT in flags field and add
>> pending_triple_fault field in struct kvm_vcpu_events, which allows
>> userspace to make/clear triple fault request. (Sean)
>> - Add a flag in kvm_x86_ops to avoid the kvm_has_notify_vmexit global
>> varialbe and its export.(Sean)
>> - v5:
>> https://lore.kernel.org/lkml/[email protected]/
>>
>>
>> v4 -> v5
>> - rename KVM_VCPUEVENTS_SHUTDOWN to KVM_VCPUEVENTS_TRIPLE_FAULT. Make it
>> bidirection and add it to get_vcpu_events. (Sean)
>> - v4:
>> https://lore.kernel.org/all/[email protected]/
>>
>>
>> v3 -> v4
>> - Change this feature to per-VM scope. (Jim)
>> - Once VM_CONTEXT_INVALID set in exit_qualification, exit to user space
>> notify this fatal case, especially the notify VM exit happens in L2.
>> (Jim)
>> - extend KVM_SET_VCPU_EVENTS to allow user space to inject a shutdown
>> event. (Jim)
>> - A minor code changes.
>> - Add document for the new KVM capability.
>> - v3:
>> https://lore.kernel.org/lkml/[email protected]/
>>
>>
>> v2 -> v3
>> - add a vcpu state notify_window_exits to record the number of
>> occurence as well as a pr_warn output. (Sean)
>> - Add the handling in nested VM to prevent L1 bypassing the restriction
>> through launching a L2. (Sean)
>> - Only kill L2 when L2 VM is context invalid, synthesize a
>> EXIT_REASON_TRIPLE_FAULT to L1 (Sean)
>> - To ease the current implementation, make module parameter
>> notify_window read-only. (Sean)
>> - Disable notify window exit by default.
>> - v2:
>> https://lore.kernel.org/lkml/[email protected]/
>>
>> v1 -> v2
>> - Default set notify window to 0, less than 0 to disable.
>> - Add more description in commit message.
>> ---
>>
>> Chenyi Qiang (2):
>> KVM: X86: Save&restore the triple fault request
>> KVM: selftests: Add a test to get/set triple fault event
>>
>> Tao Xu (1):
>> KVM: VMX: Enable Notify VM exit
>>
>> Documentation/virt/kvm/api.rst | 55 +++++++++++
>> arch/x86/include/asm/kvm_host.h | 9 ++
>> arch/x86/include/asm/vmx.h | 7 ++
>> arch/x86/include/asm/vmxfeatures.h | 1 +
>> arch/x86/include/uapi/asm/kvm.h | 4 +-
>> arch/x86/include/uapi/asm/vmx.h | 4 +-
>> arch/x86/kvm/vmx/capabilities.h | 6 ++
>> arch/x86/kvm/vmx/nested.c | 8 ++
>> arch/x86/kvm/vmx/vmx.c | 48 +++++++++-
>> arch/x86/kvm/x86.c | 33 ++++++-
>> arch/x86/kvm/x86.h | 5 +
>> include/uapi/linux/kvm.h | 10 ++
>> tools/testing/selftests/kvm/.gitignore | 1 +
>> tools/testing/selftests/kvm/Makefile | 1 +
>> .../kvm/x86_64/triple_fault_event_test.c | 96 +++++++++++++++++++
>> 15 files changed, 280 insertions(+), 8 deletions(-)
>> create mode 100644
>> tools/testing/selftests/kvm/x86_64/triple_fault_event_test.c
>>
>