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/20220524135624.22988-1-chenyi.qiang@xxxxxxxxx/
---
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/20220318074955.22428-1-chenyi.qiang@xxxxxxxxx/
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/20220310084001.10235-1-chenyi.qiang@xxxxxxxxx/
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/20220223062412.22334-1-chenyi.qiang@xxxxxxxxx/
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/20210525051204.1480610-1-tao3.xu@xxxxxxxxx/
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
