diff options
| author | Sean Christopherson <seanjc@google.com> | 2024-11-27 17:33:40 -0800 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2024-12-18 14:19:35 -0800 |
| commit | 04cd8f8628d88da7839b1643db0bef8522c39254 (patch) | |
| tree | 9fe34664714fea71ef3cc837e7b5560850bb2625 | |
| parent | 21d7f06d1a8364a57432ccc1e6167c73c043b913 (diff) | |
KVM: x86: Disallow KVM_CAP_X86_DISABLE_EXITS after vCPU creation
Reject KVM_CAP_X86_DISABLE_EXITS if vCPUs have been created, as disabling
PAUSE/MWAIT/HLT exits after vCPUs have been created is broken and useless,
e.g. except for PAUSE on SVM, the relevant intercepts aren't updated after
vCPU creation. vCPUs may also end up with an inconsistent configuration
if exits are disabled between creation of multiple vCPUs.
Cc: Hou Wenlong <houwenlong.hwl@antgroup.com>
Link: https://lore.kernel.org/all/9227068821b275ac547eb2ede09ec65d2281fe07.1680179693.git.houwenlong.hwl@antgroup.com
Link: https://lore.kernel.org/all/20230121020738.2973-2-kechenl@nvidia.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Link: https://lore.kernel.org/r/20241128013424.4096668-14-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | Documentation/virt/kvm/api.rst | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 6 |
2 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 454c2aaa155e..bbe445e6c113 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -7670,6 +7670,7 @@ branch to guests' 0x200 interrupt vector. :Architectures: x86 :Parameters: args[0] defines which exits are disabled :Returns: 0 on success, -EINVAL when args[0] contains invalid exits + or if any vCPUs have already been created Valid bits in args[0] are:: diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 503bfcbc1735..e3c3ceb54966 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6531,6 +6531,10 @@ split_irqchip_unlock: if (cap->args[0] & ~KVM_X86_DISABLE_VALID_EXITS) break; + mutex_lock(&kvm->lock); + if (kvm->created_vcpus) + goto disable_exits_unlock; + if (cap->args[0] & KVM_X86_DISABLE_EXITS_PAUSE) kvm->arch.pause_in_guest = true; @@ -6552,6 +6556,8 @@ split_irqchip_unlock: } r = 0; +disable_exits_unlock: + mutex_unlock(&kvm->lock); break; case KVM_CAP_MSR_PLATFORM_INFO: kvm->arch.guest_can_read_msr_platform_info = cap->args[0]; |