diff options
| author | Sean Christopherson <seanjc@google.com> | 2025-06-05 12:50:15 -0700 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2025-06-20 13:07:59 -0700 |
| commit | c4a37acc5193bff436a3161f2defefb0da1db011 (patch) | |
| tree | 93742ef7127ed1eef9416ecc5c999949d76984da | |
| parent | 0792c71c1c94964952339f3251818b6dcf66c19b (diff) | |
KVM: x86: Drop pending_smi vs. INIT_RECEIVED check when setting MP_STATE
Allow userspace to set a vCPU's mp_state to INIT_RECEIVED in conjunction
with a pending SMI, as rejecting that combination could result in KVM
disallowing reflecting the output from KVM_GET_VCPU_EVENTS back into KVM
via KVM_SET_VCPU_EVENTS.
At the time the check was added, smi_pending could only be set in the
context of KVM_RUN, with the vCPU in the RUNNABLE state. I.e. it was
impossible for KVM to save vCPU state such that userspace could see a
pending SMI for a vCPU in WFS.
That no longer holds true now that KVM processes requested SMIs during
KVM_GET_VCPU_EVENTS, e.g. if a vCPU receives an SMI while in WFS, and
then userspace saves vCPU state.
Note, this may partially re-open the user-triggerable WARN that was mostly
closed by commit 28bf28887976 ("KVM: x86: fix user triggerable warning in
kvm_apic_accept_events()"), but that WARN can already be triggered in
several other ways, e.g. if userspace stuffs VMXON=1 after putting the
vCPU into WFS. That issue will be addressed in an upcoming commit, in a
more robust fashion (hopefully).
Fixes: 1f7becf1b7e2 ("KVM: x86: get smi pending status correctly")
Link: https://lore.kernel.org/r/20250605195018.539901-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | arch/x86/kvm/x86.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 7227696c75e6..f183951a8ea8 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -11916,10 +11916,9 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu, /* * Pending INITs are reported using KVM_SET_VCPU_EVENTS, disallow * forcing the guest into INIT/SIPI if those events are supposed to be - * blocked. KVM prioritizes SMI over INIT, so reject INIT/SIPI state - * if an SMI is pending as well. + * blocked. */ - if ((!kvm_apic_init_sipi_allowed(vcpu) || vcpu->arch.smi_pending) && + if (!kvm_apic_init_sipi_allowed(vcpu) && (mp_state->mp_state == KVM_MP_STATE_SIPI_RECEIVED || mp_state->mp_state == KVM_MP_STATE_INIT_RECEIVED)) goto out; |