| Message ID | 20220615011622.136646-4-kechenl@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86: add per-vCPU exits disable capability | expand |
On Tue, Jun 14, 2022, Kechen Lu wrote: > From: Sean Christopherson <seanjc@google.com> > > Reject KVM_CAP_X86_DISABLE_EXITS if userspace attempts to disable MWAIT > exits and KVM previously reported (via KVM_CHECK_EXTENSION) that MWAIT is > not allowed in guest, e.g. because it's not supported or the CPU doesn't > have an aways-running APIC timer. > > Fixes: 4d5422cea3b6 ("KVM: X86: Provide a capability to disable MWAIT intercepts") > Signed-off-by: Sean Christopherson <seanjc@google.com> > --- > arch/x86/kvm/x86.c | 21 ++++++++++++++------- > 1 file changed, 14 insertions(+), 7 deletions(-) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index b419b258ed90..f31ebbb1b94f 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -4199,6 +4199,17 @@ static inline bool kvm_can_mwait_in_guest(void) > boot_cpu_has(X86_FEATURE_ARAT); > } > > +static u64 kvm_get_allowed_disable_exits(void) > +{ > + u64 r = KVM_X86_DISABLE_EXITS_HLT | KVM_X86_DISABLE_EXITS_PAUSE | > + KVM_X86_DISABLE_EXITS_CSTATE; > + > + if(kvm_can_mwait_in_guest()) Probably my fault for not fixing this during copy+paste, but add a space after the if, i.e. if (kvm_can_mwait_in_guest()) > + r |= KVM_X86_DISABLE_EXITS_MWAIT; > + > + return r; > +}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index b419b258ed90..f31ebbb1b94f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4199,6 +4199,17 @@ static inline bool kvm_can_mwait_in_guest(void) boot_cpu_has(X86_FEATURE_ARAT); } +static u64 kvm_get_allowed_disable_exits(void) +{ + u64 r = KVM_X86_DISABLE_EXITS_HLT | KVM_X86_DISABLE_EXITS_PAUSE | + KVM_X86_DISABLE_EXITS_CSTATE; + + if(kvm_can_mwait_in_guest()) + r |= KVM_X86_DISABLE_EXITS_MWAIT; + + return r; +} + static int kvm_ioctl_get_supported_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 __user *cpuid_arg) { @@ -4318,10 +4329,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = KVM_CLOCK_VALID_FLAGS; break; case KVM_CAP_X86_DISABLE_EXITS: - r |= KVM_X86_DISABLE_EXITS_HLT | KVM_X86_DISABLE_EXITS_PAUSE | - KVM_X86_DISABLE_EXITS_CSTATE; - if(kvm_can_mwait_in_guest()) - r |= KVM_X86_DISABLE_EXITS_MWAIT; + r |= kvm_get_allowed_disable_exits(); break; case KVM_CAP_X86_SMM: /* SMBASE is usually relocated above 1M on modern chipsets, @@ -6003,15 +6011,14 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, break; case KVM_CAP_X86_DISABLE_EXITS: r = -EINVAL; - if (cap->args[0] & ~KVM_X86_DISABLE_VALID_EXITS) + if (cap->args[0] & ~kvm_get_allowed_disable_exits()) break; mutex_lock(&kvm->lock); if (kvm->created_vcpus) goto disable_exits_unlock; - if ((cap->args[0] & KVM_X86_DISABLE_EXITS_MWAIT) && - kvm_can_mwait_in_guest()) + if (cap->args[0] & KVM_X86_DISABLE_EXITS_MWAIT) kvm->arch.mwait_in_guest = true; if (cap->args[0] & KVM_X86_DISABLE_EXITS_HLT) kvm->arch.hlt_in_guest = true;