On Mon, Mar 21, 2022 at 11:32:21AM -0700,
Sagi Shahar <sagis@xxxxxxxxxx> wrote:
> > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> > index 314ae43e07bf..9acb33a17445 100644
> > --- a/arch/x86/kvm/x86.c
> > +++ b/arch/x86/kvm/x86.c
> > @@ -9090,26 +9090,15 @@ static int complete_hypercall_exit(struct kvm_vcpu *vcpu)
> > return kvm_skip_emulated_instruction(vcpu);
> > }
> >
> > -int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
> > +unsigned long __kvm_emulate_hypercall(struct kvm_vcpu *vcpu, unsigned long nr,
> > + unsigned long a0, unsigned long a1,
> > + unsigned long a2, unsigned long a3,
> > + int op_64_bit)
> > {
> > - unsigned long nr, a0, a1, a2, a3, ret;
> > - int op_64_bit;
> > -
> > - if (kvm_xen_hypercall_enabled(vcpu->kvm))
> > - return kvm_xen_hypercall(vcpu);
> > -
> > - if (kvm_hv_hypercall_enabled(vcpu))
> > - return kvm_hv_hypercall(vcpu);
> > -
> > - nr = kvm_rax_read(vcpu);
> > - a0 = kvm_rbx_read(vcpu);
> > - a1 = kvm_rcx_read(vcpu);
> > - a2 = kvm_rdx_read(vcpu);
> > - a3 = kvm_rsi_read(vcpu);
> > + unsigned long ret;
> >
> > trace_kvm_hypercall(nr, a0, a1, a2, a3);
> >
> > - op_64_bit = is_64_bit_hypercall(vcpu);
> > if (!op_64_bit) {
> > nr &= 0xFFFFFFFF;
> > a0 &= 0xFFFFFFFF;
> > @@ -9118,11 +9107,6 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
> > a3 &= 0xFFFFFFFF;
> > }
> >
> > - if (static_call(kvm_x86_get_cpl)(vcpu) != 0) {
> > - ret = -KVM_EPERM;
> > - goto out;
> > - }
> > -
> > ret = -KVM_ENOSYS;
> >
> > switch (nr) {
> > @@ -9181,6 +9165,34 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
> > ret = -KVM_ENOSYS;
> > break;
> > }
> > + return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(__kvm_emulate_hypercall);
> > +
> > +int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
> > +{
> > + unsigned long nr, a0, a1, a2, a3, ret;
> > + int op_64_bit;
> > +
> > + if (kvm_xen_hypercall_enabled(vcpu->kvm))
> > + return kvm_xen_hypercall(vcpu);
> > +
> > + if (kvm_hv_hypercall_enabled(vcpu))
> > + return kvm_hv_hypercall(vcpu);
> > +
> > + nr = kvm_rax_read(vcpu);
> > + a0 = kvm_rbx_read(vcpu);
> > + a1 = kvm_rcx_read(vcpu);
> > + a2 = kvm_rdx_read(vcpu);
> > + a3 = kvm_rsi_read(vcpu);
> > + op_64_bit = is_64_bit_mode(vcpu);
>
> I think this should be "op_64_bit = is_64_bit_hypercall(vcpu);"
> is_64_bit_mode was replaced with is_64_bit_hypercall to support
> protected guests here:
> https://lore.kernel.org/all/87cztf8h43.fsf@xxxxxxxxxxxxxxxxxxxx/T/
>
> Without it, op_64_bit will be set to 0 for TD VMs which will cause the
> upper 32 bit of the registers to be cleared in __kvm_emulate_hypercall
Oops, thanks for pointing it out. I'll fix it up with next respin.
--
Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
