Messages in this thread | | | Date | Tue, 9 Apr 2024 17:28:05 +0800 | Subject | Re: [PATCH v19 097/130] KVM: x86: Split core of hypercall emulation to helper function | From | Binbin Wu <> |
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On 2/26/2024 4:26 PM, isaku.yamahata@intel.com wrote: > From: Sean Christopherson <sean.j.christopherson@intel.com> > > By necessity, TDX will use a different register ABI for hypercalls. > Break out the core functionality so that it may be reused for TDX. > > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> > --- > arch/x86/include/asm/kvm_host.h | 4 +++ > arch/x86/kvm/x86.c | 56 ++++++++++++++++++++++----------- > 2 files changed, 42 insertions(+), 18 deletions(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index e0ffef1d377d..bb8be091f996 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -2177,6 +2177,10 @@ static inline void kvm_clear_apicv_inhibit(struct kvm *kvm, > kvm_set_or_clear_apicv_inhibit(kvm, reason, false); > } > > +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, int cpl); > int kvm_emulate_hypercall(struct kvm_vcpu *vcpu); > > int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code, > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index fb7597c22f31..03950368d8db 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -10073,26 +10073,15 @@ 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, int cpl) > { > - 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; > @@ -10101,7 +10090,7 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu) > a3 &= 0xFFFFFFFF; > } > > - if (static_call(kvm_x86_get_cpl)(vcpu) != 0) { > + if (cpl) { > ret = -KVM_EPERM; > goto out; > } > @@ -10162,18 +10151,49 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu) > > WARN_ON_ONCE(vcpu->run->hypercall.flags & KVM_EXIT_HYPERCALL_MBZ); > vcpu->arch.complete_userspace_io = complete_hypercall_exit; > + /* stat is incremented on completion. */ > return 0; > } > default: > ret = -KVM_ENOSYS; > break; > } > + > out: > + ++vcpu->stat.hypercalls; > + 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;
Can it be opportunistically changed to bool type, as well as the argument type of "op_64_bit" in __kvm_emulate_hypercall()?
> + int cpl; > + > + 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_hypercall(vcpu); > + cpl = static_call(kvm_x86_get_cpl)(vcpu); > + > + ret = __kvm_emulate_hypercall(vcpu, nr, a0, a1, a2, a3, op_64_bit, cpl); > + if (nr == KVM_HC_MAP_GPA_RANGE && !ret) > + /* MAP_GPA tosses the request to the user space. */ > + return 0; > + > if (!op_64_bit) > ret = (u32)ret; > kvm_rax_write(vcpu, ret); > > - ++vcpu->stat.hypercalls; > return kvm_skip_emulated_instruction(vcpu); > } > EXPORT_SYMBOL_GPL(kvm_emulate_hypercall);
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