Commit Message
Isaku Yamahata
Feb. 26, 2024, 8:26 a.m. UTC
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; + 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);