Invoke KVM_TDX_INIT in kvm_arch_pre_create_vcpu() that KVM_TDX_INIT configures global TD state, e.g. the canonical CPUID config, and must be executed prior to creating vCPUs.
Use kvm_x86_arch_cpuid() to setup the CPUID settings for TDX VM and tie x86cpu->enable_pmu with TD's attributes. Note, this doesn't address the fact that QEMU may change the CPUID configuration when creating vCPUs, i.e. punts on refactoring QEMU to provide a stable CPUID config prior to kvm_arch_init(). Signed-off-by: Xiaoyao Li <xiaoyao...@intel.com> --- accel/kvm/kvm-all.c | 9 ++++++++- target/i386/kvm/kvm.c | 8 ++++++++ target/i386/kvm/tdx-stub.c | 5 +++++ target/i386/kvm/tdx.c | 34 ++++++++++++++++++++++++++++++++++ target/i386/kvm/tdx.h | 4 ++++ 5 files changed, 59 insertions(+), 1 deletion(-) diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index c26d602f5476..c1348c380680 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -473,10 +473,17 @@ int kvm_init_vcpu(CPUState *cpu, Error **errp) trace_kvm_init_vcpu(cpu->cpu_index, kvm_arch_vcpu_id(cpu)); + /* + * tdx_pre_create_vcpu() may call cpu_x86_cpuid(). It in turn may call + * kvm_vm_ioctl(). Set cpu->kvm_state in advance to avoid NULL pointer + * dereference. + */ + cpu->kvm_state = s; ret = kvm_arch_pre_create_vcpu(cpu); if (ret < 0) { error_setg_errno(errp, -ret, "kvm_init_vcpu: kvm_arch_pre_create_vcpu() failed"); + cpu->kvm_state = NULL; goto err; } @@ -484,11 +491,11 @@ int kvm_init_vcpu(CPUState *cpu, Error **errp) if (ret < 0) { error_setg_errno(errp, -ret, "kvm_init_vcpu: kvm_get_vcpu failed (%lu)", kvm_arch_vcpu_id(cpu)); + cpu->kvm_state = NULL; goto err; } cpu->kvm_fd = ret; - cpu->kvm_state = s; cpu->vcpu_dirty = true; cpu->dirty_pages = 0; cpu->throttle_us_per_full = 0; diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index 9c0d5be5cc23..4f491f871f3e 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -2197,6 +2197,14 @@ int kvm_arch_init_vcpu(CPUState *cs) return r; } +int kvm_arch_pre_create_vcpu(CPUState *cpu) +{ + if (is_tdx_vm()) + return tdx_pre_create_vcpu(cpu); + + return 0; +} + int kvm_arch_destroy_vcpu(CPUState *cs) { X86CPU *cpu = X86_CPU(cs); diff --git a/target/i386/kvm/tdx-stub.c b/target/i386/kvm/tdx-stub.c index 1df24735201e..2871de9d7b56 100644 --- a/target/i386/kvm/tdx-stub.c +++ b/target/i386/kvm/tdx-stub.c @@ -7,3 +7,8 @@ int tdx_kvm_init(MachineState *ms, Error **errp) { return -EINVAL; } + +int tdx_pre_create_vcpu(CPUState *cpu) +{ + return -EINVAL; +} diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c index 6fe47cf4e29e..ecb0205651bd 100644 --- a/target/i386/kvm/tdx.c +++ b/target/i386/kvm/tdx.c @@ -458,6 +458,38 @@ int tdx_kvm_init(MachineState *ms, Error **errp) return 0; } +int tdx_pre_create_vcpu(CPUState *cpu) +{ + MachineState *ms = MACHINE(qdev_get_machine()); + X86CPU *x86cpu = X86_CPU(cpu); + CPUX86State *env = &x86cpu->env; + struct kvm_tdx_init_vm init_vm; + int r = 0; + + qemu_mutex_lock(&tdx_guest->lock); + if (tdx_guest->initialized) { + goto out; + } + + memset(&init_vm, 0, sizeof(init_vm)); + init_vm.cpuid.nent = kvm_x86_arch_cpuid(env, init_vm.entries, 0); + + init_vm.attributes = tdx_guest->attributes; + init_vm.max_vcpus = ms->smp.cpus; + + r = tdx_vm_ioctl(KVM_TDX_INIT_VM, 0, &init_vm); + if (r < 0) { + error_report("KVM_TDX_INIT_VM failed %s", strerror(-r)); + goto out; + } + + tdx_guest->initialized = true; + +out: + qemu_mutex_unlock(&tdx_guest->lock); + return r; +} + /* tdx guest */ OBJECT_DEFINE_TYPE_WITH_INTERFACES(TdxGuest, tdx_guest, @@ -470,6 +502,8 @@ static void tdx_guest_init(Object *obj) { TdxGuest *tdx = TDX_GUEST(obj); + qemu_mutex_init(&tdx->lock); + tdx->attributes = 0; } diff --git a/target/i386/kvm/tdx.h b/target/i386/kvm/tdx.h index 06599b65b827..46a24ee8c7cc 100644 --- a/target/i386/kvm/tdx.h +++ b/target/i386/kvm/tdx.h @@ -17,6 +17,9 @@ typedef struct TdxGuestClass { typedef struct TdxGuest { ConfidentialGuestSupport parent_obj; + QemuMutex lock; + + bool initialized; uint64_t attributes; /* TD attributes */ } TdxGuest; @@ -29,5 +32,6 @@ bool is_tdx_vm(void); int tdx_kvm_init(MachineState *ms, Error **errp); void tdx_get_supported_cpuid(uint32_t function, uint32_t index, int reg, uint32_t *ret); +int tdx_pre_create_vcpu(CPUState *cpu); #endif /* QEMU_I386_TDX_H */ -- 2.27.0