From: Xiaoyao Li <xiaoyao...@intel.com> KVM provides TDX capabilities via sub command KVM_TDX_CAPABILITIES of IOCTL(KVM_MEMORY_ENCRYPT_OP). Get the capabilities when initializing TDX context. It will be used to validate user's setting later.
Since there is no interface reporting how many cpuid configs contains in KVM_TDX_CAPABILITIES, QEMU chooses to try starting with a known number and abort when it exceeds KVM_MAX_CPUID_ENTRIES. Besides, introduce the interfaces to invoke TDX "ioctls" at VCPU scope in preparation. Signed-off-by: Xiaoyao Li <xiaoyao...@intel.com> Link: https://lore.kernel.org/r/20250508150002.689633-6-xiaoyao...@intel.com Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- target/i386/kvm/kvm_i386.h | 2 + target/i386/kvm/kvm.c | 2 - target/i386/kvm/tdx.c | 109 ++++++++++++++++++++++++++++++++++++- 3 files changed, 109 insertions(+), 4 deletions(-) diff --git a/target/i386/kvm/kvm_i386.h b/target/i386/kvm/kvm_i386.h index 88565e8dbac..ed1e61fb8ba 100644 --- a/target/i386/kvm/kvm_i386.h +++ b/target/i386/kvm/kvm_i386.h @@ -13,6 +13,8 @@ #include "system/kvm.h" +#define KVM_MAX_CPUID_ENTRIES 100 + /* always false if !CONFIG_KVM */ #define kvm_pit_in_kernel() \ (kvm_irqchip_in_kernel() && !kvm_irqchip_is_split()) diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index d29376c5992..6d88495d476 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -1780,8 +1780,6 @@ static int hyperv_init_vcpu(X86CPU *cpu) static Error *invtsc_mig_blocker; -#define KVM_MAX_CPUID_ENTRIES 100 - static void kvm_init_xsave(CPUX86State *env) { if (has_xsave2) { diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c index 2b060fb52b9..f8ec4fa217e 100644 --- a/target/i386/kvm/tdx.c +++ b/target/i386/kvm/tdx.c @@ -10,19 +10,124 @@ */ #include "qemu/osdep.h" +#include "qemu/error-report.h" +#include "qapi/error.h" #include "qom/object_interfaces.h" #include "hw/i386/x86.h" #include "kvm_i386.h" #include "tdx.h" -static int tdx_kvm_init(ConfidentialGuestSupport *cgs, Error **errp) +static struct kvm_tdx_capabilities *tdx_caps; + +enum tdx_ioctl_level { + TDX_VM_IOCTL, + TDX_VCPU_IOCTL, +}; + +static int tdx_ioctl_internal(enum tdx_ioctl_level level, void *state, + int cmd_id, __u32 flags, void *data, + Error **errp) { - kvm_mark_guest_state_protected(); + struct kvm_tdx_cmd tdx_cmd = {}; + int r; + + const char *tdx_ioctl_name[] = { + [KVM_TDX_CAPABILITIES] = "KVM_TDX_CAPABILITIES", + [KVM_TDX_INIT_VM] = "KVM_TDX_INIT_VM", + [KVM_TDX_INIT_VCPU] = "KVM_TDX_INIT_VCPU", + [KVM_TDX_INIT_MEM_REGION] = "KVM_TDX_INIT_MEM_REGION", + [KVM_TDX_FINALIZE_VM] = "KVM_TDX_FINALIZE_VM", + [KVM_TDX_GET_CPUID] = "KVM_TDX_GET_CPUID", + }; + + tdx_cmd.id = cmd_id; + tdx_cmd.flags = flags; + tdx_cmd.data = (__u64)(unsigned long)data; + + switch (level) { + case TDX_VM_IOCTL: + r = kvm_vm_ioctl(kvm_state, KVM_MEMORY_ENCRYPT_OP, &tdx_cmd); + break; + case TDX_VCPU_IOCTL: + r = kvm_vcpu_ioctl(state, KVM_MEMORY_ENCRYPT_OP, &tdx_cmd); + break; + default: + error_setg(errp, "Invalid tdx_ioctl_level %d", level); + return -EINVAL; + } + + if (r < 0) { + error_setg_errno(errp, -r, "TDX ioctl %s failed, hw_errors: 0x%llx", + tdx_ioctl_name[cmd_id], tdx_cmd.hw_error); + } + return r; +} + +static inline int tdx_vm_ioctl(int cmd_id, __u32 flags, void *data, + Error **errp) +{ + return tdx_ioctl_internal(TDX_VM_IOCTL, NULL, cmd_id, flags, data, errp); +} + +static inline int tdx_vcpu_ioctl(CPUState *cpu, int cmd_id, __u32 flags, + void *data, Error **errp) +{ + return tdx_ioctl_internal(TDX_VCPU_IOCTL, cpu, cmd_id, flags, data, errp); +} + +static int get_tdx_capabilities(Error **errp) +{ + struct kvm_tdx_capabilities *caps; + /* 1st generation of TDX reports 6 cpuid configs */ + int nr_cpuid_configs = 6; + size_t size; + int r; + + do { + Error *local_err = NULL; + size = sizeof(struct kvm_tdx_capabilities) + + nr_cpuid_configs * sizeof(struct kvm_cpuid_entry2); + caps = g_malloc0(size); + caps->cpuid.nent = nr_cpuid_configs; + + r = tdx_vm_ioctl(KVM_TDX_CAPABILITIES, 0, caps, &local_err); + if (r == -E2BIG) { + g_free(caps); + nr_cpuid_configs *= 2; + if (nr_cpuid_configs > KVM_MAX_CPUID_ENTRIES) { + error_report("KVM TDX seems broken that number of CPUID entries" + " in kvm_tdx_capabilities exceeds limit: %d", + KVM_MAX_CPUID_ENTRIES); + error_propagate(errp, local_err); + return r; + } + error_free(local_err); + } else if (r < 0) { + g_free(caps); + error_propagate(errp, local_err); + return r; + } + } while (r == -E2BIG); + + tdx_caps = caps; return 0; } +static int tdx_kvm_init(ConfidentialGuestSupport *cgs, Error **errp) +{ + int r = 0; + + kvm_mark_guest_state_protected(); + + if (!tdx_caps) { + r = get_tdx_capabilities(errp); + } + + return r; +} + static int tdx_kvm_type(X86ConfidentialGuest *cg) { /* Do the object check */ -- 2.49.0
