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 different scope (KVM, VM and VCPU) in preparation. Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx> --- Changes in v3: - rename __tdx_ioctl() to tdx_ioctl_internal() - Pass errp in get_tdx_capabilities(); changes in v2: - Make the error message more clear; changes in v1: - start from nr_cpuid_configs = 6 for the loop; - stop the loop when nr_cpuid_configs exceeds KVM_MAX_CPUID_ENTRIES; --- target/i386/kvm/kvm.c | 2 - target/i386/kvm/kvm_i386.h | 2 + target/i386/kvm/tdx.c | 102 ++++++++++++++++++++++++++++++++++++- 3 files changed, 103 insertions(+), 3 deletions(-) diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index 7abcdebb1452..28e60c5ea4a7 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -1687,8 +1687,6 @@ 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/kvm_i386.h b/target/i386/kvm/kvm_i386.h index 55fb25fa8e2e..c3ef46a97a7b 100644 --- a/target/i386/kvm/kvm_i386.h +++ b/target/i386/kvm/kvm_i386.h @@ -13,6 +13,8 @@ #include "sysemu/kvm.h" +#define KVM_MAX_CPUID_ENTRIES 100 + #ifdef CONFIG_KVM #define kvm_pit_in_kernel() \ diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c index 621a05beeb4e..cb0040187b27 100644 --- a/target/i386/kvm/tdx.c +++ b/target/i386/kvm/tdx.c @@ -12,17 +12,117 @@ */ #include "qemu/osdep.h" +#include "qemu/error-report.h" #include "qapi/error.h" #include "qom/object_interfaces.h" +#include "sysemu/kvm.h" #include "hw/i386/x86.h" +#include "kvm_i386.h" #include "tdx.h" +static struct kvm_tdx_capabilities *tdx_caps; + +enum tdx_ioctl_level{ + TDX_PLATFORM_IOCTL, + TDX_VM_IOCTL, + TDX_VCPU_IOCTL, +}; + +static int tdx_ioctl_internal(void *state, enum tdx_ioctl_level level, int cmd_id, + __u32 flags, void *data) +{ + struct kvm_tdx_cmd tdx_cmd; + int r; + + memset(&tdx_cmd, 0x0, sizeof(tdx_cmd)); + + tdx_cmd.id = cmd_id; + tdx_cmd.flags = flags; + tdx_cmd.data = (__u64)(unsigned long)data; + + switch (level) { + case TDX_PLATFORM_IOCTL: + r = kvm_ioctl(kvm_state, KVM_MEMORY_ENCRYPT_OP, &tdx_cmd); + break; + 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_report("Invalid tdx_ioctl_level %d", level); + exit(1); + } + + return r; +} + +static inline int tdx_platform_ioctl(int cmd_id, __u32 flags, void *data) +{ + return tdx_ioctl_internal(NULL, TDX_PLATFORM_IOCTL, cmd_id, flags, data); +} + +static inline int tdx_vm_ioctl(int cmd_id, __u32 flags, void *data) +{ + return tdx_ioctl_internal(NULL, TDX_VM_IOCTL, cmd_id, flags, data); +} + +static inline int tdx_vcpu_ioctl(void *vcpu_fd, int cmd_id, __u32 flags, + void *data) +{ + return tdx_ioctl_internal(vcpu_fd, TDX_VCPU_IOCTL, cmd_id, flags, data); +} + +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 { + size = sizeof(struct kvm_tdx_capabilities) + + nr_cpuid_configs * sizeof(struct kvm_tdx_cpuid_config); + caps = g_malloc0(size); + caps->nr_cpuid_configs = nr_cpuid_configs; + + r = tdx_vm_ioctl(KVM_TDX_CAPABILITIES, 0, caps); + if (r == -E2BIG) { + g_free(caps); + nr_cpuid_configs *= 2; + if (nr_cpuid_configs > KVM_MAX_CPUID_ENTRIES) { + error_setg(errp, "%s: KVM TDX seems broken that number of CPUID " + "entries in kvm_tdx_capabilities exceeds limit %d", + __func__, KVM_MAX_CPUID_ENTRIES); + return r; + } + } else if (r < 0) { + g_free(caps); + error_setg_errno(errp, -r, "%s: KVM_TDX_CAPABILITIES failed", __func__); + return r; + } + } + while (r == -E2BIG); + + tdx_caps = caps; + + return 0; +} + int tdx_kvm_init(MachineState *ms, Error **errp) { + int r = 0; + ms->require_guest_memfd = true; - return 0; + if (!tdx_caps) { + r = get_tdx_capabilities(errp); + } + + return r; } /* tdx guest */ -- 2.34.1