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...@intel.com> --- changes from RFC v4: - 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 | 92 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 94 insertions(+), 2 deletions(-) diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index 335f87e6cc59..9e30fa9f4eb5 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -1704,8 +1704,6 @@ 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 b434feaa6b1d..6b24ab2a7813 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 + #define kvm_apic_in_kernel() (kvm_irqchip_in_kernel()) #ifdef CONFIG_KVM diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c index 77e33ae01147..89f81f7d7082 100644 --- a/target/i386/kvm/tdx.c +++ b/target/i386/kvm/tdx.c @@ -14,12 +14,104 @@ #include "qemu/osdep.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(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(NULL, TDX_PLATFORM_IOCTL, cmd_id, flags, data); +} + +static inline int tdx_vm_ioctl(int cmd_id, __u32 flags, void *data) +{ + return __tdx_ioctl(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(vcpu_fd, TDX_VCPU_IOCTL, cmd_id, flags, data); +} + +static void get_tdx_capabilities(void) +{ + struct kvm_tdx_capabilities *caps; + /* 1st generation of TDX reports 6 cpuid configs */ + int nr_cpuid_configs = 6; + int r, size; + + 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_platform_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_report("KVM TDX seems broken"); + exit(1); + } + } else if (r < 0) { + g_free(caps); + error_report("KVM_TDX_CAPABILITIES failed: %s\n", strerror(-r)); + exit(1); + } + } + while (r == -E2BIG); + + tdx_caps = caps; +} + int tdx_kvm_init(MachineState *ms, Error **errp) { + if (!tdx_caps) { + get_tdx_capabilities(); + } + return 0; } -- 2.27.0