On Fri, Aug 18, 2023 at 05:49:49AM -0400, Xiaoyao Li wrote: > 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 from v1: > - Make the error message more clear; > > 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 | 93 ++++++++++++++++++++++++++++++++++++++ > 3 files changed, 95 insertions(+), 2 deletions(-) > > diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c > index d6b988d6c2d1..ec5c07bffd38 100644 > --- a/target/i386/kvm/kvm.c > +++ b/target/i386/kvm/kvm.c > @@ -1751,8 +1751,6 @@ 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 ea3a5b174ac0..769eadbba56c 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..255c47a2a553 100644 > --- a/target/i386/kvm/tdx.c > +++ b/target/i386/kvm/tdx.c > @@ -12,14 +12,107 @@ > */ > > #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(void *state, enum tdx_ioctl_level level, int cmd_id, > + __u32 flags, void *data) Names with an initial double underscore are reserved for us by the platform implementation, so shouldn't be used in userspace app code. > +{ > + 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) Pass in 'Error **errp' > +{ > + struct kvm_tdx_capabilities *caps; > + /* 1st generation of TDX reports 6 cpuid configs */ > + int nr_cpuid_configs = 6; > + int r, size; It is preferrable to use 'size_t' for memory allocation sizes. > + > + 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_report("KVM TDX seems broken that number of CPUID entries in kvm_tdx_capabilities exceeds limit"); Include the limit in the error message, so if we ever need to change the limit, it'll be clear what limit the QEMU version was built with. Also use error_setg(errp, ...); > + exit(1); Return -1 > + } > + } else if (r < 0) { > + g_free(caps); > + error_report("KVM_TDX_CAPABILITIES failed: %s", strerror(-r)); Use error_setg_errno(errp, ...) instead of calling strerror yourself; > + exit(1); Return -1 > + } > + } > + while (r == -E2BIG); > + > + tdx_caps = caps; Return 0 > +} > + > int tdx_kvm_init(MachineState *ms, Error **errp) > { > + if (!tdx_caps) { > + get_tdx_capabilities(); Pass 'errp' into this method, and check return value for failure > + } > + > return 0; > } > > -- > 2.34.1 > With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|