On Fri, Aug 18, 2023 at 05:50:01AM -0400, Xiaoyao Li wrote:
> Validate TD attributes with tdx_caps that fixed-0 bits must be zero and
> fixed-1 bits must be set.
>
> Besides, sanity check the attribute bits that have not been supported by
> QEMU yet. e.g., debug bit, it will be allowed in the future when debug
> TD support lands in QEMU.
>
> Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
> Acked-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>
> ---
> target/i386/kvm/tdx.c | 27 +++++++++++++++++++++++++--
> 1 file changed, 25 insertions(+), 2 deletions(-)
>
> diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
> index 629abd267da8..73da15377ec3 100644
> --- a/target/i386/kvm/tdx.c
> +++ b/target/i386/kvm/tdx.c
> @@ -32,6 +32,7 @@
> (1U << KVM_FEATURE_PV_SCHED_YIELD) | \
> (1U << KVM_FEATURE_MSI_EXT_DEST_ID))
>
> +#define TDX_TD_ATTRIBUTES_DEBUG BIT_ULL(0)
> #define TDX_TD_ATTRIBUTES_SEPT_VE_DISABLE BIT_ULL(28)
> #define TDX_TD_ATTRIBUTES_PKS BIT_ULL(30)
> #define TDX_TD_ATTRIBUTES_PERFMON BIT_ULL(63)
> @@ -462,13 +463,32 @@ int tdx_kvm_init(MachineState *ms, Error **errp)
> return 0;
> }
>
> -static void setup_td_guest_attributes(X86CPU *x86cpu)
> +static int tdx_validate_attributes(TdxGuest *tdx)
> +{
> + if (((tdx->attributes & tdx_caps->attrs_fixed0) | tdx_caps->attrs_fixed1) !=
> + tdx->attributes) {
> + error_report("Invalid attributes 0x%lx for TDX VM (fixed0 0x%llx, fixed1 0x%llx)",
> + tdx->attributes, tdx_caps->attrs_fixed0, tdx_caps->attrs_fixed1);
> + return -EINVAL;
> + }
> +
> + if (tdx->attributes & TDX_TD_ATTRIBUTES_DEBUG) {
> + error_report("Current QEMU doesn't support attributes.debug[bit 0] for TDX VM");
> + return -EINVAL;
> + }
Use error_setg() in both cases, passing in a 'Error **errp' object,
and 'return -1' instead of returning an errno value.
> +
> + return 0;
> +}
> +
> +static int setup_td_guest_attributes(X86CPU *x86cpu)
> {
> CPUX86State *env = &x86cpu->env;
>
> tdx_guest->attributes |= (env->features[FEAT_7_0_ECX] & CPUID_7_0_ECX_PKS) ?
> TDX_TD_ATTRIBUTES_PKS : 0;
> tdx_guest->attributes |= x86cpu->enable_pmu ? TDX_TD_ATTRIBUTES_PERFMON : 0;
> +
> + return tdx_validate_attributes(tdx_guest);
Pass along "errp" into this
> }
>
> int tdx_pre_create_vcpu(CPUState *cpu)
> @@ -493,7 +513,10 @@ int tdx_pre_create_vcpu(CPUState *cpu)
In an earlier patch I suggested adding 'Error **errp' to this method...
> goto out_free;
> }
>
> - setup_td_guest_attributes(x86cpu);
> + r = setup_td_guest_attributes(x86cpu);
...it can also be passed into this method
> + if (r) {
> + goto out;
> + }
>
> init_vm->cpuid.nent = kvm_x86_arch_cpuid(env, init_vm->cpuid.entries, 0);
> init_vm->attributes = tdx_guest->attributes;
> --
> 2.34.1
>
With regards,
Daniel
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