On 8/21/2023 5:16 PM, Daniel P. Berrangé wrote:
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.
Will do it in next version.
thanks!
+
+ 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
