[RFC PATCH 21/23] i386/tdx: Use KVM_TDX_INIT_VCPU to pass HOB to TDVF

[Isaku Yamahata]

Specify the initial value for RCX/R8 to be the address of the HOB.
Don't propagate the value to Qemu's cache of the registers so as to
avoid implying that the register state is valid, e.g. Qemu doesn't model
TDX-SEAM behavior for initializing other GPRs.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
 target/i386/kvm/tdx.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
index 49b4355849..007d33989b 100644
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -268,10 +268,17 @@ out:
 
 void tdx_post_init_vcpu(CPUState *cpu)
 {
-    CPUX86State *env = &X86_CPU(cpu)->env;
+    MachineState *ms = MACHINE(qdev_get_machine());
+    TdxGuest *tdx = (TdxGuest *)object_dynamic_cast(OBJECT(ms->cgs),
+                                                    TYPE_TDX_GUEST);
+    TdxFirmwareEntry *hob;
+
+    if (!tdx) {
+        return;
+    }
 
-    _tdx_ioctl(cpu, KVM_TDX_INIT_VCPU, 0,
-               (void *)(unsigned long)env->regs[R_ECX]);
+    hob = tdx_get_hob_entry(tdx);
+    _tdx_ioctl(cpu, KVM_TDX_INIT_VCPU, 0, (void *)hob->address);
 }
 
 static bool tdx_guest_get_debug(Object *obj, Error **errp)
-- 
2.17.1