qemu-kvm/kvm-i386-tdx-load-TDVF-for-TD-guest.patch

From 69a39313aa07e1e4845e53e34a6b866395863c73 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Fri, 18 Jul 2025 18:03:46 +0200
Subject: [PATCH 045/115] i386/tdx: load TDVF for TD guest

RH-Author: Paolo Bonzini <pbonzini@redhat.com>
RH-MergeRequest: 391: TDX support, including attestation and device assignment
RH-Jira: RHEL-15710 RHEL-20798 RHEL-49728
RH-Acked-by: Yash Mankad <None>
RH-Acked-by: Peter Xu <peterx@redhat.com>
RH-Acked-by: David Hildenbrand <david@redhat.com>
RH-Commit: [45/115] cdf138cb88831b4c28f78cd9ad72d75465a731cf (bonzini/rhel-qemu-kvm)

TDVF(OVMF) needs to run at private memory for TD guest. TDX cannot
support pflash device since it doesn't support read-only private memory.
Thus load TDVF(OVMF) with -bios option for TDs.

Use memory_region_init_ram_guest_memfd() to allocate the MemoryRegion
for TDVF because it needs to be located at private memory.

Also store the MemoryRegion pointer of TDVF since the shared ramblock of
it can be discared after it gets copied to private ramblock.

Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Co-developed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250508150002.689633-17-xiaoyao.li@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 0dd5fe5ebeabefc7b3d7f043991b1edfe6b8eda9)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 hw/i386/x86-common.c  | 6 +++++-
 target/i386/kvm/tdx.c | 6 ++++++
 target/i386/kvm/tdx.h | 3 +++
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/hw/i386/x86-common.c b/hw/i386/x86-common.c
index 562215990d..97cd84d618 100644
--- a/hw/i386/x86-common.c
+++ b/hw/i386/x86-common.c
@@ -44,6 +44,7 @@
 #include "standard-headers/asm-x86/bootparam.h"
 #include CONFIG_DEVICES
 #include "kvm/kvm_i386.h"
+#include "kvm/tdx.h"
 
 #ifdef CONFIG_XEN_EMU
 #include "hw/xen/xen.h"
@@ -1003,11 +1004,14 @@ void x86_bios_rom_init(X86MachineState *x86ms, const char *default_firmware,
     if (machine_require_guest_memfd(MACHINE(x86ms))) {
         memory_region_init_ram_guest_memfd(&x86ms->bios, NULL, "pc.bios",
                                            bios_size, &error_fatal);
+        if (is_tdx_vm()) {
+            tdx_set_tdvf_region(&x86ms->bios);
+        }
     } else {
         memory_region_init_ram(&x86ms->bios, NULL, "pc.bios",
                                bios_size, &error_fatal);
     }
-    if (sev_enabled()) {
+    if (sev_enabled() || is_tdx_vm()) {
         /*
          * The concept of a "reset" simply doesn't exist for
          * confidential computing guests, we have to destroy and
diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
index 56ad5f599d..2522f2030d 100644
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -137,6 +137,12 @@ static int get_tdx_capabilities(Error **errp)
     return 0;
 }
 
+void tdx_set_tdvf_region(MemoryRegion *tdvf_mr)
+{
+    assert(!tdx_guest->tdvf_mr);
+    tdx_guest->tdvf_mr = tdvf_mr;
+}
+
 static int tdx_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
 {
     TdxGuest *tdx = TDX_GUEST(cgs);
diff --git a/target/i386/kvm/tdx.h b/target/i386/kvm/tdx.h
index d39e733d9f..b73461b8d8 100644
--- a/target/i386/kvm/tdx.h
+++ b/target/i386/kvm/tdx.h
@@ -30,6 +30,8 @@ typedef struct TdxGuest {
     char *mrconfigid;       /* base64 encoded sha348 digest */
     char *mrowner;          /* base64 encoded sha348 digest */
     char *mrownerconfig;    /* base64 encoded sha348 digest */
+
+    MemoryRegion *tdvf_mr;
 } TdxGuest;
 
 #ifdef CONFIG_TDX
@@ -39,5 +41,6 @@ bool is_tdx_vm(void);
 #endif /* CONFIG_TDX */
 
 int tdx_pre_create_vcpu(CPUState *cpu, Error **errp);
+void tdx_set_tdvf_region(MemoryRegion *tdvf_mr);
 
 #endif /* QEMU_I386_TDX_H */
-- 
2.50.1