i386/tdx: load TDVF for TD guest

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>

diff --git a/hw/i386/x86-common.c b/hw/i386/x86-common.c
index 1b0671c523973cbef46403dc23bca71f03e79ac6..b1b5f11e739648679f1638b1194e5da75e3ce08a 100644 (file)
--- 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"
@@ -1035,11 +1036,14 @@ 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 93a16a1aaa89132c84fec92088bb6d5b779feece..0f5acbf980bdbc84d1c0fa8406787a35b836eeda 100644 (file)
--- 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 d39e733d9fcc4e48d95457800d3c32b932e2e83b..b73461b8d8a34c7c05a9b6b99468dfefbc5a97b5 100644 (file)
--- 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 */