[PATCH v6 17/60] i386/tdx: load TDVF for TD guest

Xiaoyao Li
2024-11-05T06:37:38Z

From: Chao Peng <chao.p.peng@linux.intel.com>

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>
---
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 b86c38212eab..1df496a15eff 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"
@@ -1007,11 +1008,14 @@ 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 4193211c3190..d5ebc2430fd1 100644
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -120,6 +120,12 @@ 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 0aebc7e3f6c9..e5d836805385 100644
--- a/target/i386/kvm/tdx.h
+++ b/target/i386/kvm/tdx.h
@@ -28,6 +28,8 @@ 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
@@ -37,5 +39,6 @@ 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 */
--
2.34.1