Re: [PATCH 1/1] hw/arm/sbsa-ref: Adding TPM support for ARM SBSA-Ref machine

[Graeme Gregory]

On 25/02/2025 07:41, Kun Qin wrote:

From: Kun Qin <ku...@microsoft.com>

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2625

This change aims to add a TPM device for SBSA ref machine.

The implementation adds a TPM create routine during machine
initialization.

The backend can be the same as the rest of TPM support, by using swtpm.

This looks sensible to me.

Reviewed-by: Graeme Gregory <gra...@xora.org.uk>

Signed-off-by: Kun Qin <kuqi...@gmail.com>
---
  hw/arm/sbsa-ref.c | 24 ++++++++++++++++++++++++
  1 file changed, 24 insertions(+)

diff --git a/hw/arm/sbsa-ref.c b/hw/arm/sbsa-ref.c
index e720de306419..93eb3d1e363b 100644
--- a/hw/arm/sbsa-ref.c
+++ b/hw/arm/sbsa-ref.c
@@ -28,6 +28,8 @@
  #include "system/numa.h"
  #include "system/runstate.h"
  #include "system/system.h"
+#include "system/tpm.h"
+#include "system/tpm_backend.h"
  #include "exec/hwaddr.h"
  #include "kvm_arm.h"
  #include "hw/arm/boot.h"
@@ -94,6 +96,7 @@ enum {
      SBSA_SECURE_MEM,
      SBSA_AHCI,
      SBSA_XHCI,
+    SBSA_TPM,
  };

struct SBSAMachineState {

@@ -132,6 +135,7 @@ static const MemMapEntry sbsa_ref_memmap[] = {
      /* Space here reserved for more SMMUs */
      [SBSA_AHCI] =               { 0x60100000, 0x00010000 },
      [SBSA_XHCI] =               { 0x60110000, 0x00010000 },
+    [SBSA_TPM] =                { 0x60120000, 0x00010000 },
      /* Space here reserved for other devices */
      [SBSA_PCIE_PIO] =           { 0x7fff0000, 0x00010000 },
      /* 32-bit address PCIE MMIO space */
@@ -629,6 +633,24 @@ static void create_smmu(const SBSAMachineState *sms, 
PCIBus *bus)
      }
  }

+static void create_tpm(SBSAMachineState *sbsa, PCIBus *bus)

+{
+    Error *errp = NULL;
+    DeviceState *dev;
+
+    TPMBackend *be = qemu_find_tpm_be("tpm0");
+    if (be == NULL) {
+        error_report("Couldn't find tmp0 backend");
+        return;
+    }
+
+    dev = qdev_new(TYPE_TPM_TIS_SYSBUS);
+    object_property_set_link(OBJECT(dev), "tpmdev", OBJECT(be), &errp);
+    object_property_set_str(OBJECT(dev), "tpmdev", be->id, &errp);
+    sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
+    sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, sbsa_ref_memmap[SBSA_TPM].base);
+}
+
  static void create_pcie(SBSAMachineState *sms)
  {
      hwaddr base_ecam = sbsa_ref_memmap[SBSA_PCIE_ECAM].base;
@@ -686,6 +708,8 @@ static void create_pcie(SBSAMachineState *sms)
      pci_create_simple(pci->bus, -1, "bochs-display");

create_smmu(sms, pci->bus);

+
+    create_tpm(sms, pci->bus);
  }

static void *sbsa_ref_dtb(const struct arm_boot_info *binfo, int *fdt_size)