[xen stable-4.12] libacpi: widen TPM detection

[patchbot@xxxxxxx]

commit 050fe48dc981e0488de1f6c6c07d8110f3b7523b
Author:     Jason Andryuk <jandryuk@xxxxxxxxx>
AuthorDate: Wed Jun 24 17:17:38 2020 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Wed Jun 24 17:17:38 2020 +0200

    libacpi: widen TPM detection
    
    The hardcoded tpm_signature is too restrictive to detect many TPMs.  For
    instance, it doesn't accept a QEMU emulated TPM (VID 0x1014 DID 0x0001).
    Make the TPM detection match that in rombios which accepts a wider
    range.
    
    With this change, the TPM's TCPA ACPI table is generated and the guest
    OS can automatically load the tpm_tis driver.  It also allows seabios to
    detect and use the TPM.  However, seabios skips some TPM initialization
    when running under Xen, so it will not populate any PCRs unless modified
    to run the initialization under Xen.
    
    Signed-off-by: Jason Andryuk <jandryuk@xxxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    master commit: d3db7e043cddd7e939195e014241ce2c5d436179
    master date: 2020-06-16 10:31:08 +0200
---
 tools/libacpi/build.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/tools/libacpi/build.c b/tools/libacpi/build.c
index fa7d14e090..a61dd5583a 100644
--- a/tools/libacpi/build.c
+++ b/tools/libacpi/build.c
@@ -351,7 +351,6 @@ static int construct_secondary_tables(struct acpi_ctxt 
*ctxt,
     struct acpi_20_waet *waet;
     struct acpi_20_tcpa *tcpa;
     unsigned char *ssdt;
-    static const uint16_t tis_signature[] = {0x0001, 0x0001, 0x0001};
     void *lasa;
 
     /* MADT. */
@@ -413,9 +412,8 @@ static int construct_secondary_tables(struct acpi_ctxt 
*ctxt,
 
     /* TPM TCPA and SSDT. */
     if ( (config->table_flags & ACPI_HAS_TCPA) &&
-         (config->tis_hdr[0] == tis_signature[0]) &&
-         (config->tis_hdr[1] == tis_signature[1]) &&
-         (config->tis_hdr[2] == tis_signature[2]) )
+         (config->tis_hdr[0] != 0 && config->tis_hdr[0] != 0xffff) &&
+         (config->tis_hdr[1] != 0 && config->tis_hdr[1] != 0xffff) )
     {
         ssdt = ctxt->mem_ops.alloc(ctxt, sizeof(ssdt_tpm), 16);
         if (!ssdt) return -1;
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.12