[Qemu-devel] [PULL 3/4] ARM: ACPI: fix the AML ID format for CPU devices

[Peter Maydell]

From: Wei Huang <address@hidden>

Current QEMU will stall guest VM booting under ACPI mode when vcpu count
is >= 12. Analyzing the booting log, it turns out that DSDT table can't
be loaded correctly due to "Invalid character(s) in name (0x62303043),
repaired: [C00*]". This is because existing QEMU uses a lower case AML
ID for CPU devices (e.g. C000, C001, ..., C00a, C00b). The ACPI code
inside guest VM detects this lower case character as an invalid character
(see acpi_ut_valid_acpi_char() in drivers/acpi/acpica/utstring.c file)
and converts it to "*". This causes duplicated IDs (i.e. "C00a" ==>"C00*"
and "C00b" ==> "C00*"). So ACPI refuses to load the table.

This patch fixes the problem by changing the format with a upper case
character. It matches the CPU ID formats used in other parts of QEMU
code.

Reported-by: Eric Auger <address@hidden>
Signed-off-by: Wei Huang <address@hidden>
Reviewed-by: Shannon Zhao <address@hidden>
Reviewed-by: Eric Auger <address@hidden>
Tested-by: Eric Auger <address@hidden>
Message-id: address@hidden
Signed-off-by: Peter Maydell <address@hidden>
---
 hw/arm/virt-acpi-build.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index 28fc59c..295ec86 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -53,7 +53,7 @@ static void acpi_dsdt_add_cpus(Aml *scope, int smp_cpus)
     uint16_t i;
 
     for (i = 0; i < smp_cpus; i++) {
-        Aml *dev = aml_device("C%03x", i);
+        Aml *dev = aml_device("C%.03X", i);
         aml_append(dev, aml_name_decl("_HID", aml_string("ACPI0007")));
         aml_append(dev, aml_name_decl("_UID", aml_int(i)));
         aml_append(scope, dev);
-- 
2.7.4