Commit f460be43 authored by Wei Huang's avatar Wei Huang Committed by Peter Maydell
Browse files

ARM: ACPI: fix the AML ID format for CPU devices 



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: default avatarEric Auger <eric.auger@redhat.com>
Signed-off-by: default avatarWei Huang <wei@redhat.com>
Reviewed-by: default avatarShannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: default avatarEric Auger <eric.auger@redhat.com>
Tested-by: default avatarEric Auger <eric.auger@redhat.com>
Message-id: 1472852809-23042-1-git-send-email-wei@redhat.com
Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
parent e0fe723c

hw/arm/virt-acpi-build.c

+1 −1
Original line number Diff line number Diff line
@@ -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);