Hi,
On 9/29/20 9:22 AM, Michael S. Tsirkin wrote:
> From: Ani Sinha <a...@anisinha.ca>
>
> When acpi hotplug is turned off for both root pci bus as well as for pci
> bridges, we should not generate the related ACPI code for DSDT table or
> initialize related hw ports or reserve hw resources. This change makes
> sure all those operations are turned off in the case ACPI pci hotplug is
> off globally.
>
> In this change, we also make sure ACPI code for the PCNT method are only
> added when bsel is enabled for the corresponding pci bus or bridge hotplug
> is turned on.
I'm trying to understand the following build failure using gcc 9.3.0
on Ubuntu:
[2567/3684] Compiling C object
libqemu-x86_64-softmmu.fa.p/hw_i386_acpi-build.c.o
FAILED: libqemu-x86_64-softmmu.fa.p/hw_i386_acpi-build.c.o
../hw/i386/acpi-build.c: In function 'build_append_pci_bus_devices':
../hw/i386/acpi-build.c:496:9: error: 'method' may be used uninitialized
in this function [-Werror=maybe-uninitialized]
496 | aml_append(parent_scope, method);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
>
> As q35 machines do not use bsel for it's pci buses at this point in time, this
> change affects DSDT acpi table for q35 machines as well. Therefore, we will
> also need to commit the updated golden master DSDT table acpi binary blobs as
> well. Following is the list of blobs which needs updating:
>
> tests/data/acpi/q35/DSDT
> tests/data/acpi/q35/DSDT.acpihmat
> tests/data/acpi/q35/DSDT.bridge
> tests/data/acpi/q35/DSDT.cphp
> tests/data/acpi/q35/DSDT.dimmpxm
> tests/data/acpi/q35/DSDT.ipmibt
> tests/data/acpi/q35/DSDT.memhp
> tests/data/acpi/q35/DSDT.mmio64
> tests/data/acpi/q35/DSDT.numamem
> tests/data/acpi/q35/DSDT.tis
>
> These tables are updated in the following commit. Without the updated table
> blobs, the unit tests would fail with this patch.
>
> Signed-off-by: Ani Sinha <a...@anisinha.ca>
> Reviewed-by: Igor Mammedov <imamm...@redhat.com>
> Message-Id: <20200918084111.15339-11-...@anisinha.ca>
> Reviewed-by: Michael S. Tsirkin <m...@redhat.com>
> Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
> ---
> hw/acpi/piix4.c | 6 ++++--
> hw/i386/acpi-build.c | 25 ++++++++++++++++++-------
> 2 files changed, 22 insertions(+), 9 deletions(-)
>
> diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
> index 832f8fba82..894d357f8c 100644
> --- a/hw/acpi/piix4.c
> +++ b/hw/acpi/piix4.c
> @@ -596,8 +596,10 @@ static void piix4_acpi_system_hot_add_init(MemoryRegion
> *parent,
> "acpi-gpe0", GPE_LEN);
> memory_region_add_subregion(parent, GPE_BASE, &s->io_gpe);
>
> - acpi_pcihp_init(OBJECT(s), &s->acpi_pci_hotplug, bus, parent,
> - s->use_acpi_hotplug_bridge);
> + if (s->use_acpi_hotplug_bridge || s->use_acpi_root_pci_hotplug) {
> + acpi_pcihp_init(OBJECT(s), &s->acpi_pci_hotplug, bus, parent,
> + s->use_acpi_hotplug_bridge);
> + }
>
> s->cpu_hotplug_legacy = true;
> object_property_add_bool(OBJECT(s), "cpu-hotplug-legacy",
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index 2b17843837..8d14e4667a 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -96,6 +96,7 @@ typedef struct AcpiPmInfo {
> bool s4_disabled;
> bool pcihp_bridge_en;
> bool smi_on_cpuhp;
> + bool pcihp_root_en;
> uint8_t s4_val;
> AcpiFadtData fadt;
> uint16_t cpu_hp_io_base;
> @@ -251,6 +252,9 @@ static void acpi_get_pm_info(MachineState *machine,
> AcpiPmInfo *pm)
> pm->pcihp_bridge_en =
> object_property_get_bool(obj, "acpi-pci-hotplug-with-bridge-support",
> NULL);
> + pm->pcihp_root_en =
> + object_property_get_bool(obj, "acpi-root-pci-hotplug",
> + NULL);
> }
>
> static void acpi_get_misc_info(AcpiMiscInfo *info)
> @@ -456,10 +460,12 @@ static void build_append_pci_bus_devices(Aml
> *parent_scope, PCIBus *bus,
> }
>
> /* Append PCNT method to notify about events on local and child buses.
> - * Add unconditionally for root since DSDT expects it.
> + * Add this method for root bus only when hotplug is enabled since DSDT
> + * expects it.
> */
> - method = aml_method("PCNT", 0, AML_NOTSERIALIZED);
> -
> + if (bsel || pcihp_bridge_en) {
> + method = aml_method("PCNT", 0, AML_NOTSERIALIZED);
> + }
build_append_pci_bus_devices() is not easy to follow and could certainly
benefit from a refactor.
So here, before 'method' was always reinitialized. Now not always,
so it can be any value set in the big for() loop before...
Something is definitively wrong.
> /* If bus supports hotplug select it and notify about local events */
> if (bsel) {
> uint64_t bsel_val = qnum_get_uint(qobject_to(QNum, bsel));
> @@ -485,7 +491,10 @@ static void build_append_pci_bus_devices(Aml
> *parent_scope, PCIBus *bus,
> aml_append(method, aml_name("^S%.02X.PCNT", devfn));
> }
> }
> - aml_append(parent_scope, method);
> +
> + if (bsel || pcihp_bridge_en) {
> + aml_append(parent_scope, method);
> + }
> qobject_unref(bsel);
> }
>
> @@ -1510,7 +1519,9 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
> build_hpet_aml(dsdt);
> build_piix4_isa_bridge(dsdt);
> build_isa_devices_aml(dsdt);
> - build_piix4_pci_hotplug(dsdt);
> + if (pm->pcihp_bridge_en || pm->pcihp_root_en) {
> + build_piix4_pci_hotplug(dsdt);
> + }
> build_piix4_pci0_int(dsdt);
> } else {
> sb_scope = aml_scope("_SB");
> @@ -1579,7 +1590,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
> {
> aml_append(scope, aml_name_decl("_HID", aml_string("ACPI0006")));
>
> - if (misc->is_piix4) {
> + if (misc->is_piix4 && (pm->pcihp_bridge_en || pm->pcihp_root_en)) {
> method = aml_method("_E01", 0, AML_NOTSERIALIZED);
> aml_append(method,
> aml_acquire(aml_name("\\_SB.PCI0.BLCK"), 0xFFFF));
> @@ -1731,7 +1742,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
> crs_range_set_free(&crs_range_set);
>
> /* reserve PCIHP resources */
> - if (pm->pcihp_io_len) {
> + if (pm->pcihp_io_len && (pm->pcihp_bridge_en || pm->pcihp_root_en)) {
> dev = aml_device("PHPR");
> aml_append(dev, aml_name_decl("_HID", aml_string("PNP0A06")));
> aml_append(dev,
>
