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hw/i386/acpi-build: Deny control on PCIe Native Hot-plug in _OSC

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There are two ways to enable ACPI PCI Hot-plug:

        * Disable the Hot-plug Capable bit on PCIe slots.

This was the first approach which led to regression [1-2], as
I/O space for a port is allocated only when it is hot-pluggable,
which is determined by HPC bit.

        * Leave the HPC bit on and disable PCIe Native Hot-plug in _OSC
          method.

This removes the (future) ability of hot-plugging switches with PCIe
Native hotplug since ACPI PCI Hot-plug only works with cold-plugged
bridges. If the user wants to explicitely use this feature, they can
disable ACPI PCI Hot-plug with:
        --global ICH9-LPC.acpi-pci-hotplug-with-bridge-support=off

Change the bit in _OSC method so that the OS selects ACPI PCI Hot-plug
instead of PCIe Native.

[1] https://gitlab.com/qemu-project/qemu/-/issues/641
[2] https://bugzilla.redhat.com/show_bug.cgi?id=2006409

Signed-off-by: Julia Suvorova <jusual@redhat.com>
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20211112110857.3116853-5-imammedo@redhat.com>
Reviewed-by: Ani Sinha <ani@anisinha.ca>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Julia Suvorova 2021-11-12 06:08:56 -05:00 committed by Michael S. Tsirkin
parent be12e3a016
commit 211afe5c69
1 changed files with 8 additions and 4 deletions
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12
hw/i386/acpi-build.c
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@ -1337,7 +1337,7 @@ static void build_x86_acpi_pci_hotplug(Aml *table, uint64_t pcihp_addr)
aml_append(table, scope);
}
static Aml *build_q35_osc_method(void)
static Aml *build_q35_osc_method(bool enable_native_pcie_hotplug)
{
Aml *if_ctx;
Aml *if_ctx2;
@ -1359,8 +1359,10 @@ static Aml *build_q35_osc_method(void)
/*
* Always allow native PME, AER (no dependencies)
* Allow SHPC (PCI bridges can have SHPC controller)
* Disable PCIe Native Hot-plug if ACPI PCI Hot-plug is enabled.
*/
aml_append(if_ctx, aml_and(a_ctrl, aml_int(0x1F), a_ctrl));
aml_append(if_ctx, aml_and(a_ctrl,
aml_int(0x1E | (enable_native_pcie_hotplug ? 0x1 : 0x0)), a_ctrl));
if_ctx2 = aml_if(aml_lnot(aml_equal(aml_arg(1), aml_int(1))));
/* Unknown revision */
@ -1449,7 +1451,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
aml_append(dev, aml_name_decl("_CID", aml_eisaid("PNP0A03")));
aml_append(dev, aml_name_decl("_ADR", aml_int(0)));
aml_append(dev, aml_name_decl("_UID", aml_int(pcmc->pci_root_uid)));
aml_append(dev, build_q35_osc_method());
aml_append(dev, build_q35_osc_method(!pm->pcihp_bridge_en));
aml_append(sb_scope, dev);
if (mcfg_valid) {
aml_append(sb_scope, build_q35_dram_controller(&mcfg));
@ -1565,7 +1567,9 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
if (pci_bus_is_express(bus)) {
aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A08")));
aml_append(dev, aml_name_decl("_CID", aml_eisaid("PNP0A03")));
aml_append(dev, build_q35_osc_method());
/* Expander bridges do not have ACPI PCI Hot-plug enabled */
aml_append(dev, build_q35_osc_method(true));
} else {
aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A03")));
}