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[PATCH RFC V2 35/37] hw/arm: Support hotplug capability check using _OSC
From: |
Salil Mehta |
Subject: |
[PATCH RFC V2 35/37] hw/arm: Support hotplug capability check using _OSC method |
Date: |
Tue, 26 Sep 2023 11:36:52 +0100 |
Physical CPU hotplug results in (un)setting of ACPI _STA.Present bit. AARCH64
platforms do not support physical CPU hotplug. Virtual CPU hotplug support being
implemented toggles ACPI _STA.Enabled Bit to achieve hotplug functionality. This
is not same as physical CPU hotplug support.
In future, if ARM architecture supports physical CPU hotplug then the current
design of virtual CPU hotplug can be used unchanged. Hence, there is a need for
firmware/VMM/Qemu to support evaluation of platform wide capabilitiy related to
the *type* of CPU hotplug support present on the platform. OSPM might need this
during boot time to correctly initialize the CPUs and other related components
in the kernel.
NOTE: This implementation will be improved to add the support of *query* in the
subsequent versions. This is very minimal support to assist kernel.
ASL for the implemented _OSC method:
Method (_OSC, 4, NotSerialized) // _OSC: Operating System Capabilities
{
CreateDWordField (Arg3, Zero, CDW1)
If ((Arg0 == ToUUID ("0811b06e-4a27-44f9-8d60-3cbbc22e7b48") /*
Platform-wide Capabilities */))
{
CreateDWordField (Arg3, 0x04, CDW2)
Local0 = CDW2 /* \_SB_._OSC.CDW2 */
If ((Arg1 != One))
{
CDW1 |= 0x08
}
Local0 &= 0x00800000
If ((CDW2 != Local0))
{
CDW1 |= 0x10
}
CDW2 = Local0
}
Else
{
CDW1 |= 0x04
}
Return (Arg3)
}
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
---
hw/arm/virt-acpi-build.c | 52 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 52 insertions(+)
diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index cbccd2ca2d..377450dd16 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -861,6 +861,55 @@ static void build_fadt_rev6(GArray *table_data, BIOSLinker
*linker,
build_fadt(table_data, linker, &fadt, vms->oem_id, vms->oem_table_id);
}
+static void build_virt_osc_method(Aml *scope, VirtMachineState *vms)
+{
+ Aml *if_uuid, *else_uuid, *if_rev, *if_caps_masked, *method;
+ Aml *a_cdw1 = aml_name("CDW1");
+ Aml *a_cdw2 = aml_local(0);
+
+ method = aml_method("_OSC", 4, AML_NOTSERIALIZED);
+ aml_append(method, aml_create_dword_field(aml_arg(3), aml_int(0), "CDW1"));
+
+ /* match UUID */
+ if_uuid = aml_if(aml_equal(
+ aml_arg(0), aml_touuid("0811B06E-4A27-44F9-8D60-3CBBC22E7B48")));
+
+ aml_append(if_uuid, aml_create_dword_field(aml_arg(3), aml_int(4),
"CDW2"));
+ aml_append(if_uuid, aml_store(aml_name("CDW2"), a_cdw2));
+
+ /* check unknown revision in arg(1) */
+ if_rev = aml_if(aml_lnot(aml_equal(aml_arg(1), aml_int(1))));
+ /* set revision error bits, DWORD1 Bit[3] */
+ aml_append(if_rev, aml_or(a_cdw1, aml_int(0x08), a_cdw1));
+ aml_append(if_uuid, if_rev);
+
+ /*
+ * check support for vCPU hotplug type(=enabled) platform-wide capability
+ * in DWORD2 as sepcified in the below ACPI Specification ECR,
+ * # https://bugzilla.tianocore.org/show_bug.cgi?id=4481
+ */
+ if (vms->acpi_dev) {
+ aml_append(if_uuid, aml_and(a_cdw2, aml_int(0x800000), a_cdw2));
+ /* check if OSPM specified hotplug capability bits were masked */
+ if_caps_masked = aml_if(aml_lnot(aml_equal(aml_name("CDW2"), a_cdw2)));
+ aml_append(if_caps_masked, aml_or(a_cdw1, aml_int(0x10), a_cdw1));
+ aml_append(if_uuid, if_caps_masked);
+ }
+ aml_append(if_uuid, aml_store(a_cdw2, aml_name("CDW2")));
+
+ aml_append(method, if_uuid);
+ else_uuid = aml_else();
+
+ /* set unrecognized UUID error bits, DWORD1 Bit[2] */
+ aml_append(else_uuid, aml_or(a_cdw1, aml_int(4), a_cdw1));
+ aml_append(method, else_uuid);
+
+ aml_append(method, aml_return(aml_arg(3)));
+ aml_append(scope, method);
+
+ return;
+}
+
/* DSDT */
static void
build_dsdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
@@ -894,6 +943,9 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
VirtMachineState *vms)
} else {
acpi_dsdt_add_cpus(scope, vms);
}
+
+ build_virt_osc_method(scope, vms);
+
acpi_dsdt_add_uart(scope, &memmap[VIRT_UART],
(irqmap[VIRT_UART] + ARM_SPI_BASE));
if (vmc->acpi_expose_flash) {
--
2.34.1
- [PATCH RFC V2 27/37] hw/arm, gicv3: Changes to update GIC with vCPU hot-plug notification, (continued)
- [PATCH RFC V2 27/37] hw/arm, gicv3: Changes to update GIC with vCPU hot-plug notification, Salil Mehta, 2023/09/26
- [PATCH RFC V2 28/37] hw/intc/arm-gicv3*: Changes required to (re)init the vCPU register info, Salil Mehta, 2023/09/26
- [PATCH RFC V2 29/37] arm/virt: Update the guest(via GED) about CPU hot-(un)plug events, Salil Mehta, 2023/09/26
- [PATCH RFC V2 30/37] hw/arm: Changes required for reset and to support next boot, Salil Mehta, 2023/09/26
- [PATCH RFC V2 31/37] physmem, gdbstub: Common helping funcs/changes to *unrealize* vCPU, Salil Mehta, 2023/09/26
- [PATCH RFC V2 32/37] target/arm: Add support of *unrealize* ARMCPU during vCPU Hot-unplug, Salil Mehta, 2023/09/26
- [PATCH RFC V2 35/37] hw/arm: Support hotplug capability check using _OSC method,
Salil Mehta <=
- Re: [PATCH RFC V2 35/37] hw/arm: Support hotplug capability check using _OSC method, Gavin Shan, 2023/09/29
- [PATCH RFC V2 36/37] tcg/mttcg: enable threads to unregister in tcg_ctxs[], Salil Mehta, 2023/09/26
- [PATCH RFC V2 37/37] hw/arm/virt: Expose cold-booted CPUs as MADT GICC Enabled, Salil Mehta, 2023/09/26