Call QemuCpuhpCollectApicIds() in the root MMI handler. The APIC IDs of the hotplugged CPUs will be used for several purposes in subsequent patches.
For calling QemuCpuhpCollectApicIds(), pre-allocate both of its output arrays "PluggedApicIds" and "ToUnplugApicIds" in the driver's entry point function. The allocation size is dictated by the possible CPU count, which we fetch from "CPU_HOT_PLUG_DATA.ArrayLength". The CPU_HOT_PLUG_DATA structure in SMRAM is an out-of-band information channel between this driver and PiSmmCpuDxeSmm, underlying EFI_SMM_CPU_SERVICE_PROTOCOL. In order to consume "CPU_HOT_PLUG_DATA.ArrayLength", extend the driver's DEPEX to EFI_SMM_CPU_SERVICE_PROTOCOL. PiSmmCpuDxeSmm stores the address of CPU_HOT_PLUG_DATA to "PcdCpuHotPlugDataAddress", before it produces EFI_SMM_CPU_SERVICE_PROTOCOL. Stash the protocol at once, as it will be needed later. Cc: Ard Biesheuvel <ard.biesheu...@linaro.org> Cc: Igor Mammedov <imamm...@redhat.com> Cc: Jiewen Yao <jiewen....@intel.com> Cc: Jordan Justen <jordan.l.jus...@intel.com> Cc: Michael Kinney <michael.d.kin...@intel.com> Cc: Philippe Mathieu-Daudé <phi...@redhat.com> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1512 Signed-off-by: Laszlo Ersek <ler...@redhat.com> Acked-by: Ard Biesheuvel <ard.biesheu...@linaro.org> --- Notes: v2: - Pick up Ard's Acked-by, which is conditional on approval from Intel reviewers on Cc. (I'd like to save Ard the churn of re-acking unmodified patches.) OvmfPkg/CpuHotplugSmm/CpuHotplugSmm.inf | 7 +- OvmfPkg/CpuHotplugSmm/CpuHotplug.c | 111 +++++++++++++++++++- 2 files changed, 115 insertions(+), 3 deletions(-) diff --git a/OvmfPkg/CpuHotplugSmm/CpuHotplugSmm.inf b/OvmfPkg/CpuHotplugSmm/CpuHotplugSmm.inf index ab690a9e5e20..31c1ee1c9f6d 100644 --- a/OvmfPkg/CpuHotplugSmm/CpuHotplugSmm.inf +++ b/OvmfPkg/CpuHotplugSmm/CpuHotplugSmm.inf @@ -11,41 +11,46 @@ [Defines] PI_SPECIFICATION_VERSION = 0x00010046 # PI-1.7.0 BASE_NAME = CpuHotplugSmm FILE_GUID = 84EEA114-C6BE-4445-8F90-51D97863E363 MODULE_TYPE = DXE_SMM_DRIVER ENTRY_POINT = CpuHotplugEntry # # The following information is for reference only and not required by the build # tools. # # VALID_ARCHITECTURES = IA32 X64 # [Sources] ApicId.h CpuHotplug.c QemuCpuhp.c QemuCpuhp.h [Packages] MdePkg/MdePkg.dec OvmfPkg/OvmfPkg.dec + UefiCpuPkg/UefiCpuPkg.dec [LibraryClasses] BaseLib DebugLib MmServicesTableLib PcdLib + SafeIntLib UefiDriverEntryPoint [Protocols] gEfiMmCpuIoProtocolGuid ## CONSUMES + gEfiSmmCpuServiceProtocolGuid ## CONSUMES [Pcd] + gUefiCpuPkgTokenSpaceGuid.PcdCpuHotPlugDataAddress ## CONSUMES gUefiOvmfPkgTokenSpaceGuid.PcdQ35SmramAtDefaultSmbase ## CONSUMES [FeaturePcd] gUefiOvmfPkgTokenSpaceGuid.PcdSmmSmramRequire ## CONSUMES [Depex] - gEfiMmCpuIoProtocolGuid + gEfiMmCpuIoProtocolGuid AND + gEfiSmmCpuServiceProtocolGuid diff --git a/OvmfPkg/CpuHotplugSmm/CpuHotplug.c b/OvmfPkg/CpuHotplugSmm/CpuHotplug.c index 5df8c689c63a..42e023cb85c0 100644 --- a/OvmfPkg/CpuHotplugSmm/CpuHotplug.c +++ b/OvmfPkg/CpuHotplugSmm/CpuHotplug.c @@ -1,46 +1,76 @@ /** @file Root SMI handler for VCPU hotplug SMIs. Copyright (c) 2020, Red Hat, Inc. SPDX-License-Identifier: BSD-2-Clause-Patent **/ +#include <CpuHotPlugData.h> // CPU_HOT_PLUG_DATA #include <IndustryStandard/Q35MchIch9.h> // ICH9_APM_CNT #include <IndustryStandard/QemuCpuHotplug.h> // QEMU_CPUHP_CMD_GET_PENDING #include <Library/BaseLib.h> // CpuDeadLoop() #include <Library/DebugLib.h> // ASSERT() #include <Library/MmServicesTableLib.h> // gMmst #include <Library/PcdLib.h> // PcdGetBool() +#include <Library/SafeIntLib.h> // SafeUintnSub() #include <Protocol/MmCpuIo.h> // EFI_MM_CPU_IO_PROTOCOL +#include <Protocol/SmmCpuService.h> // EFI_SMM_CPU_SERVICE_PROTOCOL #include <Uefi/UefiBaseType.h> // EFI_STATUS +#include "ApicId.h" // APIC_ID #include "QemuCpuhp.h" // QemuCpuhpWriteCpuSelector() // // We use this protocol for accessing IO Ports. // STATIC EFI_MM_CPU_IO_PROTOCOL *mMmCpuIo; // +// The following protocol is used to report the addition or removal of a CPU to +// the SMM CPU driver (PiSmmCpuDxeSmm). +// +STATIC EFI_SMM_CPU_SERVICE_PROTOCOL *mMmCpuService; +// +// This structure is a communication side-channel between the +// EFI_SMM_CPU_SERVICE_PROTOCOL consumer (i.e., this driver) and provider +// (i.e., PiSmmCpuDxeSmm). +// +STATIC CPU_HOT_PLUG_DATA *mCpuHotPlugData; +// +// SMRAM arrays for fetching the APIC IDs of processors with pending events (of +// known event types), for the time of just one MMI. +// +// The lifetimes of these arrays match that of this driver only because we +// don't want to allocate SMRAM at OS runtime, and potentially fail (or +// fragment the SMRAM map). +// +// These arrays provide room for ("possible CPU count" minus one) APIC IDs +// each, as we don't expect every possible CPU to appear, or disappear, in a +// single MMI. The numbers of used (populated) elements in the arrays are +// determined on every MMI separately. +// +STATIC APIC_ID *mPluggedApicIds; +STATIC APIC_ID *mToUnplugApicIds; +// // Represents the registration of the CPU Hotplug MMI handler. // STATIC EFI_HANDLE mDispatchHandle; /** CPU Hotplug MMI handler function. This is a root MMI handler. @param[in] DispatchHandle The unique handle assigned to this handler by EFI_MM_SYSTEM_TABLE.MmiHandlerRegister(). @param[in] Context Context passed in by EFI_MM_SYSTEM_TABLE.MmiManage(). Due to CpuHotplugMmi() being a root MMI handler, Context is ASSERT()ed to be NULL. @param[in,out] CommBuffer Ignored, due to CpuHotplugMmi() being a root MMI handler. @param[in,out] CommBufferSize Ignored, due to CpuHotplugMmi() being a root @@ -65,162 +95,239 @@ STATIC EFI_HANDLE mDispatchHandle; but other handlers should still be called. @retval EFI_WARN_INTERRUPT_SOURCE_PENDING The MMI source is still pending, and other handlers should still be called. @retval EFI_INTERRUPT_PENDING The MMI source could not be quiesced. **/ STATIC EFI_STATUS EFIAPI CpuHotplugMmi ( IN EFI_HANDLE DispatchHandle, IN CONST VOID *Context OPTIONAL, IN OUT VOID *CommBuffer OPTIONAL, IN OUT UINTN *CommBufferSize OPTIONAL ) { EFI_STATUS Status; UINT8 ApmControl; + UINT32 PluggedCount; + UINT32 ToUnplugCount; // // Assert that we are entering this function due to our root MMI handler // registration. // ASSERT (DispatchHandle == mDispatchHandle); // // When MmiManage() is invoked to process root MMI handlers, the caller (the // MM Core) is expected to pass in a NULL Context. MmiManage() then passes // the same NULL Context to individual handlers. // ASSERT (Context == NULL); // // Read the MMI command value from the APM Control Port, to see if this is an // MMI we should care about. // Status = mMmCpuIo->Io.Read (mMmCpuIo, MM_IO_UINT8, ICH9_APM_CNT, 1, &ApmControl); if (EFI_ERROR (Status)) { DEBUG ((DEBUG_ERROR, "%a: failed to read ICH9_APM_CNT: %r\n", __FUNCTION__, Status)); // // We couldn't even determine if the MMI was for us or not. // goto Fatal; } if (ApmControl != ICH9_APM_CNT_CPU_HOTPLUG) { // // The MMI is not for us. // return EFI_WARN_INTERRUPT_SOURCE_QUIESCED; } + // + // Collect the CPUs with pending events. + // + Status = QemuCpuhpCollectApicIds ( + mMmCpuIo, + mCpuHotPlugData->ArrayLength, // PossibleCpuCount + mCpuHotPlugData->ArrayLength - 1, // ApicIdCount + mPluggedApicIds, + &PluggedCount, + mToUnplugApicIds, + &ToUnplugCount + ); + if (EFI_ERROR (Status)) { + goto Fatal; + } + if (ToUnplugCount > 0) { + DEBUG ((DEBUG_ERROR, "%a: hot-unplug is not supported yet\n", + __FUNCTION__)); + goto Fatal; + } + // // We've handled this MMI. // return EFI_SUCCESS; Fatal: ASSERT (FALSE); CpuDeadLoop (); // // We couldn't handle this MMI. // return EFI_INTERRUPT_PENDING; } // // Entry point function of this driver. // EFI_STATUS EFIAPI CpuHotplugEntry ( IN EFI_HANDLE ImageHandle, IN EFI_SYSTEM_TABLE *SystemTable ) { EFI_STATUS Status; + UINTN Size; // // This module should only be included when SMM support is required. // ASSERT (FeaturePcdGet (PcdSmmSmramRequire)); // // This driver depends on the dynamically detected "SMRAM at default SMBASE" // feature. // if (!PcdGetBool (PcdQ35SmramAtDefaultSmbase)) { return EFI_UNSUPPORTED; } // // Errors from here on are fatal; we cannot allow the boot to proceed if we // can't set up this driver to handle CPU hotplug. // // First, collect the protocols needed later. All of these protocols are // listed in our module DEPEX. // Status = gMmst->MmLocateProtocol (&gEfiMmCpuIoProtocolGuid, NULL /* Registration */, (VOID **)&mMmCpuIo); if (EFI_ERROR (Status)) { DEBUG ((DEBUG_ERROR, "%a: locate MmCpuIo: %r\n", __FUNCTION__, Status)); goto Fatal; } + Status = gMmst->MmLocateProtocol (&gEfiSmmCpuServiceProtocolGuid, + NULL /* Registration */, (VOID **)&mMmCpuService); + if (EFI_ERROR (Status)) { + DEBUG ((DEBUG_ERROR, "%a: locate MmCpuService: %r\n", __FUNCTION__, + Status)); + goto Fatal; + } + + // + // Our DEPEX on EFI_SMM_CPU_SERVICE_PROTOCOL guarantees that PiSmmCpuDxeSmm + // has pointed PcdCpuHotPlugDataAddress to CPU_HOT_PLUG_DATA in SMRAM. + // + mCpuHotPlugData = (VOID *)(UINTN)PcdGet64 (PcdCpuHotPlugDataAddress); + if (mCpuHotPlugData == NULL) { + Status = EFI_NOT_FOUND; + DEBUG ((DEBUG_ERROR, "%a: CPU_HOT_PLUG_DATA: %r\n", __FUNCTION__, Status)); + goto Fatal; + } + // + // If the possible CPU count is 1, there's nothing for this driver to do. + // + if (mCpuHotPlugData->ArrayLength == 1) { + return EFI_UNSUPPORTED; + } + // + // Allocate the data structures that depend on the possible CPU count. + // + if (RETURN_ERROR (SafeUintnSub (mCpuHotPlugData->ArrayLength, 1, &Size)) || + RETURN_ERROR (SafeUintnMult (sizeof (APIC_ID), Size, &Size))) { + Status = EFI_ABORTED; + DEBUG ((DEBUG_ERROR, "%a: invalid CPU_HOT_PLUG_DATA\n", __FUNCTION__)); + goto Fatal; + } + Status = gMmst->MmAllocatePool (EfiRuntimeServicesData, Size, + (VOID **)&mPluggedApicIds); + if (EFI_ERROR (Status)) { + DEBUG ((DEBUG_ERROR, "%a: MmAllocatePool(): %r\n", __FUNCTION__, Status)); + goto Fatal; + } + Status = gMmst->MmAllocatePool (EfiRuntimeServicesData, Size, + (VOID **)&mToUnplugApicIds); + if (EFI_ERROR (Status)) { + DEBUG ((DEBUG_ERROR, "%a: MmAllocatePool(): %r\n", __FUNCTION__, Status)); + goto ReleasePluggedApicIds; + } // // Sanity-check the CPU hotplug interface. // // Both of the following features are part of QEMU 5.0, introduced primarily // in commit range 3e08b2b9cb64..3a61c8db9d25: // // (a) the QEMU_CPUHP_CMD_GET_ARCH_ID command of the modern CPU hotplug // interface, // // (b) the "SMRAM at default SMBASE" feature. // // From these, (b) is restricted to 5.0+ machine type versions, while (a) // does not depend on machine type version. Because we ensured the stricter // condition (b) through PcdQ35SmramAtDefaultSmbase above, the (a) // QEMU_CPUHP_CMD_GET_ARCH_ID command must now be available too. While we // can't verify the presence of precisely that command, we can still verify // (sanity-check) that the modern interface is active, at least. // // Consult the "Typical usecases | Detecting and enabling modern CPU hotplug // interface" section in QEMU's "docs/specs/acpi_cpu_hotplug.txt", on the // following. // QemuCpuhpWriteCpuSelector (mMmCpuIo, 0); QemuCpuhpWriteCpuSelector (mMmCpuIo, 0); QemuCpuhpWriteCommand (mMmCpuIo, QEMU_CPUHP_CMD_GET_PENDING); if (QemuCpuhpReadCommandData2 (mMmCpuIo) != 0) { Status = EFI_NOT_FOUND; DEBUG ((DEBUG_ERROR, "%a: modern CPU hotplug interface: %r\n", __FUNCTION__, Status)); - goto Fatal; + goto ReleaseToUnplugApicIds; } // // Register the handler for the CPU Hotplug MMI. // Status = gMmst->MmiHandlerRegister ( CpuHotplugMmi, NULL, // HandlerType: root MMI handler &mDispatchHandle ); if (EFI_ERROR (Status)) { DEBUG ((DEBUG_ERROR, "%a: MmiHandlerRegister(): %r\n", __FUNCTION__, Status)); - goto Fatal; + goto ReleaseToUnplugApicIds; } return EFI_SUCCESS; +ReleaseToUnplugApicIds: + gMmst->MmFreePool (mToUnplugApicIds); + mToUnplugApicIds = NULL; + +ReleasePluggedApicIds: + gMmst->MmFreePool (mPluggedApicIds); + mPluggedApicIds = NULL; + Fatal: ASSERT (FALSE); CpuDeadLoop (); return Status; } -- 2.19.1.3.g30247aa5d201 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. 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