Add a function that collects the APIC IDs of CPUs that have just been hot-plugged, or are about to be hot-unplugged.
Pending events are only located and never cleared; QEMU's AML needs the firmware to leave the status bits intact in the hotplug register block. 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/Include/IndustryStandard/QemuCpuHotplug.h | 2 + OvmfPkg/CpuHotplugSmm/CpuHotplugSmm.inf | 1 + OvmfPkg/CpuHotplugSmm/ApicId.h | 23 +++ OvmfPkg/CpuHotplugSmm/QemuCpuhp.h | 20 ++- OvmfPkg/CpuHotplugSmm/QemuCpuhp.c | 171 +++++++++++++++++++- 5 files changed, 211 insertions(+), 6 deletions(-) diff --git a/OvmfPkg/Include/IndustryStandard/QemuCpuHotplug.h b/OvmfPkg/Include/IndustryStandard/QemuCpuHotplug.h index 3d013633501b..a34a6d3fae61 100644 --- a/OvmfPkg/Include/IndustryStandard/QemuCpuHotplug.h +++ b/OvmfPkg/Include/IndustryStandard/QemuCpuHotplug.h @@ -13,32 +13,34 @@ The new ("modern") hotplug interface appeared in QEMU v2.7.0. The macros in this header file map to the minimal subset of the modern interface that OVMF needs. **/ #ifndef QEMU_CPU_HOTPLUG_H_ #define QEMU_CPU_HOTPLUG_H_ #include <Base.h> // // Each register offset is: // - relative to the board-dependent IO base address of the register block, // - named QEMU_CPUHP_(R|W|RW)_*, according to the possible access modes of the // register, // - followed by distinguished bitmasks or values in the register. // #define QEMU_CPUHP_R_CMD_DATA2 0x0 #define QEMU_CPUHP_R_CPU_STAT 0x4 #define QEMU_CPUHP_STAT_ENABLED BIT0 +#define QEMU_CPUHP_STAT_INSERT BIT1 +#define QEMU_CPUHP_STAT_REMOVE BIT2 #define QEMU_CPUHP_RW_CMD_DATA 0x8 #define QEMU_CPUHP_W_CPU_SEL 0x0 #define QEMU_CPUHP_W_CMD 0x5 #define QEMU_CPUHP_CMD_GET_PENDING 0x0 #define QEMU_CPUHP_CMD_GET_ARCH_ID 0x3 #endif // QEMU_CPU_HOTPLUG_H_ diff --git a/OvmfPkg/CpuHotplugSmm/CpuHotplugSmm.inf b/OvmfPkg/CpuHotplugSmm/CpuHotplugSmm.inf index ac4ca4c1f4f2..ab690a9e5e20 100644 --- a/OvmfPkg/CpuHotplugSmm/CpuHotplugSmm.inf +++ b/OvmfPkg/CpuHotplugSmm/CpuHotplugSmm.inf @@ -3,44 +3,45 @@ # # Copyright (c) 2020, Red Hat, Inc. # # SPDX-License-Identifier: BSD-2-Clause-Patent ## [Defines] INF_VERSION = 1.29 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 [LibraryClasses] BaseLib DebugLib MmServicesTableLib PcdLib UefiDriverEntryPoint [Protocols] gEfiMmCpuIoProtocolGuid ## CONSUMES [Pcd] gUefiOvmfPkgTokenSpaceGuid.PcdQ35SmramAtDefaultSmbase ## CONSUMES [FeaturePcd] diff --git a/OvmfPkg/CpuHotplugSmm/ApicId.h b/OvmfPkg/CpuHotplugSmm/ApicId.h new file mode 100644 index 000000000000..3c365148ed02 --- /dev/null +++ b/OvmfPkg/CpuHotplugSmm/ApicId.h @@ -0,0 +1,23 @@ +/** @file + Type and macro definitions for representing and printing APIC IDs, compatibly + with the LocalApicLib and PrintLib classes, respectively. + + Copyright (c) 2020, Red Hat, Inc. + + SPDX-License-Identifier: BSD-2-Clause-Patent +**/ + +#ifndef APIC_ID_H_ +#define APIC_ID_H_ + +// +// The type that LocalApicLib represents an APIC ID with. +// +typedef UINT32 APIC_ID; + +// +// The PrintLib conversion specification for formatting an APIC_ID. +// +#define FMT_APIC_ID "0x%08x" + +#endif // APIC_ID_H_ diff --git a/OvmfPkg/CpuHotplugSmm/QemuCpuhp.h b/OvmfPkg/CpuHotplugSmm/QemuCpuhp.h index 82f88f0b73bb..8adaa0ad91f0 100644 --- a/OvmfPkg/CpuHotplugSmm/QemuCpuhp.h +++ b/OvmfPkg/CpuHotplugSmm/QemuCpuhp.h @@ -1,47 +1,61 @@ /** @file - Simple wrapper functions that access QEMU's modern CPU hotplug register - block. + Simple wrapper functions and utility functions that access QEMU's modern CPU + hotplug register block. - These functions thinly wrap some of the registers described in + These functions manipulate some of the registers described in "docs/specs/acpi_cpu_hotplug.txt" in the QEMU source. IO Ports are accessed via EFI_MM_CPU_IO_PROTOCOL. If a protocol call fails, these functions don't return. Copyright (c) 2020, Red Hat, Inc. SPDX-License-Identifier: BSD-2-Clause-Patent **/ #ifndef QEMU_CPUHP_H_ #define QEMU_CPUHP_H_ #include <Protocol/MmCpuIo.h> // EFI_MM_CPU_IO_PROTOCOL +#include <Uefi/UefiBaseType.h> // EFI_STATUS + +#include "ApicId.h" // APIC_ID UINT32 QemuCpuhpReadCommandData2 ( IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo ); UINT8 QemuCpuhpReadCpuStatus ( IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo ); UINT32 QemuCpuhpReadCommandData ( IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo ); VOID QemuCpuhpWriteCpuSelector ( IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo, IN UINT32 Selector ); VOID QemuCpuhpWriteCommand ( IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo, IN UINT8 Command ); +EFI_STATUS +QemuCpuhpCollectApicIds ( + IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo, + IN UINT32 PossibleCpuCount, + IN UINT32 ApicIdCount, + OUT APIC_ID *PluggedApicIds, + OUT UINT32 *PluggedCount, + OUT APIC_ID *ToUnplugApicIds, + OUT UINT32 *ToUnplugCount + ); + #endif // QEMU_CPUHP_H_ diff --git a/OvmfPkg/CpuHotplugSmm/QemuCpuhp.c b/OvmfPkg/CpuHotplugSmm/QemuCpuhp.c index 31e46f51934a..8d4a6693c8d6 100644 --- a/OvmfPkg/CpuHotplugSmm/QemuCpuhp.c +++ b/OvmfPkg/CpuHotplugSmm/QemuCpuhp.c @@ -1,27 +1,27 @@ /** @file - Simple wrapper functions that access QEMU's modern CPU hotplug register - block. + Simple wrapper functions and utility functions that access QEMU's modern CPU + hotplug register block. - These functions thinly wrap some of the registers described in + These functions manipulate some of the registers described in "docs/specs/acpi_cpu_hotplug.txt" in the QEMU source. IO Ports are accessed via EFI_MM_CPU_IO_PROTOCOL. If a protocol call fails, these functions don't return. Copyright (c) 2020, Red Hat, Inc. SPDX-License-Identifier: BSD-2-Clause-Patent **/ #include <IndustryStandard/Q35MchIch9.h> // ICH9_CPU_HOTPLUG_BASE #include <IndustryStandard/QemuCpuHotplug.h> // QEMU_CPUHP_R_CMD_DATA2 #include <Library/BaseLib.h> // CpuDeadLoop() #include <Library/DebugLib.h> // DEBUG() #include "QemuCpuhp.h" UINT32 QemuCpuhpReadCommandData2 ( IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo ) { UINT32 CommandData2; @@ -115,22 +115,187 @@ QemuCpuhpWriteCpuSelector ( VOID QemuCpuhpWriteCommand ( IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo, IN UINT8 Command ) { EFI_STATUS Status; Status = MmCpuIo->Io.Write ( MmCpuIo, MM_IO_UINT8, ICH9_CPU_HOTPLUG_BASE + QEMU_CPUHP_W_CMD, 1, &Command ); if (EFI_ERROR (Status)) { DEBUG ((DEBUG_ERROR, "%a: %r\n", __FUNCTION__, Status)); ASSERT (FALSE); CpuDeadLoop (); } } + +/** + Collect the APIC IDs of + - the CPUs that have been hot-plugged, + - the CPUs that are about to be hot-unplugged. + + This function only scans for events -- it does not modify them -- in the + hotplug registers. + + On error, the contents of the output parameters are undefined. + + @param[in] MmCpuIo The EFI_MM_CPU_IO_PROTOCOL instance for + accessing IO Ports. + + @param[in] PossibleCpuCount The number of possible CPUs in the system. Must + be positive. + + @param[in] ApicIdCount The number of elements each one of the + PluggedApicIds and ToUnplugApicIds arrays can + accommodate. Must be positive. + + @param[out] PluggedApicIds The APIC IDs of the CPUs that have been + hot-plugged. + + @param[out] PluggedCount The number of filled-in APIC IDs in + PluggedApicIds. + + @param[out] ToUnplugApicIds The APIC IDs of the CPUs that are about to be + hot-unplugged. + + @param[out] ToUnplugCount The number of filled-in APIC IDs in + ToUnplugApicIds. + + @retval EFI_INVALID_PARAMETER PossibleCpuCount is zero, or ApicIdCount is + zero. + + @retval EFI_PROTOCOL_ERROR Invalid bitmap detected in the + QEMU_CPUHP_R_CPU_STAT register. + + @retval EFI_BUFFER_TOO_SMALL There was an attempt to place more than + ApicIdCount APIC IDs into one of the + PluggedApicIds and ToUnplugApicIds arrays. + + @retval EFI_SUCCESS Output parameters have been set successfully. +**/ +EFI_STATUS +QemuCpuhpCollectApicIds ( + IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo, + IN UINT32 PossibleCpuCount, + IN UINT32 ApicIdCount, + OUT APIC_ID *PluggedApicIds, + OUT UINT32 *PluggedCount, + OUT APIC_ID *ToUnplugApicIds, + OUT UINT32 *ToUnplugCount + ) +{ + UINT32 CurrentSelector; + + if (PossibleCpuCount == 0 || ApicIdCount == 0) { + return EFI_INVALID_PARAMETER; + } + + *PluggedCount = 0; + *ToUnplugCount = 0; + + CurrentSelector = 0; + do { + UINT32 PendingSelector; + UINT8 CpuStatus; + APIC_ID *ExtendIds; + UINT32 *ExtendCount; + APIC_ID NewApicId; + + // + // Write CurrentSelector (which is valid) to the CPU selector register. + // Consequences: + // + // - Other register accesses will be permitted. + // + // - The QEMU_CPUHP_CMD_GET_PENDING command will start scanning for a CPU + // with pending events at CurrentSelector (inclusive). + // + QemuCpuhpWriteCpuSelector (MmCpuIo, CurrentSelector); + // + // Write the QEMU_CPUHP_CMD_GET_PENDING command. Consequences + // (independently of each other): + // + // - If there is a CPU with pending events, starting at CurrentSelector + // (inclusive), the CPU selector will be updated to that CPU. Note that + // the scanning in QEMU may wrap around, because we must never clear the + // event bits. + // + // - The QEMU_CPUHP_RW_CMD_DATA register will return the (possibly updated) + // CPU selector value. + // + QemuCpuhpWriteCommand (MmCpuIo, QEMU_CPUHP_CMD_GET_PENDING); + PendingSelector = QemuCpuhpReadCommandData (MmCpuIo); + if (PendingSelector < CurrentSelector) { + DEBUG ((DEBUG_VERBOSE, "%a: CurrentSelector=%u PendingSelector=%u: " + "wrap-around\n", __FUNCTION__, CurrentSelector, PendingSelector)); + break; + } + CurrentSelector = PendingSelector; + + // + // Check the known status / event bits for the currently selected CPU. + // + CpuStatus = QemuCpuhpReadCpuStatus (MmCpuIo); + if ((CpuStatus & QEMU_CPUHP_STAT_INSERT) != 0) { + // + // The "insert" event guarantees the "enabled" status; plus it excludes + // the "remove" event. + // + if ((CpuStatus & QEMU_CPUHP_STAT_ENABLED) == 0 || + (CpuStatus & QEMU_CPUHP_STAT_REMOVE) != 0) { + DEBUG ((DEBUG_ERROR, "%a: CurrentSelector=%u CpuStatus=0x%x: " + "inconsistent CPU status\n", __FUNCTION__, CurrentSelector, + CpuStatus)); + return EFI_PROTOCOL_ERROR; + } + + DEBUG ((DEBUG_VERBOSE, "%a: CurrentSelector=%u: insert\n", __FUNCTION__, + CurrentSelector)); + + ExtendIds = PluggedApicIds; + ExtendCount = PluggedCount; + } else if ((CpuStatus & QEMU_CPUHP_STAT_REMOVE) != 0) { + DEBUG ((DEBUG_VERBOSE, "%a: CurrentSelector=%u: remove\n", __FUNCTION__, + CurrentSelector)); + + ExtendIds = ToUnplugApicIds; + ExtendCount = ToUnplugCount; + } else { + DEBUG ((DEBUG_VERBOSE, "%a: CurrentSelector=%u: no event\n", + __FUNCTION__, CurrentSelector)); + break; + } + + // + // Save the APIC ID of the CPU with the pending event, to the corresponding + // APIC ID array. + // + if (*ExtendCount == ApicIdCount) { + DEBUG ((DEBUG_ERROR, "%a: APIC ID array too small\n", __FUNCTION__)); + return EFI_BUFFER_TOO_SMALL; + } + QemuCpuhpWriteCommand (MmCpuIo, QEMU_CPUHP_CMD_GET_ARCH_ID); + NewApicId = QemuCpuhpReadCommandData (MmCpuIo); + DEBUG ((DEBUG_VERBOSE, "%a: ApicId=" FMT_APIC_ID "\n", __FUNCTION__, + NewApicId)); + ExtendIds[(*ExtendCount)++] = NewApicId; + + // + // We've processed the CPU with (known) pending events, but we must never + // clear events. Therefore we need to advance past this CPU manually; + // otherwise, QEMU_CPUHP_CMD_GET_PENDING would stick to the currently + // selected CPU. + // + CurrentSelector++; + } while (CurrentSelector < PossibleCpuCount); + + DEBUG ((DEBUG_VERBOSE, "%a: PluggedCount=%u ToUnplugCount=%u\n", + __FUNCTION__, *PluggedCount, *ToUnplugCount)); + return EFI_SUCCESS; +} -- 2.19.1.3.g30247aa5d201 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#54952): https://edk2.groups.io/g/devel/message/54952 Mute This Topic: https://groups.io/mt/71575183/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
