QEMU commit 3a61c8db9d25 ("acpi: cpuhp: add CPHP_GET_CPU_ID_CMD command",
2020-01-22) introduced a new command in the modern CPU hotplug register
block that lets the firmware query the arch-specific IDs (on IA32/X64: the
APIC IDs) of CPUs. Add a macro for this command value, because we'll need
it later.At the same time, add a sanity check for the modern hotplug interface to CpuHotplugSmm. 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 | 1 + OvmfPkg/CpuHotplugSmm/CpuHotplug.c | 35 ++++++++++++++++++++ 2 files changed, 36 insertions(+) diff --git a/OvmfPkg/Include/IndustryStandard/QemuCpuHotplug.h b/OvmfPkg/Include/IndustryStandard/QemuCpuHotplug.h index cf0745610f2c..3d013633501b 100644 --- a/OvmfPkg/Include/IndustryStandard/QemuCpuHotplug.h +++ b/OvmfPkg/Include/IndustryStandard/QemuCpuHotplug.h @@ -20,24 +20,25 @@ #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_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/CpuHotplug.c b/OvmfPkg/CpuHotplugSmm/CpuHotplug.c index fd09403eabf3..5df8c689c63a 100644 --- a/OvmfPkg/CpuHotplugSmm/CpuHotplug.c +++ b/OvmfPkg/CpuHotplugSmm/CpuHotplug.c @@ -1,38 +1,41 @@ /** @file Root SMI handler for VCPU hotplug SMIs. Copyright (c) 2020, Red Hat, Inc. SPDX-License-Identifier: BSD-2-Clause-Patent **/ #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 <Protocol/MmCpuIo.h> // EFI_MM_CPU_IO_PROTOCOL #include <Uefi/UefiBaseType.h> // EFI_STATUS +#include "QemuCpuhp.h" // QemuCpuhpWriteCpuSelector() + // // We use this protocol for accessing IO Ports. // STATIC EFI_MM_CPU_IO_PROTOCOL *mMmCpuIo; // // 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. @@ -149,43 +152,75 @@ CpuHotplugEntry ( // // 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; } + // + // 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; + } + // // 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; } return EFI_SUCCESS; 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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