From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EB3E6200B8 for ; Fri, 20 Oct 2023 17:12:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="LYw0HPoL" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1697821980; x=1729357980; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=gpUiJMwmkFwlOFmFdLdipIbLm1/5/wSUBTFzSRkhCTg=; b=LYw0HPoLOQ8lB0+jccvSYpDK3cvHBM1EUn1nF4K8KUb5kbCqCHMs65mE YJWWKgoB6PioGr/Gur6vmL97V07ut7QZ1SyaaG8THS4k6Zi9bxD9x1Tdm qp27djU5wjiWdvRIoeS+GuQMjnSE5UlOlddkh/igKa8c9jIh2FnrOKuDT 4f4enPwbNq9AzDoMPrYa8kna3DBhvja4muVDmUzGXdX7/DsBIOjJhO0kf J6TkkRNKTzVcqrerr0TSPgSxtRtruJZh7pNkCyqQEtCxNSK1StmGl8XuP iK+aHDrmlkF+KRuy0PVl2XMqvgQVYO7gJf3dqba8HP4XqxUlSX015cRqu g==; X-IronPort-AV: E=McAfee;i="6600,9927,10869"; a="385424750" X-IronPort-AV: E=Sophos;i="6.03,239,1694761200"; d="scan'208";a="385424750" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Oct 2023 10:12:57 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10869"; a="761114755" X-IronPort-AV: E=Sophos;i="6.03,239,1694761200"; d="scan'208";a="761114755" Received: from gneiger-mobl3.amr.corp.intel.com (HELO [10.209.88.124]) ([10.209.88.124]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Oct 2023 10:12:56 -0700 Message-ID: Date: Fri, 20 Oct 2023 10:12:56 -0700 Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCHv2 01/13] x86/acpi: Extract ACPI MADT wakeup code into a separate file Content-Language: en-US To: "Kirill A. Shutemov" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org Cc: "Rafael J. Wysocki" , Peter Zijlstra , Adrian Hunter , Elena Reshetova , Jun Nakajima , Rick Edgecombe , Tom Lendacky , "Kalra, Ashish" , Sean Christopherson , "Huang, Kai" , Baoquan He , kexec@lists.infradead.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org References: <20231020151242.1814-1-kirill.shutemov@linux.intel.com> <20231020151242.1814-2-kirill.shutemov@linux.intel.com> From: Kuppuswamy Sathyanarayanan In-Reply-To: <20231020151242.1814-2-kirill.shutemov@linux.intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 10/20/2023 8:12 AM, Kirill A. Shutemov wrote: > In order to prepare for the expansion of support for the ACPI MADT > wakeup method, move the relevant code into a separate file. > > Introduce a new configuration option to clearly indicate dependencies > without the use of ifdefs. > > There have been no functional changes. > > Signed-off-by: Kirill A. Shutemov > --- Looks good to me. Reviewed-by: Kuppuswamy Sathyanarayanan > arch/x86/Kconfig | 7 +++ > arch/x86/include/asm/acpi.h | 5 ++ > arch/x86/kernel/acpi/Makefile | 11 ++-- > arch/x86/kernel/acpi/boot.c | 86 +----------------------------- > arch/x86/kernel/acpi/madt_wakeup.c | 81 ++++++++++++++++++++++++++++ > 5 files changed, 100 insertions(+), 90 deletions(-) > create mode 100644 arch/x86/kernel/acpi/madt_wakeup.c > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index 799102f4d909..9957a73bb386 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -1108,6 +1108,13 @@ config X86_LOCAL_APIC > depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI > select IRQ_DOMAIN_HIERARCHY > > +config X86_ACPI_MADT_WAKEUP > + def_bool y > + depends on X86_64 > + depends on ACPI > + depends on SMP > + depends on X86_LOCAL_APIC > + > config X86_IO_APIC > def_bool y > depends on X86_LOCAL_APIC || X86_UP_IOAPIC > diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h > index c8a7fc23f63c..b536b5a6a57b 100644 > --- a/arch/x86/include/asm/acpi.h > +++ b/arch/x86/include/asm/acpi.h > @@ -73,6 +73,11 @@ static inline bool acpi_skip_set_wakeup_address(void) > > #define acpi_skip_set_wakeup_address acpi_skip_set_wakeup_address > > +union acpi_subtable_headers; > + > +int __init acpi_parse_mp_wake(union acpi_subtable_headers *header, > + const unsigned long end); > + > /* > * Check if the CPU can handle C2 and deeper > */ > diff --git a/arch/x86/kernel/acpi/Makefile b/arch/x86/kernel/acpi/Makefile > index fc17b3f136fe..8c7329c88a75 100644 > --- a/arch/x86/kernel/acpi/Makefile > +++ b/arch/x86/kernel/acpi/Makefile > @@ -1,11 +1,12 @@ > # SPDX-License-Identifier: GPL-2.0 > > -obj-$(CONFIG_ACPI) += boot.o > -obj-$(CONFIG_ACPI_SLEEP) += sleep.o wakeup_$(BITS).o > -obj-$(CONFIG_ACPI_APEI) += apei.o > -obj-$(CONFIG_ACPI_CPPC_LIB) += cppc.o > +obj-$(CONFIG_ACPI) += boot.o > +obj-$(CONFIG_ACPI_SLEEP) += sleep.o wakeup_$(BITS).o > +obj-$(CONFIG_ACPI_APEI) += apei.o > +obj-$(CONFIG_ACPI_CPPC_LIB) += cppc.o > +obj-$(CONFIG_X86_ACPI_MADT_WAKEUP) += madt_wakeup.o > > ifneq ($(CONFIG_ACPI_PROCESSOR),) > -obj-y += cstate.o > +obj-y += cstate.o > endif > > diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c > index 2a0ea38955df..111bd226ad99 100644 > --- a/arch/x86/kernel/acpi/boot.c > +++ b/arch/x86/kernel/acpi/boot.c > @@ -66,13 +66,6 @@ static u64 acpi_lapic_addr __initdata = APIC_DEFAULT_PHYS_BASE; > static bool acpi_support_online_capable; > #endif > > -#ifdef CONFIG_X86_64 > -/* Physical address of the Multiprocessor Wakeup Structure mailbox */ > -static u64 acpi_mp_wake_mailbox_paddr; > -/* Virtual address of the Multiprocessor Wakeup Structure mailbox */ > -static struct acpi_madt_multiproc_wakeup_mailbox *acpi_mp_wake_mailbox; > -#endif > - > #ifdef CONFIG_X86_IO_APIC > /* > * Locks related to IOAPIC hotplug > @@ -357,60 +350,6 @@ acpi_parse_lapic_nmi(union acpi_subtable_headers * header, const unsigned long e > > return 0; > } > - > -#ifdef CONFIG_X86_64 > -static int acpi_wakeup_cpu(int apicid, unsigned long start_ip) > -{ > - /* > - * Remap mailbox memory only for the first call to acpi_wakeup_cpu(). > - * > - * Wakeup of secondary CPUs is fully serialized in the core code. > - * No need to protect acpi_mp_wake_mailbox from concurrent accesses. > - */ > - if (!acpi_mp_wake_mailbox) { > - acpi_mp_wake_mailbox = memremap(acpi_mp_wake_mailbox_paddr, > - sizeof(*acpi_mp_wake_mailbox), > - MEMREMAP_WB); > - } > - > - /* > - * Mailbox memory is shared between the firmware and OS. Firmware will > - * listen on mailbox command address, and once it receives the wakeup > - * command, the CPU associated with the given apicid will be booted. > - * > - * The value of 'apic_id' and 'wakeup_vector' must be visible to the > - * firmware before the wakeup command is visible. smp_store_release() > - * ensures ordering and visibility. > - */ > - acpi_mp_wake_mailbox->apic_id = apicid; > - acpi_mp_wake_mailbox->wakeup_vector = start_ip; > - smp_store_release(&acpi_mp_wake_mailbox->command, > - ACPI_MP_WAKE_COMMAND_WAKEUP); > - > - /* > - * Wait for the CPU to wake up. > - * > - * The CPU being woken up is essentially in a spin loop waiting to be > - * woken up. It should not take long for it wake up and acknowledge by > - * zeroing out ->command. > - * > - * ACPI specification doesn't provide any guidance on how long kernel > - * has to wait for a wake up acknowledgement. It also doesn't provide > - * a way to cancel a wake up request if it takes too long. > - * > - * In TDX environment, the VMM has control over how long it takes to > - * wake up secondary. It can postpone scheduling secondary vCPU > - * indefinitely. Giving up on wake up request and reporting error opens > - * possible attack vector for VMM: it can wake up a secondary CPU when > - * kernel doesn't expect it. Wait until positive result of the wake up > - * request. > - */ > - while (READ_ONCE(acpi_mp_wake_mailbox->command)) > - cpu_relax(); > - > - return 0; > -} > -#endif /* CONFIG_X86_64 */ > #endif /* CONFIG_X86_LOCAL_APIC */ > > #ifdef CONFIG_X86_IO_APIC > @@ -1160,29 +1099,6 @@ static int __init acpi_parse_madt_lapic_entries(void) > } > return 0; > } > - > -#ifdef CONFIG_X86_64 > -static int __init acpi_parse_mp_wake(union acpi_subtable_headers *header, > - const unsigned long end) > -{ > - struct acpi_madt_multiproc_wakeup *mp_wake; > - > - if (!IS_ENABLED(CONFIG_SMP)) > - return -ENODEV; > - > - mp_wake = (struct acpi_madt_multiproc_wakeup *)header; > - if (BAD_MADT_ENTRY(mp_wake, end)) > - return -EINVAL; > - > - acpi_table_print_madt_entry(&header->common); > - > - acpi_mp_wake_mailbox_paddr = mp_wake->base_address; > - > - apic_update_callback(wakeup_secondary_cpu_64, acpi_wakeup_cpu); > - > - return 0; > -} > -#endif /* CONFIG_X86_64 */ > #endif /* CONFIG_X86_LOCAL_APIC */ > > #ifdef CONFIG_X86_IO_APIC > @@ -1379,7 +1295,7 @@ static void __init acpi_process_madt(void) > smp_found_config = 1; > } > > -#ifdef CONFIG_X86_64 > +#ifdef CONFIG_X86_ACPI_MADT_WAKEUP > /* > * Parse MADT MP Wake entry. > */ > diff --git a/arch/x86/kernel/acpi/madt_wakeup.c b/arch/x86/kernel/acpi/madt_wakeup.c > new file mode 100644 > index 000000000000..58cdfc0b6c0a > --- /dev/null > +++ b/arch/x86/kernel/acpi/madt_wakeup.c > @@ -0,0 +1,81 @@ > +#include > +#include > +#include > +#include > +#include > + > +/* Physical address of the Multiprocessor Wakeup Structure mailbox */ > +static u64 acpi_mp_wake_mailbox_paddr; > + > +/* Virtual address of the Multiprocessor Wakeup Structure mailbox */ > +static struct acpi_madt_multiproc_wakeup_mailbox *acpi_mp_wake_mailbox; > + > +static int acpi_wakeup_cpu(int apicid, unsigned long start_ip) > +{ > + /* > + * Remap mailbox memory only for the first call to acpi_wakeup_cpu(). > + * > + * Wakeup of secondary CPUs is fully serialized in the core code. > + * No need to protect acpi_mp_wake_mailbox from concurrent accesses. > + */ > + if (!acpi_mp_wake_mailbox) { > + acpi_mp_wake_mailbox = memremap(acpi_mp_wake_mailbox_paddr, > + sizeof(*acpi_mp_wake_mailbox), > + MEMREMAP_WB); > + } > + > + /* > + * Mailbox memory is shared between the firmware and OS. Firmware will > + * listen on mailbox command address, and once it receives the wakeup > + * command, the CPU associated with the given apicid will be booted. > + * > + * The value of 'apic_id' and 'wakeup_vector' must be visible to the > + * firmware before the wakeup command is visible. smp_store_release() > + * ensures ordering and visibility. > + */ > + acpi_mp_wake_mailbox->apic_id = apicid; > + acpi_mp_wake_mailbox->wakeup_vector = start_ip; > + smp_store_release(&acpi_mp_wake_mailbox->command, > + ACPI_MP_WAKE_COMMAND_WAKEUP); > + > + /* > + * Wait for the CPU to wake up. > + * > + * The CPU being woken up is essentially in a spin loop waiting to be > + * woken up. It should not take long for it wake up and acknowledge by > + * zeroing out ->command. > + * > + * ACPI specification doesn't provide any guidance on how long kernel > + * has to wait for a wake up acknowledgement. It also doesn't provide > + * a way to cancel a wake up request if it takes too long. > + * > + * In TDX environment, the VMM has control over how long it takes to > + * wake up secondary. It can postpone scheduling secondary vCPU > + * indefinitely. Giving up on wake up request and reporting error opens > + * possible attack vector for VMM: it can wake up a secondary CPU when > + * kernel doesn't expect it. Wait until positive result of the wake up > + * request. > + */ > + while (READ_ONCE(acpi_mp_wake_mailbox->command)) > + cpu_relax(); > + > + return 0; > +} > + > +int __init acpi_parse_mp_wake(union acpi_subtable_headers *header, > + const unsigned long end) > +{ > + struct acpi_madt_multiproc_wakeup *mp_wake; > + > + mp_wake = (struct acpi_madt_multiproc_wakeup *)header; > + if (BAD_MADT_ENTRY(mp_wake, end)) > + return -EINVAL; > + > + acpi_table_print_madt_entry(&header->common); > + > + acpi_mp_wake_mailbox_paddr = mp_wake->base_address; > + > + apic_update_callback(wakeup_secondary_cpu_64, acpi_wakeup_cpu); > + > + return 0; > +} -- Sathyanarayanan Kuppuswamy Linux Kernel Developer