From: Arnd Bergmann <arnd@arndb.de>
To: Michael Kelley <mikelley@microsoft.com>
Cc: Will Deacon <will@kernel.org>, Ard Biesheuvel <ardb@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Marc Zyngier <maz@kernel.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
gregkh <gregkh@linuxfoundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
linux-hyperv@vger.kernel.org,
linux-efi <linux-efi@vger.kernel.org>,
linux-arch <linux-arch@vger.kernel.org>,
wei.liu@kernel.org, Vitaly Kuznetsov <vkuznets@redhat.com>,
"K. Y. Srinivasan" <kys@microsoft.com>,
Sunil Muthuswamy <sunilmut@microsoft.com>,
Boqun Feng <boqun.feng@gmail.com>
Subject: Re: [PATCH v7 07/10] arm64: hyperv: Initialize hypervisor on boot
Date: Mon, 24 Aug 2020 20:33:59 +0200 [thread overview]
Message-ID: <CAK8P3a1NXVJON+apBZeVDdx_bqQmenab8srqJDWS_VFVpAncRA@mail.gmail.com> (raw)
In-Reply-To: <1598287583-71762-8-git-send-email-mikelley@microsoft.com>
On Mon, Aug 24, 2020 at 6:48 PM Michael Kelley <mikelley@microsoft.com> wrote:
>
> /*
> + * This function is invoked via the ACPI clocksource probe mechanism. We
> + * don't actually use any values from the ACPI GTDT table, but we set up
> + * the Hyper-V synthetic clocksource and do other initialization for
> + * interacting with Hyper-V the first time. Using early_initcall to invoke
> + * this function is too late because interrupts are already enabled at that
> + * point, and hv_init_clocksource() must run before interrupts are enabled.
> + *
> + * 1. Setup the guest ID.
> + * 2. Get features and hints info from Hyper-V
> + * 3. Setup per-cpu VP indices.
> + * 4. Initialize the Hyper-V clocksource.
> + */
> +
> +static int __init hyperv_init(struct acpi_table_header *table)
> +{
> + struct hv_get_vp_registers_output result;
> + u32 a, b, c, d;
> + u64 guest_id;
> + int i, cpuhp;
> +
> + /*
> + * If we're in a VM on Hyper-V, the ACPI hypervisor_id field will
> + * have the string "MsHyperV".
> + */
> + if (strncmp((char *)&acpi_gbl_FADT.hypervisor_id, "MsHyperV", 8))
> + return -EINVAL;
> +
> + /* Setup the guest ID */
> + guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0);
> + hv_set_vpreg(HV_REGISTER_GUEST_OSID, guest_id);
> +
> + /* Get the features and hints from Hyper-V */
> + hv_get_vpreg_128(HV_REGISTER_FEATURES, &result);
> + ms_hyperv.features = result.as32.a;
> + ms_hyperv.misc_features = result.as32.c;
> +
> + hv_get_vpreg_128(HV_REGISTER_ENLIGHTENMENTS, &result);
> + ms_hyperv.hints = result.as32.a;
> +
> + pr_info("Hyper-V: Features 0x%x, hints 0x%x, misc 0x%x\n",
> + ms_hyperv.features, ms_hyperv.hints, ms_hyperv.misc_features);
> +
> + /*
> + * If Hyper-V has crash notifications, set crash_kexec_post_notifiers
> + * so that we will report the panic to Hyper-V before running kdump.
> + */
> + if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE)
> + crash_kexec_post_notifiers = true;
> +
> + /* Get information about the Hyper-V host version */
> + hv_get_vpreg_128(HV_REGISTER_HYPERVISOR_VERSION, &result);
> + a = result.as32.a;
> + b = result.as32.b;
> + c = result.as32.c;
> + d = result.as32.d;
> + pr_info("Hyper-V: Host Build %d.%d.%d.%d-%d-%d\n",
> + b >> 16, b & 0xFFFF, a, d & 0xFFFFFF, c, d >> 24);
> +
> + /* Allocate and initialize percpu VP index array */
> + hv_vp_index = kmalloc_array(num_possible_cpus(), sizeof(*hv_vp_index),
> + GFP_KERNEL);
> + if (!hv_vp_index)
> + return -ENOMEM;
> +
> + for (i = 0; i < num_possible_cpus(); i++)
> + hv_vp_index[i] = VP_INVAL;
> +
> + cpuhp = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
> + "arm64/hyperv_init:online", hv_cpu_init, NULL);
> + if (cpuhp < 0)
> + goto free_vp_index;
> +
> + hv_init_clocksource();
> + if (hv_stimer_alloc())
> + goto remove_cpuhp_state;
> +
> + hyperv_initialized = true;
> + return 0;
> +
> +remove_cpuhp_state:
> + cpuhp_remove_state(cpuhp);
> +free_vp_index:
> + kfree(hv_vp_index);
> + hv_vp_index = NULL;
> + return -EINVAL;
> +}
> +TIMER_ACPI_DECLARE(hyperv, ACPI_SIG_GTDT, hyperv_init);
I think this has come up before, and I still don't consider it an acceptable
hack to hook platform initialization code into the timer code.
Please split out the timer into a standalone driver in drivers/clocksource
that can get reviewed by the clocksource maintainers.
Arnd
next prev parent reply other threads:[~2020-08-24 18:34 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-24 16:46 [PATCH v7 00/10] Enable Linux guests on Hyper-V on ARM64 Michael Kelley
2020-08-24 16:46 ` [PATCH v7 01/10] arm/arm64: smccc-1.1: Add vendor specific owner definition Michael Kelley
2020-08-24 16:46 ` [PATCH v7 02/10] arm64: hyperv: Add core Hyper-V include files Michael Kelley
2020-08-24 18:38 ` Arnd Bergmann
2020-08-24 16:46 ` [PATCH v7 03/10] arm64: hyperv: Add hypercall and register access functions Michael Kelley
2020-08-24 16:46 ` [PATCH v7 04/10] arm64: hyperv: Add memory alloc/free functions for Hyper-V size pages Michael Kelley
2020-08-24 16:46 ` [PATCH v7 05/10] arm64: hyperv: Add interrupt handlers for VMbus and stimer Michael Kelley
2020-08-24 18:54 ` Arnd Bergmann
2020-08-25 22:04 ` Michael Kelley
2020-08-26 7:14 ` Arnd Bergmann
2020-08-24 16:46 ` [PATCH v7 06/10] arm64: hyperv: Add kexec and panic handlers Michael Kelley
2020-08-24 16:46 ` [PATCH v7 07/10] arm64: hyperv: Initialize hypervisor on boot Michael Kelley
2020-08-24 18:33 ` Arnd Bergmann [this message]
2020-08-25 21:20 ` Michael Kelley
2020-08-26 7:18 ` Arnd Bergmann
2020-08-24 16:46 ` [PATCH v7 08/10] Drivers: hv: vmbus: Add hooks for per-CPU IRQ Michael Kelley
2020-08-24 16:46 ` [PATCH v7 09/10] arm64: efi: Export screen_info Michael Kelley
2020-08-24 17:21 ` Ard Biesheuvel
2020-08-24 17:35 ` Greg KH
2020-08-24 17:40 ` Michael Kelley
2020-08-24 17:52 ` Greg KH
2020-08-24 16:46 ` [PATCH v7 10/10] Drivers: hv: Enable Hyper-V code to be built on ARM64 Michael Kelley
2020-08-24 17:24 ` Ard Biesheuvel
2020-08-24 17:28 ` Michael Kelley
2020-08-25 8:47 ` Ben Dooks
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