From: Boqun Feng <boqun.feng@gmail.com>
To: Michael Kelley <mikelley@microsoft.com>
Cc: will@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org,
linux-efi@vger.kernel.org, wei.liu@kernel.org, kys@microsoft.com,
sthemmin@microsoft.com, ardb@kernel.org
Subject: Re: [PATCH v11 2/5] arm64: hyperv: Add panic handler
Date: Wed, 21 Jul 2021 22:54:36 +0800 [thread overview]
Message-ID: <YPg1LNq62LMZiXLX@boqun-archlinux> (raw)
In-Reply-To: <1626793023-13830-3-git-send-email-mikelley@microsoft.com>
On Tue, Jul 20, 2021 at 07:57:00AM -0700, Michael Kelley wrote:
> Add a function to inform Hyper-V about a guest panic.
>
> This code is built only when CONFIG_HYPERV is enabled.
>
> Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Regards,
Boqun
> ---
> arch/arm64/hyperv/hv_core.c | 52 +++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 52 insertions(+)
>
> diff --git a/arch/arm64/hyperv/hv_core.c b/arch/arm64/hyperv/hv_core.c
> index 4c5dc0f..b54c347 100644
> --- a/arch/arm64/hyperv/hv_core.c
> +++ b/arch/arm64/hyperv/hv_core.c
> @@ -127,3 +127,55 @@ u64 hv_get_vpreg(u32 msr)
> return output.as64.low;
> }
> EXPORT_SYMBOL_GPL(hv_get_vpreg);
> +
> +/*
> + * hyperv_report_panic - report a panic to Hyper-V. This function uses
> + * the older version of the Hyper-V interface that admittedly doesn't
> + * pass enough information to be useful beyond just recording the
> + * occurrence of a panic. The parallel hv_kmsg_dump() uses the
> + * new interface that allows reporting 4 Kbytes of data, which is much
> + * more useful. Hyper-V on ARM64 always supports the newer interface, but
> + * we retain support for the older version because the sysadmin is allowed
> + * to disable the newer version via sysctl in case of information security
> + * concerns about the more verbose version.
> + */
> +void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die)
> +{
> + static bool panic_reported;
> + u64 guest_id;
> +
> + /* Don't report a panic to Hyper-V if we're not going to panic */
> + if (in_die && !panic_on_oops)
> + return;
> +
> + /*
> + * We prefer to report panic on 'die' chain as we have proper
> + * registers to report, but if we miss it (e.g. on BUG()) we need
> + * to report it on 'panic'.
> + *
> + * Calling code in the 'die' and 'panic' paths ensures that only
> + * one CPU is running this code, so no atomicity is needed.
> + */
> + if (panic_reported)
> + return;
> + panic_reported = true;
> +
> + guest_id = hv_get_vpreg(HV_REGISTER_GUEST_OSID);
> +
> + /*
> + * Hyper-V provides the ability to store only 5 values.
> + * Pick the passed in error value, the guest_id, the PC,
> + * and the SP.
> + */
> + hv_set_vpreg(HV_REGISTER_CRASH_P0, err);
> + hv_set_vpreg(HV_REGISTER_CRASH_P1, guest_id);
> + hv_set_vpreg(HV_REGISTER_CRASH_P2, regs->pc);
> + hv_set_vpreg(HV_REGISTER_CRASH_P3, regs->sp);
> + hv_set_vpreg(HV_REGISTER_CRASH_P4, 0);
> +
> + /*
> + * Let Hyper-V know there is crash data available
> + */
> + hv_set_vpreg(HV_REGISTER_CRASH_CTL, HV_CRASH_CTL_CRASH_NOTIFY);
> +}
> +EXPORT_SYMBOL_GPL(hyperv_report_panic);
> --
> 1.8.3.1
>
next prev parent reply other threads:[~2021-07-21 14:56 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-20 14:56 [PATCH v11 0/5] Enable Linux guests on Hyper-V on ARM64 Michael Kelley
2021-07-20 14:56 ` [PATCH v11 1/5] arm64: hyperv: Add Hyper-V hypercall and register access utilities Michael Kelley
2021-07-20 14:57 ` [PATCH v11 2/5] arm64: hyperv: Add panic handler Michael Kelley
2021-07-21 14:54 ` Boqun Feng [this message]
2021-07-27 17:08 ` Sunil Muthuswamy
2021-07-20 14:57 ` [PATCH v11 3/5] arm64: hyperv: Initialize hypervisor on boot Michael Kelley
2021-07-21 14:55 ` Boqun Feng
2021-07-27 17:05 ` Sunil Muthuswamy
2021-08-02 15:55 ` Marc Zyngier
2021-08-02 16:26 ` Mark Rutland
2021-08-02 17:13 ` Michael Kelley
2021-07-20 14:57 ` [PATCH v11 4/5] arm64: efi: Export screen_info Michael Kelley
2021-07-20 14:57 ` [PATCH v11 5/5] Drivers: hv: Enable Hyper-V code to be built on ARM64 Michael Kelley
2021-07-21 14:52 ` Boqun Feng
2021-08-02 15:15 ` [PATCH v11 0/5] Enable Linux guests on Hyper-V " Michael Kelley
2021-08-02 16:01 ` Marc Zyngier
2021-08-02 16:28 ` Mark Rutland
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