From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 6565625A2AA; Fri, 7 Mar 2025 23:29:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741390200; cv=none; b=aiawAF/O0OmBNV1IhROsCgIuJuR9Vbb/601jQOooyXrQZgiJd+DH8WtB3sMLvv+B+oxpOJQxZUwJTpONnAWmcPlvYAPrpgVCl9J1mJUtLSrF9Dev8fWoEBEhedsqLFFAZaWf2nCTQAmigqjuYRL1JrG68IqAVwicQPQ2QS8MRJ0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741390200; c=relaxed/simple; bh=ghtf9o1+ukra4sjj1qaV7WcfHLJToxMprIy+KxQS0G4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=EMRIa5GnXA8hMjzxU2ydeAB8Ce2nSZvG0cZdhH0Hd8+BNn+ZRlAARy8e8zJdZJqC3eIiz68Ofm59QtNdZ2GnrptrCx1FcXcEV8IgmA8d1jbplvzRUqFeAw035eW6kdhAFmTmnVSndq8OvSS91vw7yu0oUXBa7PRcjazKFSI0hDI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=kwuSZI9P; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="kwuSZI9P" Received: from [10.0.0.114] (c-67-182-156-199.hsd1.wa.comcast.net [67.182.156.199]) by linux.microsoft.com (Postfix) with ESMTPSA id 850AF2038F3E; Fri, 7 Mar 2025 15:29:52 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 850AF2038F3E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1741390193; bh=A+S4RIbdJJnLd8q03RHbHALetITl10NO/5kMAF25RI4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=kwuSZI9PwG4viI97Hm3DoeHH2U9GBgal8aEQ1fN6b4NxNi1YF4VCJP6opazvgnQ0O bqFTaDP+78vMUGaD0QWLd6fF64ipXAE4/mPqy7+zMzkpRNWYgA0dXdtDxz1mEMoeuY PqCIUH3akwZU2TzJZBkInP56RdekIKeCi96/Qt4Q= Message-ID: <86bf7bae-9423-4413-8986-364d96243c82@linux.microsoft.com> Date: Fri, 7 Mar 2025 15:29:35 -0800 Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 08/10] x86: hyperv: Add mshv_handler irq handler and setup function To: Michael Kelley , "linux-hyperv@vger.kernel.org" , "x86@kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "linux-arch@vger.kernel.org" , "linux-acpi@vger.kernel.org" Cc: "kys@microsoft.com" , "haiyangz@microsoft.com" , "wei.liu@kernel.org" , "decui@microsoft.com" , "catalin.marinas@arm.com" , "will@kernel.org" , "tglx@linutronix.de" , "mingo@redhat.com" , "bp@alien8.de" , "dave.hansen@linux.intel.com" , "hpa@zytor.com" , "daniel.lezcano@linaro.org" , "joro@8bytes.org" , "robin.murphy@arm.com" , "arnd@arndb.de" , "jinankjain@linux.microsoft.com" , "muminulrussell@gmail.com" , "skinsburskii@linux.microsoft.com" , "mrathor@linux.microsoft.com" , "ssengar@linux.microsoft.com" , "apais@linux.microsoft.com" , "Tianyu.Lan@microsoft.com" , "stanislav.kinsburskiy@gmail.com" , "gregkh@linuxfoundation.org" , "vkuznets@redhat.com" , "prapal@linux.microsoft.com" , "muislam@microsoft.com" , "anrayabh@linux.microsoft.com" , "rafael@kernel.org" , "lenb@kernel.org" , "corbet@lwn.net" References: <1740611284-27506-1-git-send-email-nunodasneves@linux.microsoft.com> <1740611284-27506-9-git-send-email-nunodasneves@linux.microsoft.com> Content-Language: en-US From: Nuno Das Neves In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 3/7/2025 9:44 AM, Michael Kelley wrote: > From: Nuno Das Neves Sent: Wednesday, February 26, 2025 3:08 PM > >> >> This will handle SYNIC interrupts such as intercepts, doorbells, and >> scheduling messages intended for the mshv driver. > > Could you provide a bit more detailed commit message? How does > the mshv_handler() relate to the vmbus_handler()? From the code > mshv_handler() goes first, and I'm assuming it processes what it > knows about (intercepts, doorbells, scheduling messages?) and > then hands off control to the vmbus_handler() to handle the usual > VMbus-related message and channel interrupts. But it would be > nice to have the commit message or code comments describe the > overall intent and any obscure aspects of the relationship. > > And avoid references to "This" or "This patch". :-) > You've described it pretty well, I don't know if there's too much more to say given this patch doesn't introduce the handler code. I can try to improve it, something like: " mshv_handler() will be used to process messages related to managing guest partitions such as intercepts, doorbells, and scheduling messages. In a (non-nested) root partition, the same interrupt vector is shared between the vmbus and mshv_root drivers. Introduce a stub for mshv_handler() and call it in sysvec_hyperv_callback alongside vmbus_handler(). Even though both handlers will be called for every Hyper-V interrupt, the messages for each driver are delivered to different offsets within the SYNIC message page, so they won't step on each other. " Does that work? Nuno >> >> Signed-off-by: Nuno Das Neves >> Reviewed-by: Wei Liu >> Reviewed-by: Tianyu Lan >> --- >> arch/x86/kernel/cpu/mshyperv.c | 9 +++++++++ >> drivers/hv/hv_common.c | 5 +++++ >> include/asm-generic/mshyperv.h | 1 + >> 3 files changed, 15 insertions(+) >> >> diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c >> index 0116d0e96ef9..616e9a5d77b4 100644 >> --- a/arch/x86/kernel/cpu/mshyperv.c >> +++ b/arch/x86/kernel/cpu/mshyperv.c >> @@ -107,6 +107,7 @@ void hv_set_msr(unsigned int reg, u64 value) >> } >> EXPORT_SYMBOL_GPL(hv_set_msr); >> >> +static void (*mshv_handler)(void); >> static void (*vmbus_handler)(void); >> static void (*hv_stimer0_handler)(void); >> static void (*hv_kexec_handler)(void); >> @@ -117,6 +118,9 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_callback) >> struct pt_regs *old_regs = set_irq_regs(regs); >> >> inc_irq_stat(irq_hv_callback_count); >> + if (mshv_handler) >> + mshv_handler(); >> + >> if (vmbus_handler) >> vmbus_handler(); >> >> @@ -126,6 +130,11 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_callback) >> set_irq_regs(old_regs); >> } >> >> +void hv_setup_mshv_handler(void (*handler)(void)) >> +{ >> + mshv_handler = handler; >> +} >> + >> void hv_setup_vmbus_handler(void (*handler)(void)) >> { >> vmbus_handler = handler; >> diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c >> index 2763cb6d3678..f5a07fd9a03b 100644 >> --- a/drivers/hv/hv_common.c >> +++ b/drivers/hv/hv_common.c >> @@ -677,6 +677,11 @@ void __weak hv_remove_vmbus_handler(void) >> } >> EXPORT_SYMBOL_GPL(hv_remove_vmbus_handler); >> >> +void __weak hv_setup_mshv_handler(void (*handler)(void)) >> +{ >> +} >> +EXPORT_SYMBOL_GPL(hv_setup_mshv_handler); >> + >> void __weak hv_setup_kexec_handler(void (*handler)(void)) >> { >> } >> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h >> index 1f46d19a16aa..a05f12e63ccd 100644 >> --- a/include/asm-generic/mshyperv.h >> +++ b/include/asm-generic/mshyperv.h >> @@ -208,6 +208,7 @@ void hv_setup_kexec_handler(void (*handler)(void)); >> void hv_remove_kexec_handler(void); >> void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs)); >> void hv_remove_crash_handler(void); >> +void hv_setup_mshv_handler(void (*handler)(void)); >> >> extern int vmbus_interrupt; >> extern int vmbus_irq; >> -- >> 2.34.1