From: Thomas Gleixner <tglx@linutronix.de>
To: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: LKML <linux-kernel@vger.kernel.org>, X86 Kernel <x86@kernel.org>,
iommu@lists.linux.dev, Lu Baolu <baolu.lu@linux.intel.com>,
kvm@vger.kernel.org, Dave Hansen <dave.hansen@intel.com>,
Joerg Roedel <joro@8bytes.org>, "H. Peter Anvin" <hpa@zytor.com>,
Borislav Petkov <bp@alien8.de>, Ingo Molnar <mingo@redhat.com>,
Raj Ashok <ashok.raj@intel.com>,
"Tian, Kevin" <kevin.tian@intel.com>,
maz@kernel.org, peterz@infradead.org, seanjc@google.com,
Robin Murphy <robin.murphy@arm.com>,
jacob.jun.pan@linux.intel.com
Subject: Re: [PATCH RFC 12/13] iommu/vt-d: Add a helper to retrieve PID address
Date: Tue, 13 Feb 2024 09:21:47 +0100 [thread overview]
Message-ID: <87le7oixk4.ffs@tglx> (raw)
In-Reply-To: <20240126153047.5e42e5d0@jacob-builder>
On Fri, Jan 26 2024 at 15:30, Jacob Pan wrote:
> On Wed, 06 Dec 2023 21:19:11 +0100, Thomas Gleixner <tglx@linutronix.de>
> wrote:
>> > +static u64 get_pi_desc_addr(struct irq_data *irqd)
>> > +{
>> > + int cpu =
>> > cpumask_first(irq_data_get_effective_affinity_mask(irqd));
>>
>> The effective affinity mask is magically correct when this is called?
>>
> My understanding is that remappable device MSIs have the following
> hierarchy,e.g.
SNIP
> Here the parent APIC chip does apic_set_affinity() which will set up
> effective mask before posted MSI affinity change.
>
> Maybe I missed some cases?
The function is only used in intel_ir_reconfigure_irte_posted() in the
next patch, but it's generally available. So I asked that question
because if it's called in some other context then it's going to be not
guaranteed.
That also begs the question why this function exists in the first
place. This really can be part of intel_ir_reconfigure_irte_posted(),
which makes it clear what the context is, no?
Thanks,
tglx
next prev parent reply other threads:[~2024-02-13 8:21 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-12 4:16 [PATCH RFC 00/13] Coalesced Interrupt Delivery with posted MSI Jacob Pan
2023-11-12 4:16 ` [PATCH RFC 01/13] x86: Move posted interrupt descriptor out of vmx code Jacob Pan
2023-12-06 16:33 ` Thomas Gleixner
2023-12-08 4:54 ` Jacob Pan
2023-12-08 9:31 ` Thomas Gleixner
2023-12-08 23:21 ` Jacob Pan
2023-12-09 0:28 ` Jacob Pan
2023-11-12 4:16 ` [PATCH RFC 02/13] x86: Add a Kconfig option for posted MSI Jacob Pan
2023-12-06 16:35 ` Thomas Gleixner
2023-12-09 21:24 ` Jacob Pan
2023-11-12 4:16 ` [PATCH RFC 03/13] x86: Reserved a per CPU IDT vector for posted MSIs Jacob Pan
2023-12-06 16:47 ` Thomas Gleixner
2023-12-09 21:53 ` Jacob Pan
2023-11-12 4:16 ` [PATCH RFC 04/13] iommu/vt-d: Add helper and flag to check/disable posted MSI Jacob Pan
2023-12-06 16:49 ` Thomas Gleixner
2023-11-12 4:16 ` [PATCH RFC 05/13] x86/irq: Set up per host CPU posted interrupt descriptors Jacob Pan
2023-11-12 4:16 ` [PATCH RFC 06/13] x86/irq: Unionize PID.PIR for 64bit access w/o casting Jacob Pan
2023-12-06 16:51 ` Thomas Gleixner
2023-11-12 4:16 ` [PATCH RFC 07/13] x86/irq: Add helpers for checking Intel PID Jacob Pan
2023-12-06 19:02 ` Thomas Gleixner
2024-01-26 23:31 ` Jacob Pan
2023-11-12 4:16 ` [PATCH RFC 08/13] x86/irq: Factor out calling ISR from common_interrupt Jacob Pan
2023-11-12 4:16 ` [PATCH RFC 09/13] x86/irq: Install posted MSI notification handler Jacob Pan
2023-11-15 12:42 ` Peter Zijlstra
2023-11-15 20:05 ` Jacob Pan
2023-11-15 12:56 ` Peter Zijlstra
2023-11-15 20:04 ` Jacob Pan
2023-11-15 20:25 ` Peter Zijlstra
2023-12-06 19:50 ` Thomas Gleixner
2023-12-08 4:46 ` Jacob Pan
2023-12-08 11:52 ` Thomas Gleixner
2023-12-08 20:02 ` Jacob Pan
2024-01-26 23:32 ` Jacob Pan
2023-12-06 19:14 ` Thomas Gleixner
2023-11-12 4:16 ` [PATCH RFC 10/13] x86/irq: Handle potential lost IRQ during migration and CPU offline Jacob Pan
2023-12-06 20:09 ` Thomas Gleixner
2023-11-12 4:16 ` [PATCH RFC 11/13] iommu/vt-d: Add an irq_chip for posted MSIs Jacob Pan
2023-12-06 20:15 ` Thomas Gleixner
2024-01-26 23:31 ` Jacob Pan
2023-12-06 20:44 ` Thomas Gleixner
2023-12-13 3:42 ` Jacob Pan
2023-11-12 4:16 ` [PATCH RFC 12/13] iommu/vt-d: Add a helper to retrieve PID address Jacob Pan
2023-12-06 20:19 ` Thomas Gleixner
2024-01-26 23:30 ` Jacob Pan
2024-02-13 8:21 ` Thomas Gleixner [this message]
2024-02-13 19:31 ` Jacob Pan
2023-11-12 4:16 ` [PATCH RFC 13/13] iommu/vt-d: Enable posted mode for device MSIs Jacob Pan
2023-12-06 20:26 ` Thomas Gleixner
2023-12-13 22:00 ` Jacob Pan
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