From: "Li, ZhenHua" <zhen-hual@hp.com>
To: Feng Wu <feng.wu@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>,
dwmw2@infradead.org, jiang.liu@linux.intel.com,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
"Li, ZhenHua" <zhen-hual@hp.com>
Subject: Re: [v4 0/8] Add VT-d Posted-Interrupts support - IOMMU part
Date: Fri, 03 Apr 2015 16:12:45 +0800 [thread overview]
Message-ID: <551E4B7D.6020108@hp.com> (raw)
In-Reply-To: <20150402112833.GN4441@8bytes.org>
Hi Feng Wu,
In my patchset, I created a new member ir_table->base_old_phys; In the
normal kernel, everything is the same. In kdump kernel, ir_table->base
is used for a buffer, and ir_table->base_old_phys is the physical
address of the tables used by the old kernel, also being used by the
current kernel.
I did this in modify_irte():
set_64bit(&irte->high, irte_modified->high);
+
+#ifdef CONFIG_CRASH_DUMP
+ if (is_kdump_kernel())
+ __iommu_update_old_irte(iommu, index);
+#endif
__iommu_flush_cache(iommu, irte, sizeof(*irte));
Here the irte tables are stored in two places:
iommu->ir_table->base : It is a buffer in kdump kernel, which is the
running kernel;
iommu->ir_table->base_old_phys : It is the irte used by the old kernel;
And function __iommu_update_old_irte is used to save the content of
iommu->ir_table->base to iommu->ir_table->base_old_phys. Because in
kdump kernel, the vt-d is using ir_table->base_old_phys, not
ir_table->base, so we need to copy the updated ir_table->base to
ir_table->base_old_phys .
Thanks
Zhenhua
On 04/02/2015 07:28 PM, Joerg Roedel wrote:
> On Mon, Feb 02, 2015 at 04:06:56PM +0800, Feng Wu wrote:
>> VT-d Posted-Interrupts is an enhancement to CPU side Posted-Interrupt.
>> With VT-d Posted-Interrupts enabled, external interrupts from
>> direct-assigned devices can be delivered to guests without VMM
>> intervention when guest is running in non-root mode.
>>
>> You can find the VT-d Posted-Interrtups Spec. in the following URL:
>> http://www.intel.com/content/www/us/en/intelligent-systems/intel-technology/vt-directed-io-spec.html
>>
>> This series was part of http://thread.gmane.org/gmane.linux.kernel.iommu/7708. To make things clear, send out IOMMU part here.
>
> Besides the modify_irte() changes I asked for the patch-set looks good.
> I just have some concerns what these changes mean for the VT-d kdump
> improvements Zhen-Hua Li is working on. Can you please discuss the
> implications of having both patch-sets applied with him and make sure
> they work together? I think in its current form your patch-set breaks
> the kdump support patches. I added Zhen-Hua to Cc.
>
> Thanks,
>
> Joerg
>
next prev parent reply other threads:[~2015-04-03 8:13 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-02 8:06 [v4 0/8] Add VT-d Posted-Interrupts support - IOMMU part Feng Wu
2015-02-02 8:06 ` [v4 1/8] iommu: Add new member capability to struct irq_remap_ops Feng Wu
2015-02-02 8:06 ` [v4 2/8] iommu, x86: Define new irte structure for VT-d Posted-Interrupts Feng Wu
2015-03-23 11:57 ` Joerg Roedel
2015-03-24 2:32 ` Wu, Feng
2015-03-31 15:16 ` Joerg Roedel
2015-04-01 8:51 ` Wu, Feng
2015-02-02 8:06 ` [v4 3/8] iommu, x86: Implement irq_set_vcpu_affinity for intel_ir_chip Feng Wu
2015-02-02 8:07 ` [v4 4/8] iommu, x86: No need to migrating irq for VT-d Posted-Interrupts Feng Wu
2015-02-02 8:07 ` [v4 5/8] iommu, x86: Add cap_pi_support() to detect VT-d PI capability Feng Wu
2015-02-02 8:07 ` [v4 6/8] iommu, x86: Setup Posted-Interrupts capability for Intel iommu Feng Wu
2015-02-02 8:07 ` [v4 7/8] iommu, x86: define irq_remapping_cap() Feng Wu
2015-02-02 8:07 ` [v4 8/8] iommu, x86: Properly handler PI for IOMMU hotplug Feng Wu
2015-04-02 11:28 ` [v4 0/8] Add VT-d Posted-Interrupts support - IOMMU part Joerg Roedel
2015-04-03 8:12 ` Li, ZhenHua [this message]
2015-04-07 5:02 ` Wu, Feng
-- strict thread matches above, loose matches on Subject: below --
2015-02-02 8:01 Feng Wu
2015-02-02 8:17 ` Wu, Feng
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