From: Tianyu Lan <ltykernel@gmail•com>
To: Boris Ostrovsky <boris.ostrovsky@oracle•com>,
kys@microsoft•com, haiyangz@microsoft•com,
sthemmin@microsoft•com, wei.liu@kernel•org, decui@microsoft•com,
tglx@linutronix•de, mingo@redhat•com, bp@alien8•de,
x86@kernel•org, hpa@zytor•com, arnd@arndb•de,
dave.hansen@linux•intel.com, luto@kernel•org,
peterz@infradead•org, akpm@linux-foundation•org,
kirill.shutemov@linux•intel.com, rppt@kernel•org,
hannes@cmpxchg•org, cai@lca•pw, krish.sadhukhan@oracle•com,
saravanand@fb•com, Tianyu.Lan@microsoft•com,
konrad.wilk@oracle•com, hch@lst•de, m.szyprowski@samsung•com,
robin.murphy@arm•com, jgross@suse•com, sstabellini@kernel•org,
joro@8bytes•org, will@kernel•org, xen-devel@lists•xenproject.org,
davem@davemloft•net, kuba@kernel•org, jejb@linux•ibm.com,
martin.petersen@oracle•com
Cc: iommu@lists•linux-foundation.org, linux-arch@vger•kernel.org,
linux-hyperv@vger•kernel.org, linux-kernel@vger•kernel.org,
linux-scsi@vger•kernel.org, netdev@vger•kernel.org,
vkuznets@redhat•com, thomas.lendacky@amd•com,
brijesh.singh@amd•com, sunilmut@microsoft•com
Subject: Re: [RFC PATCH V3 09/11] HV/IOMMU: Enable swiotlb bounce buffer for Isolation VM
Date: Thu, 3 Jun 2021 23:37:06 +0800 [thread overview]
Message-ID: <1cdf4e6e-6499-e209-d499-7ab82992040b@gmail.com> (raw)
In-Reply-To: <d6714e8b-dcb6-798b-59a4-5bb68f789564@oracle.com>
On 6/3/2021 12:02 AM, Boris Ostrovsky wrote:
>
> On 6/2/21 11:01 AM, Tianyu Lan wrote:
>> Hi Boris:
>> Thanks for your review.
>>
>> On 6/2/2021 9:16 AM, Boris Ostrovsky wrote:
>>>
>>> On 5/30/21 11:06 AM, Tianyu Lan wrote:
>>>> @@ -91,6 +92,6 @@ int pci_xen_swiotlb_init_late(void)
>>>> EXPORT_SYMBOL_GPL(pci_xen_swiotlb_init_late);
>>>> IOMMU_INIT_FINISH(2,
>>>> - NULL,
>>>> + hyperv_swiotlb_detect,
>>>> pci_xen_swiotlb_init,
>>>> NULL);
>>>
>>>
>>> Could you explain this change?
>>
>> Hyper-V allocates its own swiotlb bounce buffer and the default
>> swiotlb buffer should not be allocated. swiotlb_init() in pci_swiotlb_init() is to allocate default swiotlb buffer.
>> To achieve this, put hyperv_swiotlb_detect() as the first entry in the iommu_table_entry list. The detect loop in the pci_iommu_alloc() will exit once hyperv_swiotlb_detect() is called in Hyper-V VM and other iommu_table_entry callback will not be called.
>
>
>
> Right. But pci_xen_swiotlb_detect() will only do something for Xen PV guests, and those guests don't run on hyperV. It's either xen_pv_domain() (i.e. hypervisor_is_type(X86_HYPER_XEN_PV)) or hypervisor_is_type(X86_HYPER_MS_HYPERV) but never both. So I don't think there needs to be a dependency between the two callbacks.
Yes, the dependency is between hyperv_swiotlb_detect() and
pci_swiotlb_detect_override()/pci_swiotlb_detect_4gb(). Now
pci_swiotlb_detect_override() and pci_swiotlb_detect_4gb() depends on
pci_xen_swiotlb_detect(). To keep dependency between
hyperv_swiotlb_detect() and pci_swiotlb_detect_override/4gb(), make
pci_xen_swiotlb_detect() depends on hyperv_swiotlb_detect() and just to
keep order in the IOMMU table. Current iommu_table_entry only has one
depend callback and this is why I put xen depends on hyperv detect function.
Thanks.
next prev parent reply other threads:[~2021-06-03 15:38 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-30 15:06 [RFC PATCH V3 00/11] x86/Hyper-V: Add Hyper-V Isolation VM support Tianyu Lan
2021-05-30 15:06 ` [RFC PATCH V3 01/11] x86/HV: Initialize GHCB page in Isolation VM Tianyu Lan
2021-06-07 6:41 ` Christoph Hellwig
2021-06-07 8:14 ` Tianyu Lan
2021-06-09 12:38 ` Joerg Roedel
2021-06-10 14:13 ` Tianyu Lan
2021-05-30 15:06 ` [RFC PATCH V3 02/11] x86/HV: Initialize shared memory boundary in the " Tianyu Lan
2021-05-30 15:06 ` [RFC PATCH V3 03/11] x86/Hyper-V: Add new hvcall guest address host visibility support Tianyu Lan
2021-05-30 18:25 ` Borislav Petkov
2021-05-31 4:08 ` Tianyu Lan
2021-06-10 9:47 ` Vitaly Kuznetsov
2021-06-10 14:18 ` Tianyu Lan
2021-05-30 15:06 ` [RFC PATCH V3 04/11] HV: Add Write/Read MSR registers via ghcb Tianyu Lan
2021-06-09 12:46 ` Joerg Roedel
2021-06-10 14:15 ` Tianyu Lan
2021-05-30 15:06 ` [RFC PATCH V3 05/11] HV: Add ghcb hvcall support for SNP VM Tianyu Lan
2021-06-09 12:49 ` Joerg Roedel
2021-05-30 15:06 ` [RFC PATCH V3 06/11] HV/Vmbus: Add SNP support for VMbus channel initiate message Tianyu Lan
2021-05-30 15:06 ` [RFC PATCH V3 07/11] HV/Vmbus: Initialize VMbus ring buffer for Isolation VM Tianyu Lan
2021-05-30 15:06 ` [RFC PATCH V3 08/11] swiotlb: Add bounce buffer remap address setting function Tianyu Lan
2021-06-07 6:43 ` Christoph Hellwig
2021-06-07 14:56 ` Tianyu Lan
2021-06-10 14:25 ` Tianyu Lan
2021-06-14 7:12 ` Christoph Hellwig
2021-06-14 13:29 ` Tom Lendacky
2021-06-14 13:37 ` Tianyu Lan
2021-06-14 13:42 ` Tianyu Lan
2021-06-14 13:49 ` Robin Murphy
2021-06-14 15:32 ` Christoph Hellwig
2021-06-15 15:24 ` Tianyu Lan
2021-07-12 9:40 ` Tianyu Lan
2021-05-30 15:06 ` [RFC PATCH V3 09/11] HV/IOMMU: Enable swiotlb bounce buffer for Isolation VM Tianyu Lan
2021-06-02 1:16 ` Boris Ostrovsky
2021-06-02 15:01 ` Tianyu Lan
2021-06-02 16:02 ` Boris Ostrovsky
2021-06-03 15:37 ` Tianyu Lan [this message]
2021-06-03 17:04 ` Boris Ostrovsky
2021-06-07 6:44 ` Christoph Hellwig
2021-05-30 15:06 ` [RFC PATCH V3 10/11] HV/Netvsc: Add Isolation VM support for netvsc driver Tianyu Lan
2021-06-07 6:50 ` Christoph Hellwig
2021-06-07 15:21 ` Tianyu Lan
2021-06-14 7:09 ` Christoph Hellwig
2021-06-14 14:04 ` Tianyu Lan
2021-06-14 15:33 ` Christoph Hellwig
2021-06-15 14:31 ` Tianyu Lan
2021-06-10 9:52 ` Vitaly Kuznetsov
2021-05-30 15:06 ` [RFC PATCH V3 11/11] HV/Storvsc: Add Isolation VM support for storvsc driver Tianyu Lan
2021-06-07 6:46 ` Christoph Hellwig
2021-06-07 14:59 ` Tianyu Lan
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1cdf4e6e-6499-e209-d499-7ab82992040b@gmail.com \
--to=ltykernel@gmail$(echo .)com \
--cc=Tianyu.Lan@microsoft$(echo .)com \
--cc=akpm@linux-foundation$(echo .)org \
--cc=arnd@arndb$(echo .)de \
--cc=boris.ostrovsky@oracle$(echo .)com \
--cc=bp@alien8$(echo .)de \
--cc=brijesh.singh@amd$(echo .)com \
--cc=cai@lca$(echo .)pw \
--cc=dave.hansen@linux$(echo .)intel.com \
--cc=davem@davemloft$(echo .)net \
--cc=decui@microsoft$(echo .)com \
--cc=haiyangz@microsoft$(echo .)com \
--cc=hannes@cmpxchg$(echo .)org \
--cc=hch@lst$(echo .)de \
--cc=hpa@zytor$(echo .)com \
--cc=iommu@lists$(echo .)linux-foundation.org \
--cc=jejb@linux$(echo .)ibm.com \
--cc=jgross@suse$(echo .)com \
--cc=joro@8bytes$(echo .)org \
--cc=kirill.shutemov@linux$(echo .)intel.com \
--cc=konrad.wilk@oracle$(echo .)com \
--cc=krish.sadhukhan@oracle$(echo .)com \
--cc=kuba@kernel$(echo .)org \
--cc=kys@microsoft$(echo .)com \
--cc=linux-arch@vger$(echo .)kernel.org \
--cc=linux-hyperv@vger$(echo .)kernel.org \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=linux-scsi@vger$(echo .)kernel.org \
--cc=luto@kernel$(echo .)org \
--cc=m.szyprowski@samsung$(echo .)com \
--cc=martin.petersen@oracle$(echo .)com \
--cc=mingo@redhat$(echo .)com \
--cc=netdev@vger$(echo .)kernel.org \
--cc=peterz@infradead$(echo .)org \
--cc=robin.murphy@arm$(echo .)com \
--cc=rppt@kernel$(echo .)org \
--cc=saravanand@fb$(echo .)com \
--cc=sstabellini@kernel$(echo .)org \
--cc=sthemmin@microsoft$(echo .)com \
--cc=sunilmut@microsoft$(echo .)com \
--cc=tglx@linutronix$(echo .)de \
--cc=thomas.lendacky@amd$(echo .)com \
--cc=vkuznets@redhat$(echo .)com \
--cc=wei.liu@kernel$(echo .)org \
--cc=will@kernel$(echo .)org \
--cc=x86@kernel$(echo .)org \
--cc=xen-devel@lists$(echo .)xenproject.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox