From: Tianyu Lan <ltykernel@gmail.com>
To: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Tianyu Lan <Tianyu.Lan@microsoft.com>,
linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org,
netdev@vger.kernel.org, thomas.lendacky@amd.com,
brijesh.singh@amd.com, sunilmut@microsoft.com, kys@microsoft.com,
haiyangz@microsoft.com, sthemmin@microsoft.com,
wei.liu@kernel.org, tglx@linutronix.de, mingo@redhat.com,
bp@alien8.de, x86@kernel.org, hpa@zytor.com, davem@davemloft.net,
kuba@kernel.org, gregkh@linuxfoundation.org
Subject: Re: [RFC PATCH 1/12] x86/Hyper-V: Add visibility parameter for vmbus_establish_gpadl()
Date: Fri, 5 Mar 2021 14:06:18 +0800 [thread overview]
Message-ID: <e4be1a18-c882-50ef-3ac7-7838c9dfa5ba@gmail.com> (raw)
In-Reply-To: <87y2f4cidh.fsf@vitty.brq.redhat.com>
Hi Vitaly:
Thanks for your review.
On 3/4/2021 12:27 AM, Vitaly Kuznetsov wrote:
> Tianyu Lan <ltykernel@gmail.com> writes:
>
>> From: Tianyu Lan <Tianyu.Lan@microsoft.com>
>>
>> Add visibility parameter for vmbus_establish_gpadl() and prepare
>> to change host visibility when create gpadl for buffer.
>>
>
> "No functional change" as you don't actually use the parameter.
Yes, will add it into commit log.
>
>> Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com>
>> Co-Developed-by: Sunil Muthuswamy <sunilmut@microsoft.com>
>> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
>
> Nit: Sunil's SoB looks misleading because the patch is from you,
> Co-Developed-by should be sufficient.
>
Will update.
>> ---
>> arch/x86/include/asm/hyperv-tlfs.h | 9 +++++++++
>> drivers/hv/channel.c | 20 +++++++++++---------
>> drivers/net/hyperv/netvsc.c | 8 ++++++--
>> drivers/uio/uio_hv_generic.c | 7 +++++--
>> include/linux/hyperv.h | 3 ++-
>> 5 files changed, 33 insertions(+), 14 deletions(-)
>>
>> diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
>> index e6cd3fee562b..fb1893a4c32b 100644
>> --- a/arch/x86/include/asm/hyperv-tlfs.h
>> +++ b/arch/x86/include/asm/hyperv-tlfs.h
>> @@ -236,6 +236,15 @@ enum hv_isolation_type {
>> /* TSC invariant control */
>> #define HV_X64_MSR_TSC_INVARIANT_CONTROL 0x40000118
>>
>> +/* Hyper-V GPA map flags */
>> +#define HV_MAP_GPA_PERMISSIONS_NONE 0x0
>> +#define HV_MAP_GPA_READABLE 0x1
>> +#define HV_MAP_GPA_WRITABLE 0x2
>> +
>> +#define VMBUS_PAGE_VISIBLE_READ_ONLY HV_MAP_GPA_READABLE
>> +#define VMBUS_PAGE_VISIBLE_READ_WRITE (HV_MAP_GPA_READABLE|HV_MAP_GPA_WRITABLE)
>> +#define VMBUS_PAGE_NOT_VISIBLE HV_MAP_GPA_PERMISSIONS_NONE
>> +
>
> Are these x86-only? If not, then we should probably move these defines
> to include/asm-generic/hyperv-tlfs.h. In case they are, we should do
> something as we're using them from arch neutral places.
>
> Also, could you please add a comment stating that these flags define
> host's visibility of a page and not guest's (this seems to be not
> obvious at least to me).
>
>> /*
>> * Declare the MSR used to setup pages used to communicate with the hypervisor.
>> */
>> diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
>> index 0bd202de7960..daa21cc72beb 100644
>> --- a/drivers/hv/channel.c
>> +++ b/drivers/hv/channel.c
>> @@ -242,7 +242,7 @@ EXPORT_SYMBOL_GPL(vmbus_send_modifychannel);
>> */
>> static int create_gpadl_header(enum hv_gpadl_type type, void *kbuffer,
>> u32 size, u32 send_offset,
>> - struct vmbus_channel_msginfo **msginfo)
>> + struct vmbus_channel_msginfo **msginfo, u32 visibility)
>> {
>> int i;
>> int pagecount;
>> @@ -391,7 +391,7 @@ static int create_gpadl_header(enum hv_gpadl_type type, void *kbuffer,
>> static int __vmbus_establish_gpadl(struct vmbus_channel *channel,
>> enum hv_gpadl_type type, void *kbuffer,
>> u32 size, u32 send_offset,
>> - u32 *gpadl_handle)
>> + u32 *gpadl_handle, u32 visibility)
>> {
>> struct vmbus_channel_gpadl_header *gpadlmsg;
>> struct vmbus_channel_gpadl_body *gpadl_body;
>> @@ -405,7 +405,8 @@ static int __vmbus_establish_gpadl(struct vmbus_channel *channel,
>> next_gpadl_handle =
>> (atomic_inc_return(&vmbus_connection.next_gpadl_handle) - 1);
>>
>> - ret = create_gpadl_header(type, kbuffer, size, send_offset, &msginfo);
>> + ret = create_gpadl_header(type, kbuffer, size, send_offset,
>> + &msginfo, visibility);
>> if (ret)
>> return ret;
>>
>> @@ -496,10 +497,10 @@ static int __vmbus_establish_gpadl(struct vmbus_channel *channel,
>> * @gpadl_handle: some funky thing
>> */
>> int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
>> - u32 size, u32 *gpadl_handle)
>> + u32 size, u32 *gpadl_handle, u32 visibility)
>> {
>> return __vmbus_establish_gpadl(channel, HV_GPADL_BUFFER, kbuffer, size,
>> - 0U, gpadl_handle);
>> + 0U, gpadl_handle, visibility);
>> }
>> EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
>>
>> @@ -610,10 +611,11 @@ static int __vmbus_open(struct vmbus_channel *newchannel,
>> newchannel->ringbuffer_gpadlhandle = 0;
>>
>> err = __vmbus_establish_gpadl(newchannel, HV_GPADL_RING,
>> - page_address(newchannel->ringbuffer_page),
>> - (send_pages + recv_pages) << PAGE_SHIFT,
>> - newchannel->ringbuffer_send_offset << PAGE_SHIFT,
>> - &newchannel->ringbuffer_gpadlhandle);
>> + page_address(newchannel->ringbuffer_page),
>> + (send_pages + recv_pages) << PAGE_SHIFT,
>> + newchannel->ringbuffer_send_offset << PAGE_SHIFT,
>> + &newchannel->ringbuffer_gpadlhandle,
>> + VMBUS_PAGE_VISIBLE_READ_WRITE);
>
> Nit: I liked the original alignment more and we can avoid the unneeded
> code churn.
>
>> if (err)
>> goto error_clean_ring;
>>
>> diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
>> index 2353623259f3..bb72c7578330 100644
>> --- a/drivers/net/hyperv/netvsc.c
>> +++ b/drivers/net/hyperv/netvsc.c
>> @@ -333,7 +333,8 @@ static int netvsc_init_buf(struct hv_device *device,
>> */
>> ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
>> buf_size,
>> - &net_device->recv_buf_gpadl_handle);
>> + &net_device->recv_buf_gpadl_handle,
>> + VMBUS_PAGE_VISIBLE_READ_WRITE);
>> if (ret != 0) {
>> netdev_err(ndev,
>> "unable to establish receive buffer's gpadl\n");
>> @@ -422,10 +423,13 @@ static int netvsc_init_buf(struct hv_device *device,
>> /* Establish the gpadl handle for this buffer on this
>> * channel. Note: This call uses the vmbus connection rather
>> * than the channel to establish the gpadl handle.
>> + * Send buffer should theoretically be only marked as "read-only", but
>> + * the netvsp for some reason needs write capabilities on it.
>> */
>> ret = vmbus_establish_gpadl(device->channel, net_device->send_buf,
>> buf_size,
>> - &net_device->send_buf_gpadl_handle);
>> + &net_device->send_buf_gpadl_handle,
>> + VMBUS_PAGE_VISIBLE_READ_WRITE);
>> if (ret != 0) {
>> netdev_err(ndev,
>> "unable to establish send buffer's gpadl\n");
>> diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c
>> index 0330ba99730e..813a7bee5139 100644
>> --- a/drivers/uio/uio_hv_generic.c
>> +++ b/drivers/uio/uio_hv_generic.c
>> @@ -29,6 +29,7 @@
>> #include <linux/hyperv.h>
>> #include <linux/vmalloc.h>
>> #include <linux/slab.h>
>> +#include <asm/mshyperv.h>
>>
>> #include "../hv/hyperv_vmbus.h"
>>
>> @@ -295,7 +296,8 @@ hv_uio_probe(struct hv_device *dev,
>> }
>>
>> ret = vmbus_establish_gpadl(channel, pdata->recv_buf,
>> - RECV_BUFFER_SIZE, &pdata->recv_gpadl);
>> + RECV_BUFFER_SIZE, &pdata->recv_gpadl,
>> + VMBUS_PAGE_VISIBLE_READ_WRITE);
>> if (ret)
>> goto fail_close;
>>
>> @@ -315,7 +317,8 @@ hv_uio_probe(struct hv_device *dev,
>> }
>>
>> ret = vmbus_establish_gpadl(channel, pdata->send_buf,
>> - SEND_BUFFER_SIZE, &pdata->send_gpadl);
>> + SEND_BUFFER_SIZE, &pdata->send_gpadl,
>> + VMBUS_PAGE_VISIBLE_READ_ONLY);
>
> Actually, this is the only place where you use 'READ_ONLY' mapping --
> which makes me wonder if it's actually worth it or we can hard-code
> VMBUS_PAGE_VISIBLE_READ_WRITE for now and avoid this additional
> parameter.
>
Another option is to set host visibility out of vmbus_establish_gpadl().
There are three places calling vmbus_establish_gpadl(). Vmbus, netvsc
and uio drivers.
>> if (ret)
>> goto fail_close;
>>
>> diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
>> index f1d74dcf0353..016fdca20d6e 100644
>> --- a/include/linux/hyperv.h
>> +++ b/include/linux/hyperv.h
>> @@ -1179,7 +1179,8 @@ extern int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
>> extern int vmbus_establish_gpadl(struct vmbus_channel *channel,
>> void *kbuffer,
>> u32 size,
>> - u32 *gpadl_handle);
>> + u32 *gpadl_handle,
>> + u32 visibility);
>>
>> extern int vmbus_teardown_gpadl(struct vmbus_channel *channel,
>> u32 gpadl_handle);
>
next prev parent reply other threads:[~2021-03-05 6:06 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-28 15:03 [RFC PATCH 00/12] x86/Hyper-V: Add Hyper-V Isolation VM support Tianyu Lan
2021-02-28 15:03 ` [RFC PATCH 1/12] x86/Hyper-V: Add visibility parameter for vmbus_establish_gpadl() Tianyu Lan
2021-03-03 16:27 ` Vitaly Kuznetsov
2021-03-05 6:06 ` Tianyu Lan [this message]
2021-02-28 15:03 ` [RFC PATCH 2/12] x86/Hyper-V: Add new hvcall guest address host visibility support Tianyu Lan
2021-03-03 16:58 ` Vitaly Kuznetsov
2021-03-05 6:23 ` Tianyu Lan
2021-02-28 15:03 ` [RFC PATCH 3/12] x86/HV: Initialize GHCB page and shared memory boundary Tianyu Lan
2021-03-03 17:05 ` Vitaly Kuznetsov
2021-02-28 15:03 ` [RFC PATCH 4/12] HV: Add Write/Read MSR registers via ghcb Tianyu Lan
2021-03-03 17:16 ` Vitaly Kuznetsov
2021-03-05 6:37 ` Tianyu Lan
2021-02-28 15:03 ` [RFC PATCH 5/12] HV: Add ghcb hvcall support for SNP VM Tianyu Lan
2021-03-03 17:21 ` Vitaly Kuznetsov
2021-03-05 15:21 ` Tianyu Lan
2021-02-28 15:03 ` [RFC PATCH 6/12] HV/Vmbus: Add SNP support for VMbus channel initiate message Tianyu Lan
2021-02-28 15:03 ` [RFC PATCH 7/12] hv/vmbus: Initialize VMbus ring buffer for Isolation VM Tianyu Lan
2021-02-28 15:03 ` [RFC PATCH 8/12] x86/Hyper-V: Initialize bounce buffer page cache and list Tianyu Lan
2021-02-28 15:03 ` [RFC PATCH 9/12] x86/Hyper-V: Add new parameter for vmbus_sendpacket_pagebuffer()/mpb_desc() Tianyu Lan
2021-02-28 15:03 ` [RFC PATCH 10/12] HV: Add bounce buffer support for Isolation VM Tianyu Lan
2021-02-28 15:03 ` [RFC PATCH 11/12] HV/Netvsc: Add Isolation VM support for netvsc driver Tianyu Lan
2021-02-28 15:03 ` [RFC PATCH 12/12] HV/Storvsc: Add bounce buffer support for Storvsc Tianyu Lan
2021-03-01 6:54 ` Christoph Hellwig
2021-03-01 13:43 ` Tianyu Lan
2021-03-01 19:45 ` [EXTERNAL] " Sunil Muthuswamy
2021-03-02 16:03 ` 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=e4be1a18-c882-50ef-3ac7-7838c9dfa5ba@gmail.com \
--to=ltykernel@gmail.com \
--cc=Tianyu.Lan@microsoft.com \
--cc=bp@alien8.de \
--cc=brijesh.singh@amd.com \
--cc=davem@davemloft.net \
--cc=gregkh@linuxfoundation.org \
--cc=haiyangz@microsoft.com \
--cc=hpa@zytor.com \
--cc=kuba@kernel.org \
--cc=kys@microsoft.com \
--cc=linux-hyperv@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=netdev@vger.kernel.org \
--cc=sthemmin@microsoft.com \
--cc=sunilmut@microsoft.com \
--cc=tglx@linutronix.de \
--cc=thomas.lendacky@amd.com \
--cc=vkuznets@redhat.com \
--cc=wei.liu@kernel.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
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;
as well as URLs for NNTP newsgroup(s).