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From: Juergen Gross <jgross@suse.com>
To: Ankur Arora <ankur.a.arora@oracle.com>,
	linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org
Cc: pbonzini@redhat.com, boris.ostrovsky@oracle.com,
	sstabellini@kernel.org, joao.m.martins@oracle.com,
	konrad.wilk@oracle.com
Subject: Re: [Xen-devel] [RFC PATCH 12/16] xen/xenbus: support xenbus frontend/backend with xenhost_t
Date: Mon, 17 Jun 2019 11:50:26 +0200
Message-ID: <af5e0319-b850-b263-2ce1-7719b66194e4@suse.com> (raw)
In-Reply-To: <20190509172540.12398-13-ankur.a.arora@oracle.com>

On 09.05.19 19:25, Ankur Arora wrote:
> As part of xenbus init, both frontend, backend interfaces need to talk
> on the correct xenbus. This might be a local xenstore (backend) or might
> be a XS_PV/XS_HVM interface (frontend) which needs to talk over xenbus
> with the remote xenstored. We bootstrap all of these with evtchn/gfn
> parameters from (*setup_xs)().
> 
> Given this we can do appropriate device discovery (in case of frontend)
> and device connectivity for the backend.
> Once done, we stash the xenhost_t * in xen_bus_type, xenbus_device or
> xenbus_watch and then the frontend and backend devices implicitly use
> the correct interface.
> 
> The rest of patch is just changing the interfaces where needed.
> 
> Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
> ---
>   drivers/block/xen-blkback/blkback.c        |  10 +-
>   drivers/net/xen-netfront.c                 |  14 +-
>   drivers/pci/xen-pcifront.c                 |   4 +-
>   drivers/xen/cpu_hotplug.c                  |   4 +-
>   drivers/xen/manage.c                       |  28 +--
>   drivers/xen/xen-balloon.c                  |   8 +-
>   drivers/xen/xenbus/xenbus.h                |  45 ++--
>   drivers/xen/xenbus/xenbus_client.c         |  32 +--
>   drivers/xen/xenbus/xenbus_comms.c          | 121 +++++-----
>   drivers/xen/xenbus/xenbus_dev_backend.c    |  30 ++-
>   drivers/xen/xenbus/xenbus_dev_frontend.c   |  22 +-
>   drivers/xen/xenbus/xenbus_probe.c          | 246 +++++++++++++--------
>   drivers/xen/xenbus/xenbus_probe_backend.c  |  19 +-
>   drivers/xen/xenbus/xenbus_probe_frontend.c |  65 +++---
>   drivers/xen/xenbus/xenbus_xs.c             | 188 +++++++++-------
>   include/xen/xen-ops.h                      |   3 +
>   include/xen/xenbus.h                       |  54 +++--
>   include/xen/xenhost.h                      |  20 ++
>   18 files changed, 536 insertions(+), 377 deletions(-)
> 
> diff --git a/drivers/xen/xenbus/xenbus_dev_frontend.c b/drivers/xen/xenbus/xenbus_dev_frontend.c
> index c3e201025ef0..d6e0c397c6a0 100644
> --- a/drivers/xen/xenbus/xenbus_dev_frontend.c
> +++ b/drivers/xen/xenbus/xenbus_dev_frontend.c
> @@ -58,10 +58,14 @@
>   
>   #include <xen/xenbus.h>
>   #include <xen/xen.h>
> +#include <xen/interface/xen.h>
> +#include <xen/xenhost.h>
>   #include <asm/xen/hypervisor.h>
>   
>   #include "xenbus.h"
>   
> +static xenhost_t *xh;
> +
>   /*
>    * An element of a list of outstanding transactions, for which we're
>    * still waiting a reply.
> @@ -312,13 +316,13 @@ static void xenbus_file_free(struct kref *kref)
>   	 */
>   
>   	list_for_each_entry_safe(trans, tmp, &u->transactions, list) {
> -		xenbus_transaction_end(trans->handle, 1);
> +		xenbus_transaction_end(xh, trans->handle, 1);
>   		list_del(&trans->list);
>   		kfree(trans);
>   	}
>   
>   	list_for_each_entry_safe(watch, tmp_watch, &u->watches, list) {
> -		unregister_xenbus_watch(&watch->watch);
> +		unregister_xenbus_watch(xh, &watch->watch);
>   		list_del(&watch->list);
>   		free_watch_adapter(watch);
>   	}
> @@ -450,7 +454,7 @@ static int xenbus_write_transaction(unsigned msg_type,
>   		   (!strcmp(msg->body, "T") || !strcmp(msg->body, "F"))))
>   		return xenbus_command_reply(u, XS_ERROR, "EINVAL");
>   
> -	rc = xenbus_dev_request_and_reply(&msg->hdr, u);
> +	rc = xenbus_dev_request_and_reply(xh, &msg->hdr, u);
>   	if (rc && trans) {
>   		list_del(&trans->list);
>   		kfree(trans);
> @@ -489,7 +493,7 @@ static int xenbus_write_watch(unsigned msg_type, struct xenbus_file_priv *u)
>   		watch->watch.callback = watch_fired;
>   		watch->dev_data = u;
>   
> -		err = register_xenbus_watch(&watch->watch);
> +		err = register_xenbus_watch(xh, &watch->watch);
>   		if (err) {
>   			free_watch_adapter(watch);
>   			rc = err;
> @@ -500,7 +504,7 @@ static int xenbus_write_watch(unsigned msg_type, struct xenbus_file_priv *u)
>   		list_for_each_entry(watch, &u->watches, list) {
>   			if (!strcmp(watch->token, token) &&
>   			    !strcmp(watch->watch.node, path)) {
> -				unregister_xenbus_watch(&watch->watch);
> +				unregister_xenbus_watch(xh, &watch->watch);
>   				list_del(&watch->list);
>   				free_watch_adapter(watch);
>   				break;
> @@ -618,8 +622,9 @@ static ssize_t xenbus_file_write(struct file *filp,
>   static int xenbus_file_open(struct inode *inode, struct file *filp)
>   {
>   	struct xenbus_file_priv *u;
> +	struct xenstore_private *xs = xs_priv(xh);
>   
> -	if (xen_store_evtchn == 0)
> +	if (xs->store_evtchn == 0)
>   		return -ENOENT;
>   
>   	nonseekable_open(inode, filp);
> @@ -687,6 +692,11 @@ static int __init xenbus_init(void)
>   	if (!xen_domain())
>   		return -ENODEV;
>   
> +	if (xen_driver_domain() && xen_nested())
> +		xh = xh_remote;
> +	else
> +		xh = xh_default;

This precludes any mixed use of L0 and L1 frontends. With this move you
make it impossible to e.g. use a driver domain for networking in L1 with
a L1-local PV disk, or pygrub in L1 dom0.


Juergen

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  reply index

Thread overview: 66+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-09 17:25 [Xen-devel] [RFC PATCH 00/16] xenhost support Ankur Arora
2019-05-09 17:25 ` [Xen-devel] [RFC PATCH 01/16] x86/xen: add xenhost_t interface Ankur Arora
2019-06-07 15:04   ` Juergen Gross
2019-06-11  7:16     ` Ankur Arora
2019-06-14 11:52       ` Juergen Gross
2019-05-09 17:25 ` Ankur Arora
2019-05-09 17:25 ` [RFC PATCH 02/16] x86/xen: cpuid support in xenhost_t Ankur Arora
2019-05-09 17:25   ` [Xen-devel] " Ankur Arora
2019-06-12 21:09   ` Andrew Cooper
2019-05-09 17:25 ` [Xen-devel] [RFC PATCH 03/16] x86/xen: make hypercall_page generic Ankur Arora
2019-05-09 17:25 ` Ankur Arora
2019-05-09 17:25 ` [RFC PATCH 04/16] x86/xen: hypercall support for xenhost_t Ankur Arora
2019-05-09 17:25 ` [Xen-devel] " Ankur Arora
2019-06-12 21:15   ` Andrew Cooper
2019-06-14  7:20     ` Ankur Arora
2019-06-14  7:35       ` Juergen Gross
2019-06-14  8:00         ` Andrew Cooper
2019-05-09 17:25 ` [RFC PATCH 05/16] x86/xen: add feature support in xenhost_t Ankur Arora
2019-05-09 17:25 ` [Xen-devel] " Ankur Arora
2019-05-09 17:25 ` [Xen-devel] [RFC PATCH 06/16] x86/xen: add shared_info support to xenhost_t Ankur Arora
2019-06-07 15:08   ` Juergen Gross
2019-06-08  5:01     ` Ankur Arora
2019-05-09 17:25 ` Ankur Arora
2019-05-09 17:25 ` [RFC PATCH 07/16] x86/xen: make vcpu_info part of xenhost_t Ankur Arora
2019-05-09 17:25   ` [Xen-devel] " Ankur Arora
2019-06-14 11:53   ` Juergen Gross
2019-06-17  6:28     ` Ankur Arora
2019-05-09 17:25 ` [RFC PATCH 08/16] x86/xen: irq/upcall handling with multiple xenhosts Ankur Arora
2019-05-09 17:25 ` [Xen-devel] " Ankur Arora
2019-06-14 12:01   ` Juergen Gross
2019-05-09 17:25 ` [RFC PATCH 09/16] xen/evtchn: support evtchn in xenhost_t Ankur Arora
2019-05-09 17:25 ` [Xen-devel] " Ankur Arora
2019-06-14 12:04   ` Juergen Gross
2019-06-17  6:09     ` Ankur Arora
2019-05-09 17:25 ` [RFC PATCH 10/16] xen/balloon: support ballooning " Ankur Arora
2019-05-09 17:25 ` [Xen-devel] " Ankur Arora
2019-06-17  9:28   ` Juergen Gross
2019-06-19  2:24     ` Ankur Arora
2019-05-09 17:25 ` [RFC PATCH 11/16] xen/grant-table: make grant-table xenhost aware Ankur Arora
2019-05-09 17:25   ` [Xen-devel] " Ankur Arora
2019-06-17  9:36   ` Juergen Gross
2019-06-19  2:25     ` Ankur Arora
2019-05-09 17:25 ` [RFC PATCH 12/16] xen/xenbus: support xenbus frontend/backend with xenhost_t Ankur Arora
2019-05-09 17:25 ` [Xen-devel] " Ankur Arora
2019-06-17  9:50   ` Juergen Gross [this message]
2019-06-19  2:38     ` Ankur Arora
2019-05-09 17:25 ` [Xen-devel] [RFC PATCH 13/16] drivers/xen: gnttab, evtchn, xenbus API changes Ankur Arora
2019-06-17 10:07   ` Juergen Gross
2019-06-19  2:55     ` Ankur Arora
2019-05-09 17:25 ` Ankur Arora
2019-05-09 17:25 ` [Xen-devel] [RFC PATCH 14/16] xen/blk: " Ankur Arora
2019-06-17 10:14   ` Juergen Gross
2019-06-19  2:59     ` Ankur Arora
2019-05-09 17:25 ` Ankur Arora
2019-05-09 17:25 ` [RFC PATCH 15/16] xen/net: " Ankur Arora
2019-05-09 17:25 ` [Xen-devel] " Ankur Arora
2019-06-17 10:14   ` Juergen Gross
2019-05-09 17:25 ` [Xen-devel] [RFC PATCH 16/16] xen/grant-table: host_addr fixup in mapping on xenhost_r0 Ankur Arora
2019-06-17 10:55   ` Juergen Gross
2019-06-19  3:02     ` Ankur Arora
2019-05-09 17:25 ` Ankur Arora
2019-06-07 14:51 ` [Xen-devel] [RFC PATCH 00/16] xenhost support Juergen Gross
2019-06-07 15:22   ` Joao Martins
2019-06-07 16:21     ` Juergen Gross
2019-06-08  5:50       ` Ankur Arora
2019-06-08  5:33   ` Ankur Arora

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