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* [PATCH 06/14 v4] xen/arm: vpl011: Add a new domctl API to initialize vpl011
@ 2017-06-06 10:03 Bhupinder Thakur
  0 siblings, 0 replies; 18+ messages in thread
From: Bhupinder Thakur @ 2017-06-06 10:03 UTC (permalink / raw)
  To: xen-devel; +Cc: Wei Liu, Julien Grall, Stefano Stabellini, Ian Jackson

Add a new domctl API to initialize vpl011. It takes the GFN and console
backend domid as input and returns an event channel to be used for
sending and receiving events from Xen.

Xen will communicate with xenconsole using GFN as the ring buffer and
the event channel to transmit and receive pl011 data on the guest domain's
behalf.

Signed-off-by: Bhupinder Thakur <bhupinder.thakur@linaro.org>
---

Changes since v3:
- Added a new arch specific function libxl__arch_domain_create_finish(), which
  calls the vpl011 initialization function. For x86 this function does not do
  anything.
- domain_vpl011_init() takes a pointer to a structure which contains all the 
  required information such as console_domid, gfn instead of passing parameters
  separately.
- Dropped a DOMCTL API defined for de-initializing vpl011 as that should be
  taken care when the domain is destroyed (and not dependent on userspace 
  libraries/applications).

Changes since v2:
- Replaced the DOMCTL APIs defined for get/set of event channel and GFN with 
  a set of DOMCTL APIs for initializing and de-initializing vpl011 emulation.

 tools/libxc/include/xenctrl.h | 17 +++++++++++++++++
 tools/libxc/xc_domain.c       | 23 ++++++++++++++++++++++
 tools/libxl/libxl_arch.h      |  7 +++++++
 tools/libxl/libxl_arm.c       | 19 +++++++++++++++++++
 tools/libxl/libxl_dom.c       |  6 +++++-
 tools/libxl/libxl_x86.c       |  8 ++++++++
 xen/arch/arm/domain.c         |  2 ++
 xen/arch/arm/domctl.c         | 44 ++++++++++++++++++++++++++++++++++++++++---
 xen/include/public/domctl.h   | 12 ++++++++++++
 9 files changed, 134 insertions(+), 4 deletions(-)

diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
index 1629f41..77425dd 100644
--- a/tools/libxc/include/xenctrl.h
+++ b/tools/libxc/include/xenctrl.h
@@ -884,6 +884,23 @@ int xc_vcpu_getcontext(xc_interface *xch,
                        uint32_t domid,
                        uint32_t vcpu,
                        vcpu_guest_context_any_t *ctxt);
+/**
+ * This function initializes the vpl011 emulation and returns
+ * the event to be used by the backend for communicating with
+ * the emulation code.
+ *
+ * @parm xch a handle to an open hypervisor interface
+ * @parm domid the domain to get information from
+ * @parm console_domid the domid of the backend console
+ * @parm gfn the guest pfn to be used as the ring buffer
+ * @parm evtchn the event channel to be used for events
+ * @return 0 on success, negative error on failure
+ */
+int xc_dom_vpl011_init(xc_interface *xch,
+                       uint32_t domid,
+                       uint32_t console_domid,
+                       xen_pfn_t gfn,
+                       evtchn_port_t *evtchn);
 
 /**
  * This function returns information about the XSAVE state of a particular
diff --git a/tools/libxc/xc_domain.c b/tools/libxc/xc_domain.c
index 00909ad4..a8efd5e 100644
--- a/tools/libxc/xc_domain.c
+++ b/tools/libxc/xc_domain.c
@@ -343,6 +343,29 @@ int xc_domain_get_guest_width(xc_interface *xch, uint32_t domid,
     return 0;
 }
 
+int xc_dom_vpl011_init(xc_interface *xch,
+                       uint32_t domid,
+                       uint32_t console_domid,
+                       xen_pfn_t gfn,
+                       evtchn_port_t *evtchn)
+{
+    DECLARE_DOMCTL;
+    int rc = 0;
+
+    domctl.cmd = XEN_DOMCTL_vuart_op;
+    domctl.domain = (domid_t)domid;
+    domctl.u.vuart_op.cmd = XEN_DOMCTL_VUART_OP_INIT_VPL011;
+    domctl.u.vuart_op.console_domid = console_domid;
+    domctl.u.vuart_op.gfn = gfn;
+
+    if ( (rc = do_domctl(xch, &domctl)) < 0 )
+        return rc;
+
+    *evtchn = domctl.u.vuart_op.evtchn;
+
+    return rc;
+}
+
 int xc_domain_getinfo(xc_interface *xch,
                       uint32_t first_domid,
                       unsigned int max_doms,
diff --git a/tools/libxl/libxl_arch.h b/tools/libxl/libxl_arch.h
index 5e1fc60..d1ca9c6 100644
--- a/tools/libxl/libxl_arch.h
+++ b/tools/libxl/libxl_arch.h
@@ -32,6 +32,13 @@ _hidden
 int libxl__arch_domain_create(libxl__gc *gc, libxl_domain_config *d_config,
                uint32_t domid);
 
+/* arch specific internal domain creation finish function */
+_hidden
+int libxl__arch_domain_create_finish(libxl__gc *gc,
+                                     libxl_domain_build_info *info,
+                                     uint32_t domid,
+                                     libxl__domain_build_state *state);
+
 /* setup arch specific hardware description, i.e. DTB on ARM */
 _hidden
 int libxl__arch_domain_init_hw_description(libxl__gc *gc,
diff --git a/tools/libxl/libxl_arm.c b/tools/libxl/libxl_arm.c
index d842d88..b60dfa9 100644
--- a/tools/libxl/libxl_arm.c
+++ b/tools/libxl/libxl_arm.c
@@ -106,6 +106,25 @@ int libxl__arch_domain_create(libxl__gc *gc, libxl_domain_config *d_config,
     return 0;
 }
 
+int libxl__arch_domain_create_finish(libxl__gc *gc,
+                                     libxl_domain_build_info *info,
+                                     uint32_t domid,
+                                     libxl__domain_build_state *state)
+{
+    int ret = 0;
+
+    if ( info->arch_arm.vuart &&
+         (ret = xc_dom_vpl011_init(CTX->xch,
+                                   domid,
+                                   state->console_domid,
+                                   xc_get_vuart_gfn(),
+                                   &state->vuart_port)) != 0 ) {
+        LOG(ERROR, "xc_dom_vpl011_init failed\n");
+    }
+
+    return ret;
+}
+
 int libxl__arch_extra_memory(libxl__gc *gc,
                              const libxl_domain_build_info *info,
                              uint64_t *out)
diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index 5d914a5..187c5bd 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -587,7 +587,10 @@ retry_transaction:
             goto retry_transaction;
     xs_introduce_domain(ctx->xsh, domid, state->store_mfn, state->store_port);
     free(vm_path);
-    return 0;
+
+    rc = libxl__arch_domain_create_finish(gc, info, domid, state);
+
+    return rc;
 }
 
 static int set_vnuma_info(libxl__gc *gc, uint32_t domid,
@@ -788,6 +791,7 @@ int libxl__build_pv(libxl__gc *gc, uint32_t domid,
     if (xc_dom_translated(dom)) {
         state->console_mfn = dom->console_pfn;
         state->store_mfn = dom->xenstore_pfn;
+        state->vuart_gfn = dom->vuart_gfn;
     } else {
         state->console_mfn = xc_dom_p2m(dom, dom->console_pfn);
         state->store_mfn = xc_dom_p2m(dom, dom->xenstore_pfn);
diff --git a/tools/libxl/libxl_x86.c b/tools/libxl/libxl_x86.c
index 455f6f0..3544028 100644
--- a/tools/libxl/libxl_x86.c
+++ b/tools/libxl/libxl_x86.c
@@ -358,6 +358,14 @@ out:
     return ret;
 }
 
+int libxl__arch_domain_create_finish(libxl__gc *gc,
+                                     libxl_domain_build_info *info,
+                                     uint32_t domid,
+                                     libxl__domain_build_state *state)
+{
+    return 0;
+}
+
 int libxl__arch_extra_memory(libxl__gc *gc,
                              const libxl_domain_build_info *info,
                              uint64_t *out)
diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index 76310ed..9e150ba 100644
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -665,6 +665,8 @@ fail:
 
 void arch_domain_destroy(struct domain *d)
 {
+    domain_vpl011_deinit(d);
+
     /* IOMMU page table is shared with P2M, always call
      * iommu_domain_destroy() before p2m_teardown().
      */
diff --git a/xen/arch/arm/domctl.c b/xen/arch/arm/domctl.c
index 971caec..741679b 100644
--- a/xen/arch/arm/domctl.c
+++ b/xen/arch/arm/domctl.c
@@ -5,13 +5,15 @@
  */
 
 #include <xen/types.h>
-#include <xen/lib.h>
+#include <public/domctl.h>
 #include <xen/errno.h>
-#include <xen/sched.h>
+#include <xen/guest_access.h>
 #include <xen/hypercall.h>
 #include <xen/iocap.h>
+#include <xen/lib.h>
+#include <xen/mm.h>
+#include <xen/sched.h>
 #include <xsm/xsm.h>
-#include <public/domctl.h>
 
 void arch_get_domain_info(const struct domain *d,
                           struct xen_domctl_getdomaininfo *info)
@@ -119,6 +121,42 @@ long arch_do_domctl(struct xen_domctl *domctl, struct domain *d,
         d->disable_migrate = domctl->u.disable_migrate.disable;
         return 0;
 
+    case XEN_DOMCTL_vuart_op:
+    {
+        int rc;
+        struct xen_domctl_vuart_op *vuart_op = &domctl->u.vuart_op;
+
+        switch(vuart_op->cmd)
+        {
+        case XEN_DOMCTL_VUART_OP_INIT_VPL011:
+
+            if ( !d->creation_finished )
+            {
+                struct vpl011_init_info info;
+
+                info.console_domid = vuart_op->console_domid;
+                info.gfn = _gfn(vuart_op->gfn);
+
+                rc = domain_vpl011_init(d, &info);
+                if ( !rc )
+                {
+                    vuart_op->evtchn = info.evtchn;
+                    rc = __copy_to_guest(u_domctl, domctl, 1);
+                }
+            }
+            else
+            {
+                rc = - EPERM;
+            }
+            break;
+
+        default:
+            rc = -EINVAL;
+            break;
+        }
+
+        return rc;
+    }
     default:
     {
         int rc;
diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index e6cf211..c6ff458 100644
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -36,6 +36,7 @@
 #include "grant_table.h"
 #include "hvm/save.h"
 #include "memory.h"
+#include "event_channel.h"
 
 #define XEN_DOMCTL_INTERFACE_VERSION 0x0000000d
 
@@ -1138,6 +1139,15 @@ struct xen_domctl_psr_cat_op {
     uint32_t target;    /* IN */
     uint64_t data;      /* IN/OUT */
 };
+
+struct xen_domctl_vuart_op {
+#define XEN_DOMCTL_VUART_OP_INIT_VPL011  0
+        uint32_t cmd;           /* XEN_DOMCTL_VUART_OP_* */
+        uint32_t console_domid; /* IN */
+        xen_pfn_t gfn;          /* IN */
+        evtchn_port_t evtchn;   /* OUT */
+};
+
 typedef struct xen_domctl_psr_cat_op xen_domctl_psr_cat_op_t;
 DEFINE_XEN_GUEST_HANDLE(xen_domctl_psr_cat_op_t);
 
@@ -1218,6 +1228,7 @@ struct xen_domctl {
 #define XEN_DOMCTL_monitor_op                    77
 #define XEN_DOMCTL_psr_cat_op                    78
 #define XEN_DOMCTL_soft_reset                    79
+#define XEN_DOMCTL_vuart_op                      80
 #define XEN_DOMCTL_gdbsx_guestmemio            1000
 #define XEN_DOMCTL_gdbsx_pausevcpu             1001
 #define XEN_DOMCTL_gdbsx_unpausevcpu           1002
@@ -1280,6 +1291,7 @@ struct xen_domctl {
         struct xen_domctl_psr_cmt_op        psr_cmt_op;
         struct xen_domctl_monitor_op        monitor_op;
         struct xen_domctl_psr_cat_op        psr_cat_op;
+        struct xen_domctl_vuart_op          vuart_op;
         uint8_t                             pad[128];
     } u;
 };
-- 
2.7.4


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^ permalink raw reply related	[flat|nested] 18+ messages in thread
* [PATCH 00/14 v4] PL011 emulation support in Xen
@ 2017-06-06 17:25 Bhupinder Thakur
  2017-06-06 17:25 ` [PATCH 06/14 v4] xen/arm: vpl011: Add a new domctl API to initialize vpl011 Bhupinder Thakur
  0 siblings, 1 reply; 18+ messages in thread
From: Bhupinder Thakur @ 2017-06-06 17:25 UTC (permalink / raw)
  To: xen-devel; +Cc: Wei Liu, Julien Grall, Stefano Stabellini, Ian Jackson

PL011 emulation for guests in Xen
===================================
Linaro has published VM System specification for ARM Processors, which
provides a set of guidelines for both guest OS and hypervisor implementations, 
such that building OS images according to these guidelines guarantees
that those images can also run on hypervisors compliant with this specification.

One of the spec requirements is that the hypervisor must provide an
emulated PL011 UART as a serial console which meets the minimum requirements in 
SBSA UART as defined in appendix B of the following 
ARM Server Base Architecture Document:

https://static.docs.arm.com/den0029/a/Server_Base_System_Architecture_v3_1_ARM_DEN_0029A.pdf.

This feature allows the Xen guests to use SBSA compliant pl011 UART as 
as a console. 

Note that SBSA pl011 UART is a subset of full featured ARM pl011 UART and
supports only a subset of registers as mentioned below. It does not support
rx/tx DMA.

Currently, Xen supports paravirtualized (aka PV console) and an emulated serial 
consoles. This feature will expose an emulated SBSA pl011 UART console to the
guest, which a user can access using xenconsole.

The device tree passed to the guest VM will contain the pl011 MMIO address 
range and an irq for receiving rx/tx pl011 interrupts. The device tree format 
is specified in Documentation/devicetree/bindings/serial/arm_sbsa_uart.txt.

The Xen hypervisor will expose two types of interfaces to the backend and domU. 

The interface exposed to domU will be an emulated pl011 UART by emulating the 
access to the following pl011 registers by the guest.

- Data register (DR)            - RW
- Raw interrupt status register (RIS)   - RO
- Masked interrupt status register (MIS)- RO
- Interrupt Mask (IMSC)         - RW
- Interrupt Clear (ICR)         - WO

It will also inject the pl011 interrupts to the guest in the following 
conditions:

- incoming data in the rx buffer for the guest
- there is space in the tx buffer for the guest to write more data

The interface exposed to the backend will be the same PV console interface, 
which minimizes the changes required in xenconsole to support a new pl011 console.

This interface has rx and tx ring buffers and an event channel for 
sending/receiving events from the backend. 

So essentially Xen handles the data on behalf of domU and the backend. Any data 
written by domU is captured by Xen and written to the TX (OUT) ring buffer 
and a pl011 event is raised to the backend to read the TX ring buffer.
 
Similarly on reciving a pl011 event, Xen injects an interrupt to guest to
indicate there is data available in the RX (IN) ring buffer.

The pl011 UART state is completely captured in the set of registers 
mentioned above and this state is updated everytime there is an event from 
the backend or there is register read/write access from domU. 

For example, if domU has masked the rx interrupt in the IMSC register, then Xen 
will not inject an interrupt to guest and will just update the RIS register. 
Once the interrupt is unmasked by guest, the interrupt will be delivered to the 
guest.

Changes summary:

Xen Hypervisor
===============

1. Add emulation code to emulate read/write access to pl011 registers and pl011 
   interrupts:
    - It emulates DR read/write by reading and writing from/to the IN and 
      OUT ring buffers and raising an event to dom0 when there is data in 
      the OUT ring buffer and injecting an interrupt to the guest when there 
      is data in the IN ring buffer.
    - Other registers are related to interrupt management and essentially 
      control when interrupts are delivered to the guest.

2. Add a new domctl API to initialize vpl011 emulation in Xen.

3. Enable vpl011 emulation for a domain based on a libxl option passed during 
   domain creation.

Toolstack
==========

1. Add a new option "vuart" in the domU configuration file to enable/disable vuart.

2. Create a SBSA UART DT node in the guest device tree. It uses a fixed
   vpl011 SPI IRQ number and MMIO address.

3. Call vpl011 init DOMCTL API to enable vpl011 emulation.

5. Add a new vuart xenstore node, which contains:
    - ring-ref
    - event channel
    - buffer limit
    - type

Xenconsoled
============

1. Split the domain structure to support multiple consoles.

2. Modify different APIs such as buffer_append() etc. to operate on the 
   console structure.
   
3. Add support for handling multiple consoles.

4. Add support for vuart console:

The vpl011 changes available at the following repo:

url: ssh://git@git.linaro.org:/people/bhupinder.thakur/xen.git
branch: vpl011_v4

There are some TBD items which need to be looked at in the future:

1. Currently UEFI firmware logs the output to hvc console only. How can 
   UEFI firmware be made aware of pl011 console and how it can use it
   as a console instead of hvc.
2. Linux seems to have hvc console as the default console i.e. if no
   console is specified then it uses hvc as the console. How can an 
   option be provided in Linux to select either hvc or pl011 as the 
   default console.

3. ACPI support for pl011 device.

CC: ij
CC: wl
CC: ss
CC: jg
CC: kw

Bhupinder Thakur (14):
  xen/arm: vpl011: Move vgic register access functions to vreg.h
  xen/arm: vpl011: Define generic vreg_reg* access functions in vreg.h
  xen/arm: vpl011: Add pl011 uart emulation in Xen
  xen/arm: vpl011: Add support for vuart in libxl
  xen/arm: vpl011: Allocate a new GFN in the toolstack for vuart
  xen/arm: vpl011: Add a new domctl API to initialize vpl011
  xen/arm: vpl011: Add a new vuart node in the xenstore
  xen/arm: vpl011: Modify xenconsole to define and use a new console    
    structure
  xen/arm: vpl011: Modify xenconsole functions to take console structure
    as input
  xen/arm: vpl011: Modify xenconsole to support multiple consoles
  xen/arm: vpl011: Add support for vuart console in xenconsole
  xen/arm: vpl011: Add a new vuart console type to xenconsole client
  xen/arm: vpl011: Add a pl011 uart DT node in the guest device tree
  xen/arm: vpl011: Update documentation for vuart console support

 config/arm32.mk                      |   1 +
 config/arm64.mk                      |   1 +
 docs/man/xl.cfg.pod.5.in             |   9 +
 docs/misc/console.txt                |  44 ++-
 tools/console/Makefile               |   4 +-
 tools/console/client/main.c          |  25 +-
 tools/console/daemon/io.c            | 544 ++++++++++++++++++++++++-----------
 tools/libxc/include/xc_dom.h         |   3 +
 tools/libxc/include/xenctrl.h        |  17 ++
 tools/libxc/xc_dom_arm.c             |  12 +-
 tools/libxc/xc_dom_boot.c            |   2 +
 tools/libxc/xc_domain.c              |  23 ++
 tools/libxl/libxl.h                  |   6 +
 tools/libxl/libxl_arch.h             |   7 +
 tools/libxl/libxl_arm.c              |  71 ++++-
 tools/libxl/libxl_console.c          |  47 +++
 tools/libxl/libxl_create.c           |  12 +-
 tools/libxl/libxl_device.c           |   9 +-
 tools/libxl/libxl_dom.c              |   8 +-
 tools/libxl/libxl_internal.h         |   7 +
 tools/libxl/libxl_types.idl          |   7 +
 tools/libxl/libxl_types_internal.idl |   1 +
 tools/libxl/libxl_x86.c              |   8 +
 tools/xl/Makefile                    |   4 +
 tools/xl/xl_cmdtable.c               |   4 +
 tools/xl/xl_console.c                |  11 +-
 tools/xl/xl_parse.c                  |   8 +
 xen/arch/arm/Kconfig                 |   5 +
 xen/arch/arm/Makefile                |   1 +
 xen/arch/arm/domain.c                |   2 +
 xen/arch/arm/domctl.c                |  44 ++-
 xen/arch/arm/vgic-v2.c               |  28 +-
 xen/arch/arm/vgic-v3.c               |  40 +--
 xen/arch/arm/vpl011.c                | 418 +++++++++++++++++++++++++++
 xen/include/asm-arm/domain.h         |   6 +
 xen/include/asm-arm/pl011-uart.h     |   2 +
 xen/include/asm-arm/vgic.h           | 111 +------
 xen/include/asm-arm/vpl011.h         |  74 +++++
 xen/include/asm-arm/vreg.h           | 109 +++++++
 xen/include/public/arch-arm.h        |   6 +
 xen/include/public/domctl.h          |  12 +
 xen/include/public/io/console.h      |   4 +
 42 files changed, 1421 insertions(+), 336 deletions(-)
 create mode 100644 xen/arch/arm/vpl011.c
 create mode 100644 xen/include/asm-arm/vpl011.h

-- 
2.7.4


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^ permalink raw reply	[flat|nested] 18+ messages in thread
end of thread, other threads:[~2017-06-21 10:18 UTC | newest]

Thread overview: 18+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-06-06 10:03 [PATCH 06/14 v4] xen/arm: vpl011: Add a new domctl API to initialize vpl011 Bhupinder Thakur
  -- strict thread matches above, loose matches on Subject: below --
2017-06-06 17:25 [PATCH 00/14 v4] PL011 emulation support in Xen Bhupinder Thakur
2017-06-06 17:25 ` [PATCH 06/14 v4] xen/arm: vpl011: Add a new domctl API to initialize vpl011 Bhupinder Thakur
2017-06-06 23:26   ` Stefano Stabellini
2017-06-09 14:06     ` Julien Grall
2017-06-09 18:32       ` Stefano Stabellini
2017-06-14  7:35     ` Bhupinder Thakur
2017-06-14  8:34       ` Bhupinder Thakur
2017-06-09 14:13   ` Julien Grall
2017-06-14  9:16     ` Bhupinder Thakur
2017-06-14 10:15       ` Julien Grall
2017-06-15  6:33         ` Bhupinder Thakur
2017-06-19 10:59           ` Bhupinder Thakur
2017-06-19 11:01             ` Julien Grall
2017-06-19 11:47               ` Wei Liu
2017-06-19 13:11                 ` Bhupinder Thakur
2017-06-20 11:16                   ` Julien Grall
2017-06-20 11:42                     ` Wei Liu
2017-06-21 10:18                     ` Bhupinder Thakur

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