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From: Oleksandr <olekstysh@gmail.com>
To: Stefano Stabellini <sstabellini@kernel.org>,
	Julien Grall <julien@xen.org>
Cc: xen-devel@lists.xenproject.org,
	Julien Grall <julien.grall@arm.com>,
	Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>,
	Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Subject: Re: [PATCH V4 14/24] arm/ioreq: Introduce arch specific bits for IOREQ/DM features
Date: Thu, 21 Jan 2021 11:31:00 +0200	[thread overview]
Message-ID: <4c682b4c-2deb-6d3a-fee1-588e36c89a93@gmail.com> (raw)
In-Reply-To: <alpine.DEB.2.21.2101201147100.14528@sstabellini-ThinkPad-T480s>


On 20.01.21 21:47, Stefano Stabellini wrote:

Hi Julien, Stefano


> On Wed, 20 Jan 2021, Julien Grall wrote:
>> Hi Stefano,
>>
>> On 20/01/2021 00:50, Stefano Stabellini wrote:
>>> On Tue, 19 Jan 2021, Oleksandr wrote:
>>>> diff --git a/xen/arch/arm/ioreq.c b/xen/arch/arm/ioreq.c
>>>> index 40b9e59..0508bd8 100644
>>>> --- a/xen/arch/arm/ioreq.c
>>>> +++ b/xen/arch/arm/ioreq.c
>>>> @@ -101,12 +101,10 @@ enum io_state try_fwd_ioserv(struct cpu_user_regs
>>>> *regs,
>>>>
>>>>    bool arch_ioreq_complete_mmio(void)
>>>>    {
>>>> -    struct vcpu *v = current;
>>>>        struct cpu_user_regs *regs = guest_cpu_user_regs();
>>>>        const union hsr hsr = { .bits = regs->hsr };
>>>> -    paddr_t addr = v->io.req.addr;
>>>>
>>>> -    if ( try_handle_mmio(regs, hsr, addr) == IO_HANDLED )
>>>> +    if ( handle_ioserv(regs, current) == IO_HANDLED )
>>>>        {
>>>>            advance_pc(regs, hsr);
>>>>            return true;
>>> Yes, but I think we want to keep the check
>>>
>>>       vio->req.state == STATE_IORESP_READY
>>>
>>> So maybe (uncompiled, untested):
>>>
>>>       if ( v->io.req.state != STATE_IORESP_READY )
>>>           return false;
>> Is it possible to reach this function with v->io.req.state !=
>> STATE_IORESP_READY? If not, then I would suggest to add an
>> ASSERT_UNREACHABLE() before the return.
> If I am reading the state machine right it should *not* be possible to
> get here with v->io.req.state != STATE_IORESP_READY, so yes,
> ASSERT_UNREACHABLE() would work.
Agree here. If the assumption is not correct (unlikely), I think I will 
catch this during testing.
In addition, we can probably drop case STATE_IORESP_READY in 
try_fwd_ioserv().


[not tested]


diff --git a/xen/arch/arm/ioreq.c b/xen/arch/arm/ioreq.c
index 40b9e59..c7ee1a7 100644
--- a/xen/arch/arm/ioreq.c
+++ b/xen/arch/arm/ioreq.c
@@ -71,9 +71,6 @@ enum io_state try_fwd_ioserv(struct cpu_user_regs *regs,
      case STATE_IOREQ_NONE:
          break;

-    case STATE_IORESP_READY:
-        return IO_HANDLED;
-
      default:
          gdprintk(XENLOG_ERR, "wrong state %u\n", vio->req.state);
          return IO_ABORT;
@@ -104,9 +101,14 @@ bool arch_ioreq_complete_mmio(void)
      struct vcpu *v = current;
      struct cpu_user_regs *regs = guest_cpu_user_regs();
      const union hsr hsr = { .bits = regs->hsr };
-    paddr_t addr = v->io.req.addr;

-    if ( try_handle_mmio(regs, hsr, addr) == IO_HANDLED )
+    if ( v->io.req.state != STATE_IORESP_READY )
+    {
+        ASSERT_UNREACHABLE();
+        return false;
+    }
+
+    if ( handle_ioserv(regs, v) == IO_HANDLED )
      {
          advance_pc(regs, hsr);
          return true;


-- 
Regards,

Oleksandr Tyshchenko



  reply	other threads:[~2021-01-21  9:31 UTC|newest]

Thread overview: 144+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-12 21:52 [PATCH V4 00/24] IOREQ feature (+ virtio-mmio) on Arm Oleksandr Tyshchenko
2021-01-12 21:52 ` [PATCH V4 01/24] x86/ioreq: Prepare IOREQ feature for making it common Oleksandr Tyshchenko
2021-01-15 15:16   ` Julien Grall
2021-01-15 16:41   ` Jan Beulich
2021-01-16  9:48     ` Oleksandr
2021-01-18  8:22   ` Paul Durrant
2021-01-12 21:52 ` [PATCH V4 02/24] x86/ioreq: Add IOREQ_STATUS_* #define-s and update code for moving Oleksandr Tyshchenko
2021-01-15 15:17   ` Julien Grall
2021-01-18  8:24   ` Paul Durrant
2021-01-12 21:52 ` [PATCH V4 03/24] x86/ioreq: Provide out-of-line wrapper for the handle_mmio() Oleksandr Tyshchenko
2021-01-15 14:48   ` Alex Bennée
2021-01-15 15:19   ` Julien Grall
2021-01-18  8:29   ` Paul Durrant
2021-01-12 21:52 ` [PATCH V4 04/24] xen/ioreq: Make x86's IOREQ feature common Oleksandr Tyshchenko
2021-01-15 14:55   ` Alex Bennée
2021-01-15 15:23   ` Julien Grall
2021-01-18  8:48   ` Paul Durrant
2021-01-12 21:52 ` [PATCH V4 05/24] xen/ioreq: Make x86's hvm_ioreq_needs_completion() common Oleksandr Tyshchenko
2021-01-15 15:25   ` Julien Grall
2021-01-20  8:48   ` Alex Bennée
2021-01-20  9:31     ` Julien Grall
2021-01-12 21:52 ` [PATCH V4 06/24] xen/ioreq: Make x86's hvm_mmio_first(last)_byte() common Oleksandr Tyshchenko
2021-01-15 15:34   ` Julien Grall
2021-01-20  8:57   ` Alex Bennée
2021-01-20 16:15   ` Jan Beulich
2021-01-20 20:47     ` Oleksandr
2021-01-12 21:52 ` [PATCH V4 07/24] xen/ioreq: Make x86's hvm_ioreq_(page/vcpu/server) structs common Oleksandr Tyshchenko
2021-01-15 15:36   ` Julien Grall
2021-01-18  8:59   ` Paul Durrant
2021-01-20  8:58   ` Alex Bennée
2021-01-12 21:52 ` [PATCH V4 08/24] xen/ioreq: Move x86's ioreq_server to struct domain Oleksandr Tyshchenko
2021-01-15 15:44   ` Julien Grall
2021-01-18  9:09   ` Paul Durrant
2021-01-20  9:00   ` Alex Bennée
2021-01-12 21:52 ` [PATCH V4 09/24] xen/ioreq: Make x86's IOREQ related dm-op handling common Oleksandr Tyshchenko
2021-01-18  9:17   ` Paul Durrant
2021-01-18 10:19     ` Oleksandr
2021-01-18 10:34       ` Paul Durrant
2021-01-20 16:21   ` Jan Beulich
2021-01-21 10:23     ` Oleksandr
2021-01-21 10:27       ` Jan Beulich
2021-01-21 11:13         ` Oleksandr
2021-01-12 21:52 ` [PATCH V4 10/24] xen/ioreq: Move x86's io_completion/io_req fields to struct vcpu Oleksandr Tyshchenko
2021-01-15 19:34   ` Julien Grall
2021-01-18  9:35   ` Paul Durrant
2021-01-20 16:24   ` Jan Beulich
2021-01-12 21:52 ` [PATCH V4 11/24] xen/mm: Make x86's XENMEM_resource_ioreq_server handling common Oleksandr Tyshchenko
2021-01-14  3:58   ` Wei Chen
2021-01-14 15:31     ` Oleksandr
2021-01-15 14:35       ` Alex Bennée
2021-01-18 17:42         ` Oleksandr
2021-01-18  9:38   ` Paul Durrant
2021-01-12 21:52 ` [PATCH V4 12/24] xen/ioreq: Remove "hvm" prefixes from involved function names Oleksandr Tyshchenko
2021-01-18  9:55   ` Paul Durrant
2021-01-12 21:52 ` [PATCH V4 13/24] xen/ioreq: Use guest_cmpxchg64() instead of cmpxchg() Oleksandr Tyshchenko
2021-01-15 19:37   ` Julien Grall
2021-01-17 11:32     ` Oleksandr
2021-01-18 10:00   ` Paul Durrant
2021-01-12 21:52 ` [PATCH V4 14/24] arm/ioreq: Introduce arch specific bits for IOREQ/DM features Oleksandr Tyshchenko
2021-01-15  0:55   ` Stefano Stabellini
2021-01-17 12:45     ` Oleksandr
2021-01-20  0:23       ` Stefano Stabellini
2021-01-21  9:51         ` Oleksandr
2021-01-15 20:26   ` Julien Grall
2021-01-17 17:11     ` Oleksandr
2021-01-17 18:07       ` Julien Grall
2021-01-17 18:52         ` Oleksandr
2021-01-18 19:17           ` Julien Grall
2021-01-19 15:20             ` Oleksandr
2021-01-20  0:50               ` Stefano Stabellini
2021-01-20 15:57                 ` Julien Grall
2021-01-20 19:47                   ` Stefano Stabellini
2021-01-21  9:31                     ` Oleksandr [this message]
2021-01-21 21:34                       ` Stefano Stabellini
2021-01-20 15:50           ` Julien Grall
2021-01-21  8:50             ` Oleksandr
2021-01-27 10:24               ` Jan Beulich
2021-01-27 12:22                 ` Oleksandr
2021-01-27 12:52                   ` Jan Beulich
2021-01-18 10:44       ` Jan Beulich
2021-01-18 15:52         ` Oleksandr
2021-01-18 16:00           ` Jan Beulich
2021-01-18 16:29             ` Oleksandr
2021-01-12 21:52 ` [PATCH V4 15/24] xen/arm: Stick around in leave_hypervisor_to_guest until I/O has completed Oleksandr Tyshchenko
2021-01-15  1:12   ` Stefano Stabellini
2021-01-15 20:55   ` Julien Grall
2021-01-17 20:23     ` Oleksandr
2021-01-18 10:57       ` Julien Grall
2021-01-18 13:23         ` Oleksandr
2021-01-12 21:52 ` [PATCH V4 16/24] xen/mm: Handle properly reference in set_foreign_p2m_entry() on Arm Oleksandr Tyshchenko
2021-01-15  1:19   ` Stefano Stabellini
2021-01-15 20:59   ` Julien Grall
2021-01-21 13:57   ` Jan Beulich
2021-01-21 18:42     ` Oleksandr
2021-01-12 21:52 ` [PATCH V4 17/24] xen/ioreq: Introduce domain_has_ioreq_server() Oleksandr Tyshchenko
2021-01-15  1:24   ` Stefano Stabellini
2021-01-18 10:23   ` Paul Durrant
2021-01-12 21:52 ` [PATCH V4 18/24] xen/dm: Introduce xendevicemodel_set_irq_level DM op Oleksandr Tyshchenko
2021-01-15  1:32   ` Stefano Stabellini
2021-01-12 21:52 ` [PATCH V4 19/24] xen/arm: io: Abstract sign-extension Oleksandr Tyshchenko
2021-01-15  1:35   ` Stefano Stabellini
2021-01-12 21:52 ` [PATCH V4 20/24] xen/arm: io: Harden sign extension check Oleksandr Tyshchenko
2021-01-15  1:48   ` Stefano Stabellini
2021-01-22 10:15   ` Volodymyr Babchuk
2021-01-12 21:52 ` [PATCH V4 21/24] xen/ioreq: Make x86's send_invalidate_req() common Oleksandr Tyshchenko
2021-01-18 10:31   ` Paul Durrant
2021-01-21 14:02     ` Jan Beulich
2021-01-12 21:52 ` [PATCH V4 22/24] xen/arm: Add mapcache invalidation handling Oleksandr Tyshchenko
2021-01-15  2:11   ` Stefano Stabellini
2021-01-21 19:47     ` Oleksandr
2021-01-12 21:52 ` [PATCH V4 23/24] libxl: Introduce basic virtio-mmio support on Arm Oleksandr Tyshchenko
2021-01-15 21:30   ` Julien Grall
2021-01-17 22:22     ` Oleksandr
2021-01-20 16:40       ` Julien Grall
2021-01-20 20:35         ` Stefano Stabellini
2021-02-09 21:04         ` Oleksandr
2021-01-12 21:52 ` [PATCH V4 24/24] [RFC] libxl: Add support for virtio-disk configuration Oleksandr Tyshchenko
2021-01-14 17:20   ` Ian Jackson
2021-01-16  9:05     ` Oleksandr
2021-01-15 22:01   ` Julien Grall
2021-01-18  8:32     ` Oleksandr
2021-01-20 17:05       ` Julien Grall
2021-02-10  9:02         ` Oleksandr
2021-03-06 19:52           ` Julien Grall
2021-01-14  3:55 ` [PATCH V4 00/24] IOREQ feature (+ virtio-mmio) on Arm Wei Chen
2021-01-14 15:23   ` Oleksandr
2021-01-07 14:35     ` [ANNOUNCE] Xen 4.15 release schedule and feature tracking Ian Jackson
2021-01-07 15:45       ` Oleksandr
2021-01-14 16:11         ` [PATCH V4 00/24] IOREQ feature (+ virtio-mmio) on Arm Ian Jackson
2021-01-14 18:41           ` Oleksandr
2021-01-14 16:06       ` [ANNOUNCE] Xen 4.15 release schedule and feature tracking Ian Jackson
2021-01-14 19:02         ` Andrew Cooper
2021-01-15  9:57           ` Jan Beulich
2021-01-15 10:00             ` Julien Grall
2021-01-15 10:52             ` Andrew Cooper
2021-01-15 10:59               ` Andrew Cooper
2021-01-15 11:08                 ` Jan Beulich
2021-01-15 10:43           ` Bertrand Marquis
2021-01-15 15:14           ` Lengyel, Tamas
2021-01-28 22:55             ` Dario Faggioli
2021-01-28 18:26           ` Dario Faggioli
2021-01-28 22:15             ` Dario Faggioli
2021-01-29  8:38             ` Jan Beulich
2021-01-29  9:22               ` Dario Faggioli

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