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* [PATCH] libxl: Remove qxl support for the 4.3 release
@ 2013-05-24 15:20 George Dunlap
  2013-05-28 16:51 ` Ian Jackson
  2013-05-29 15:01 ` George Dunlap
  0 siblings, 2 replies; 24+ messages in thread
From: George Dunlap @ 2013-05-24 15:20 UTC (permalink / raw)
  To: xen-devel; +Cc: George Dunlap, Ian Jackson, Fabio Fantoni, Ian Campbell

The qxl drivers for Windows and Linux end up calling instructions
that cannot be used for MMIO at the moment.  Just for the 4.3 release,
remove qxl support.

This patch should be reverted as soon as the 4.4 development window opens.

The issue in question:

(XEN) emulate.c:88:d18 bad mmio size 16
(XEN) io.c:201:d18 MMIO emulation failed @ 0033:7fd2de390430: f3 0f 6f
19 41 83 e8 403

The instruction in question is "movdqu (%rcx),%xmm3".  Xen knows how
to emulate it, but unfortunately %xmm3 is 16 bytes long, and the interface
between Xen and qemu at the moment would appear to only allow MMIO accesses
of 8 bytes.

It's too late in the release cycle to find a fix or a workaround.

Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
CC: Ian Jackson <ian.jackson@citrix.com>
CC: Ian Campbell <ian.campbell@citrix.com>
CC: Fabio Fantoni <fabio.fantoni@m2r.biz>
---
 docs/man/xl.cfg.pod.5       |   10 +---------
 tools/libxl/libxl_create.c  |   16 ----------------
 tools/libxl/libxl_dm.c      |   13 -------------
 tools/libxl/libxl_types.idl |    1 -
 tools/libxl/xl_cmdimpl.c    |    2 --
 5 files changed, 1 insertion(+), 41 deletions(-)

diff --git a/docs/man/xl.cfg.pod.5 b/docs/man/xl.cfg.pod.5
index e0c3bb2..a0c7430 100644
--- a/docs/man/xl.cfg.pod.5
+++ b/docs/man/xl.cfg.pod.5
@@ -1005,9 +1005,6 @@ the amount of video ram is fixed at 4MB which is sufficient
 for 1024x768 at 32 bpp and videoram option is currently working
 only when using the upstream qemu-xen device-model.
 
-For B<qxl> vga, the default is both default and minimal 128MB.
-If B<videoram> is set less than 128MB, an error will be triggered.
-
 =item B<stdvga=BOOLEAN>
 
 Select a standard VGA card with VBE (VESA BIOS Extensions) as the
@@ -1019,14 +1016,9 @@ This option is deprecated, use vga="stdvga" instead.
 
 =item B<vga="STRING">
 
-Selects the emulated video card (stdvga|cirrus|qxl).
+Selects the emulated video card (stdvga|cirrus).
 The default is cirrus.
 
-In general, QXL should work with the Spice remote display protocol
-for acceleration, and QXL driver is necessary in guest in this case.
-QXL can also work with the VNC protocol, but it will be like a standard
-VGA without acceleration.
-
 =item B<vnc=BOOLEAN>
 
 Allow access to the display via the VNC protocol.  This enables the
diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
index cb9c822..0c32d0b 100644
--- a/tools/libxl/libxl_create.c
+++ b/tools/libxl/libxl_create.c
@@ -213,22 +213,6 @@ int libxl__domain_build_info_setdefault(libxl__gc *gc,
         if (b_info->shadow_memkb == LIBXL_MEMKB_DEFAULT)
             b_info->shadow_memkb = 0;
 
-        if (b_info->u.hvm.vga.kind == LIBXL_VGA_INTERFACE_TYPE_QXL) {
-            if (b_info->device_model_version ==
-               LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN) {
-                if (b_info->video_memkb == LIBXL_MEMKB_DEFAULT) {
-                    b_info->video_memkb = (128 * 1024);
-                } else if (b_info->video_memkb < (128 * 1024)) {
-                    LOG(ERROR,
-                        "128 Mib videoram is the minimum for qxl default");
-                    return ERROR_INVAL;
-                }
-            } else {
-                LOG(ERROR,"qemu upstream required for qxl vga");
-                return ERROR_INVAL;
-            }
-        }
-
         if (b_info->u.hvm.vga.kind == LIBXL_VGA_INTERFACE_TYPE_STD &&
             b_info->device_model_version ==
             LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN) {
diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c
index d10a58f..4e56ffa 100644
--- a/tools/libxl/libxl_dm.c
+++ b/tools/libxl/libxl_dm.c
@@ -191,8 +191,6 @@ static char ** libxl__build_device_model_args_old(libxl__gc *gc,
             break;
         case LIBXL_VGA_INTERFACE_TYPE_CIRRUS:
             break;
-        case LIBXL_VGA_INTERFACE_TYPE_QXL:
-            break;
         }
 
         if (b_info->u.hvm.boot) {
@@ -479,17 +477,6 @@ static char ** libxl__build_device_model_args_new(libxl__gc *gc,
                     libxl__sizekb_to_mb(b_info->video_memkb)), NULL);
             }
             break;
-        case LIBXL_VGA_INTERFACE_TYPE_QXL:
-            /* QXL have 2 ram regions, ram and vram */
-            flexarray_vappend(dm_args, "-vga", "qxl", NULL);
-            if (b_info->video_memkb) {
-                flexarray_vappend(dm_args, "-global",
-                    GCSPRINTF("qxl-vga.vram_size_mb=%"PRIu64,
-                    (b_info->video_memkb/2/1024)), "-global",
-                    GCSPRINTF("qxl-vga.ram_size_mb=%"PRIu64,
-                    (b_info->video_memkb/2/1024)), NULL);
-            }
-            break;
         }
 
         if (b_info->u.hvm.boot) {
diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
index 8262cba..d218a2d 100644
--- a/tools/libxl/libxl_types.idl
+++ b/tools/libxl/libxl_types.idl
@@ -130,7 +130,6 @@ libxl_shutdown_reason = Enumeration("shutdown_reason", [
 libxl_vga_interface_type = Enumeration("vga_interface_type", [
     (1, "CIRRUS"),
     (2, "STD"),
-    (3, "QXL"),
     ], init_val = 0)
 
 #
diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index e13a64e..148320c 100644
--- a/tools/libxl/xl_cmdimpl.c
+++ b/tools/libxl/xl_cmdimpl.c
@@ -1456,8 +1456,6 @@ skip_vfb:
                 b_info->u.hvm.vga.kind = LIBXL_VGA_INTERFACE_TYPE_STD;
             } else if (!strcmp(buf, "cirrus")) {
                 b_info->u.hvm.vga.kind = LIBXL_VGA_INTERFACE_TYPE_CIRRUS;
-            } else if (!strcmp(buf, "qxl")) {
-                b_info->u.hvm.vga.kind = LIBXL_VGA_INTERFACE_TYPE_QXL;
             } else {
                 fprintf(stderr, "Unknown vga \"%s\" specified\n", buf);
                 exit(1);
-- 
1.7.9.5

^ permalink raw reply related	[flat|nested] 24+ messages in thread
* Re: [PATCH] libxl: Remove qxl support for the 4.3 release
@ 2013-09-18  8:07 Jan Beulich
  2013-09-18 12:29 ` Fabio Fantoni
  2013-09-19 10:09 ` George Dunlap
  0 siblings, 2 replies; 24+ messages in thread
From: Jan Beulich @ 2013-09-18  8:07 UTC (permalink / raw)
  To: Fabio Fantoni; +Cc: George Dunlap, Andrew Cooper, Keir Fraser, xen-devel

[-- Attachment #1: Type: text/plain, Size: 2264 bytes --]

>>> On 16.09.13 at 16:10, Fabio Fantoni <fabio.fantoni@m2r.biz> wrote:
> Il 05/07/2013 18:59, George Dunlap ha scritto:
>> On Wed, May 29, 2013 at 11:25 PM, Andrew Cooper
>> <andrew.cooper3@citrix.com> wrote:
>>> On 29/05/2013 08:43, Ian Campbell wrote:
>>>> On Tue, 2013-05-28 at 19:09 +0100, Keir Fraser wrote:
>>>>> On 28/05/2013 17:51, "Ian Jackson" <Ian.Jackson@eu.citrix.com> wrote:
>>>>>
>>>>>> George Dunlap writes ("[PATCH] libxl: Remove qxl support for the 4.3
>>>>>> release"):
>>>>>>> The qxl drivers for Windows and Linux end up calling instructions
>>>>>>> that cannot be used for MMIO at the moment.  Just for the 4.3 release,
>>>>>>> remove qxl support.
>>>>>>>
>>>>>>> This patch should be reverted as soon as the 4.4 development window opens.
>>>>>>>
>>>>>>> The issue in question:
>>>>>>>
>>>>>>> (XEN) emulate.c:88:d18 bad mmio size 16
>>>>>>> (XEN) io.c:201:d18 MMIO emulation failed @ 0033:7fd2de390430: f3 0f 6f
>>>>>>> 19 41 83 e8 403
>>>>>>>
>>>>>>> The instruction in question is "movdqu (%rcx),%xmm3".  Xen knows how
>>>>>>> to emulate it, but unfortunately %xmm3 is 16 bytes long, and the interface
>>>>>>> between Xen and qemu at the moment would appear to only allow MMIO accesses
>>>>>>> of 8 bytes.
>>>>>>>
>>>>>>> It's too late in the release cycle to find a fix or a workaround.
>>>>>> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
>>>>> It could be plumbed through hvmemul_do_io's multi-cycle read/write logic,
>>>>> and done as two 8-byte cycles to qemu. This would avoid bloating the ioreq
>>>>> structure that communicates to qemu.
>>>> Are you proposing we do this for 4.3? I'm not sure how big that change
>>>> would be in terms of impact (just that one instruction, any 16 byte
>>>> operand?).
>>>>
>>>> Of course even if we did this for 4.3 we don't know what the next issue
>>>> will be with QXL.
>>>>
>>>> Ian.
>>> Furthermore, AVX instruction emulation would require support for 32byte
>>> operands.  I don't see the multi-cycle logic scaling sensibly.
>> Andrew, Keir, Jan, does any one of you fancy taking this on for 4.4?
> 
> Is there someone that can add full support for SSE on hvm domUs?
> Thanks for any reply.

Mind giving the attached patch a try?

Jan


[-- Attachment #2: x86-HVM-emul-split-large.patch --]
[-- Type: text/plain, Size: 6729 bytes --]

--- a/xen/arch/x86/hvm/emulate.c
+++ b/xen/arch/x86/hvm/emulate.c
@@ -438,6 +438,7 @@ static int __hvmemul_read(
 {
     struct vcpu *curr = current;
     unsigned long addr, reps = 1;
+    unsigned int off, chunk = min_t(unsigned int, bytes, sizeof(long));
     uint32_t pfec = PFEC_page_present;
     struct hvm_vcpu_io *vio = &curr->arch.hvm_vcpu.hvm_io;
     paddr_t gpa;
@@ -447,16 +448,38 @@ static int __hvmemul_read(
         seg, offset, bytes, &reps, access_type, hvmemul_ctxt, &addr);
     if ( rc != X86EMUL_OKAY )
         return rc;
+    off = addr & (PAGE_SIZE - 1);
+    /*
+     * We only need to handle sizes actual instruction operands can have. All
+     * such sizes are either powers of 2 or the sum of two powers of 2. Thus
+     * picking as initial chunk size the largest power of 2 not greater than
+     * the total size will always result in only power-of-2 size requests
+     * issued to hvmemul_do_mmio() (hvmemul_do_io() rejects non-powers-of-2).
+     */
+    while ( chunk & (chunk - 1) )
+        chunk &= chunk - 1;
+    if ( off + bytes > PAGE_SIZE )
+        while ( off & (chunk - 1) )
+            chunk >>= 1;
 
     if ( unlikely(vio->mmio_gva == (addr & PAGE_MASK)) && vio->mmio_gva )
     {
-        unsigned int off = addr & (PAGE_SIZE - 1);
         if ( access_type == hvm_access_insn_fetch )
             return X86EMUL_UNHANDLEABLE;
         gpa = (((paddr_t)vio->mmio_gpfn << PAGE_SHIFT) | off);
-        if ( (off + bytes) <= PAGE_SIZE )
-            return hvmemul_do_mmio(gpa, &reps, bytes, 0,
-                                   IOREQ_READ, 0, p_data);
+        while ( (off + chunk) <= PAGE_SIZE )
+        {
+            rc = hvmemul_do_mmio(gpa, &reps, chunk, 0, IOREQ_READ, 0, p_data);
+            if ( rc != X86EMUL_OKAY || bytes == chunk )
+                return rc;
+            addr += chunk;
+            off += chunk;
+            gpa += chunk;
+            p_data += chunk;
+            bytes -= chunk;
+            if ( bytes < chunk )
+                chunk = bytes;
+        }
     }
 
     if ( (seg != x86_seg_none) &&
@@ -473,14 +496,32 @@ static int __hvmemul_read(
         return X86EMUL_EXCEPTION;
     case HVMCOPY_unhandleable:
         return X86EMUL_UNHANDLEABLE;
-    case  HVMCOPY_bad_gfn_to_mfn:
+    case HVMCOPY_bad_gfn_to_mfn:
         if ( access_type == hvm_access_insn_fetch )
             return X86EMUL_UNHANDLEABLE;
-        rc = hvmemul_linear_to_phys(
-            addr, &gpa, bytes, &reps, pfec, hvmemul_ctxt);
-        if ( rc != X86EMUL_OKAY )
-            return rc;
-        return hvmemul_do_mmio(gpa, &reps, bytes, 0, IOREQ_READ, 0, p_data);
+        rc = hvmemul_linear_to_phys(addr, &gpa, chunk, &reps, pfec,
+                                    hvmemul_ctxt);
+        while ( rc == X86EMUL_OKAY )
+        {
+            rc = hvmemul_do_mmio(gpa, &reps, chunk, 0, IOREQ_READ, 0, p_data);
+            if ( rc != X86EMUL_OKAY || bytes == chunk )
+                break;
+            addr += chunk;
+            off += chunk;
+            p_data += chunk;
+            bytes -= chunk;
+            if ( bytes < chunk )
+                chunk = bytes;
+            if ( off < PAGE_SIZE )
+                gpa += chunk;
+            else
+            {
+                rc = hvmemul_linear_to_phys(addr, &gpa, chunk, &reps, pfec,
+                                            hvmemul_ctxt);
+                off = 0;
+            }
+        }
+        return rc;
     case HVMCOPY_gfn_paged_out:
         return X86EMUL_RETRY;
     case HVMCOPY_gfn_shared:
@@ -537,6 +578,7 @@ static int hvmemul_write(
         container_of(ctxt, struct hvm_emulate_ctxt, ctxt);
     struct vcpu *curr = current;
     unsigned long addr, reps = 1;
+    unsigned int off, chunk = min_t(unsigned int, bytes, sizeof(long));
     uint32_t pfec = PFEC_page_present | PFEC_write_access;
     struct hvm_vcpu_io *vio = &curr->arch.hvm_vcpu.hvm_io;
     paddr_t gpa;
@@ -546,14 +588,30 @@ static int hvmemul_write(
         seg, offset, bytes, &reps, hvm_access_write, hvmemul_ctxt, &addr);
     if ( rc != X86EMUL_OKAY )
         return rc;
+    off = addr & (PAGE_SIZE - 1);
+    /* See the respective comment in __hvmemul_read(). */
+    while ( chunk & (chunk - 1) )
+        chunk &= chunk - 1;
+    if ( off + bytes > PAGE_SIZE )
+        while ( off & (chunk - 1) )
+            chunk >>= 1;
 
     if ( unlikely(vio->mmio_gva == (addr & PAGE_MASK)) && vio->mmio_gva )
     {
-        unsigned int off = addr & (PAGE_SIZE - 1);
         gpa = (((paddr_t)vio->mmio_gpfn << PAGE_SHIFT) | off);
-        if ( (off + bytes) <= PAGE_SIZE )
-            return hvmemul_do_mmio(gpa, &reps, bytes, 0,
-                                   IOREQ_WRITE, 0, p_data);
+        while ( (off + chunk) <= PAGE_SIZE )
+        {
+            rc = hvmemul_do_mmio(gpa, &reps, chunk, 0, IOREQ_WRITE, 0, p_data);
+            if ( rc != X86EMUL_OKAY || bytes == chunk )
+                return rc;
+            addr += chunk;
+            off += chunk;
+            gpa += chunk;
+            p_data += chunk;
+            bytes -= chunk;
+            if ( bytes < chunk )
+                chunk = bytes;
+        }
     }
 
     if ( (seg != x86_seg_none) &&
@@ -569,12 +627,29 @@ static int hvmemul_write(
     case HVMCOPY_unhandleable:
         return X86EMUL_UNHANDLEABLE;
     case HVMCOPY_bad_gfn_to_mfn:
-        rc = hvmemul_linear_to_phys(
-            addr, &gpa, bytes, &reps, pfec, hvmemul_ctxt);
-        if ( rc != X86EMUL_OKAY )
-            return rc;
-        return hvmemul_do_mmio(gpa, &reps, bytes, 0,
-                               IOREQ_WRITE, 0, p_data);
+        rc = hvmemul_linear_to_phys(addr, &gpa, chunk, &reps, pfec,
+                                    hvmemul_ctxt);
+        while ( rc == X86EMUL_OKAY )
+        {
+            rc = hvmemul_do_mmio(gpa, &reps, chunk, 0, IOREQ_WRITE, 0, p_data);
+            if ( rc != X86EMUL_OKAY || bytes == chunk )
+                break;
+            addr += chunk;
+            off += chunk;
+            p_data += chunk;
+            bytes -= chunk;
+            if ( bytes < chunk )
+                chunk = bytes;
+            if ( off < PAGE_SIZE )
+                gpa += chunk;
+            else
+            {
+                rc = hvmemul_linear_to_phys(addr, &gpa, chunk, &reps, pfec,
+                                            hvmemul_ctxt);
+                off = 0;
+            }
+        }
+        return rc;
     case HVMCOPY_gfn_paged_out:
         return X86EMUL_RETRY;
     case HVMCOPY_gfn_shared:

[-- Attachment #3: Type: text/plain, Size: 126 bytes --]

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^ permalink raw reply	[flat|nested] 24+ messages in thread
end of thread, other threads:[~2013-09-19 11:08 UTC | newest]

Thread overview: 24+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-05-24 15:20 [PATCH] libxl: Remove qxl support for the 4.3 release George Dunlap
2013-05-28 16:51 ` Ian Jackson
2013-05-28 18:09   ` Keir Fraser
2013-05-29  7:43     ` Ian Campbell
2013-05-29 22:25       ` Andrew Cooper
2013-07-05 16:59         ` George Dunlap
2013-09-16 14:10           ` Fabio Fantoni
2013-09-16 14:28             ` Jan Beulich
2013-09-16 14:49               ` Fabio Fantoni
2013-05-29 10:24     ` George Dunlap
2013-05-30  8:57   ` Ian Campbell
2013-05-29 15:01 ` George Dunlap
  -- strict thread matches above, loose matches on Subject: below --
2013-09-18  8:07 Jan Beulich
2013-09-18 12:29 ` Fabio Fantoni
2013-09-18 12:42   ` Jan Beulich
2013-09-18 14:12     ` Fabio Fantoni
2013-09-18 14:30       ` Jan Beulich
2013-09-18 15:26         ` Fabio Fantoni
     [not found]         ` <5239C616.8000507@m2r.biz>
2013-09-18 15:35           ` Jan Beulich
     [not found]           ` <5239E46802000078000F4764@nat28.tlf.novell.com>
2013-09-19  9:22             ` Fabio Fantoni
     [not found]             ` <523AC243.1050406@m2r.biz>
2013-09-19 10:01               ` Jan Beulich
     [not found]               ` <523AE7AB02000078000F4A15@nat28.tlf.novell.com>
2013-09-19 10:04                 ` George Dunlap
     [not found]                 ` <523ACC26.6030307@eu.citrix.com>
2013-09-19 11:08                   ` Fabio Fantoni
2013-09-19 10:09 ` George Dunlap

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