restructure results

2 files changed, 0 insertions, 1885 deletions

diff --git a/results/classifier/012/TCG/13442371 b/results/classifier/012/TCG/13442371
deleted file mode 100644
index 9b38694e..00000000
--- a/results/classifier/012/TCG/13442371
+++ /dev/null
@@ -1,387 +0,0 @@
-TCG: 0.901
-other: 0.886
-device: 0.883
-assembly: 0.877
-register: 0.871
-arm: 0.867
-debug: 0.866
-mistranslation: 0.859
-vnc: 0.858
-permissions: 0.854
-graphic: 0.850
-kernel virtual machine: 0.850
-semantic: 0.850
-PID: 0.849
-architecture: 0.846
-risc-v: 0.846
-performance: 0.841
-files: 0.837
-x86: 0.836
-socket: 0.831
-boot: 0.815
-network: 0.811
-
-[Qemu-devel] [BUG] nanoMIPS support problem related to extract2 support for i386 TCG target
-
-Hello, Richard, Peter, and others.
-
-As a part of activities before 4.1 release, I tested nanoMIPS support
-in QEMU (which was officially fully integrated in 4.0, is currently
-limited to system mode only, and was tested in a similar fashion right
-prior to 4.0).
-
-This support appears to be broken now. Following command line works in
-4.0, but results in kernel panic for the current tip of the tree:
-
-~/Build/qemu-test-revert-c6fb8c0cf704/mipsel-softmmu/qemu-system-mipsel
--cpu I7200 -kernel generic_nano32r6el_page4k -M malta -serial stdio -m
-1G -hda nanomips32r6_le_sf_2017.05-03-59-gf5595d6.ext4 -append
-"mem=256m@0x0 rw console=ttyS0 vga=cirrus vesa=0x111 root=/dev/sda"
-
-(kernel and rootfs image files used in this commend line can be
-downloaded from the locations mentioned in our user guide)
-
-The quick bisect points to the commit:
-
-commit c6fb8c0cf704c4a1a48c3e99e995ad4c58150dab
-Author: Richard Henderson <address@hidden>
-Date:   Mon Feb 25 11:42:35 2019 -0800
-
-    tcg/i386: Support INDEX_op_extract2_{i32,i64}
-
-    Signed-off-by: Richard Henderson <address@hidden>
-
-Please advise on further actions.
-
-Yours,
-Aleksandar
-
-On Fri, Jul 12, 2019 at 8:09 PM Aleksandar Markovic
-<address@hidden> wrote:
->
->
-Hello, Richard, Peter, and others.
->
->
-As a part of activities before 4.1 release, I tested nanoMIPS support
->
-in QEMU (which was officially fully integrated in 4.0, is currently
->
-limited to system mode only, and was tested in a similar fashion right
->
-prior to 4.0).
->
->
-This support appears to be broken now. Following command line works in
->
-4.0, but results in kernel panic for the current tip of the tree:
->
->
-~/Build/qemu-test-revert-c6fb8c0cf704/mipsel-softmmu/qemu-system-mipsel
->
--cpu I7200 -kernel generic_nano32r6el_page4k -M malta -serial stdio -m
->
-1G -hda nanomips32r6_le_sf_2017.05-03-59-gf5595d6.ext4 -append
->
-"mem=256m@0x0 rw console=ttyS0 vga=cirrus vesa=0x111 root=/dev/sda"
->
->
-(kernel and rootfs image files used in this commend line can be
->
-downloaded from the locations mentioned in our user guide)
->
->
-The quick bisect points to the commit:
->
->
-commit c6fb8c0cf704c4a1a48c3e99e995ad4c58150dab
->
-Author: Richard Henderson <address@hidden>
->
-Date:   Mon Feb 25 11:42:35 2019 -0800
->
->
-tcg/i386: Support INDEX_op_extract2_{i32,i64}
->
->
-Signed-off-by: Richard Henderson <address@hidden>
->
->
-Please advise on further actions.
->
-Just to add a data point:
-
-If the following change is applied:
-
-diff --git a/tcg/i386/tcg-target.h b/tcg/i386/tcg-target.h
-index 928e8b8..b6a4cf2 100644
---- a/tcg/i386/tcg-target.h
-+++ b/tcg/i386/tcg-target.h
-@@ -124,7 +124,7 @@ extern bool have_avx2;
- #define TCG_TARGET_HAS_deposit_i32      1
- #define TCG_TARGET_HAS_extract_i32      1
- #define TCG_TARGET_HAS_sextract_i32     1
--#define TCG_TARGET_HAS_extract2_i32     1
-+#define TCG_TARGET_HAS_extract2_i32     0
- #define TCG_TARGET_HAS_movcond_i32      1
- #define TCG_TARGET_HAS_add2_i32         1
- #define TCG_TARGET_HAS_sub2_i32         1
-@@ -163,7 +163,7 @@ extern bool have_avx2;
- #define TCG_TARGET_HAS_deposit_i64      1
- #define TCG_TARGET_HAS_extract_i64      1
- #define TCG_TARGET_HAS_sextract_i64     0
--#define TCG_TARGET_HAS_extract2_i64     1
-+#define TCG_TARGET_HAS_extract2_i64     0
- #define TCG_TARGET_HAS_movcond_i64      1
- #define TCG_TARGET_HAS_add2_i64         1
- #define TCG_TARGET_HAS_sub2_i64         1
-
-... the problem disappears.
-
-
->
-Yours,
->
-Aleksandar
-
-On Fri, Jul 12, 2019 at 8:19 PM Aleksandar Markovic
-<address@hidden> wrote:
->
->
-On Fri, Jul 12, 2019 at 8:09 PM Aleksandar Markovic
->
-<address@hidden> wrote:
->
->
->
-> Hello, Richard, Peter, and others.
->
->
->
-> As a part of activities before 4.1 release, I tested nanoMIPS support
->
-> in QEMU (which was officially fully integrated in 4.0, is currently
->
-> limited to system mode only, and was tested in a similar fashion right
->
-> prior to 4.0).
->
->
->
-> This support appears to be broken now. Following command line works in
->
-> 4.0, but results in kernel panic for the current tip of the tree:
->
->
->
-> ~/Build/qemu-test-revert-c6fb8c0cf704/mipsel-softmmu/qemu-system-mipsel
->
-> -cpu I7200 -kernel generic_nano32r6el_page4k -M malta -serial stdio -m
->
-> 1G -hda nanomips32r6_le_sf_2017.05-03-59-gf5595d6.ext4 -append
->
-> "mem=256m@0x0 rw console=ttyS0 vga=cirrus vesa=0x111 root=/dev/sda"
->
->
->
-> (kernel and rootfs image files used in this commend line can be
->
-> downloaded from the locations mentioned in our user guide)
->
->
->
-> The quick bisect points to the commit:
->
->
->
-> commit c6fb8c0cf704c4a1a48c3e99e995ad4c58150dab
->
-> Author: Richard Henderson <address@hidden>
->
-> Date:   Mon Feb 25 11:42:35 2019 -0800
->
->
->
->     tcg/i386: Support INDEX_op_extract2_{i32,i64}
->
->
->
->     Signed-off-by: Richard Henderson <address@hidden>
->
->
->
-> Please advise on further actions.
->
->
->
->
-Just to add a data point:
->
->
-If the following change is applied:
->
->
-diff --git a/tcg/i386/tcg-target.h b/tcg/i386/tcg-target.h
->
-index 928e8b8..b6a4cf2 100644
->
---- a/tcg/i386/tcg-target.h
->
-+++ b/tcg/i386/tcg-target.h
->
-@@ -124,7 +124,7 @@ extern bool have_avx2;
->
-#define TCG_TARGET_HAS_deposit_i32      1
->
-#define TCG_TARGET_HAS_extract_i32      1
->
-#define TCG_TARGET_HAS_sextract_i32     1
->
--#define TCG_TARGET_HAS_extract2_i32     1
->
-+#define TCG_TARGET_HAS_extract2_i32     0
->
-#define TCG_TARGET_HAS_movcond_i32      1
->
-#define TCG_TARGET_HAS_add2_i32         1
->
-#define TCG_TARGET_HAS_sub2_i32         1
->
-@@ -163,7 +163,7 @@ extern bool have_avx2;
->
-#define TCG_TARGET_HAS_deposit_i64      1
->
-#define TCG_TARGET_HAS_extract_i64      1
->
-#define TCG_TARGET_HAS_sextract_i64     0
->
--#define TCG_TARGET_HAS_extract2_i64     1
->
-+#define TCG_TARGET_HAS_extract2_i64     0
->
-#define TCG_TARGET_HAS_movcond_i64      1
->
-#define TCG_TARGET_HAS_add2_i64         1
->
-#define TCG_TARGET_HAS_sub2_i64         1
->
->
-... the problem disappears.
->
-It looks the problem is in this code segment in of tcg_gen_deposit_i32():
-
-        if (ofs == 0) {
-            tcg_gen_extract2_i32(ret, arg1, arg2, len);
-            tcg_gen_rotli_i32(ret, ret, len);
-            goto done;
-        }
-
-)
-
-If that code segment is deleted altogether (which effectively forces
-usage of "fallback" part of tcg_gen_deposit_i32()), the problem also
-vanishes (without changes from my previous mail).
-
->
->
-> Yours,
->
-> Aleksandar
-
-Aleksandar Markovic <address@hidden> writes:
-
->
-Hello, Richard, Peter, and others.
->
->
-As a part of activities before 4.1 release, I tested nanoMIPS support
->
-in QEMU (which was officially fully integrated in 4.0, is currently
->
-limited to system mode only, and was tested in a similar fashion right
->
-prior to 4.0).
->
->
-This support appears to be broken now. Following command line works in
->
-4.0, but results in kernel panic for the current tip of the tree:
->
->
-~/Build/qemu-test-revert-c6fb8c0cf704/mipsel-softmmu/qemu-system-mipsel
->
--cpu I7200 -kernel generic_nano32r6el_page4k -M malta -serial stdio -m
->
-1G -hda nanomips32r6_le_sf_2017.05-03-59-gf5595d6.ext4 -append
->
-"mem=256m@0x0 rw console=ttyS0 vga=cirrus vesa=0x111 root=/dev/sda"
->
->
-(kernel and rootfs image files used in this commend line can be
->
-downloaded from the locations mentioned in our user guide)
->
->
-The quick bisect points to the commit:
->
->
-commit c6fb8c0cf704c4a1a48c3e99e995ad4c58150dab
->
-Author: Richard Henderson <address@hidden>
->
-Date:   Mon Feb 25 11:42:35 2019 -0800
->
->
-tcg/i386: Support INDEX_op_extract2_{i32,i64}
->
->
-Signed-off-by: Richard Henderson <address@hidden>
->
->
-Please advise on further actions.
-Please see the fix:
-
-  Subject: [PATCH for-4.1] tcg: Fix constant folding of INDEX_op_extract2_i32
-  Date: Tue,  9 Jul 2019 14:19:00 +0200
-  Message-Id: <address@hidden>
-
->
->
-Yours,
->
-Aleksandar
---
-Alex Bennée
-
-On Sat, Jul 13, 2019 at 9:21 AM Alex Bennée <address@hidden> wrote:
->
->
-Please see the fix:
->
->
-Subject: [PATCH for-4.1] tcg: Fix constant folding of INDEX_op_extract2_i32
->
-Date: Tue,  9 Jul 2019 14:19:00 +0200
->
-Message-Id: <address@hidden>
->
-Thanks, this fixed the behavior.
-
-Sincerely,
-Aleksandar
-
->
->
->
->
-> Yours,
->
-> Aleksandar
->
->
->
---
->
-Alex Bennée
->
-
diff --git a/results/classifier/012/TCG/80604314 b/results/classifier/012/TCG/80604314
deleted file mode 100644
index df83f21d..00000000
--- a/results/classifier/012/TCG/80604314
+++ /dev/null
@@ -1,1498 +0,0 @@
-TCG: 0.923
-mistranslation: 0.922
-performance: 0.919
-device: 0.917
-debug: 0.901
-graphic: 0.901
-other: 0.898
-PID: 0.896
-permissions: 0.892
-semantic: 0.890
-architecture: 0.888
-assembly: 0.886
-socket: 0.884
-register: 0.881
-vnc: 0.881
-risc-v: 0.880
-arm: 0.869
-network: 0.865
-files: 0.861
-boot: 0.860
-x86: 0.828
-kernel virtual machine: 0.824
-
-[BUG] vhost-vdpa: qemu-system-s390x crashes with second virtio-net-ccw device
-
-When I start qemu with a second virtio-net-ccw device (i.e. adding
--device virtio-net-ccw in addition to the autogenerated device), I get
-a segfault. gdb points to
-
-#0  0x000055d6ab52681d in virtio_net_get_config (vdev=<optimized out>, 
-    config=0x55d6ad9e3f80 "RT") at /home/cohuck/git/qemu/hw/net/virtio-net.c:146
-146         if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
-
-(backtrace doesn't go further)
-
-Starting qemu with no additional "-device virtio-net-ccw" (i.e., only
-the autogenerated virtio-net-ccw device is present) works. Specifying
-several "-device virtio-net-pci" works as well.
-
-Things break with 1e0a84ea49b6 ("vhost-vdpa: introduce vhost-vdpa net
-client"), 38140cc4d971 ("vhost_net: introduce set_config & get_config")
-works (in-between state does not compile).
-
-This is reproducible with tcg as well. Same problem both with
---enable-vhost-vdpa and --disable-vhost-vdpa.
-
-Have not yet tried to figure out what might be special with
-virtio-ccw... anyone have an idea?
-
-[This should probably be considered a blocker?]
-
-On Fri, Jul 24, 2020 at 03:27:18PM +0200, Cornelia Huck wrote:
->
-When I start qemu with a second virtio-net-ccw device (i.e. adding
->
--device virtio-net-ccw in addition to the autogenerated device), I get
->
-a segfault. gdb points to
->
->
-#0  0x000055d6ab52681d in virtio_net_get_config (vdev=<optimized out>,
->
-config=0x55d6ad9e3f80 "RT") at
->
-/home/cohuck/git/qemu/hw/net/virtio-net.c:146
->
-146       if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
->
->
-(backtrace doesn't go further)
->
->
-Starting qemu with no additional "-device virtio-net-ccw" (i.e., only
->
-the autogenerated virtio-net-ccw device is present) works. Specifying
->
-several "-device virtio-net-pci" works as well.
->
->
-Things break with 1e0a84ea49b6 ("vhost-vdpa: introduce vhost-vdpa net
->
-client"), 38140cc4d971 ("vhost_net: introduce set_config & get_config")
->
-works (in-between state does not compile).
-Ouch. I didn't test all in-between states :(
-But I wish we had a 0-day instrastructure like kernel has,
-that catches things like that.
-
->
-This is reproducible with tcg as well. Same problem both with
->
---enable-vhost-vdpa and --disable-vhost-vdpa.
->
->
-Have not yet tried to figure out what might be special with
->
-virtio-ccw... anyone have an idea?
->
->
-[This should probably be considered a blocker?]
-
-On Fri, 24 Jul 2020 09:30:58 -0400
-"Michael S. Tsirkin" <mst@redhat.com> wrote:
-
->
-On Fri, Jul 24, 2020 at 03:27:18PM +0200, Cornelia Huck wrote:
->
-> When I start qemu with a second virtio-net-ccw device (i.e. adding
->
-> -device virtio-net-ccw in addition to the autogenerated device), I get
->
-> a segfault. gdb points to
->
->
->
-> #0  0x000055d6ab52681d in virtio_net_get_config (vdev=<optimized out>,
->
->     config=0x55d6ad9e3f80 "RT") at
->
-> /home/cohuck/git/qemu/hw/net/virtio-net.c:146
->
-> 146     if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
->
->
->
-> (backtrace doesn't go further)
-The core was incomplete, but running under gdb directly shows that it
-is just a bog-standard config space access (first for that device).
-
-The cause of the crash is that nc->peer is not set... no idea how that
-can happen, not that familiar with that part of QEMU. (Should the code
-check, or is that really something that should not happen?)
-
-What I don't understand is why it is set correctly for the first,
-autogenerated virtio-net-ccw device, but not for the second one, and
-why virtio-net-pci doesn't show these problems. The only difference
-between -ccw and -pci that comes to my mind here is that config space
-accesses for ccw are done via an asynchronous operation, so timing
-might be different.
-
->
->
->
-> Starting qemu with no additional "-device virtio-net-ccw" (i.e., only
->
-> the autogenerated virtio-net-ccw device is present) works. Specifying
->
-> several "-device virtio-net-pci" works as well.
->
->
->
-> Things break with 1e0a84ea49b6 ("vhost-vdpa: introduce vhost-vdpa net
->
-> client"), 38140cc4d971 ("vhost_net: introduce set_config & get_config")
->
-> works (in-between state does not compile).
->
->
-Ouch. I didn't test all in-between states :(
->
-But I wish we had a 0-day instrastructure like kernel has,
->
-that catches things like that.
-Yep, that would be useful... so patchew only builds the complete series?
-
->
->
-> This is reproducible with tcg as well. Same problem both with
->
-> --enable-vhost-vdpa and --disable-vhost-vdpa.
->
->
->
-> Have not yet tried to figure out what might be special with
->
-> virtio-ccw... anyone have an idea?
->
->
->
-> [This should probably be considered a blocker?]
-I think so, as it makes s390x unusable with more that one
-virtio-net-ccw device, and I don't even see a workaround.
-
-On Fri, Jul 24, 2020 at 04:56:27PM +0200, Cornelia Huck wrote:
->
-On Fri, 24 Jul 2020 09:30:58 -0400
->
-"Michael S. Tsirkin" <mst@redhat.com> wrote:
->
->
-> On Fri, Jul 24, 2020 at 03:27:18PM +0200, Cornelia Huck wrote:
->
-> > When I start qemu with a second virtio-net-ccw device (i.e. adding
->
-> > -device virtio-net-ccw in addition to the autogenerated device), I get
->
-> > a segfault. gdb points to
->
-> >
->
-> > #0  0x000055d6ab52681d in virtio_net_get_config (vdev=<optimized out>,
->
-> >     config=0x55d6ad9e3f80 "RT") at
->
-> > /home/cohuck/git/qemu/hw/net/virtio-net.c:146
->
-> > 146           if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
->
-> >
->
-> > (backtrace doesn't go further)
->
->
-The core was incomplete, but running under gdb directly shows that it
->
-is just a bog-standard config space access (first for that device).
->
->
-The cause of the crash is that nc->peer is not set... no idea how that
->
-can happen, not that familiar with that part of QEMU. (Should the code
->
-check, or is that really something that should not happen?)
->
->
-What I don't understand is why it is set correctly for the first,
->
-autogenerated virtio-net-ccw device, but not for the second one, and
->
-why virtio-net-pci doesn't show these problems. The only difference
->
-between -ccw and -pci that comes to my mind here is that config space
->
-accesses for ccw are done via an asynchronous operation, so timing
->
-might be different.
-Hopefully Jason has an idea. Could you post a full command line
-please? Do you need a working guest to trigger this? Does this trigger
-on an x86 host?
-
->
-> >
->
-> > Starting qemu with no additional "-device virtio-net-ccw" (i.e., only
->
-> > the autogenerated virtio-net-ccw device is present) works. Specifying
->
-> > several "-device virtio-net-pci" works as well.
->
-> >
->
-> > Things break with 1e0a84ea49b6 ("vhost-vdpa: introduce vhost-vdpa net
->
-> > client"), 38140cc4d971 ("vhost_net: introduce set_config & get_config")
->
-> > works (in-between state does not compile).
->
->
->
-> Ouch. I didn't test all in-between states :(
->
-> But I wish we had a 0-day instrastructure like kernel has,
->
-> that catches things like that.
->
->
-Yep, that would be useful... so patchew only builds the complete series?
->
->
->
->
-> > This is reproducible with tcg as well. Same problem both with
->
-> > --enable-vhost-vdpa and --disable-vhost-vdpa.
->
-> >
->
-> > Have not yet tried to figure out what might be special with
->
-> > virtio-ccw... anyone have an idea?
->
-> >
->
-> > [This should probably be considered a blocker?]
->
->
-I think so, as it makes s390x unusable with more that one
->
-virtio-net-ccw device, and I don't even see a workaround.
-
-On Fri, 24 Jul 2020 11:17:57 -0400
-"Michael S. Tsirkin" <mst@redhat.com> wrote:
-
->
-On Fri, Jul 24, 2020 at 04:56:27PM +0200, Cornelia Huck wrote:
->
-> On Fri, 24 Jul 2020 09:30:58 -0400
->
-> "Michael S. Tsirkin" <mst@redhat.com> wrote:
->
->
->
-> > On Fri, Jul 24, 2020 at 03:27:18PM +0200, Cornelia Huck wrote:
->
-> > > When I start qemu with a second virtio-net-ccw device (i.e. adding
->
-> > > -device virtio-net-ccw in addition to the autogenerated device), I get
->
-> > > a segfault. gdb points to
->
-> > >
->
-> > > #0  0x000055d6ab52681d in virtio_net_get_config (vdev=<optimized out>,
->
-> > >     config=0x55d6ad9e3f80 "RT") at
->
-> > > /home/cohuck/git/qemu/hw/net/virtio-net.c:146
->
-> > > 146         if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
->
-> > >
->
-> > > (backtrace doesn't go further)
->
->
->
-> The core was incomplete, but running under gdb directly shows that it
->
-> is just a bog-standard config space access (first for that device).
->
->
->
-> The cause of the crash is that nc->peer is not set... no idea how that
->
-> can happen, not that familiar with that part of QEMU. (Should the code
->
-> check, or is that really something that should not happen?)
->
->
->
-> What I don't understand is why it is set correctly for the first,
->
-> autogenerated virtio-net-ccw device, but not for the second one, and
->
-> why virtio-net-pci doesn't show these problems. The only difference
->
-> between -ccw and -pci that comes to my mind here is that config space
->
-> accesses for ccw are done via an asynchronous operation, so timing
->
-> might be different.
->
->
-Hopefully Jason has an idea. Could you post a full command line
->
-please? Do you need a working guest to trigger this? Does this trigger
->
-on an x86 host?
-Yes, it does trigger with tcg-on-x86 as well. I've been using
-
-s390x-softmmu/qemu-system-s390x -M s390-ccw-virtio,accel=tcg -cpu qemu,zpci=on 
--m 1024 -nographic -device virtio-scsi-ccw,id=scsi0,devno=fe.0.0001 
--drive file=/path/to/image,format=qcow2,if=none,id=drive-scsi0-0-0-0 
--device 
-scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0,bootindex=1
- 
--device virtio-net-ccw
-
-It seems it needs the guest actually doing something with the nics; I
-cannot reproduce the crash if I use the old advent calendar moon buggy
-image and just add a virtio-net-ccw device.
-
-(I don't think it's a problem with my local build, as I see the problem
-both on my laptop and on an LPAR.)
-
->
->
-> > >
->
-> > > Starting qemu with no additional "-device virtio-net-ccw" (i.e., only
->
-> > > the autogenerated virtio-net-ccw device is present) works. Specifying
->
-> > > several "-device virtio-net-pci" works as well.
->
-> > >
->
-> > > Things break with 1e0a84ea49b6 ("vhost-vdpa: introduce vhost-vdpa net
->
-> > > client"), 38140cc4d971 ("vhost_net: introduce set_config & get_config")
->
-> > > works (in-between state does not compile).
->
-> >
->
-> > Ouch. I didn't test all in-between states :(
->
-> > But I wish we had a 0-day instrastructure like kernel has,
->
-> > that catches things like that.
->
->
->
-> Yep, that would be useful... so patchew only builds the complete series?
->
->
->
-> >
->
-> > > This is reproducible with tcg as well. Same problem both with
->
-> > > --enable-vhost-vdpa and --disable-vhost-vdpa.
->
-> > >
->
-> > > Have not yet tried to figure out what might be special with
->
-> > > virtio-ccw... anyone have an idea?
->
-> > >
->
-> > > [This should probably be considered a blocker?]
->
->
->
-> I think so, as it makes s390x unusable with more that one
->
-> virtio-net-ccw device, and I don't even see a workaround.
->
-
-On 2020/7/24 下午11:34, Cornelia Huck wrote:
-On Fri, 24 Jul 2020 11:17:57 -0400
-"Michael S. Tsirkin"<mst@redhat.com>  wrote:
-On Fri, Jul 24, 2020 at 04:56:27PM +0200, Cornelia Huck wrote:
-On Fri, 24 Jul 2020 09:30:58 -0400
-"Michael S. Tsirkin"<mst@redhat.com>  wrote:
-On Fri, Jul 24, 2020 at 03:27:18PM +0200, Cornelia Huck wrote:
-When I start qemu with a second virtio-net-ccw device (i.e. adding
--device virtio-net-ccw in addition to the autogenerated device), I get
-a segfault. gdb points to
-
-#0  0x000055d6ab52681d in virtio_net_get_config (vdev=<optimized out>,
-     config=0x55d6ad9e3f80 "RT") at 
-/home/cohuck/git/qemu/hw/net/virtio-net.c:146
-146         if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
-
-(backtrace doesn't go further)
-The core was incomplete, but running under gdb directly shows that it
-is just a bog-standard config space access (first for that device).
-
-The cause of the crash is that nc->peer is not set... no idea how that
-can happen, not that familiar with that part of QEMU. (Should the code
-check, or is that really something that should not happen?)
-
-What I don't understand is why it is set correctly for the first,
-autogenerated virtio-net-ccw device, but not for the second one, and
-why virtio-net-pci doesn't show these problems. The only difference
-between -ccw and -pci that comes to my mind here is that config space
-accesses for ccw are done via an asynchronous operation, so timing
-might be different.
-Hopefully Jason has an idea. Could you post a full command line
-please? Do you need a working guest to trigger this? Does this trigger
-on an x86 host?
-Yes, it does trigger with tcg-on-x86 as well. I've been using
-
-s390x-softmmu/qemu-system-s390x -M s390-ccw-virtio,accel=tcg -cpu qemu,zpci=on
--m 1024 -nographic -device virtio-scsi-ccw,id=scsi0,devno=fe.0.0001
--drive file=/path/to/image,format=qcow2,if=none,id=drive-scsi0-0-0-0
--device 
-scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0,bootindex=1
--device virtio-net-ccw
-
-It seems it needs the guest actually doing something with the nics; I
-cannot reproduce the crash if I use the old advent calendar moon buggy
-image and just add a virtio-net-ccw device.
-
-(I don't think it's a problem with my local build, as I see the problem
-both on my laptop and on an LPAR.)
-It looks to me we forget the check the existence of peer.
-
-Please try the attached patch to see if it works.
-
-Thanks
-0001-virtio-net-check-the-existence-of-peer-before-accesi.patch
-Description:
-Text Data
-
-On Sat, 25 Jul 2020 08:40:07 +0800
-Jason Wang <jasowang@redhat.com> wrote:
-
->
-On 2020/7/24 下午11:34, Cornelia Huck wrote:
->
-> On Fri, 24 Jul 2020 11:17:57 -0400
->
-> "Michael S. Tsirkin"<mst@redhat.com>  wrote:
->
->
->
->> On Fri, Jul 24, 2020 at 04:56:27PM +0200, Cornelia Huck wrote:
->
->>> On Fri, 24 Jul 2020 09:30:58 -0400
->
->>> "Michael S. Tsirkin"<mst@redhat.com>  wrote:
->
->>>
->
->>>> On Fri, Jul 24, 2020 at 03:27:18PM +0200, Cornelia Huck wrote:
->
->>>>> When I start qemu with a second virtio-net-ccw device (i.e. adding
->
->>>>> -device virtio-net-ccw in addition to the autogenerated device), I get
->
->>>>> a segfault. gdb points to
->
->>>>>
->
->>>>> #0  0x000055d6ab52681d in virtio_net_get_config (vdev=<optimized out>,
->
->>>>>      config=0x55d6ad9e3f80 "RT") at
->
->>>>> /home/cohuck/git/qemu/hw/net/virtio-net.c:146
->
->>>>> 146         if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
->
->>>>>
->
->>>>> (backtrace doesn't go further)
->
->>> The core was incomplete, but running under gdb directly shows that it
->
->>> is just a bog-standard config space access (first for that device).
->
->>>
->
->>> The cause of the crash is that nc->peer is not set... no idea how that
->
->>> can happen, not that familiar with that part of QEMU. (Should the code
->
->>> check, or is that really something that should not happen?)
->
->>>
->
->>> What I don't understand is why it is set correctly for the first,
->
->>> autogenerated virtio-net-ccw device, but not for the second one, and
->
->>> why virtio-net-pci doesn't show these problems. The only difference
->
->>> between -ccw and -pci that comes to my mind here is that config space
->
->>> accesses for ccw are done via an asynchronous operation, so timing
->
->>> might be different.
->
->> Hopefully Jason has an idea. Could you post a full command line
->
->> please? Do you need a working guest to trigger this? Does this trigger
->
->> on an x86 host?
->
-> Yes, it does trigger with tcg-on-x86 as well. I've been using
->
->
->
-> s390x-softmmu/qemu-system-s390x -M s390-ccw-virtio,accel=tcg -cpu
->
-> qemu,zpci=on
->
-> -m 1024 -nographic -device virtio-scsi-ccw,id=scsi0,devno=fe.0.0001
->
-> -drive file=/path/to/image,format=qcow2,if=none,id=drive-scsi0-0-0-0
->
-> -device
->
-> scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0,bootindex=1
->
-> -device virtio-net-ccw
->
->
->
-> It seems it needs the guest actually doing something with the nics; I
->
-> cannot reproduce the crash if I use the old advent calendar moon buggy
->
-> image and just add a virtio-net-ccw device.
->
->
->
-> (I don't think it's a problem with my local build, as I see the problem
->
-> both on my laptop and on an LPAR.)
->
->
->
-It looks to me we forget the check the existence of peer.
->
->
-Please try the attached patch to see if it works.
-Thanks, that patch gets my guest up and running again. So, FWIW,
-
-Tested-by: Cornelia Huck <cohuck@redhat.com>
-
-Any idea why this did not hit with virtio-net-pci (or the autogenerated
-virtio-net-ccw device)?
-
-On 2020/7/27 下午2:43, Cornelia Huck wrote:
-On Sat, 25 Jul 2020 08:40:07 +0800
-Jason Wang <jasowang@redhat.com> wrote:
-On 2020/7/24 下午11:34, Cornelia Huck wrote:
-On Fri, 24 Jul 2020 11:17:57 -0400
-"Michael S. Tsirkin"<mst@redhat.com>  wrote:
-On Fri, Jul 24, 2020 at 04:56:27PM +0200, Cornelia Huck wrote:
-On Fri, 24 Jul 2020 09:30:58 -0400
-"Michael S. Tsirkin"<mst@redhat.com>  wrote:
-On Fri, Jul 24, 2020 at 03:27:18PM +0200, Cornelia Huck wrote:
-When I start qemu with a second virtio-net-ccw device (i.e. adding
--device virtio-net-ccw in addition to the autogenerated device), I get
-a segfault. gdb points to
-
-#0  0x000055d6ab52681d in virtio_net_get_config (vdev=<optimized out>,
-      config=0x55d6ad9e3f80 "RT") at 
-/home/cohuck/git/qemu/hw/net/virtio-net.c:146
-146         if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
-
-(backtrace doesn't go further)
-The core was incomplete, but running under gdb directly shows that it
-is just a bog-standard config space access (first for that device).
-
-The cause of the crash is that nc->peer is not set... no idea how that
-can happen, not that familiar with that part of QEMU. (Should the code
-check, or is that really something that should not happen?)
-
-What I don't understand is why it is set correctly for the first,
-autogenerated virtio-net-ccw device, but not for the second one, and
-why virtio-net-pci doesn't show these problems. The only difference
-between -ccw and -pci that comes to my mind here is that config space
-accesses for ccw are done via an asynchronous operation, so timing
-might be different.
-Hopefully Jason has an idea. Could you post a full command line
-please? Do you need a working guest to trigger this? Does this trigger
-on an x86 host?
-Yes, it does trigger with tcg-on-x86 as well. I've been using
-
-s390x-softmmu/qemu-system-s390x -M s390-ccw-virtio,accel=tcg -cpu qemu,zpci=on
--m 1024 -nographic -device virtio-scsi-ccw,id=scsi0,devno=fe.0.0001
--drive file=/path/to/image,format=qcow2,if=none,id=drive-scsi0-0-0-0
--device 
-scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0,bootindex=1
--device virtio-net-ccw
-
-It seems it needs the guest actually doing something with the nics; I
-cannot reproduce the crash if I use the old advent calendar moon buggy
-image and just add a virtio-net-ccw device.
-
-(I don't think it's a problem with my local build, as I see the problem
-both on my laptop and on an LPAR.)
-It looks to me we forget the check the existence of peer.
-
-Please try the attached patch to see if it works.
-Thanks, that patch gets my guest up and running again. So, FWIW,
-
-Tested-by: Cornelia Huck <cohuck@redhat.com>
-
-Any idea why this did not hit with virtio-net-pci (or the autogenerated
-virtio-net-ccw device)?
-It can be hit with virtio-net-pci as well (just start without peer).
-For autogenerated virtio-net-cww, I think the reason is that it has
-already had a peer set.
-Thanks
-
-On Mon, 27 Jul 2020 15:38:12 +0800
-Jason Wang <jasowang@redhat.com> wrote:
-
->
-On 2020/7/27 下午2:43, Cornelia Huck wrote:
->
-> On Sat, 25 Jul 2020 08:40:07 +0800
->
-> Jason Wang <jasowang@redhat.com> wrote:
->
->
->
->> On 2020/7/24 下午11:34, Cornelia Huck wrote:
->
->>> On Fri, 24 Jul 2020 11:17:57 -0400
->
->>> "Michael S. Tsirkin"<mst@redhat.com>  wrote:
->
->>>
->
->>>> On Fri, Jul 24, 2020 at 04:56:27PM +0200, Cornelia Huck wrote:
->
->>>>> On Fri, 24 Jul 2020 09:30:58 -0400
->
->>>>> "Michael S. Tsirkin"<mst@redhat.com>  wrote:
->
->>>>>
->
->>>>>> On Fri, Jul 24, 2020 at 03:27:18PM +0200, Cornelia Huck wrote:
->
->>>>>>> When I start qemu with a second virtio-net-ccw device (i.e. adding
->
->>>>>>> -device virtio-net-ccw in addition to the autogenerated device), I get
->
->>>>>>> a segfault. gdb points to
->
->>>>>>>
->
->>>>>>> #0  0x000055d6ab52681d in virtio_net_get_config (vdev=<optimized out>,
->
->>>>>>>       config=0x55d6ad9e3f80 "RT") at
->
->>>>>>> /home/cohuck/git/qemu/hw/net/virtio-net.c:146
->
->>>>>>> 146       if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
->
->>>>>>>
->
->>>>>>> (backtrace doesn't go further)
->
->>>>> The core was incomplete, but running under gdb directly shows that it
->
->>>>> is just a bog-standard config space access (first for that device).
->
->>>>>
->
->>>>> The cause of the crash is that nc->peer is not set... no idea how that
->
->>>>> can happen, not that familiar with that part of QEMU. (Should the code
->
->>>>> check, or is that really something that should not happen?)
->
->>>>>
->
->>>>> What I don't understand is why it is set correctly for the first,
->
->>>>> autogenerated virtio-net-ccw device, but not for the second one, and
->
->>>>> why virtio-net-pci doesn't show these problems. The only difference
->
->>>>> between -ccw and -pci that comes to my mind here is that config space
->
->>>>> accesses for ccw are done via an asynchronous operation, so timing
->
->>>>> might be different.
->
->>>> Hopefully Jason has an idea. Could you post a full command line
->
->>>> please? Do you need a working guest to trigger this? Does this trigger
->
->>>> on an x86 host?
->
->>> Yes, it does trigger with tcg-on-x86 as well. I've been using
->
->>>
->
->>> s390x-softmmu/qemu-system-s390x -M s390-ccw-virtio,accel=tcg -cpu
->
->>> qemu,zpci=on
->
->>> -m 1024 -nographic -device virtio-scsi-ccw,id=scsi0,devno=fe.0.0001
->
->>> -drive file=/path/to/image,format=qcow2,if=none,id=drive-scsi0-0-0-0
->
->>> -device
->
->>> scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0,bootindex=1
->
->>> -device virtio-net-ccw
->
->>>
->
->>> It seems it needs the guest actually doing something with the nics; I
->
->>> cannot reproduce the crash if I use the old advent calendar moon buggy
->
->>> image and just add a virtio-net-ccw device.
->
->>>
->
->>> (I don't think it's a problem with my local build, as I see the problem
->
->>> both on my laptop and on an LPAR.)
->
->>
->
->> It looks to me we forget the check the existence of peer.
->
->>
->
->> Please try the attached patch to see if it works.
->
-> Thanks, that patch gets my guest up and running again. So, FWIW,
->
->
->
-> Tested-by: Cornelia Huck <cohuck@redhat.com>
->
->
->
-> Any idea why this did not hit with virtio-net-pci (or the autogenerated
->
-> virtio-net-ccw device)?
->
->
->
-It can be hit with virtio-net-pci as well (just start without peer).
-Hm, I had not been able to reproduce the crash with a 'naked' -device
-virtio-net-pci. But checking seems to be the right idea anyway.
-
->
->
-For autogenerated virtio-net-cww, I think the reason is that it has
->
-already had a peer set.
-Ok, that might well be.
-
-On 2020/7/27 下午4:41, Cornelia Huck wrote:
-On Mon, 27 Jul 2020 15:38:12 +0800
-Jason Wang <jasowang@redhat.com> wrote:
-On 2020/7/27 下午2:43, Cornelia Huck wrote:
-On Sat, 25 Jul 2020 08:40:07 +0800
-Jason Wang <jasowang@redhat.com> wrote:
-On 2020/7/24 下午11:34, Cornelia Huck wrote:
-On Fri, 24 Jul 2020 11:17:57 -0400
-"Michael S. Tsirkin"<mst@redhat.com>  wrote:
-On Fri, Jul 24, 2020 at 04:56:27PM +0200, Cornelia Huck wrote:
-On Fri, 24 Jul 2020 09:30:58 -0400
-"Michael S. Tsirkin"<mst@redhat.com>  wrote:
-On Fri, Jul 24, 2020 at 03:27:18PM +0200, Cornelia Huck wrote:
-When I start qemu with a second virtio-net-ccw device (i.e. adding
--device virtio-net-ccw in addition to the autogenerated device), I get
-a segfault. gdb points to
-
-#0  0x000055d6ab52681d in virtio_net_get_config (vdev=<optimized out>,
-       config=0x55d6ad9e3f80 "RT") at 
-/home/cohuck/git/qemu/hw/net/virtio-net.c:146
-146         if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
-
-(backtrace doesn't go further)
-The core was incomplete, but running under gdb directly shows that it
-is just a bog-standard config space access (first for that device).
-
-The cause of the crash is that nc->peer is not set... no idea how that
-can happen, not that familiar with that part of QEMU. (Should the code
-check, or is that really something that should not happen?)
-
-What I don't understand is why it is set correctly for the first,
-autogenerated virtio-net-ccw device, but not for the second one, and
-why virtio-net-pci doesn't show these problems. The only difference
-between -ccw and -pci that comes to my mind here is that config space
-accesses for ccw are done via an asynchronous operation, so timing
-might be different.
-Hopefully Jason has an idea. Could you post a full command line
-please? Do you need a working guest to trigger this? Does this trigger
-on an x86 host?
-Yes, it does trigger with tcg-on-x86 as well. I've been using
-
-s390x-softmmu/qemu-system-s390x -M s390-ccw-virtio,accel=tcg -cpu qemu,zpci=on
--m 1024 -nographic -device virtio-scsi-ccw,id=scsi0,devno=fe.0.0001
--drive file=/path/to/image,format=qcow2,if=none,id=drive-scsi0-0-0-0
--device 
-scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0,bootindex=1
--device virtio-net-ccw
-
-It seems it needs the guest actually doing something with the nics; I
-cannot reproduce the crash if I use the old advent calendar moon buggy
-image and just add a virtio-net-ccw device.
-
-(I don't think it's a problem with my local build, as I see the problem
-both on my laptop and on an LPAR.)
-It looks to me we forget the check the existence of peer.
-
-Please try the attached patch to see if it works.
-Thanks, that patch gets my guest up and running again. So, FWIW,
-
-Tested-by: Cornelia Huck <cohuck@redhat.com>
-
-Any idea why this did not hit with virtio-net-pci (or the autogenerated
-virtio-net-ccw device)?
-It can be hit with virtio-net-pci as well (just start without peer).
-Hm, I had not been able to reproduce the crash with a 'naked' -device
-virtio-net-pci. But checking seems to be the right idea anyway.
-Sorry for being unclear, I meant for networking part, you just need
-start without peer, and you need a real guest (any Linux) that is trying
-to access the config space of virtio-net.
-Thanks
-For autogenerated virtio-net-cww, I think the reason is that it has
-already had a peer set.
-Ok, that might well be.
-
-On Mon, Jul 27, 2020 at 04:51:23PM +0800, Jason Wang wrote:
->
->
-On 2020/7/27 下午4:41, Cornelia Huck wrote:
->
-> On Mon, 27 Jul 2020 15:38:12 +0800
->
-> Jason Wang <jasowang@redhat.com> wrote:
->
->
->
-> > On 2020/7/27 下午2:43, Cornelia Huck wrote:
->
-> > > On Sat, 25 Jul 2020 08:40:07 +0800
->
-> > > Jason Wang <jasowang@redhat.com> wrote:
->
-> > > > On 2020/7/24 下午11:34, Cornelia Huck wrote:
->
-> > > > > On Fri, 24 Jul 2020 11:17:57 -0400
->
-> > > > > "Michael S. Tsirkin"<mst@redhat.com>  wrote:
->
-> > > > > > On Fri, Jul 24, 2020 at 04:56:27PM +0200, Cornelia Huck wrote:
->
-> > > > > > > On Fri, 24 Jul 2020 09:30:58 -0400
->
-> > > > > > > "Michael S. Tsirkin"<mst@redhat.com>  wrote:
->
-> > > > > > > > On Fri, Jul 24, 2020 at 03:27:18PM +0200, Cornelia Huck wrote:
->
-> > > > > > > > > When I start qemu with a second virtio-net-ccw device (i.e.
->
-> > > > > > > > > adding
->
-> > > > > > > > > -device virtio-net-ccw in addition to the autogenerated
->
-> > > > > > > > > device), I get
->
-> > > > > > > > > a segfault. gdb points to
->
-> > > > > > > > >
->
-> > > > > > > > > #0  0x000055d6ab52681d in virtio_net_get_config
->
-> > > > > > > > > (vdev=<optimized out>,
->
-> > > > > > > > >        config=0x55d6ad9e3f80 "RT") at
->
-> > > > > > > > > /home/cohuck/git/qemu/hw/net/virtio-net.c:146
->
-> > > > > > > > > 146     if (nc->peer->info->type ==
->
-> > > > > > > > > NET_CLIENT_DRIVER_VHOST_VDPA) {
->
-> > > > > > > > >
->
-> > > > > > > > > (backtrace doesn't go further)
->
-> > > > > > > The core was incomplete, but running under gdb directly shows
->
-> > > > > > > that it
->
-> > > > > > > is just a bog-standard config space access (first for that
->
-> > > > > > > device).
->
-> > > > > > >
->
-> > > > > > > The cause of the crash is that nc->peer is not set... no idea
->
-> > > > > > > how that
->
-> > > > > > > can happen, not that familiar with that part of QEMU. (Should
->
-> > > > > > > the code
->
-> > > > > > > check, or is that really something that should not happen?)
->
-> > > > > > >
->
-> > > > > > > What I don't understand is why it is set correctly for the
->
-> > > > > > > first,
->
-> > > > > > > autogenerated virtio-net-ccw device, but not for the second
->
-> > > > > > > one, and
->
-> > > > > > > why virtio-net-pci doesn't show these problems. The only
->
-> > > > > > > difference
->
-> > > > > > > between -ccw and -pci that comes to my mind here is that config
->
-> > > > > > > space
->
-> > > > > > > accesses for ccw are done via an asynchronous operation, so
->
-> > > > > > > timing
->
-> > > > > > > might be different.
->
-> > > > > > Hopefully Jason has an idea. Could you post a full command line
->
-> > > > > > please? Do you need a working guest to trigger this? Does this
->
-> > > > > > trigger
->
-> > > > > > on an x86 host?
->
-> > > > > Yes, it does trigger with tcg-on-x86 as well. I've been using
->
-> > > > >
->
-> > > > > s390x-softmmu/qemu-system-s390x -M s390-ccw-virtio,accel=tcg -cpu
->
-> > > > > qemu,zpci=on
->
-> > > > > -m 1024 -nographic -device virtio-scsi-ccw,id=scsi0,devno=fe.0.0001
->
-> > > > > -drive file=/path/to/image,format=qcow2,if=none,id=drive-scsi0-0-0-0
->
-> > > > > -device
->
-> > > > > scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0,bootindex=1
->
-> > > > > -device virtio-net-ccw
->
-> > > > >
->
-> > > > > It seems it needs the guest actually doing something with the nics;
->
-> > > > > I
->
-> > > > > cannot reproduce the crash if I use the old advent calendar moon
->
-> > > > > buggy
->
-> > > > > image and just add a virtio-net-ccw device.
->
-> > > > >
->
-> > > > > (I don't think it's a problem with my local build, as I see the
->
-> > > > > problem
->
-> > > > > both on my laptop and on an LPAR.)
->
-> > > > It looks to me we forget the check the existence of peer.
->
-> > > >
->
-> > > > Please try the attached patch to see if it works.
->
-> > > Thanks, that patch gets my guest up and running again. So, FWIW,
->
-> > >
->
-> > > Tested-by: Cornelia Huck <cohuck@redhat.com>
->
-> > >
->
-> > > Any idea why this did not hit with virtio-net-pci (or the autogenerated
->
-> > > virtio-net-ccw device)?
->
-> >
->
-> > It can be hit with virtio-net-pci as well (just start without peer).
->
-> Hm, I had not been able to reproduce the crash with a 'naked' -device
->
-> virtio-net-pci. But checking seems to be the right idea anyway.
->
->
->
-Sorry for being unclear, I meant for networking part, you just need start
->
-without peer, and you need a real guest (any Linux) that is trying to access
->
-the config space of virtio-net.
->
->
-Thanks
-A pxe guest will do it, but that doesn't support ccw, right?
-
-I'm still unclear why this triggers with ccw but not pci -
-any idea?
-
->
->
->
->
-> > For autogenerated virtio-net-cww, I think the reason is that it has
->
-> > already had a peer set.
->
-> Ok, that might well be.
->
->
->
->
-
-On 2020/7/27 下午7:43, Michael S. Tsirkin wrote:
-On Mon, Jul 27, 2020 at 04:51:23PM +0800, Jason Wang wrote:
-On 2020/7/27 下午4:41, Cornelia Huck wrote:
-On Mon, 27 Jul 2020 15:38:12 +0800
-Jason Wang<jasowang@redhat.com>  wrote:
-On 2020/7/27 下午2:43, Cornelia Huck wrote:
-On Sat, 25 Jul 2020 08:40:07 +0800
-Jason Wang<jasowang@redhat.com>  wrote:
-On 2020/7/24 下午11:34, Cornelia Huck wrote:
-On Fri, 24 Jul 2020 11:17:57 -0400
-"Michael S. Tsirkin"<mst@redhat.com>   wrote:
-On Fri, Jul 24, 2020 at 04:56:27PM +0200, Cornelia Huck wrote:
-On Fri, 24 Jul 2020 09:30:58 -0400
-"Michael S. Tsirkin"<mst@redhat.com>   wrote:
-On Fri, Jul 24, 2020 at 03:27:18PM +0200, Cornelia Huck wrote:
-When I start qemu with a second virtio-net-ccw device (i.e. adding
--device virtio-net-ccw in addition to the autogenerated device), I get
-a segfault. gdb points to
-
-#0  0x000055d6ab52681d in virtio_net_get_config (vdev=<optimized out>,
-        config=0x55d6ad9e3f80 "RT") at 
-/home/cohuck/git/qemu/hw/net/virtio-net.c:146
-146         if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
-
-(backtrace doesn't go further)
-The core was incomplete, but running under gdb directly shows that it
-is just a bog-standard config space access (first for that device).
-
-The cause of the crash is that nc->peer is not set... no idea how that
-can happen, not that familiar with that part of QEMU. (Should the code
-check, or is that really something that should not happen?)
-
-What I don't understand is why it is set correctly for the first,
-autogenerated virtio-net-ccw device, but not for the second one, and
-why virtio-net-pci doesn't show these problems. The only difference
-between -ccw and -pci that comes to my mind here is that config space
-accesses for ccw are done via an asynchronous operation, so timing
-might be different.
-Hopefully Jason has an idea. Could you post a full command line
-please? Do you need a working guest to trigger this? Does this trigger
-on an x86 host?
-Yes, it does trigger with tcg-on-x86 as well. I've been using
-
-s390x-softmmu/qemu-system-s390x -M s390-ccw-virtio,accel=tcg -cpu qemu,zpci=on
--m 1024 -nographic -device virtio-scsi-ccw,id=scsi0,devno=fe.0.0001
--drive file=/path/to/image,format=qcow2,if=none,id=drive-scsi0-0-0-0
--device 
-scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0,bootindex=1
--device virtio-net-ccw
-
-It seems it needs the guest actually doing something with the nics; I
-cannot reproduce the crash if I use the old advent calendar moon buggy
-image and just add a virtio-net-ccw device.
-
-(I don't think it's a problem with my local build, as I see the problem
-both on my laptop and on an LPAR.)
-It looks to me we forget the check the existence of peer.
-
-Please try the attached patch to see if it works.
-Thanks, that patch gets my guest up and running again. So, FWIW,
-
-Tested-by: Cornelia Huck<cohuck@redhat.com>
-
-Any idea why this did not hit with virtio-net-pci (or the autogenerated
-virtio-net-ccw device)?
-It can be hit with virtio-net-pci as well (just start without peer).
-Hm, I had not been able to reproduce the crash with a 'naked' -device
-virtio-net-pci. But checking seems to be the right idea anyway.
-Sorry for being unclear, I meant for networking part, you just need start
-without peer, and you need a real guest (any Linux) that is trying to access
-the config space of virtio-net.
-
-Thanks
-A pxe guest will do it, but that doesn't support ccw, right?
-Yes, it depends on the cli actually.
-I'm still unclear why this triggers with ccw but not pci -
-any idea?
-I don't test pxe but I can reproduce this with pci (just start a linux
-guest without a peer).
-Thanks
-
-On Mon, Jul 27, 2020 at 08:44:09PM +0800, Jason Wang wrote:
->
->
-On 2020/7/27 下午7:43, Michael S. Tsirkin wrote:
->
-> On Mon, Jul 27, 2020 at 04:51:23PM +0800, Jason Wang wrote:
->
-> > On 2020/7/27 下午4:41, Cornelia Huck wrote:
->
-> > > On Mon, 27 Jul 2020 15:38:12 +0800
->
-> > > Jason Wang<jasowang@redhat.com>  wrote:
->
-> > >
->
-> > > > On 2020/7/27 下午2:43, Cornelia Huck wrote:
->
-> > > > > On Sat, 25 Jul 2020 08:40:07 +0800
->
-> > > > > Jason Wang<jasowang@redhat.com>  wrote:
->
-> > > > > > On 2020/7/24 下午11:34, Cornelia Huck wrote:
->
-> > > > > > > On Fri, 24 Jul 2020 11:17:57 -0400
->
-> > > > > > > "Michael S. Tsirkin"<mst@redhat.com>   wrote:
->
-> > > > > > > > On Fri, Jul 24, 2020 at 04:56:27PM +0200, Cornelia Huck wrote:
->
-> > > > > > > > > On Fri, 24 Jul 2020 09:30:58 -0400
->
-> > > > > > > > > "Michael S. Tsirkin"<mst@redhat.com>   wrote:
->
-> > > > > > > > > > On Fri, Jul 24, 2020 at 03:27:18PM +0200, Cornelia Huck
->
-> > > > > > > > > > wrote:
->
-> > > > > > > > > > > When I start qemu with a second virtio-net-ccw device
->
-> > > > > > > > > > > (i.e. adding
->
-> > > > > > > > > > > -device virtio-net-ccw in addition to the autogenerated
->
-> > > > > > > > > > > device), I get
->
-> > > > > > > > > > > a segfault. gdb points to
->
-> > > > > > > > > > >
->
-> > > > > > > > > > > #0  0x000055d6ab52681d in virtio_net_get_config
->
-> > > > > > > > > > > (vdev=<optimized out>,
->
-> > > > > > > > > > >         config=0x55d6ad9e3f80 "RT") at
->
-> > > > > > > > > > > /home/cohuck/git/qemu/hw/net/virtio-net.c:146
->
-> > > > > > > > > > > 146         if (nc->peer->info->type ==
->
-> > > > > > > > > > > NET_CLIENT_DRIVER_VHOST_VDPA) {
->
-> > > > > > > > > > >
->
-> > > > > > > > > > > (backtrace doesn't go further)
->
-> > > > > > > > > The core was incomplete, but running under gdb directly
->
-> > > > > > > > > shows that it
->
-> > > > > > > > > is just a bog-standard config space access (first for that
->
-> > > > > > > > > device).
->
-> > > > > > > > >
->
-> > > > > > > > > The cause of the crash is that nc->peer is not set... no
->
-> > > > > > > > > idea how that
->
-> > > > > > > > > can happen, not that familiar with that part of QEMU.
->
-> > > > > > > > > (Should the code
->
-> > > > > > > > > check, or is that really something that should not happen?)
->
-> > > > > > > > >
->
-> > > > > > > > > What I don't understand is why it is set correctly for the
->
-> > > > > > > > > first,
->
-> > > > > > > > > autogenerated virtio-net-ccw device, but not for the second
->
-> > > > > > > > > one, and
->
-> > > > > > > > > why virtio-net-pci doesn't show these problems. The only
->
-> > > > > > > > > difference
->
-> > > > > > > > > between -ccw and -pci that comes to my mind here is that
->
-> > > > > > > > > config space
->
-> > > > > > > > > accesses for ccw are done via an asynchronous operation, so
->
-> > > > > > > > > timing
->
-> > > > > > > > > might be different.
->
-> > > > > > > > Hopefully Jason has an idea. Could you post a full command
->
-> > > > > > > > line
->
-> > > > > > > > please? Do you need a working guest to trigger this? Does
->
-> > > > > > > > this trigger
->
-> > > > > > > > on an x86 host?
->
-> > > > > > > Yes, it does trigger with tcg-on-x86 as well. I've been using
->
-> > > > > > >
->
-> > > > > > > s390x-softmmu/qemu-system-s390x -M s390-ccw-virtio,accel=tcg
->
-> > > > > > > -cpu qemu,zpci=on
->
-> > > > > > > -m 1024 -nographic -device
->
-> > > > > > > virtio-scsi-ccw,id=scsi0,devno=fe.0.0001
->
-> > > > > > > -drive
->
-> > > > > > > file=/path/to/image,format=qcow2,if=none,id=drive-scsi0-0-0-0
->
-> > > > > > > -device
->
-> > > > > > > scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0,bootindex=1
->
-> > > > > > > -device virtio-net-ccw
->
-> > > > > > >
->
-> > > > > > > It seems it needs the guest actually doing something with the
->
-> > > > > > > nics; I
->
-> > > > > > > cannot reproduce the crash if I use the old advent calendar
->
-> > > > > > > moon buggy
->
-> > > > > > > image and just add a virtio-net-ccw device.
->
-> > > > > > >
->
-> > > > > > > (I don't think it's a problem with my local build, as I see the
->
-> > > > > > > problem
->
-> > > > > > > both on my laptop and on an LPAR.)
->
-> > > > > > It looks to me we forget the check the existence of peer.
->
-> > > > > >
->
-> > > > > > Please try the attached patch to see if it works.
->
-> > > > > Thanks, that patch gets my guest up and running again. So, FWIW,
->
-> > > > >
->
-> > > > > Tested-by: Cornelia Huck<cohuck@redhat.com>
->
-> > > > >
->
-> > > > > Any idea why this did not hit with virtio-net-pci (or the
->
-> > > > > autogenerated
->
-> > > > > virtio-net-ccw device)?
->
-> > > > It can be hit with virtio-net-pci as well (just start without peer).
->
-> > > Hm, I had not been able to reproduce the crash with a 'naked' -device
->
-> > > virtio-net-pci. But checking seems to be the right idea anyway.
->
-> > Sorry for being unclear, I meant for networking part, you just need start
->
-> > without peer, and you need a real guest (any Linux) that is trying to
->
-> > access
->
-> > the config space of virtio-net.
->
-> >
->
-> > Thanks
->
-> A pxe guest will do it, but that doesn't support ccw, right?
->
->
->
-Yes, it depends on the cli actually.
->
->
->
->
->
-> I'm still unclear why this triggers with ccw but not pci -
->
-> any idea?
->
->
->
-I don't test pxe but I can reproduce this with pci (just start a linux guest
->
-without a peer).
->
->
-Thanks
->
-Might be a good addition to a unit test. Not sure what would the
-test do exactly: just make sure guest runs? Looks like a lot of work
-for an empty test ... maybe we can poke at the guest config with
-qtest commands at least.
-
--- 
-MST
-
-On 2020/7/27 下午9:16, Michael S. Tsirkin wrote:
-On Mon, Jul 27, 2020 at 08:44:09PM +0800, Jason Wang wrote:
-On 2020/7/27 下午7:43, Michael S. Tsirkin wrote:
-On Mon, Jul 27, 2020 at 04:51:23PM +0800, Jason Wang wrote:
-On 2020/7/27 下午4:41, Cornelia Huck wrote:
-On Mon, 27 Jul 2020 15:38:12 +0800
-Jason Wang<jasowang@redhat.com>  wrote:
-On 2020/7/27 下午2:43, Cornelia Huck wrote:
-On Sat, 25 Jul 2020 08:40:07 +0800
-Jason Wang<jasowang@redhat.com>  wrote:
-On 2020/7/24 下午11:34, Cornelia Huck wrote:
-On Fri, 24 Jul 2020 11:17:57 -0400
-"Michael S. Tsirkin"<mst@redhat.com>   wrote:
-On Fri, Jul 24, 2020 at 04:56:27PM +0200, Cornelia Huck wrote:
-On Fri, 24 Jul 2020 09:30:58 -0400
-"Michael S. Tsirkin"<mst@redhat.com>   wrote:
-On Fri, Jul 24, 2020 at 03:27:18PM +0200, Cornelia Huck wrote:
-When I start qemu with a second virtio-net-ccw device (i.e. adding
--device virtio-net-ccw in addition to the autogenerated device), I get
-a segfault. gdb points to
-
-#0  0x000055d6ab52681d in virtio_net_get_config (vdev=<optimized out>,
-         config=0x55d6ad9e3f80 "RT") at 
-/home/cohuck/git/qemu/hw/net/virtio-net.c:146
-146         if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
-
-(backtrace doesn't go further)
-The core was incomplete, but running under gdb directly shows that it
-is just a bog-standard config space access (first for that device).
-
-The cause of the crash is that nc->peer is not set... no idea how that
-can happen, not that familiar with that part of QEMU. (Should the code
-check, or is that really something that should not happen?)
-
-What I don't understand is why it is set correctly for the first,
-autogenerated virtio-net-ccw device, but not for the second one, and
-why virtio-net-pci doesn't show these problems. The only difference
-between -ccw and -pci that comes to my mind here is that config space
-accesses for ccw are done via an asynchronous operation, so timing
-might be different.
-Hopefully Jason has an idea. Could you post a full command line
-please? Do you need a working guest to trigger this? Does this trigger
-on an x86 host?
-Yes, it does trigger with tcg-on-x86 as well. I've been using
-
-s390x-softmmu/qemu-system-s390x -M s390-ccw-virtio,accel=tcg -cpu qemu,zpci=on
--m 1024 -nographic -device virtio-scsi-ccw,id=scsi0,devno=fe.0.0001
--drive file=/path/to/image,format=qcow2,if=none,id=drive-scsi0-0-0-0
--device 
-scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0,bootindex=1
--device virtio-net-ccw
-
-It seems it needs the guest actually doing something with the nics; I
-cannot reproduce the crash if I use the old advent calendar moon buggy
-image and just add a virtio-net-ccw device.
-
-(I don't think it's a problem with my local build, as I see the problem
-both on my laptop and on an LPAR.)
-It looks to me we forget the check the existence of peer.
-
-Please try the attached patch to see if it works.
-Thanks, that patch gets my guest up and running again. So, FWIW,
-
-Tested-by: Cornelia Huck<cohuck@redhat.com>
-
-Any idea why this did not hit with virtio-net-pci (or the autogenerated
-virtio-net-ccw device)?
-It can be hit with virtio-net-pci as well (just start without peer).
-Hm, I had not been able to reproduce the crash with a 'naked' -device
-virtio-net-pci. But checking seems to be the right idea anyway.
-Sorry for being unclear, I meant for networking part, you just need start
-without peer, and you need a real guest (any Linux) that is trying to access
-the config space of virtio-net.
-
-Thanks
-A pxe guest will do it, but that doesn't support ccw, right?
-Yes, it depends on the cli actually.
-I'm still unclear why this triggers with ccw but not pci -
-any idea?
-I don't test pxe but I can reproduce this with pci (just start a linux guest
-without a peer).
-
-Thanks
-Might be a good addition to a unit test. Not sure what would the
-test do exactly: just make sure guest runs? Looks like a lot of work
-for an empty test ... maybe we can poke at the guest config with
-qtest commands at least.
-That should work or we can simply extend the exist virtio-net qtest to
-do that.
-Thanks
-