Re: [Qemu-devel] [Bug 1191606] Re: qemu crashes with iscsi initiator (libiscsi) when using virtio

[Laszlo Ersek <lersek@redhat.com>]

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On 06/19/13 06:34, ronnie sahlberg wrote:
> I can reproduce with current QEMU.
> 
> Ubuntu 13 crashes with if=virtio but if=ide is fine.
> 
> 
> But it seems dependent on the guest/kernel.
> 
> For example Fedora-18-x86_64-Live-Desktop.iso  installs and runs just
> fine, even with virtio
> But both ubuntu-12.04-desktop-amd64.iso or
> ubuntu-13.04-desktop-amd64.iso crash with if=virtio
> 
> 
> Stack backtrace I got is
> #0  0x00007f7a9e22d037 in __GI_raise (sig=sig@entry=6)
>     at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
> #1  0x00007f7a9e230698 in __GI_abort () at abort.c:90
> #2  0x00007f7aa0a93ec8 in qemu_ram_addr_from_host_nofail (
>     ptr=ptr@entry=0x2020202024008000) at /DATA/SRC/qemu-kvm/qemu/exec.c:1399
> #3  0x00007f7aa0a94a50 in address_space_unmap (as=<optimised out>,
>     buffer=0x2020202024008000, len=<optimised out>, is_write=<optimised out>,
>     access_len=1) at /DATA/SRC/qemu-kvm/qemu/exec.c:2155
> #4  0x00007f7aa0a94bef in cpu_physical_memory_unmap (buffer=<optimised out>,
>     len=<optimised out>, is_write=<optimised out>, access_len=<optimised out>)
>     at /DATA/SRC/qemu-kvm/qemu/exec.c:2189
> #5  0x00007f7aa0ad7867 in virtqueue_fill (vq=vq@entry=0x7f7aa34277f0,
>     elem=elem@entry=0x7f7aa37ca328, len=1, idx=idx@entry=0)
>     at /DATA/SRC/qemu-kvm/qemu/hw/virtio/virtio.c:243
> #6  0x00007f7aa0ad79cf in virtqueue_push (vq=0x7f7aa34277f0,
>     elem=elem@entry=0x7f7aa37ca328, len=<optimised out>)
>     at /DATA/SRC/qemu-kvm/qemu/hw/virtio/virtio.c:279
> #7  0x00007f7aa0aa9989 in virtio_blk_req_complete (
>     req=req@entry=0x7f7aa37ca320, status=status@entry=0)
>     at /DATA/SRC/qemu-kvm/qemu/hw/block/virtio-blk.c:49
> #8  0x00007f7aa0aa9ffb in virtio_blk_handle_request (
>     req=req@entry=0x7f7aa37ca320, mrb=mrb@entry=0x7fff7a7b2060)
>     at /DATA/SRC/qemu-kvm/qemu/hw/block/virtio-blk.c:376

Can you try the attached patch? It will produce quite a bit of output on
stderr.

Thanks
Laszlo

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>From 18b0c531e9ff1c33cce517c308c8330dd7d33a43 Mon Sep 17 00:00:00 2001
From: Laszlo Ersek <lersek@redhat.com>
Date: Wed, 19 Jun 2013 10:37:31 +0200
Subject: [PATCH] log map/unmap in virtqueue_map_sg() and virtqueue_fill(), plus blk req type


Signed-off-by: Laszlo Ersek <lersek@redhat.com>
---
 hw/block/virtio-blk.c |    1 +
 hw/virtio/virtio.c    |    9 +++++++++
 2 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index cf12469..14cf898 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -358,6 +358,7 @@ static void virtio_blk_handle_request(VirtIOBlockReq *req,
     req->in = (void *)req->elem.in_sg[req->elem.in_num - 1].iov_base;
 
     type = ldl_p(&req->out->type);
+    fprintf(stderr, "%s: type=0x%08" PRIx32 "\n", __FUNCTION__, type);
 
     if (type & VIRTIO_BLK_T_FLUSH) {
         virtio_blk_handle_flush(req, mrb);
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 8176c14..0af31c5 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -240,6 +240,9 @@ void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
     for (i = 0; i < elem->in_num; i++) {
         size_t size = MIN(len - offset, elem->in_sg[i].iov_len);
 
+        fprintf(stderr, "%s: unmapping hva=%p for length=%zu, "
+                "access_len=%zu, is_write=1\n", __FUNCTION__,
+                elem->in_sg[i].iov_base, elem->in_sg[i].iov_len, size);
         cpu_physical_memory_unmap(elem->in_sg[i].iov_base,
                                   elem->in_sg[i].iov_len,
                                   1, size);
@@ -248,6 +251,9 @@ void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
     }
 
     for (i = 0; i < elem->out_num; i++)
+        fprintf(stderr, "%s: unmapping hva=%p for length=access_len=%zu, "
+                "is_write=0\n", __FUNCTION__,  elem->out_sg[i].iov_base,
+                elem->out_sg[i].iov_len);
         cpu_physical_memory_unmap(elem->out_sg[i].iov_base,
                                   elem->out_sg[i].iov_len,
                                   0, elem->out_sg[i].iov_len);
@@ -430,6 +436,9 @@ void virtqueue_map_sg(struct iovec *sg, hwaddr *addr,
             error_report("virtio: trying to map MMIO memory");
             exit(1);
         }
+        fprintf(stderr, "%s: mapped gpa=" TARGET_FMT_plx " at hva=%p "
+                "for length=%" HWADDR_PRIu ", is_write=%d\n", __FUNCTION__,
+                addr[i], sg[i].iov_base, len, is_write);
     }
 }
 
-- 
1.7.1