Re: [Qemu-devel] VM can not boot after commit 235e898

[Dunrong Huang]

On Tue, Jun 4, 2013 at 3:51 PM, Gleb Natapov <address@hidden> wrote:

On Tue, Jun 04, 2013 at 03:47:47PM +0800, Dunrong Huang wrote:
> On Tue, Jun 4, 2013 at 2:47 PM, Paolo Bonzini <address@hidden> wrote:
>
> > Il 04/06/2013 05:47, Dunrong Huang ha scritto:
> > >
> > > QEMU command:
> > > ~/usr/bin/qemu-system-x86_64 -enable-kvm -m 1024 debian-append.img
> > >
> > > git bisect tells that the following commit causes this bug:
> > >
> > > commit 235e8982ad393e5611cb892df54881c872eea9e1
> > > Author: Jordan Justen <address@hidden
> > > <mailto:address@hidden>>
> > > Date:   Wed May 29 01:27:26 2013 -0700
> > >
> > >     kvm: support using KVM_MEM_READONLY flag for regions
> > >
> > >     For readonly memory regions and rom devices in romd_mode,
> > >     we make use of the KVM_MEM_READONLY. A slot that uses
> > >     KVM_MEM_READONLY can be read from and code can execute from the
> > >     region, but writes will exit to qemu.
> > >
> > > After reverting this commit, VM can boot normally.
> >
> > A patch is queued for that.  Using kernel 3.8 or reverting the commit
> > will both work.
> >
> Ok, thanks for information, I will try it.
>

The fix is 651eb0f4 and you claim it is still fails for you. This is
strange because the commit fixed the problem for everyone else. Can you
double check that you are testing the right commit and you recompiled
and reinstalled?

 

I am sure 651eb0f4 does not fix this problem.

My test environment is below:

* config.log:

# head -n 2 config.log 

# QEMU configure log 2013年 06月 04日 星期二 16:12:59 CST

# Configured with: './configure' '--prefix=/root/usr' '--enable-kvm' '--enable-werror' '--enable-debug' '--enable-debug-tcg' '--enable-debug-info' '--enable-sdl' '--enable-gtk' '--enable-virtfs' '--enable-vnc' '--enable-mixemu' '--enable-vnc-tls' '--enable-vnc-sasl' '--enable-vnc-jpeg' '--enable-vnc-png' '--enable-vnc-ws' '--enable-curses' '--enable-curl' '--enable-nptl' '--enable-system' '--enable-user' '--enable-linux-user' '--enable-guest-base' '--enable-uuid' '--enable-vde' '--enable-linux-aio' '--enable-cap-ng' '--enable-attr' '--enable-docs' '--enable-vhost-net' '--enable-spice' '--enable-usb-redir' '--enable-smartcard-nss' '--enable-tpm' '--enable-guest-agent' '--target-list=x86_64-softmmu'

* kernel version:

# uname -a

Linux gentoo-company 3.8.2-gentoo #1 SMP Fri Mar 8 11:44:36 CST 2013 x86_64 Intel(R) Core(TM)2 Duo CPU E7500 @ 2.93GHz GenuineIntel GNU/Linux

* details of git tree:

# git log HEAD --oneline

1713924 gtk: don't use g_object_unref on GdkCursor

41686a9 gtk: don't resize window when enabling scaling

651eb0f fix double free the memslot in kvm_set_phys_mem

25b4833 configure: Report unknown target names more helpfully

6e92f82 configure: Autogenerate default target list

0ded1fe Merge remote-tracking branch 'pmaydell/arm-devs.next' into staging

95669e6 i.MX: Improve EPIT timer code.

6539ed2 exynos4210.c: register rom_mem for memory migration

* QEMU command line:

x86_64-softmmu/qemu-system-x86_64 -enable-kvm -cdrom /mnt/nfs/Images/ISO/ubuntu-12.04-dvd-amd64.iso 

After disable KVM_MEM_READONLY flag like below, VM can boot normally.

diff --git a/kvm-all.c b/kvm-all.c

index 405480e..c33ba6e 100644

--- a/kvm-all.c

+++ b/kvm-all.c

@@ -774,7 +774,7 @@ static void kvm_set_phys_mem(MemoryRegionSection *section, bool add)

     mem->memory_size = size;

     mem->start_addr = start_addr;

     mem->ram = ram;

-    mem->flags = kvm_mem_flags(s, log_dirty, readonly_flag);

+    mem->flags = kvm_mem_flags(s, log_dirty, false);

 

     err = kvm_set_user_memory_region(s, mem);

     if (err) {

I can provide more details if needed.

--
                        Gleb.

--

Best Regards,

Dunrong Huang 

Homepage: http://mathslinux.org