Date: Mon, 25 Apr 2016 12:52:44 +0200
From: Borislav Petkov <bp@alien8.de>
To: Andrey Utkin <andrey_utkin@fastmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>, linux-kernel@vger.kernel.org,
        x86@kernel.org, Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH v2] Enhance kvmconfig
Message-ID: <20160425105243.GA28454@pd.tnic>
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On Mon, Apr 25, 2016 at 03:49:04AM +0300, Andrey Utkin wrote:
> IMO "bare minimum" term makes sense if it boots.

Boots where? On every system? You know that won't fly.

This bare minimum is trying to be of help only. No one says you should
be able to boot *every* guest kernel config with this.

For example, if your guest root fs image is ext4, then you must enable
ext4 support in the guest kernel. But that doesn't mean we need to carry
everything in kvmconfig. If we did, then we don't need it at all -
people can simply do "make allmodconfig" and have it all.

The idea of kvmconfig is to OR in the bare minimum of options into your
current .config and thus make the kernel more useful when booted as a
kvm guest - you'd still need to go and adjust it to your particular qemu
invocation.

In any case, here's how I'm booting my guests. You can see, for example,
that I'm using rtl8139 nic in the guest and for that I have it enabled
in my guest kernel .config.

$ qemu-system-x86_64
-enable-kvm
-gdb tcp::1234
-cpu Opteron_G5
-m 2048
-hda /home/boris/kvm/debian/sid-x86_64.img
-boot menu=off,order=c
-localtime
-net nic,model=rtl8139,macaddr=12:34:56:78:12:34
-net user,hostfwd=tcp::1235-:22
-usbdevice tablet
-kernel /home/boris/kernel/linux-2.6/arch/x86/boot/bzImage
-append "root=/dev/sda1 resume=/dev/sdb1 debug ignore_loglevel log_buf_len=16M earlyprintk=ttyS0,115200 console=ttyS0,115200 console=tty0 "
-monitor pty
-soundhw hda
-serial file:/home/boris/kvm/test-x86_64-1235.log
-snapshot
-smp 8
-virtfs local,path=/tmp,mount_tag=tmp,security_model=none

HTH.

-- 
Regards/Gruss,
    Boris.

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