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Re: [Qemu-devel] [PATCH v12 2/5] apic: use per CPU AS to map APIC MMIO f
From: |
Eduardo Habkost |
Subject: |
Re: [Qemu-devel] [PATCH v12 2/5] apic: use per CPU AS to map APIC MMIO for TCG |
Date: |
Fri, 2 Oct 2015 16:21:23 -0300 |
User-agent: |
Mutt/1.5.23 (2014-03-12) |
On Fri, Oct 02, 2015 at 03:24:24PM -0300, Eduardo Habkost wrote:
> On Tue, Sep 22, 2015 at 02:29:01PM +0200, Igor Mammedov wrote:
> > On Wed, 16 Sep 2015 17:19:12 +0800
> > Zhu Guihua <address@hidden> wrote:
> >
> > > TCG supports per CPU address space, and the emulation quality is
> > > a bit better with it.
> > > So use per CPU address space to map APIC MMIO area. This allows the
> > > APIC base address of each cpu to be moved independent of others.
> > >
> > > Signed-off-by: Zhu Guihua <address@hidden>
> >
> > Reviewed-by: Igor Mammedov <address@hidden>
>
> The series seems to be OK when using KVM, but something is wrong with TCG.
>
> After applying this patch, my Fedora 20 image hangs on boot at:
>
> [ OK ] Started udev Coldplug all Devices.
> Starting dracut initqueue hook...
> [ OK ] Reached target System Initialization.
> [ OK ] Reached target Basic System.
> [ 8.988420] ACPI: PCI Interrupt Link [LNKD] enabled at IRQ 11
>
>
> Before this patch, boot continues with:
>
> [ OK ] Reached target Basic System.
> [ 8.523293] ACPI: PCI Interrupt Link [LNKD] enabled at IRQ 11
> [ 9.230955] vda: vda1
> [ OK ] Started dracut initqueue hook.
> Mounting /sysroot...
>
> I am running QEMU as:
> $ ./x86_64-softmmu/qemu-system-x86_64 -drive
> if=virtio,file=/home/ehabkost/system/vmachines/Fedora-x86_64-20-20131211.1-sda.qcow2,format=qcow2
> -machine pc,accel=tcg -smp 8,sockets=2,threads=2,cores=2,maxcpus=16 -serial
> stdio -nographic -monitor none
Debugging revealed that this broke MSI delivery of virtio notifications.
Writes to PCIDevice::bus_master_as (at msi_send_message()) don't get
delivered to the APIC memory region anymore.
This patch doesn't seem to be required for the removal of ICC bus, so I
am applying the rest of the series anyway. If you see any problem with
that, please let me know.
--
Eduardo