|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] PVHVM VCPU hotplug mechanism via ACPI hotplug doesn't work in Xen 4.[1, 2, 3]
On 08/05/13 12:14, Stefano Stabellini wrote: On Tue, 7 May 2013, Konrad Rzeszutek Wilk wrote:On Tue, May 07, 2013 at 12:16:25AM +0000, Ross Philipson wrote:-----Original Message----- From: xen-devel-bounces@xxxxxxxxxxxxx [mailto:xen-devel- bounces@xxxxxxxxxxxxx] On Behalf Of Ross Philipson Sent: Monday, May 06, 2013 5:07 PM To: Konrad Rzeszutek Wilk; jinsong.liu@xxxxxxxxx; Stefano Stabellini; xen-devel@xxxxxxxxxxxxxxxxxxx Subject: Re: [Xen-devel] PVHVM VCPU hotplug mechanism via ACPI hotplug doesn't work in Xen 4.[1, 2, 3]-----Original Message----- From: xen-devel-bounces@xxxxxxxxxxxxx [mailto:xen-devel- bounces@xxxxxxxxxxxxx] On Behalf Of Konrad Rzeszutek Wilk Sent: Monday, May 06, 2013 11:45 AM To: jinsong.liu@xxxxxxxxx; Stefano Stabellini; xen- devel@xxxxxxxxxxxxxxxxxxx Subject: [Xen-devel] PVHVM VCPU hotplug mechanism via ACPI hotplug doesn't work in Xen 4.[1, 2, 3] Which is probably the case b/c the Linux side implementation for such simple operation as : echo 0 > /sys/devices/system/cpu/cpu1/online echo 1 > /sys/devices/system/cpu/cpu1/online would have blown up so nobody tested it? Now that is fixed (v3.10 + http://lists.xen.org/archives/html/xen- devel/2013-05/msg00503.html) I tried to do 'xm vcpu-set latest X' for a PVHVM guest. The first iteration was using this simple guest config: builder='hvm' disk = [ 'file:/mnt/lab/latest/root_image.iso,hdc:cdrom,r'] memory = 2048 boot="d" maxvcpus=4 vcpus=4 serial='pty' vnclisten="0.0.0.0" name="latest" vif = [ 'mac=00:0F:4B:00:00:68, bridge=switch' ] And I tried simple combinations of 'x[m|l] vcpu-set latest 2|3|4' and none of them worked. In Xen 4.1 (and Xen 4.3 if I use:device_model_version="qemu-xen- traditional") I saw that the qemu log does the right thing: .. snip.. Remove vcpu 2 Remove vcpu 1 and the guest's ACPI SCI is incrementing: # cat /proc/interrupts |grep acpi 9: 1 0 0 IO-APIC-fasteoi acpi # cat /proc/interrupts |grep acpi 9: 2 0 0 IO-APIC-fasteoi acpi But nothing looks to be happening. Where should I look? The ACPI DSDT is a bit daunting. Has this ever worked in the past? If so, what code ran to hotplug CPUs?I am looking at qemu-traditional (I believe it is traditional here: http://xenbits.xen.org/gitweb/?p=qemu-xen-unstable.git;a=summary). The code for raising the SCI for processor hotplug doesn't look quite right to me. This is the code I see in qemu_cpu_add_remove: if (gpe_state.gpe0_en[0] & 4) { qemu_set_irq(sci_irq, 1); qemu_set_irq(sci_irq, 0); } I would expect the code to actually set the GPE status bit for the GPE register in question (in this case bit 2 for _L02), maybe: if ((gpe_state.gpe0_en[0] & 4)&& ((gpe_state.gpe0_sts[0] & 4) == 0)) { gpe_state.gpe0_sts[0] &= 4; qemu_irq_raise(sci_irq); } I also don't understand why it is raising the SCI as level and then edge. That GPE is defined in the DSDT as level: /* Define GPE control method '_L02'. */ push_block("Scope", "\\_GPE"); push_block("Method", "_L02"); stmt("Return", "\\_SB.PRSC()"); Maybe look at how the PCI hotplug GPE's occur (ACPI_PHP_GPE_BIT). Without setting a status register the SCI may just be going in the bit bucket. Anyway hope this is helpful at all...Never mind, I missed the calls above to enable_processor and disable_processor which seem to be doing the right thing (long day on a plane). My sample code above had a type-o but g->gpe0_sts[0] |= 4; looks right. I still don't understand why it raises the SCI level then edge though.Neither do I but it actually looks to work. The problem I had was that the $@$@#( generic hotplug code has a race, which means that udev never ends up onlining the CPU (https://lkml.org/lkml/2012/4/30/198) So it looks like the CPU nevers gets onlined - and it did not until I manually wrote a script to online the CPUs. Now it can online, albeit I am hitting another bug <sigh>: [ 41.465296] CPU 1 got hotplugged [ 41.469607] installing Xen timer for CPU 1 [ 41.475935] SMP alternatives: lockdep: fixing up alternatives [ 41.483014] SMP alternatives: switching to SMP code [ 41.499193] smpboot: Booting Node 0 Processor 1 APIC 0x4 [ 41.517099] ------------[ cut here ]------------ [ 41.519532] kernel BUG at /home/konrad/ssd/konrad/linux/arch/x86/xen/time.c:337! [ 41.519532] invalid opcode: 0000 [#1] SMP [ 41.519532] Modules linked in: dm_multipath dm_mod iscsi_boot_sysfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi libcrc32c crc32c sg sr_mod cdrom ata_generic crc32c_intel ata_piix libata scsi_mod xen_blkfront xen_netfront fb_sys_fops sysimgblt sysfillrect syscopyarea xen_kbdfront xenfs xen_privcmd [ 41.519532] CPU 1 [ 41.519532] Pid: 0, comm: swapper/1 Not tainted 3.9.0upstream-00022-g49c1bf1-dirty #3 Xen HVM domU [ 41.519532] RIP: 0010:[<ffffffff81044f5c>] [<ffffffff81044f5c>] xen_vcpuop_set_mode+0x3c/0x80 [ 41.519532] RSP: 0000:ffff880074467db8 EFLAGS: 00010082 [ 41.519532] RAX: ffffffffffffffea RBX: ffff880074a2be40 RCX: 0000000000000001 [ 41.519532] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000009 [ 41.519532] RBP: ffff880074467db8 R08: 0000000000000001 R09: 0000000000000000 [ 41.519532] R10: 0000000000000008 R11: 0000000000000001 R12: 0000000000000001 [ 41.519532] R13: 0000000000000082 R14: 0000000000000000 R15: 0000000000000082 [ 41.519532] FS: 0000000000000000(0000) GS:ffff880074a20000(0000) knlGS:0000000000000000 [ 41.519532] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 41.519532] CR2: 0000000000000000 CR3: 0000000001c0c000 CR4: 00000000000406e0 [ 41.519532] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 41.519532] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 41.519532] Process swapper/1 (pid: 0, threadinfo ffff880074466000, task ffff880074464300) [ 41.519532] Stack: [ 41.519532] ffff880074467dd8 ffffffff810e8385 ffff880074a2be40 ffff880074a2be40 [ 41.519532] ffff880074467df8 ffffffff810e83e6 ffff880074467df8 0000000000000000 [ 41.519532] ffff880074467e28 ffffffff810e84b7 ffffffff810e8ae4 ffff880074a2be40 [ 41.519532] Call Trace: [ 41.519532] [<ffffffff810e8385>] clockevents_set_mode+0x25/0x70 [ 41.519532] [<ffffffff810e83e6>] clockevents_shutdown+0x16/0x30 [ 41.519532] [<ffffffff810e84b7>] clockevents_exchange_device+0xb7/0x110 [ 41.519532] [<ffffffff810e8ae4>] ? tick_notify+0x114/0x420 [ 41.519532] [<ffffffff810e8b99>] tick_notify+0x1c9/0x420 [ 41.519532] [<ffffffff810e8221>] ? clockevents_register_device+0x31/0x170 [ 41.519532] [<ffffffff8169dd9d>] notifier_call_chain+0x4d/0x70 [ 41.519532] [<ffffffff810be851>] raw_notifier_call_chain+0x11/0x20 [ 41.519532] [<ffffffff810e82d0>] clockevents_register_device+0xe0/0x170 [ 41.519532] [<ffffffff8104502c>] xen_setup_cpu_clockevents+0x2c/0x50 [ 41.519532] [<ffffffff81045066>] xen_hvm_setup_cpu_clockevents+0x16/0x20 [ 41.519532] [<ffffffff8168d48f>] start_secondary+0x1ea/0x1f9 [ 41.519532] Code: 73 2d 48 63 c9 bf 09 00 00 00 31 d2 48 89 ce e8 bb c3 fb ff 85 c0 75 13 bf 07 00 00 00 48 89 ce 31 d2 e8 a8 c3 fb ff 85 c0 74 09 <0f> 0b eb fe 83 ff 03 74 02 c9 c3 bf 07 00 00 00 48 63 f1 31 d2 [ 41.519532] RIP [<ffffffff81044f5c>] xen_vcpuop_set_mode+0x3c/0x80 [ 41.519532] RSP <ffff880074467db8> [ 41.519532] ---[ end trace a182694869545b1a ]--- [ 41.519532] Kernel panic - not syncing: Attempted to kill the idle task! Thought this is using xend, as you cannot in xl have maxvcpus != vcpus. Did you mean maxvcpus != vcpus, or maxvcpus > pcpus? -George _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
|
 |
Lists.xenproject.org is hosted with RackSpace, monitoring our |