From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35930) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z0njp-00055F-Kf for qemu-devel@nongnu.org; Fri, 05 Jun 2015 05:16:30 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z0njl-0007ol-HP for qemu-devel@nongnu.org; Fri, 05 Jun 2015 05:16:29 -0400 Received: from e28smtp08.in.ibm.com ([122.248.162.8]:45216) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z0njk-0007jC-T6 for qemu-devel@nongnu.org; Fri, 05 Jun 2015 05:16:25 -0400 Received: from /spool/local by e28smtp08.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 5 Jun 2015 14:46:21 +0530 Date: Fri, 5 Jun 2015 14:45:59 +0530 From: Bharata B Rao Message-ID: <20150605091559.GD25832@in.ibm.com> References: <1433478358-993-1-git-send-email-bharata@linux.vnet.ibm.com> <1433478358-993-9-git-send-email-bharata@linux.vnet.ibm.com> <55715942.2090201@ozlabs.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <55715942.2090201@ozlabs.ru> Subject: Re: [Qemu-devel] [PATCH v4 8/8] xics_kvm: Add cpu_destroy method to XICS Reply-To: bharata@linux.vnet.ibm.com List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Kardashevskiy Cc: thuth@redhat.com, mdroth@linux.vnet.ibm.com, agraf@suse.de, qemu-devel@nongnu.org, qemu-ppc@nongnu.org, tyreld@linux.vnet.ibm.com, nfont@linux.vnet.ibm.com, david@gibson.dropbear.id.au On Fri, Jun 05, 2015 at 06:09:38PM +1000, Alexey Kardashevskiy wrote: > On 06/05/2015 02:25 PM, Bharata B Rao wrote: > >XICS is setup for each CPU during initialization. Provide a routine > >to undo the same when CPU is unplugged. Also ensure xics reset doesn't set > >irq for CPUs that are already unplugged. > > > >This allows reboot of a VM that has undergone CPU hotplug and unplug > >to work correctly. > > > >Signed-off-by: Bharata B Rao > >--- > > hw/intc/xics.c | 14 ++++++++++++++ > > hw/intc/xics_kvm.c | 15 +++++++++++++-- > > include/hw/ppc/xics.h | 2 ++ > > 3 files changed, 29 insertions(+), 2 deletions(-) > > > >diff --git a/hw/intc/xics.c b/hw/intc/xics.c > >index 924b1ae..3f87f82 100644 > >--- a/hw/intc/xics.c > >+++ b/hw/intc/xics.c > >@@ -44,6 +44,20 @@ static int get_cpu_index_by_dt_id(int cpu_dt_id) > > return -1; > > } > > > >+void xics_cpu_destroy(XICSState *icp, PowerPCCPU *cpu) > > > xics_cpu_destroy() is not used by anything, may be push it later with the > stuff which needs it? Yeah it is not used in this patchset, will leave to David/agraf to see if they want this dropped from this series. > > > >+{ > >+ CPUState *cs = CPU(cpu); > >+ XICSStateClass *info = XICS_COMMON_GET_CLASS(icp); > >+ ICPState *ss = &icp->ss[cs->cpu_index]; > >+ > >+ assert(cs->cpu_index < icp->nr_servers); > >+ > >+ ss->output = NULL; > >+ if (info->cpu_destroy) { > >+ info->cpu_destroy(icp, cpu); > >+ } > >+} > >+ > > void xics_cpu_setup(XICSState *icp, PowerPCCPU *cpu) > > { > > CPUState *cs = CPU(cpu); > >diff --git a/hw/intc/xics_kvm.c b/hw/intc/xics_kvm.c > >index d58729c..e35f319 100644 > >--- a/hw/intc/xics_kvm.c > >+++ b/hw/intc/xics_kvm.c > >@@ -109,8 +109,10 @@ static void icp_kvm_reset(DeviceState *dev) > > icp->pending_priority = 0xff; > > icp->mfrr = 0xff; > > > >- /* Make all outputs are deasserted */ > >- qemu_set_irq(icp->output, 0); > >+ /* Make all outputs are deasserted only if the CPU thread is in use */ > >+ if (icp->output) { > >+ qemu_set_irq(icp->output, 0); > >+ } > > > This feels unrelated to what the patch claims that it does. Or > xics_cpu_destroy() somehow indirectly calls icp_kvm_reset()? When a VM is rebooted, device_reset of icp device will result in icp_kvm_reset() which will do qemu_set_irq(). This shouldn't happen for a CPU that is already removed. So above check ensures that we don't try to desssert irq for a removed CPU. Regards, Bharata.