From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51021) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WwqDa-0004pA-0V for qemu-devel@nongnu.org; Tue, 17 Jun 2014 06:02:24 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WwqDR-0003h3-SV for qemu-devel@nongnu.org; Tue, 17 Jun 2014 06:02:17 -0400 Message-ID: <53A01220.90009@suse.de> Date: Tue, 17 Jun 2014 12:02:08 +0200 From: Alexander Graf MIME-Version: 1.0 References: <1402574971-26672-2-git-send-email-nikunj@linux.vnet.ibm.com> <53A006A9.90108@suse.de> <871tunc288.fsf@linux.vnet.ibm.com> <53A01006.6080800@suse.de> <87y4wvamb3.fsf@linux.vnet.ibm.com> In-Reply-To: <87y4wvamb3.fsf@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2] ppc: spapr-rtas - implement os-term rtas call List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Nikunj A Dadhania , qemu-devel@nongnu.org Cc: aik@au1.ibm.com, qemu-ppc@nongnu.org On 17.06.14 11:59, Nikunj A Dadhania wrote: > Alexander Graf writes: > >> On 17.06.14 11:30, Nikunj A Dadhania wrote: >>> Alexander Graf writes: >>> >>>> On 12.06.14 14:09, Nikunj A Dadhania wrote: >>>>> PAPR compliant guest calls this in absence of kdump. After >>>>> receiving this call qemu could trigger a guest dump. This guest dump >>>>> can be used to analyse using crash tool. >>>>> >>>>> Signed-off-by: Nikunj A Dadhania >>>>> --- >>>>> >>>>> v2: indentation fixes >>>>> >>>>> hw/ppc/spapr_rtas.c | 32 ++++++++++++++++++++++++++++++++ >>>>> 1 file changed, 32 insertions(+) >>>>> >>>>> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c >>>>> index ea4a2b2..f030e73 100644 >>>>> --- a/hw/ppc/spapr_rtas.c >>>>> +++ b/hw/ppc/spapr_rtas.c >>>>> @@ -29,6 +29,8 @@ >>>>> #include "sysemu/char.h" >>>>> #include "hw/qdev.h" >>>>> #include "sysemu/device_tree.h" >>>>> +#include "qapi/qmp/qjson.h" >>>>> +#include "monitor/monitor.h" >>>>> >>>>> #include "hw/ppc/spapr.h" >>>>> #include "hw/ppc/spapr_vio.h" >>>>> @@ -267,6 +269,34 @@ static void rtas_ibm_set_system_parameter(PowerPCCPU *cpu, >>>>> rtas_st(rets, 0, ret); >>>>> } >>>>> >>>>> +static void rtas_ibm_os_term(PowerPCCPU *cpu, >>>>> + sPAPREnvironment *spapr, >>>>> + uint32_t token, uint32_t nargs, >>>>> + target_ulong args, >>>>> + uint32_t nret, target_ulong rets) >>>>> +{ >>>>> + target_ulong ret = 0; >>>>> + QObject *data; >>>>> + >>>>> + data = qobject_from_jsonf("{ 'action': %s }", "pause"); >>>>> + monitor_protocol_event(QEVENT_GUEST_PANICKED, data); >>>>> + qobject_decref(data); >>>>> + vm_stop(RUN_STATE_GUEST_PANICKED); >>>>> + >>>>> + rtas_st(rets, 0, ret); >>>>> +} >>>>> + >>>>> +static void rtas_ibm_ext_os_term(PowerPCCPU *cpu, >>>>> + sPAPREnvironment *spapr, >>>>> + uint32_t token, uint32_t nargs, >>>>> + target_ulong args, >>>>> + uint32_t nret, target_ulong rets) >>>>> +{ >>>>> + target_ulong ret = 0; >>>>> + >>>>> + rtas_st(rets, 0, ret); >>>>> +} >>>>> + >>>>> static struct rtas_call { >>>>> const char *name; >>>>> spapr_rtas_fn fn; >>>>> @@ -392,6 +422,8 @@ static void core_rtas_register_types(void) >>>>> rtas_ibm_get_system_parameter); >>>>> spapr_rtas_register("ibm,set-system-parameter", >>>>> rtas_ibm_set_system_parameter); >>>>> + spapr_rtas_register("ibm,os-term", rtas_ibm_os_term); >>>>> + spapr_rtas_register("ibm,extended-os-term", rtas_ibm_ext_os_term); >>>> Why do we need the extended-os-term if we don't do anything with it? >>> Linux kernel checks for both of them because of legacy: >>> >>> arch/powerpc/kernel/rtas.c: >>> >>> void rtas_os_term(char *str) >>> { >>> [...] >>> /* >>> * Firmware with the ibm,extended-os-term property is guaranteed >>> * to always return from an ibm,os-term call. Earlier versions without >>> * this property may terminate the partition which we want to avoid >>> * since it interferes with panic_timeout. >> But we do not return from the RTAS call, so we don't adhere to the >> extended semantics? > But you would return without calling os-term call if > ibm,extended-os-term isnt registered. For that reason I h ave defined a > stub. I appreciate the hacker mentality, but Linux explicitly checks on ibm,extended-os-term to ensure that the hypervisor does not stop the VM when it calls ibm,os-term. However, the implementation above does stop the VM when the guest calls ibm,os-term. Why was that check put into place? Alex