Patchwork [03/13] pseries: Use new method to correct reset sequence

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Submitter David Gibson
Date Sept. 13, 2012, 2:57 a.m.
Message ID <1347505041-27411-4-git-send-email-david@gibson.dropbear.id.au>
Download mbox | patch
Permalink /patch/183473/
State New
Headers show

Comments

David Gibson - Sept. 13, 2012, 2:57 a.m.
A number of things need to occur during reset of the PAPR
paravirtualized platform in a specific order.  For example, the hash
table needs to be cleared before the CPUs are reset, so that they
initialize their register state correctly, and the CPUs need to have
their main reset called before we set up the entry point state on the
boot cpu.  We also need to have the main qdev reset happen before the
creation and installation of the device tree for the new boot, because
we need the state of the devices settled to correctly construct the
device tree.

We currently do the pseries once-per-reset initializations done from a
reset handler.  However we can't adequately control when this handler
is called during the reset - in particular we can't guarantee it
happens after all the qdev resets (since qdevs might be registered
after the machine init function has executed).

This patch uses the new QEMUMachine reset method to to fix this
problem, ensuring the various order dependent reset steps happen in
the correct order.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 hw/spapr.c |    9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)
Andreas Färber - Sept. 13, 2012, 2:08 p.m.
David,

Am 13.09.2012 04:57, schrieb David Gibson:
> A number of things need to occur during reset of the PAPR
> paravirtualized platform in a specific order.  For example, the hash
> table needs to be cleared before the CPUs are reset, so that they
> initialize their register state correctly, and the CPUs need to have
> their main reset called before we set up the entry point state on the
> boot cpu.  We also need to have the main qdev reset happen before the
> creation and installation of the device tree for the new boot, because
> we need the state of the devices settled to correctly construct the
> device tree.
> 
> We currently do the pseries once-per-reset initializations done from a
> reset handler.  However we can't adequately control when this handler
> is called during the reset - in particular we can't guarantee it
> happens after all the qdev resets (since qdevs might be registered
> after the machine init function has executed).
> 
> This patch uses the new QEMUMachine reset method to to fix this
> problem, ensuring the various order dependent reset steps happen in
> the correct order.
> 
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

I'm pretty sure I already added

Reviewed-by: Andreas Färber <afaerber@suse.de>

in another thread. Please don't constantly regroup your patches or at
least carry over the tags.

Thanks,
Andreas

Patch

diff --git a/hw/spapr.c b/hw/spapr.c
index d88525a..68542e8 100644
--- a/hw/spapr.c
+++ b/hw/spapr.c
@@ -559,13 +559,13 @@  static void emulate_spapr_hypercall(CPUPPCState *env)
     env->gpr[3] = spapr_hypercall(env, env->gpr[3], &env->gpr[4]);
 }
 
-static void spapr_reset(void *opaque)
+static void ppc_spapr_reset(void)
 {
-    sPAPREnvironment *spapr = (sPAPREnvironment *)opaque;
-
     /* flush out the hash table */
     memset(spapr->htab, 0, spapr->htab_size);
 
+    qemu_devices_reset();
+
     /* Load the fdt */
     spapr_finalize_fdt(spapr, spapr->fdt_addr, spapr->rtas_addr,
                        spapr->rtas_size);
@@ -845,14 +845,13 @@  static void ppc_spapr_init(ram_addr_t ram_size,
                                             boot_device, kernel_cmdline,
                                             pteg_shift + 7);
     assert(spapr->fdt_skel != NULL);
-
-    qemu_register_reset(spapr_reset, spapr);
 }
 
 static QEMUMachine spapr_machine = {
     .name = "pseries",
     .desc = "pSeries Logical Partition (PAPR compliant)",
     .init = ppc_spapr_init,
+    .reset = ppc_spapr_reset,
     .max_cpus = MAX_CPUS,
     .no_parallel = 1,
     .use_scsi = 1,