| Message ID | 20230511085337.3688527-1-alxndr@bu.edu (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | pnv_lpc: disable reentrancy detection for lpc-hc | expand |
Hello Alexander On 5/11/23 10:53, Alexander Bulekov wrote: > As lpc-hc is designed for re-entrant calls from xscom, mark it > re-entrancy safe. > > Reported-by: Thomas Huth <thuth@redhat.com> > Signed-off-by: Alexander Bulekov <alxndr@bu.edu> > --- > hw/ppc/pnv_lpc.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/hw/ppc/pnv_lpc.c b/hw/ppc/pnv_lpc.c > index 01f44c19eb..67fd049a7f 100644 > --- a/hw/ppc/pnv_lpc.c > +++ b/hw/ppc/pnv_lpc.c > @@ -738,6 +738,8 @@ static void pnv_lpc_realize(DeviceState *dev, Error **errp) > &lpc->opb_master_regs); > memory_region_init_io(&lpc->lpc_hc_regs, OBJECT(dev), &lpc_hc_ops, lpc, > "lpc-hc", LPC_HC_REGS_OPB_SIZE); > + /* xscom writes to lpc-hc. As such mark lpc-hc re-entrancy safe */ > + lpc->lpc_hc_regs.disable_reentrancy_guard = true; > memory_region_add_subregion(&lpc->opb_mr, LPC_HC_REGS_OPB_ADDR, > &lpc->lpc_hc_regs); > The warning changed : qemu-system-ppc64: warning: Blocked re-entrant IO on MemoryRegion: lpc-opb-master at addr: 0x8 I will take a look unless you know exactly what to do. Thanks, C.
On 230511 1104, Cédric Le Goater wrote: > Hello Alexander > > On 5/11/23 10:53, Alexander Bulekov wrote: > > As lpc-hc is designed for re-entrant calls from xscom, mark it > > re-entrancy safe. > > > > Reported-by: Thomas Huth <thuth@redhat.com> > > Signed-off-by: Alexander Bulekov <alxndr@bu.edu> > > --- > > hw/ppc/pnv_lpc.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/hw/ppc/pnv_lpc.c b/hw/ppc/pnv_lpc.c > > index 01f44c19eb..67fd049a7f 100644 > > --- a/hw/ppc/pnv_lpc.c > > +++ b/hw/ppc/pnv_lpc.c > > @@ -738,6 +738,8 @@ static void pnv_lpc_realize(DeviceState *dev, Error **errp) > > &lpc->opb_master_regs); > > memory_region_init_io(&lpc->lpc_hc_regs, OBJECT(dev), &lpc_hc_ops, lpc, > > "lpc-hc", LPC_HC_REGS_OPB_SIZE); > > + /* xscom writes to lpc-hc. As such mark lpc-hc re-entrancy safe */ > > + lpc->lpc_hc_regs.disable_reentrancy_guard = true; > > memory_region_add_subregion(&lpc->opb_mr, LPC_HC_REGS_OPB_ADDR, > > &lpc->lpc_hc_regs); > > The warning changed : > > qemu-system-ppc64: warning: Blocked re-entrant IO on MemoryRegion: lpc-opb-master at addr: 0x8 > > I will take a look unless you know exactly what to do. > That does not show up for me with "./qemu-system-ppc64 -M powernv8" Do I need to boot a kernel to see the message? I was worried that there might be other re-entrant IO in this device. Maybe there should be a way to just mark the whole device re-entrancy safe.
On 5/11/23 11:15, Alexander Bulekov wrote: > On 230511 1104, Cédric Le Goater wrote: >> Hello Alexander >> >> On 5/11/23 10:53, Alexander Bulekov wrote: >>> As lpc-hc is designed for re-entrant calls from xscom, mark it >>> re-entrancy safe. >>> >>> Reported-by: Thomas Huth <thuth@redhat.com> >>> Signed-off-by: Alexander Bulekov <alxndr@bu.edu> >>> --- >>> hw/ppc/pnv_lpc.c | 2 ++ >>> 1 file changed, 2 insertions(+) >>> >>> diff --git a/hw/ppc/pnv_lpc.c b/hw/ppc/pnv_lpc.c >>> index 01f44c19eb..67fd049a7f 100644 >>> --- a/hw/ppc/pnv_lpc.c >>> +++ b/hw/ppc/pnv_lpc.c >>> @@ -738,6 +738,8 @@ static void pnv_lpc_realize(DeviceState *dev, Error **errp) >>> &lpc->opb_master_regs); >>> memory_region_init_io(&lpc->lpc_hc_regs, OBJECT(dev), &lpc_hc_ops, lpc, >>> "lpc-hc", LPC_HC_REGS_OPB_SIZE); >>> + /* xscom writes to lpc-hc. As such mark lpc-hc re-entrancy safe */ >>> + lpc->lpc_hc_regs.disable_reentrancy_guard = true; >>> memory_region_add_subregion(&lpc->opb_mr, LPC_HC_REGS_OPB_ADDR, >>> &lpc->lpc_hc_regs); >> >> The warning changed : >> >> qemu-system-ppc64: warning: Blocked re-entrant IO on MemoryRegion: lpc-opb-master at addr: 0x8 >> >> I will take a look unless you know exactly what to do. >> > > That does not show up for me with "./qemu-system-ppc64 -M powernv8" > Do I need to boot a kernel to see the message? There are other processors: powernv10 IBM PowerNV (Non-Virtualized) POWER10 powernv8 IBM PowerNV (Non-Virtualized) POWER8 powernv IBM PowerNV (Non-Virtualized) POWER9 (alias of powernv9) powernv9 IBM PowerNV (Non-Virtualized) POWER9 Region lpc->opb_master_regs needs to be tagged also for powernv9 and powernv10. Thanks, C. > I was worried that there might be other re-entrant IO in this device. > Maybe there should be a way to just mark the whole device re-entrancy > safe.
On 11/05/2023 11:15, Alexander Bulekov wrote: > On 230511 1104, Cédric Le Goater wrote: >> Hello Alexander >> >> On 5/11/23 10:53, Alexander Bulekov wrote: >>> As lpc-hc is designed for re-entrant calls from xscom, mark it >>> re-entrancy safe. >>> >>> Reported-by: Thomas Huth <thuth@redhat.com> >>> Signed-off-by: Alexander Bulekov <alxndr@bu.edu> >>> --- >>> hw/ppc/pnv_lpc.c | 2 ++ >>> 1 file changed, 2 insertions(+) >>> >>> diff --git a/hw/ppc/pnv_lpc.c b/hw/ppc/pnv_lpc.c >>> index 01f44c19eb..67fd049a7f 100644 >>> --- a/hw/ppc/pnv_lpc.c >>> +++ b/hw/ppc/pnv_lpc.c >>> @@ -738,6 +738,8 @@ static void pnv_lpc_realize(DeviceState *dev, Error **errp) >>> &lpc->opb_master_regs); >>> memory_region_init_io(&lpc->lpc_hc_regs, OBJECT(dev), &lpc_hc_ops, lpc, >>> "lpc-hc", LPC_HC_REGS_OPB_SIZE); >>> + /* xscom writes to lpc-hc. As such mark lpc-hc re-entrancy safe */ >>> + lpc->lpc_hc_regs.disable_reentrancy_guard = true; >>> memory_region_add_subregion(&lpc->opb_mr, LPC_HC_REGS_OPB_ADDR, >>> &lpc->lpc_hc_regs); >> >> The warning changed : >> >> qemu-system-ppc64: warning: Blocked re-entrant IO on MemoryRegion: lpc-opb-master at addr: 0x8 >> >> I will take a look unless you know exactly what to do. >> > > That does not show up for me with "./qemu-system-ppc64 -M powernv8" > Do I need to boot a kernel to see the message? > > I was worried that there might be other re-entrant IO in this device. > Maybe there should be a way to just mark the whole device re-entrancy > safe. Hello, I was also started hitting it, with machine powernv10. And indeed, disabling the check on both lpc_hc_regs and opb_master_regs should be all we need (and it's working fine for me). Fred
On 15/05/2023 14.48, Frederic Barrat wrote: > > > On 11/05/2023 11:15, Alexander Bulekov wrote: >> On 230511 1104, Cédric Le Goater wrote: >>> Hello Alexander >>> >>> On 5/11/23 10:53, Alexander Bulekov wrote: >>>> As lpc-hc is designed for re-entrant calls from xscom, mark it >>>> re-entrancy safe. >>>> >>>> Reported-by: Thomas Huth <thuth@redhat.com> >>>> Signed-off-by: Alexander Bulekov <alxndr@bu.edu> >>>> --- >>>> hw/ppc/pnv_lpc.c | 2 ++ >>>> 1 file changed, 2 insertions(+) >>>> >>>> diff --git a/hw/ppc/pnv_lpc.c b/hw/ppc/pnv_lpc.c >>>> index 01f44c19eb..67fd049a7f 100644 >>>> --- a/hw/ppc/pnv_lpc.c >>>> +++ b/hw/ppc/pnv_lpc.c >>>> @@ -738,6 +738,8 @@ static void pnv_lpc_realize(DeviceState *dev, Error >>>> **errp) >>>> &lpc->opb_master_regs); >>>> memory_region_init_io(&lpc->lpc_hc_regs, OBJECT(dev), >>>> &lpc_hc_ops, lpc, >>>> "lpc-hc", LPC_HC_REGS_OPB_SIZE); >>>> + /* xscom writes to lpc-hc. As such mark lpc-hc re-entrancy safe */ >>>> + lpc->lpc_hc_regs.disable_reentrancy_guard = true; >>>> memory_region_add_subregion(&lpc->opb_mr, LPC_HC_REGS_OPB_ADDR, >>>> &lpc->lpc_hc_regs); >>> >>> The warning changed : >>> >>> qemu-system-ppc64: warning: Blocked re-entrant IO on MemoryRegion: >>> lpc-opb-master at addr: 0x8 >>> >>> I will take a look unless you know exactly what to do. >>> >> >> That does not show up for me with "./qemu-system-ppc64 -M powernv8" >> Do I need to boot a kernel to see the message? >> >> I was worried that there might be other re-entrant IO in this device. >> Maybe there should be a way to just mark the whole device re-entrancy >> safe. > > Hello, > > I was also started hitting it, with machine powernv10. And indeed, disabling > the check on both lpc_hc_regs and opb_master_regs should be all we need (and > it's working fine for me). Alexander, could you please respin your patch to fix the opb_master_regs, too? Thomas
On 5/26/23 09:06, Thomas Huth wrote: > On 15/05/2023 14.48, Frederic Barrat wrote: >> >> >> On 11/05/2023 11:15, Alexander Bulekov wrote: >>> On 230511 1104, Cédric Le Goater wrote: >>>> Hello Alexander >>>> >>>> On 5/11/23 10:53, Alexander Bulekov wrote: >>>>> As lpc-hc is designed for re-entrant calls from xscom, mark it >>>>> re-entrancy safe. >>>>> >>>>> Reported-by: Thomas Huth <thuth@redhat.com> >>>>> Signed-off-by: Alexander Bulekov <alxndr@bu.edu> >>>>> --- >>>>> hw/ppc/pnv_lpc.c | 2 ++ >>>>> 1 file changed, 2 insertions(+) >>>>> >>>>> diff --git a/hw/ppc/pnv_lpc.c b/hw/ppc/pnv_lpc.c >>>>> index 01f44c19eb..67fd049a7f 100644 >>>>> --- a/hw/ppc/pnv_lpc.c >>>>> +++ b/hw/ppc/pnv_lpc.c >>>>> @@ -738,6 +738,8 @@ static void pnv_lpc_realize(DeviceState *dev, Error **errp) >>>>> &lpc->opb_master_regs); >>>>> memory_region_init_io(&lpc->lpc_hc_regs, OBJECT(dev), &lpc_hc_ops, lpc, >>>>> "lpc-hc", LPC_HC_REGS_OPB_SIZE); >>>>> + /* xscom writes to lpc-hc. As such mark lpc-hc re-entrancy safe */ >>>>> + lpc->lpc_hc_regs.disable_reentrancy_guard = true; >>>>> memory_region_add_subregion(&lpc->opb_mr, LPC_HC_REGS_OPB_ADDR, >>>>> &lpc->lpc_hc_regs); >>>> >>>> The warning changed : >>>> >>>> qemu-system-ppc64: warning: Blocked re-entrant IO on MemoryRegion: lpc-opb-master at addr: 0x8 >>>> >>>> I will take a look unless you know exactly what to do. >>>> >>> >>> That does not show up for me with "./qemu-system-ppc64 -M powernv8" >>> Do I need to boot a kernel to see the message? >>> >>> I was worried that there might be other re-entrant IO in this device. >>> Maybe there should be a way to just mark the whole device re-entrancy >>> safe. >> >> Hello, >> >> I was also started hitting it, with machine powernv10. And indeed, disabling the check on both lpc_hc_regs and opb_master_regs should be all we need (and it's working fine for me). > > Alexander, could you please respin your patch to fix the opb_master_regs, too? I will do it. C.
diff --git a/hw/ppc/pnv_lpc.c b/hw/ppc/pnv_lpc.c index 01f44c19eb..67fd049a7f 100644 --- a/hw/ppc/pnv_lpc.c +++ b/hw/ppc/pnv_lpc.c @@ -738,6 +738,8 @@ static void pnv_lpc_realize(DeviceState *dev, Error **errp) &lpc->opb_master_regs); memory_region_init_io(&lpc->lpc_hc_regs, OBJECT(dev), &lpc_hc_ops, lpc, "lpc-hc", LPC_HC_REGS_OPB_SIZE); + /* xscom writes to lpc-hc. As such mark lpc-hc re-entrancy safe */ + lpc->lpc_hc_regs.disable_reentrancy_guard = true; memory_region_add_subregion(&lpc->opb_mr, LPC_HC_REGS_OPB_ADDR, &lpc->lpc_hc_regs);
As lpc-hc is designed for re-entrant calls from xscom, mark it re-entrancy safe. Reported-by: Thomas Huth <thuth@redhat.com> Signed-off-by: Alexander Bulekov <alxndr@bu.edu> --- hw/ppc/pnv_lpc.c | 2 ++ 1 file changed, 2 insertions(+)